Textbook of Applied Forestry 9789698237936

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Managing Editors Iqrar Ahmad Khan & Muhammad Farooq

Textbook of Applied Forestry M. Tahir Siddiqui M. Farrakh Nawaz

University of Agriculture Faisalabad Pakistan

Prof. Dr. M. Tahir Siddiqui University of Agriculture, Faisalabad 38040, Pakistan Dr. M. Farrakh Nawaz University of Agriculture, Faisalabad 38040, Pakistan

ISBN 978-969-8237-93-6

© University of Agriculture, Faisalabad, Pakistan 2017 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from the University of Agriculture, Faisalabad, Pakistan. Permissions for use may be obtained in writing to the Office of the Books and Magazines, University of Agriculture, Faisalabad, Pakistan. Violations areliable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in theabsence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.

Foreword The digital age has its preferences. The reading time has been encroached upon by a watching time. The access to information is easy and a plenty where Wikipedia has emerged as the most powerful encyclopedia ever. Yet, a book is a book! We wish to promote the habit of reading books. Finding books is not difficult or expensive (www.pdfdrive.com) but a local context and indigenous experiences could be missing. The University of Agriculture, Faisalabad (UAF) has achieved global rankings of its flagship programs and acceptance as a leader in the field of agriculture and allied sciences. A competent faculty, the stimulating ecosystem and its learning environment have attracted increasing attention. Publication of books is an important KPI for any institution of higher learning. Hence, UAF has embarked upon an ambitious ‘books project’ to provide reference texts and to occupy our space as a knowledge powerhouse. It is intended that the UAF books shall be made available in both paper and electronic versions for a wider reach and affordability. UAF offers more than 160 degree programs where agriculture remains our priority. There are about 20 institutions other than UAF who are also offering similar degree programs. Yet, there is no strong history of indigenously produced text/reference books that students and scholars could access. The last major effort dates back to the early 1990’s when a USAID funded TIPAN project produced a few multiauthor text books. Those books are now obsoleted but still in demand because of lack of alternatives. The knowledge explosion simply demands that we undertake and expand the process anew. Considering the significance of this project, I have personally overseen the entire process of short listing of the topics, assemblage of authors, review of contents and editorial work of 29 books being written in the first phase of this project. Each book has editor(s) who worked with a group of authors writing chapters of their choice and expertise. The draft texts were peer reviewed and language corrected as much as possible. There was a considerable consultation and revision undertaken before the final drafts were accepted for formatting and printing process. This series of books cover a very broad range of subjects from theoretical physics and electronic image processing to hard core agricultural subjects and public policy. It is my considered opinion that the books produced here will find a wide acceptance across the country and overseas. That will serve a very important purpose of improving quality of teaching and learning. The reference texts will also be equally valued by the researchers and enthusiastic practitioners. Hopefully, this is a beginning of unleashing the knowledge potential of UAF which shall be continued. It is my dream to open a bookshop at UAF like the ones that we find in highly ranked universities across the globe.

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Foreword

Pakistan is blessed with diverse agro-ecological zones suited for raising forest and developing rangelands. Yet, we have only 4.8% of the land covered by forest for many reasons. There is ample opportunity for tree-crop integration to promote farm forestry. However, a locally authored comprehensive textbook in the subject of forestry has been lacking. The publication of this book shall fill the knowledge gap to improve the quality of education in forestry. Before concluding, I wish to record my appreciation for my coworker Dr. Muhammad Farooq who worked skillfully and tirelessly towards achieving a daunting task. Equally important was the contribution of the authors and editors of this book. I also acknowledge the financial support for this project provided by the USDA endowment fund available to UAF.

Prof. Iqrar A. Khan (Sitara-e-Imtiaz) Vice Chancellor Unviersity of Agriculture, Faisalabad Pakistan

Preface According to official statements, the current area under forests is only 4.7% of total surface area of Pakistan. However, the forest area to land ratio in Pakistan in 2010 was 2.19 percent as reported by World Bank (2012), which is not only one of the lowest in the world, but unfortunately, Pakistan has also the highest rate of deforestation in Asia. This forest cover is too small to maintain ecological balance and to fulfil the environmental, social and economic needs of Pakistan. This meager forest area is far away from the recommended forest area of 25% to get sustainable benefits and ecological balance. Pakistan is at 110th position regarding forest resources in the world as reported by United Nations General Assembly in 2011. Moreover, due to several administrative, financial and technical problems, in the last decade, Pakistan has lost about 0.21 million hectare of forests with deforestation rate of 2.1%. Rapid decrease in forest cover has led to increased, environmental degradation, pollution, land-degradation, loss of bio-diversity and low agriculture yield. To slow down the deforestation rate and to make Pakistan a green country, there is urgent need to engage trained professionals with up-to-date knowledge of modern forestry in the public and private sector. So, idea was conceived to develop a comprehensive Textbook of Applied Forestry that will cover basic concepts, elements and advances in Forestry. Moreover, this book will serve as ready reference for all necessary information that a forester may require to enhance his professional and research skills. This book has been prepared by the contribution of several national and international experts in the relevant field of forestry discipline. Although there are some national and international books available in Forestry but no particular book on Applied Forestry with reference to Pakistan is available. International books do not address the demands of local foresters due to different set of environmental, social and administrative conditions in Pakistan. This book contains 13 chapters. Chapter 1 deals with global importance of forests and various strategies have been proposed to decrease the deforestation rate in Pakistan. Chapter 2 deals with different forests types of Pakistan, their ecological distribution and dominant tree species in each forest type. Chapter 3 entails anatomical characteristics of trees belonging to both angiosperms and gymnosperms. It also describes major physiological functions and processes in the trees. Chapter 4 describes forest ecology using both Autecological and Synecological approaches. Chapter 5 deals with forest nursery establishment. Types of nurseries according to objectives of establishment have also been discussed and major nursery tools are enlisted. Chapter 6 describes importance of forests and natural sites as ecotourism. Accordingly, soil reclamation of problematic soils (saline, waterlogged, clayey and wind eroded soils) through afforestation has been discussed in Chapter 7. Chapter 8 describes the major diseases of trees and their preventions. Chapter 9 describes, in detail, the status, prospects and challenges to agroforestry in Pakistan. Chapter vii

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10 describes the major vertebrate pests of forest plantations and Indian crested porcupine has been discussed as the major vertebrate pest in Pakistan. In Chapter 11, urban forestry and tree planting in urban areas has been discussed. Chapter 12 highlights the important role of forest to mitigate climate change through carbon sequestration. Different carbon sequestration methods are also described in this chapter. Chapter 13 deals with forest soils. It describes soil-tree interactions and soil improvement. Use of trees for soil reclamation of polluted soils is also discussed in this chapter. A detailed glossary and subject index is also given at the end of the book. It is hoped that this endeavor will serve as a textbook for students of forestry as well as M.Sc. (Hons.) and Ph.D. scholars covering their educational and research need. This book will be of great facilitation in the preparation of academic and competitive exams like CSS. A general reader can also take help in understanding the importance of forests in environmental amelioration and economic uplift of the society.

Prof. Dr. M. Tahir Siddiqui Dr. Muhammad Farrakh Nawaz

Chapter 1

Introduction M.T. Siddiqui and M.F. Nawaz*

Abstract A forest is a biotic community of fauna and flora predominated by trees and woody vegetation that covers a large area. Forest have appeared on Earth about 350 million years ago and reached a peak about 270 million to 220 million years ago during the Carboniferous period. Today, forests cover about one third of the earth’s land surface. Forests played a vital role in the survival, development, and growth of human society. They not only provide industrial wood, fuelwood, shelter and forage for livestock but also improve the quality and quantity of water, reduce erosion and runoff, store carbon, increase soil texture and fertility, provide habitat, reduce air pollution and surrounding temperature and provide several recreational activities to mankind. Pakistan has only 4.8% of its area under forests which is far behind the country need. Pakistan has natural forest cover only 2.2% and losing its forests at the rate of 1.66% per year, all because of increasing population pressure, land clearance for agriculture, timber mafia, over-exploitation of resources and forest fires. There is urgent need of law implementation and adoption of necessary strategies to protect and improve the forests of Pakistan. Keywords: Trees; Pakistan; Forest; Degradation; Threats.

1.1.

Significance of Forestry

Trees are the oldest companion of man, which provided safety, fuel, food, clothing and shelter when man first moved to the Earth from heavenly abode. In fact, quest

* M.T. Siddiqui˧ and M.F. Nawaz Department of Forestry and Range Management, University of Agriculture, Faisalabad, Pakistan. ˧ Corresponding author’s e-mail: [email protected]

Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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Introduction

for wood, which is the principal building material and fuel of the past societies, has triggered large population movements. The discovery of how to keep and use fire, the idea of the wheel, and the concept of lever, are many fundamental civilizing concepts of man that seem to have been developed from wood over a period of many millennia. Actually, wood is indispensable for human existence right from the beginning of life on Earth till to date and associated with human civilization for its multiple uses and properties. With the advent of modern time in mid- sixteenth century and later during industrial revolution in eighteenth century, importance of forests as a source of wood for industries (iron and bronze manufacture), ship building and protection of river catchments for sustainedsupply of clean water was recognized at a time when forest area began to diminish with increasing population and expansion of agriculture. Wood was used as fuel in locomotives before the discovery of coal: For instance, Changa Manga plantation was established in 1866 to supply fuel for railway engines and some plantations in Punjab and Sindh supplied wood to Indus flotilla at that time. At the close of 20th century, the concept of forest conservation for climatic and environmental stability, sustainable development, control of desertification and conservation of biological diversity is being highlighted in many international forums. The importance of forests is significant in countries like Pakistan, which has arid and hot climate over more than 70 per cent of its area and where percentage of forest area is very low i.e. 4.8%. In addition to supply of traditional goods and services like wood, fodder, water, wildlife and recreation, forests also protect river catchments in hilly regions and ensure sustained supply of good quality water for irrigation and power generation. Furthermore, sustained agricultural and industrial development in Pakistan is not possible without sustained supply of water in the rivers. Rapid disappearance of forests and reduced tree growth over major part of the country in last two decades has accentuated the problem of aridity, soil degradation, extremes of climate and spread of deserts. There is acute shortage of wood and wood products with concomitant rise in their prices and absence of substantial wood-based industries. It has also adversely affected the programmes of socioeconomic uplift of large population. Annual expenditure on import of wood products, especially, pulp and paper is very high which could be one of the reasons in overall low literacy rate of the country. Pakistan is one of the countries in Asia and Africa, where forests are too meagre to fulfil the needs of the people.

1.2.

Distribution of World’s Forest Resources

Forest can be defined as land with a tree cover of more than 10% or an area of more than 0.5ha under perennial woody vegetation with a minimum height of 5 m at maturity and this land should not be predominantly used for agricultural purposes. Worldwide distribution of forest area, according to FAO (2001, 2003) is given in Table 1.1. Europe which includes the Russian Federation (27% of world’s forest area) has the maximum forest area of the region as compared to any other regions. South America has the highest percentage forest cover and the second highest forest area.

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Africa has 22% of its land area as forest, which is below the world average of 30%. Africa has the second largest wood biomass (17%) after South America. Asia has a large area of tropical rainforest in the south-eastern mainland: Indonesia and New Guinea. It also has significant areas of drier tropical forest, subtropical forest, temperate forest and even a small occurrence of boreal forest. Asia has the lowest percentage of the forest cover (18%) of any of the regions. However, it has the largest area of forest plantations, particularly in China, India, Japan, Thailand, Turkey and Vietnam. Australia- a prominent region of Oceania is famous for having tropical dry forests predominate. It has moist tropical rainforest in the north, subtropical humid forest in the east and temperate oceanic forest in the south —east and subtropical dry forest in the south- west. New Zealand-another prominent country of the Oceania has subtropical humid (warm temperate) forest in the north island and temperate oceanic forest in the South Island. Table 1.1. Worldwide distribution of forests Regions

Forest land area area (%) (106 ha)

Africa Asia Europe North & Cent. America Oceania South America World

650 548 1039 549

22 17 46 26

world forest area (%) 17 14 27 14

198 886 3869

23 51 30

5 23 100

world Plantation Forest area woody area Change biomass (106 ha) (%/year) 1990-2000 (%) 17 8 -0.8 11 116 -0.1 14 32 +0.1 12 18 -0.1 3 43 100

3 10 187

-0.2 -0.4 -0.2

Source: Sands (2005)

North and Central America have all kinds of forest types varying from tropical rainforest to boreal tundra woodlands. The region is dominated in area by the USA and Canada. Both countries have almost equal forest area and both about the same percentage of forest cover (Canada 27% and USA 25%). The forests are mainly subtropical and temperate in the USA, and temperate but mainly boreal in Canada. Consequently, the wood biomass is greater in the USA (24.4 billion tonnes) than Canada (20.2 billion tonnes).

1.3.

Forest Spectrum in Pakistan

A forest is a biotic community of fauna and flora predominated by trees and woody vegetation that cover a large area. It supports an array of complex flora and fauna, and forms a distinctive microclimate as compared to other land uses. Each forest type has specific species composition, size, diversity, and density, due to specific temperature and precipitation. No matter what type the forest is, the plant sizes,

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Introduction

canopy density, litter floor, and root systems are significantly taller, greater, thicker, and deeper respectively than other vegetation types. These characteristics enable forests not only to provide several natural resources, but also to perform a variety of environmental functions. Forest resources may include timber, water, soil, wildlife, vegetation, minerals, and recreation. Except for minerals, all these resources are greatly affected by forestry activities. Some resources can be destroyed, depending on the intensity and extent of the forestry activity. Environmental functions performed by forests may include control of water and wind erosion, protection of headwater and reservoir watershed and riparian zone, sand dune and stream-bank stabilization, landslide and avalanche prevention, preservation of wildlife habitats and gene pools, mitigation of flood damage and wind speed, and sinks for atmospheric carbon dioxide. Many established forests have been managed to achieve one or more of these environmental functions, while others are preserved to prevent loss in biodiversity and degradation of the ecosystem. The forests of Pakistan reflect great physiographic, climatic and edaphic contrasts. Pakistan is an oblong stretch of land between the Arabian Sea and Karakoram mountains, lying diagonally between 24° N and 37° N latitudes and 61° E and 75° E longitudes and covering an area of 87.98 million hectares (Siddiqui 1997). Topographically, the country has a continuous massive mountainous tract in the north, the west and the south west and a large fertile plain: the Indus plain. The northern mountain system, comprising of the Karakoram, the great Himalayas, and the Hindu-Kush, has enormous mass of snow and glaciers and 100 peaks of over 5400 m in elevation including K-2 (8, 616 m according to Desio (1988) that is the second highest peak in the world. The mountain system occupies one third area of the country. The western mountain ranges, not as high as in the north, comprise the Sufed Koh and the Sulaiman while the south-western ranges form a high, dry and cold Balochistan plateau. Characteristically, the mountain slopes are steep, even precipitous, making fragile watershed areas and associated forest vegetation extremely important from hydrological point of view. The valleys are narrow. The mountains are continuously undergoing natural process of erosion. The nature of climate with high intensity rainfall in summer and steep slopes in the northern regions are prone to erosion and landslides. The Indus plain have two distinct features; the alluvial plain and sand dunal desert. The country is drained by five rivers; namely, Indus, Jhelum, Chenab, Ravi and Sutlej. Of these Indus arising in snow covered northern mountain ranges flows towards south through the Punjab and Sindh plains into a wide delta before entering Arabian Sea. Other rivers join it on the way, together feeding one of the largest irrigation systems in the world. The great river system of Indus in Pakistan derives a part of their water supply from sources which lie in the high lands beyond the Himalayas and the western mountains, and part from countless valleys which lie hidden within the mountain folds. Much of the silt of the alluvial plain is from natural geological erosion of mountains in the north brought down by rivers. Thal desert lies between the rivers Indus and Jhelum, while Cholistan and Thar Desert occur on the south-east of the country.

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A great variety of parent rock types occur in Pakistan, which exert considerable influence on the properties of soil. The rocks found in Pakistan can be classified into three major groups, viz., the igneous rocks, the sedimentary rocks and the metamorphic rocks. In the Himalayan regions, the common rock types are metamorphic which are gneisses, schists, slates and phyllites with some quartzite and marble. In the northern part of Indus plain, between Sargodha and Shahkot small outcrops of phyllites and quartzites occur. Granite, syenite, diorite, gabbro, dolerite and peridotite are more common types of igneous rocks, which occur in Dir, Swat, Chitral, Gilgit, Zhob, Chagai, Las Bela and Nagarparker. According to FAO (2010), Pakistan has the natural forest cover of only 2.2% or 1,687,000 ha and losing its forests at the rate of 1.66% or 42,000 ha per year (Data from 1990 to 2010). Pakistan’s forests contain about 213 million metric tons of carbon and Pakistan has some 4950 species of vascular plants of which about 7.5% are endemic, meaning they exist in no other country. It is also worth mentioning that major needs for industrial wood (72%) and fuelwood (90%) of the country are fulfilled by the wood from farmland (Rahim and Hasnain 2010). Between 1996 and 2000, the average roundwood production and industrial roundwood production per year in Pakistan was 31.66 million m3 and 2.35 million m3 respectively. However, the big bucks were spent to import about 5,32,000 m3 per year of industrial roundwood (FAO 2002). According to FAO (2002), Pakistan’s forests, in spite of having very small forest per capita (only 0.05 ha/capita against world average of 1.0 ha/capita) providing employment to 500,000 workers and contributing 0.3 percent to GNP. Furthermore, Pakistani forests including farm-forests are supplying 32% of Pakistan’s total energy needs in the form of fuelwood, providing forage for one third of Pakistan’s 86 million head of livestock and saving Pakistan’s agriculture, which contribute about 26% of GDP, by ensuring good quality irrigation water in river based gigantic irrigation system.

1.4.

Benefits of Forests

Forests have appeared on Earth about 350 million years ago, and reached a peak about 270 million to 220 million years ago during the Carboniferous period. Today, forests cover about one third of the earth’s land surface. They are the most distinguished type of vegetation community and provide many resources and environmental functions that far exceed those of other vegetation covers. Accordingly, forests have always played a vital role in the survival, development, and growth of human society since prehistoric times. Healthy forests always improve the quality of environment. Before discussing the benefits of forest, it is important to understand the four categories of functional forests: Production forests, protection forests, preservation forests, and public forests. The functions for which a forest is managed are directly related with site and environmental conditions. However, the ownership, economic constraints, and prospective value of the forest play an important role in determining management objectives. Production forests: The main purpose of production forests is to obtain financial profit from the forest by producing timber, pulpwood, fuels, wildlife, forest and

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Introduction

agricultural by-products, livestock, and recreation services. In rural areas of the tropical regions, a sizeable population lives in and around forests. They grow crops in the forest for food and harvest branch and litter for fuel. India has started a social program in which people plant and grow trees in back yards and community woodlots for fuel and other purposes. Many feasibility studies have shown that power stations could be operated and liquid fuel ethanol could be produced by growing trees in “energy plantations” (Fung 1982). Forest grazing is also a common practice that often damages trees, destroys litter floor, and compacts soils. These exploitive adverse practices interrupt nutrient cycling in the forest, increase soil and water erosion, deplete land productivity, and eventually cause the disappearance of forests or reduction in the forests production. In the pursuit of maximum economic gain from a forest, exploitive uses of its resources should be avoided. Best management practices should be incorporated in all forestry activities so that land productivity can be maintained and water quality should not be impaired. Protection forests: On rough terrain, steep slopes, streambanks, water resource areas, wind prone regions, or potential landslide sites, forests are often established to reduce soil erosion, increase sand stability, improve water quality, retain reservoir capacity, mitigate flood damage, and attenuate air pollution. Forests are also managed to protect habitats for birds, fish and other animals. Protection forests ensure environmental functions; economic income is insignificant or even totally ignored. Since protection forests are there to protect a specific site and environmental condition, species used are more restrictive, and management activities need to assure the sustainability of the forest. Protection forests are usually in areas sensitive to environmental problems; clear cutting, grazing, cropping, and litter harvesting should not be practiced. A clear-cut in these sensitive areas would make artificial regeneration very difficult or too long to establish. It can consequently make the destruction of forests in the protected area devastating. Thus, legal enforcement is required to preserves the protection forests any kind of damage due to cultivation, harvesting, grazing, and other impairing activities. In fact, all forests can be considered protective in view of their function as sinks of atmospheric carbon dioxide, and their effective role to control or reduce global warming. An estimate of potential carbon sequestering in the tropical closedforest landscape is about 1 .5 to 3.2 Pg C per year (I Pg= 1015 g or 1 Gt) or 31 to 58%of the current CO2 emission by fossil fuels (Brown and Lugo 1992). A sustainable forest-management plan should be developed that can provide simultaneously both a profitable income from the forest and an inexpensive way to reduce accumulation of CO2 in the atmosphere. Preservation forests: It has been estimated that about 30% of Earth’s surface vegetation has been damaged since farming began. According to another estimate, between 1981 and 1990, about 12% or l68 × 106 ha of the highly bio-diversified tropical forests in 62 tropical countries were lost due to deforestation (FAO 1990). Loss of forests leads to the loss of many plant and animal species from the genetic and pharmaceutical pools of the world. The nature and ecosystems of managed forests are different from those of the virgin forests. Impacts on the hydrological

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cycle, soil and nutrient losses, and climate changes are highly significant and well documented. Public forests: Forests that are developed and managed for the public to provide recreation are referred as public forest. They may include parks, botanic gardens, zoos, and wildlife refuges. Most public forests have been declared as national, state, and city parks. The national parks are dedicated to preserve vegetation, wildlife, natural wonders, cultural heritages, and historical monuments for people’s pleasure and health. They also provide educational and awareness programs through forest trails and on-site boards about environment and biodiversity.

1.4.1. Environmental Functions The physical environment of Earth is composed of three phases; atmosphere, hydrosphere, and lithosphere. Which form the so-called geosphere of Earth. The interface of these three phases is life, or biosphere, and the combination of geosphere and biosphere is called ecosphere. Forests are largest and biggest system in the biosphere and with profound impacts to the environment. Major functions of forests can be divided into hydrological, climatological, mechanical, biological and societal.

1.4.2. Hydrological Forests affect both water quantity and quality. Firstly, the amount of precipitation that reaches the mineral soil is reduced by canopy interception. Secondly, a great amount of soil moisture is transpired to the air through the roots- stem-leaf system. Finally, the root systems, organic matter, and litter floor increase the infiltration rate and soil moisture-holding capacity. Combine effect of these processes makes overland runoff less, runoff timing longer, and water yield cleaner in forested watersheds than in nonforested watersheds. A reduced amount of runoff carries less sediment and debris to the stream. This reduced runoff, combined with the shielding and shading effects of canopies, the binding effect of root systems, and screening effect of forest floor, makes stream flow from forested watersheds have less sediment, lower dissolved elements, cooler temperature, and higher dissolved oxygen. The importance of forests to purify water can be recognized by the fact that about a third (33 out of 105) of the world’s largest cities obtain a significant proportion of their drinking water directly from protected areas and other 13 cities are managing forests at high priority to obtain good quality water (Dudley and Stolton 2003).

1.4.3. Climatological The Earth’s surface characteristics such as topography, water, land, and vegetation, play an important role in the atmosphere near the ground. These conditions modify water and energy exchanges between Earth and the atmosphere and affect the local and regional patterns of the atmospheric circulation. This is especially true in the forest because of its height, canopy density and depth, and area covered. Solar

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Introduction

radiation is the major energy source that affects the climate of Earth. In a forest, canopies usually receive more incoming solar radiation than pasturelands or the bare ground because of its dark colour and great roughness, but only a fraction of the received energy is transmitted to the ground surface. On the other hand, the emission of long wave radiation from the ground surface to the sky is reduced due to the shielding effect of forest canopies and less wind movement in the heat transfer processes. Thus, the forest can cause net radiation to be greater and air and soil temperatures to be cooler in summer and warmer in winter. The most significant effect of forests on precipitation is canopy interception, which reduces the net amount of radiation reaching the soil and delays snowmelt. Perhaps the largest-scale climatological functions of forests are carbon storage and the release of oxygen by photosynthesis. The world’s forests have been estimated to contain 358 × 1015 g or 80% of all above-ground carbon and 787 × 1015 g or 40% of all below ground (soils, litter, and roots) terrestrial carbon. Estimates for annual emissions of CO2 by fossil-fuel and land-use change for 1980-1989 were 5.4±0.5 × 1015 g of carbon per year (Dixon et al. 1994).

1.4.4. Mechanical Forests are the most efficient means of controlling soil water erosion by: 1) 2) 3) 4) 5)

Reducing overland runoff through canopy interception and transpiration. Increasing soil porosity through the organic horizon and root systems. Slowing down overland flow velocity through litter coverage. Reducing the terminal velocity of raindrops through canopy interception. Enhancing soil aggregates and binding through root reinforcement.

As a result, the soil erosion rate from a forested watershed can be 1000 times less than that of a bare-ground watershed (Patric 1976). Forest clearing along a stream bank often causes severe channel erosion and even stream bank collapse. Like raindrops and streamflow. Wind has energy to detach and transport soil particles. The detachment, rate of soil movement, and transport capacity grow with the second, third, and fifth powers of wind’s drag velocity (Eimern et al. 1964). In addition to protecting against water and wind erosion, a forest can also protect against avalanches if it occupies the zone of potential occurrence areas. The shadow cast by shelterbelts along with the retardation of wind speed has a great impact on soil evaporation and soil moisture conservation.

1.4.5. Biological Forests provide habitats for an array of fauna and flora that live and properly develop in a particular environment. They not only are genetic pools for life on earth, but also play a crucial role in the stability and viability of the biosphere. The biosphere is a large-scale life-support system with all components mutually interactive in a state of equilibrium. Large scale alterations of forests or destruction of habitats can lose species of potential importance to human health, medicine, food production, and other uses. Most important, a chain reaction and the cumulative

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effects, if not corrected in time, may lead to a collapse of food chains and to a biological disaster.

1.4.6. Societal Cool and shaded forests, with their vast area, wilderness setting and fresh air are ideal places for people to relax from tension, pressure, and hectic activities. Green canopies with blue sky and white clouds are a natural beauty to our eyes, and the environmental tranquillity relaxes our ears and minds. Thus, many recreation and leisure-time activities- picnicking, sightseeing, bird watching, hiking, camping, and canoeing- take place in forest areas. Psychologists have even used “forest bath”, a mental solace in the forest environment, as a treatment for persons with depression. Cardiologists have also discovered that frequent forest bath can support the proper heart functioning and decrease the chances of heart attack. Furthermore, retreating from hectic cities to wilderness even at higher costs has become a part of lifestyle in modern cities of developed countries. The presence of forests can benefit the health of people living in their vicinity. This may be attributable to the continuous replenishment of oxygen and reduction of dust and air pollutants in forested areas. City and traffic noise can be attenuated and ill looking scenes can be blocked by a greenbelt of trees. Wilderness areas serve as field laboratories for various research and educational purposes. They provide opportunities for the public to study and appreciate forest ecosystems, ecological processes, landscapes, and natural resources conservation.

1.5.

Threats to Forests

The most serious threats to the forests, such as deforestation, over cutting, over lopping grazing, forest fires, and air pollution is a result of human activities. Naturally induced insects, disease, tornadoes, volcanic eruptions, and storms can cause substantial damage to forests; but these are considered as a little threat to forests. Weakened trees created by overcrowding, age, or other agents are less resistant to insect and disease attacks. Their populations build up easily in these weakened trees and then spread to the entire forest. In many cases, poor forest management can cause a massive wind-throw of timber in forested areas. Unless active salvage actions are taken, there are more chances for insect infestations and wildfire outbreaks.

1.5.1. Deforestation and Grazing In the lower latitudes, because of population and economic pressures, deforestation and grazing caused a net loss of tropical forests of 167.8 × 106 ha in the 1980s. These forests were lost in most cases due to shifting cultivation. In the middle latitudes, however, reforestation and conservation programs have increased temperate forests and other woodlands. Thus, deforestation and forest grazing are more a regional and global issue in the lower latitudes, and a local issue in the middle latitudes.

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Introduction

1.5.2. Forest Fires Like precipitation and wind, wildfire is a natural phenomenon, which is very dangerous to forests, but it occurs less frequently than any other weather events. From the management point of view, fires can cause on-site and off-site as well as detrimental and beneficial effects to soils, water, nutrients, vegetation and wildlife. The intensity and duration of these effects depend on the type of vegetation, the severity and frequency of fires, the type of burning (ground, surface, or crown fires), season, slope, aspect, soil texture, and climatic conditions. Virtually all terrestrial ecosystems have been affected by fire at one time or another. Foresters consider forest fires a great threat because they can destroy the forest and its protective functions, reduce the value of existing timbers, induce insect or disease infestation, damage the recreational and scenic value, and delay forest regeneration.

1.5.3. Air Pollution Air pollution is the concentration of certain chemicals or particles in the air at levels that can cause harmful effects on humans, plants, animals, structures, soils, and water. Pollutants originate from natural events such as ocean splash, wind erosion, forest fires, and volcanic eruptions, or from human activities such as fuel and industrial emissions. These pollutants can react with the chemicals and moisture present in the air to form induced pollutants. Air pollutants, including acid deposition, gaseous sulphur oxide, ozone, and heavy metals, have adverse impacts on forest vegetation. Acute vegetation damage caused by smelters, power plants, and other sources of air pollution have been reported frequently. However, the most widespread effects of air pollution on the forest are probably due to acid deposition. Acid deposition can adversely affect forest vegetation either directly by damaging protective surface structures (cuticles) of the canopy or indirectly through the acceleration of soil acidification. The damage of cuticle layer can lead to malfunction of guard cells, alteration of leaf- and root-exudation processes, interference with reproduction, water stress, and leaching of minerals from the canopy. The soil acidification can lead to leaches of basic nutrient ions, alterations of nutrient availability; slow down of microbiological processes, reduction of microbial populations and variety, and increases in ion toxicity level to plants. These combined effects on soils and plants can ultimately result in leaf discoloration and abscission, and in reduction of forest growth, productivity, and species diversity.

1.6.

Deforestation Causes in Pakistan

Deforestation remains one of the most intractable environmental problems of today. About one third the size of the original forest cover has disappeared so far. Despite continuous efforts by the world community, deforestation continues unabated in most parts of the world, with serious consequences for the human abodes, ecosystems, and global climate. Pakistan also faces serious problem of depletion of its forest reserves. Approximately 39000 ha of forest are being cleared every year

M.T. Siddiqui and M.F. Nawaz

11

in Pakistan (FAO 2001). If deforestation continues at this pace, it is feared that Pakistan will lose most of its forests within the next thirty to forty years. Factors responsible are: 1) A population of 180 million people for meeting their needs (fuel, timber, shelter, forage for livestock, raw material for wood based industries and agricultural implements etc.) 2) Population pressure for urbanization and industrialization. 3) Land clearance for agriculture, infra-structure development for example residential areas, roads, dams, official buildings, etc.,) 4) Grazing pressure of forest/range inhabitants by over-exploitation of resources. 5) Forest fires also result in quantum loss of forest cover. 6) Timber mafia is an alarming threat for deforestation e.g., in 2010 flood, wood worth Rs. 12 billion was confiscated at Chashma Barrage. Such incidents are common in KP and AJK. 7) Market forces which have seen soaring timber prices for many years 8) Ill equipped Forest department; it lacks human and financial resources, and relevant technical expertise. The general perception among planners is that over population is the primary culprit behind forest degradation. Moreover, people living close to forestlands, and using it for their needs, show an imprudent behavior towards these forests and use it in an unsustainable manner. Since most of the forests in Pakistan are state owned/managed, and responsibility for the protection/conservation of these forests rests with the state, therefore, any inquiry into the causes of forest degradation in Pakistan must analyse the state’s role in it. Putting the entire burden of deforestation on ‘other factors’ shifts attention away from more important causes (namely, failure of government to manage forests), and leads to wrong policy conclusions.

1.7.

Strategies for future

1.7.1. Training of Foresters and Forest Management Forest department is using traditional methods to manage the forest resources. In fact, before the division of subcontinent, we had more than 25% forest area and policy of the British Government was also to protect the forests. So, foresters were given a complete training like in military services and they were even equipped with weapons against timber mafia. But after the independence of Pakistan and India, most of the forests went to India and a meagre forest area was given to newly born state of Pakistan. However, instead of changing our policies from the protection of forests to increasing the forest area, we continued the same policies. Even today, all the foresters in the PFI (Pakistan Forest Institute) are trained in the similar way. Now we need research oriented officers in the field and not merely the

12

Introduction

persons with military like trainings. It is strongly recommended that the lower forestry staff like Forest Guard and Forest Block Officer should be given a real hard training because they spend the most of their time in the field but all the officers should be competent professionals and trained researchers. Other option is that to recruit the trained foresters (officers) in a competitive way from all the academic institutions of the country and then give them a training of 6 month in a selected institution as the practice for CSP officers.

1.7.2. Promotion of Participatory Approach Forest Department rarely involves the local people to plant the trees in forest areas. In many foreign countries, on special events, local people are invited to plant the trees on their name and take care of them throughout their lives. Globally, the concepts of social forestry, agro-forestry, community forestry and urban forestry are more prudent than state forestry. It is recommended that foresters should be trained to involve local people in planting and post planting operations. This will result in protecting and promoting trees through participatory approach.

1.7.3. Strong Collaboration Among Forest Department, Universities/Colleges and Research Institutes In Pakistan, poor collaboration exists between Forest Department and other Forestry universities/research institutions. A strong collaboration between Forest Department and research universities and institutions is mandatory for solving the current problems of forests and deficiency of forest resources.

1.7.4. Provision of Funds and Facilities Adequate facilities and funds are essential for afforestation and protection of forests, so, Govt. should provide basic facilities to protect and promote forests.

1.7.5. Concept of High Conservation Value Forest (HCVF) Forests contribute directly to the purification of the air we breathe in and the water we drink; protect river basins from erosion, regulate the flow of water courses and reduce the risk of floods. Forests also help to control the excess carbon dioxide in the world’s atmosphere; it is estimated that they can absorb more CO2 from the atmosphere than is emitted by natural phenomena and industrial activity. Nowadays the classic principle of the single-use forest has been replaced by the idea of multiple use, an idea that is being expressed with increasing persuasiveness. Apart from wood shortage, such phenomena also cause loss of soil fertility, reduced ecosystem diversity and the destruction of habitats. The foundation of Conservation Value Forests (HCVF) lies in managing and protecting these forests. In Pakistan, there is a urgent need of defining the HCVF at spatial level and declaring their HCVF status to protect them at maximum level.

M.T. Siddiqui and M.F. Nawaz

13

1.7.6. Sustainability in Utilization of Forests In all developed countries, sustainability of forest yield is given more priority than maximum forest yield occasionally. It means extracting the yield of a forest that doesn’t damage that forest. For maintaining the sustainability of Pakistani forest, an urgent research is required at spatial level to determine the forest yield potentials and pertinent management tools by considering the local climatic and soil conditions. Judicious working plan is the key to successful management of the forest as well as ensuring its sustainability.

1.7.7. Forest as Industry Forests do not mean only an aesthetic land but in many countries, they are dealt as an industry which not only generates revenue but also provides employment to local people. For example, in Canada it was estimated in 1997 that forests provided about 830, 000 direct and indirect jobs and added about $60 billion in Canadian economy each year. Therefore, economic analysis of our forests at national level will help us to devise the policies for a profitable investment.

1.7.8. Involvement of Local People (Participatory Forestry) Successful stories of many countries revealed that they attained the goals of reforestation in the country by involving the local people, private owners, industrialists and city governments. A good example of it is agroforestry in Pakistan, farmers are earning much more by selling the trees after completion of their rotation as compared to revenues generated by Forest Department. Government should provide helping hand to agroforesters by regulating timber market and establishing wood based industries.

1.7.9. Optimum Land Use of Marginal Lands At international level, every inch of soil available is used in a productive way. In Pakistan, it is estimated that about 6.5 million hectares of soil is degraded either due to salinity or waterlogging and can not be used for regular cultivation. However, trees have the great diversity and potential for survival in these problem soils. Suitable species of trees can be planted on these soils by involving the owners of these lands. Planting of suitable trees on these lands will provide the wood and economical benefits to the land owner as well by improving the soil and providing other environmental benefits.

1.7.10. Introduction of New Species Introduction of exotic tree species play a vital role in greening the Earth. For instance, New Zealand remained successful to stop the deforestation by introducing the new fast growing species (Pinus radiata) from California to fulfil the demand of local industries. Research is required to introduce the new species in Pakistan which have the potential to survive in the arid and semi arid climatic conditions of Pakistan and produce a good quality wood.

14

Introduction

1.7.11. Mechanization and Use of Advanced Tools In modern countries, all the silvicultural operations from sowing to harvesting are carried out by machines. Mechanization of forests avoids delay in operations and brings sustainability in products. In Pakistan, mechanization can bring revolution in forest production by adequate release of funds. Similarly, advance management equipments and monitoring tools like GIS, advance communication systems, mobility and weapons can help a lot Forest Department to cope with illegal cutting or theft of trees.

1.7.12. Modelling of Forest Yield Prediction of forest yield and the effects of different environmental factors (like climate change) on the forests models are frequently used in advanced countries. If there is a fire out break in a forest, the destination of the fire is predictable through the developed models. To develop or to validate he models, excessive data are required. In advanced countries, all the data acquired by Forest Department is online and can be used to conduct research. But in Pakistan, data about forests or tree growth is rarely acquired or kept secret. Researchers in the Forest Department are few, so, data are rarely used. It is therefore recommended that data on forest growth acquired by Forest Department should be displayed and used by collaborating with any research institution to prepare models or to validate the foreign models under Pakistani climatic conditions. These models can be largely helpful to predict about outputs from a forest.

1.7.13. Implementation of Laws Formation of new laws that can be implemented and complete implementation of existing laws is the key to success of all developed countries for managing the forests. But in Pakistan, the case is with other departments and laws; same is with the Forest Department and Forest, there are well written clear laws about every aspect of forest management and protection but their implementations are hardly 10%. For example, the major factor involved in illegal cutting and theft of trees in irrigated plantations of Pakistan is the presence of saw machines just near the forest area. Labour or other residential persons cut and sell the trees to these saw machines. By law, there could be no saw machine in 5 kilometres periphery of a forest. So, if all these saw machines are pushed out of 5 kilometers, all the saw machines are compelled to maintain their buying and selling record and if these records are checked on regular basis; half of the illegal theft of wood from irrigated plantation can be stopped. Similarly, making the Forest Check Post functional and increasing their numbers can reduce the theft and illegal cuttings of trees. So; if implementation of forest laws can be ensured, we can bring the deforestation rate to its minimum level.

M.T. Siddiqui and M.F. Nawaz

15

References Brown, S and A.E. Lugo (1992). Aboveground biomass estimates for tropical moist forests of the Brazilian Amazon. Interciencia Caracas 17: 8-18. Desio, A (1988). Which is the Highest Mountain in the World? Memories, Series VIII, Vol. XIX, Roma (1989), pp. 36. Dixon, R.K., S. Brown, R. Houghton, A. Solomon, M. Trexler and J. Wisniewski (1994). Carbon pools and flux of global forest ecosystems. Science 263: 185189. Dudley, N and S. Stolton (2003). Running pure: the importance of forest protected areas to drinking water. World Bank/ World Wildlife Fund. Alliance for Forest Conservation and Sustainable Use, Washington, DC. Eimern, J.V., R. Karshon, L.A. Razu-mova and G.W. Robertson (1964). Windbreaks and Shelterbelts. World Meteorological Organization (UNO), Geneva, Switzerland. Tech. Note No. 59, pp. 188. FAO (2002). An overview of forest products statistics in South and Southeast Asia, Food and Agriculture Organization (UNO), FAO Regional Office for Asia and the Pacific, Bangkok 10200, Thailand. FAO (2010). Global Forest Resources Assessment, Food and Agriculture Organization (United Nations). Rome, Italy. Fung, P (1982). Keynote speech forests-a source of energy, Tropical Forests: Source of Energy through Optimisation and Diversification: Proceedings, International Forestry Seminar, 11-15 November 1980, Serdang, Selangor, Malaysia. Penerbit Universiti Pertanian Malaysia, pp. 193. Patric, J. H (1976). Soil erosion in the eastern forest. J. For.74: 671-677. Rahim, S.M.A and S. Hasnain (2010). Agroforestry trends in Punjab, Pakistan. Afr. J. Environ. Sci. Technol. 4: 639-650. Sands, R (2005). Forestry in a Global Context. CABI Publishing, UK. Siddiqui, KM (1997). Asia-pacific forestry sector outlook study Working paper series. Working Paper No: APFSOS/WP/11. Country report – Pakistan. FAO, Regional Office for Asia and the Pacific, Bangkok, Thiland.

Chapter 2

Forest Types of Pakistan F. Rasheed, S. Yaqoob and H.M. Ahmad*

Abstract Pakistan is blessed with diversity of climatic and soil conditions that support various forest types. In this chapter, various forest types are discussed in details that include information on various regions where they exist along with their climatic condition, vegetation type and any silvicultural practices if prevalent are presented. Furthermore, the conclusion portion briefly encompasses the major reasons of the forest declines in Pakistan and the steps that can be taken to curtail such menace. Keywords: Forest types; Silviculture systems; Climatic conditions; Key species.

2.1.

Introduction

The forests of Pakistan reflect the country’s physiographic, climatic and edaphic diversity. Pakistan is an oblong stretch of land that runs from Arabian Sea up to Karakoram Mountain between 24°N and 37°N latitudes and 61°E and 75°E longitudes. Total area of the country is 87.98 million hectares. Topography of the country comprises of massive mountainous tracts in the North, the West and the South-West along with a large fertile plain called the Indus plain. The northern mountain system includes the Karakoram, the great Himalayas, and the HinduKush that has one of the biggest masses of snow, glaciers and 100 peaks that are over 5,400 m in elevation. K-2 (8,563 m) is the second highest peak in the world. The mountain slopes are steep therefore fragile watersheds making associated

* F. Rasheed˧, S. Yaqoob and H.M. Ahmad Department of Forestry and Range Management, University of Agriculture, Faisalabad, Pakistan. ˧ Corresponding author’s e-mail: [email protected]

Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

17

18

Forest Types of Pakistan

forest vegetation extremely important from hydrological point of view. The Indus plain has two distinct landforms; the alluvial plain and sandy deserts. Indus River starts from snow covered northern mountain ranges and bisect the country and produce a wide delta before entering the Arabian Sea. Four rivers i.e. Jhelum, Chenab, Ravi and Sutlej enter the main Indus River from the East at Panjnad and together these rivers fabricate one of the largest irrigation systems in the world. Despite this extensive irrigation system, Pakistan is poor in forest wealth, which is mainly due to arid to semi arid climate that prevails in most parts of the country (Figure 2.1). According to forest Sector Master Plan (FSMP) 1992, out of total land area of the country (87.98 million ha), only 4.8% (4.2 million ha) are natural forest cover, 0.117% (103,000 ha) are irrigated plantation and (32.40%) 28.507 million ha are rangelands. FAO (2007) recorded that the total area of forests was 5.01% (4.34 million ha, Figure 2.1) out of which 3.44 million ha is state owned and tree cover on private lands or farmlands is about 0.887% (0.781 million ha). Most of the forest area in the country exists in the northern parts especially in Khyber Pakhtunkhwa (KPK) and Azad Jammu & Kashmir (AJK) that has coniferous and scrub forest (Table 2.1). Other main types of forests include the Jumiper, Chilghoza, scrub, riverine and mangrove forests. Irrigated plantations also are important source of timber in the country and are mainly present in Punjab and Sindh Provinces. Table 2.1 Province wise breakup of area under various forest types. Area under each forest type is represented in hectares (ha) MAJOR FOREST TYPES & STATUS IN PAKISTAN PROVINCE/REGION/TERRITORY Landcover class

Khyber Pakhtunkhwa Punjab Sindh Balochistan Gilgit-Baltistan Azad Jammu Kashmir FATA Islamabad Total

Alpine scrub & Grassland

649597

0

0

0

636125

122398

0

0

1408120

Sub-Apline Forest

44543

0

0

0

23679

7519

0

0

75741

Moist Temperate

391769

17249

0

0

0

161842

1648

0

572508

Dry Temerate Forest

532591

0

0

97367

254961

27776

317986

0

1230681

Oak Forest

83480

0

0

0

58851

3484

28588

0

174403

Subtropical Chir Pine Forest

217752

27283

0

0

0

111335

5877

0

362247

Subtropical Broad Evergreen

236019

333246

0

294636

0

95757

134044

14124

1107826

Drytropical Thorn Forest

12007

0

0

76746

0

0

34126

0

122879

Forest Plantations

3970

110905 74867

0

0

0

9610

4433

203785

0

28218 190776

0

0

0

0

0

218994

Reverine Forest Mangroves Forest Total

Source: FAO (2007)

0 2171728

0

353062

516901 618705

2360

0

0

0

0

355422

471109

973616

530111

531879

18557

5832606

F. Rasheed, S. Yaqoob and HM Ahmad

19

Fig. 2.1 Distribution of forests and tree cover in Pakistan. Source: FSMP (1992).

2.2.

Alpine Scrub forest

Alpine scrubs are found on mountain tops or high elevations in the extreme northern area of Pakistan. These forests form narrow belt around the mountain tops below the snowline also called alpine pastures and include mountainous region of Himalayas, Karakourm and Hindukush that rises to an elevation that ranges from 4000 m or above from the sea level. Due to extreme elevations, these regions are not easy accessible and experience very long and sever winter with heavy snow falls that may rise to 6 feet annually. Climate is harsh with mean annual temperature and precipitation ranging between 1-6°C and 500-600 mm respectively. The forest type is not fit for good tree growth however scrub formation is common dense and profusely mixed with grasses that may rise up to 0.5 to 2 m high (Siddiqui, 1997). Vegetation is characterized by the development of flexible stem and branches to withstand snow pressure and herbaceous flora include palatable grasses commonly used for grazing and browsing by the local herds. The species include shrubs: Willow (Salix babylonica), Sumblu (Berberis lyceum), Phut (Lonicera japonica), Chan (Rhododendron arboreum), Juniper(Juniperus communis), Ephedra (Ephedra nebrodensis), Guchh (Viburnum nervosum) andgrasses: Draba trineriva, Polygonum affine, Saxifraga sibirica, Primula capitelaita. These regions mostly serve as watersheds and commonly managed for recreational purposes.

20

2.3.

Forest Types of Pakistan

Sub-Alpine Forest

Sub-alpine forest covers the topmost region for tree formation that includes Himalayas, Karakourm, Hindukush, Hazara, Sawat, Dir, Chitral, Skardu, Gilgit (Northern Areas) and Kashmir regions. These forests exist below the alpine scrub zone at an elevation ranging from 3350 to 4000 m or up to the timber line. Vegetation includes the evergreen conifers in the upper elevation like Fir and Blue Pine and evergreen broad-leaved trees dominated by Birch at the lower end. Deciduous shrubby undergrowth of Rhododendrons, Guch, and Willow, etc. is also common. Climate is less intense in comparison to the alpine scrub and is characterized by short summer and severs long winter with mean annual average temperature and precipitation ranges is about 10°C and 650-900 m respectively. Snowfall is of great importance that may exceed 1m annually therefore soil formation is very slow and rocks are therefore with little soil cover. Dwarf junipers trees are abundant towards the upper limit that rarely exceeds 8 m in height however the broad leaf species on the lower limits commonly exceeds 9 m in height and the shrub growth remain between 1-3 m. common species found in this forest types are Conifers: Only few conifer species occur in this forest type which are Fir or Partal (Abies pindrow), Kail or Blue Pine (Pinus wallichiana) Juniper (Juniperus communis), Broadleaved: Birch (Betula utilus), Guchh (Viburnum nervosum), Chan (Rhododendron arboreum), Batangi (Pyrus pashia), Willow (Salix acmophylla), (Salix babylonica),(Salix tetrasperma) and Grasses: (Primula capiteliata),(Phleum alpinum), (Agrostis gigantean). Managed under selection wood system, these forests are highly valuable watersheds and are also used for recreational purposes.

2.4.

Himalayan Dry Temperate Forest

These forests occur at elevation between 1700 – 3350 m and cover parts of Chitral, NilamValley (AJK), Gilgit, Sakardu, Hunza, Upper parts of Suleiman Mountain Range to the North West including Takht-i-Suleiman, Tribal areas (Wazirstan), district Loralai (Ziarat). These forests are located just below the sub alpine forests and mixes with moist temperate forest towards the lower boundaries. Climate is characterized by long and cold winters and short dry summer with mean annual temperature and precipitation that less than 500mm and 5 -15°C respectively. Being beyond effective reach of the Monsoon penetration, these forests have open canopy as trees are wide spread with poor productivity with open scrub undergrowth. Grazing and browsing is common and intense by goats and sheep, which are damaging the natural balance of palatable and unpalatable species composition in these forests. Some shrub species of medicinal and aromatic importance like Artemisia species are also found in these forests. Dry zone deodar, Pinus gerardiana (Chalghoza) and Quercus ilex are the main species. Higher up, blue pine communities occur and in the driest inner tracts, forests of blue pine, Juniperus macropoda (Abhal, Shupa, Shur) and some Picea smithiana (e.g. in Gilgit) are found locally. The vegetation includes Conifers: Deodar (Cedrus deodara), Chalghoza (Pinus gerardiana), Blue Pine (Pinus wallichiana), Spruce

F. Rasheed, S. Yaqoob and HM Ahmad

21

(Picea smithiana), Pencil Juniper (Juniperus macropoda), (Juniperus excelsa), Barmi (Taxus bacata), Broadleaved: Walnut (Juglans regia), White oak (Quercus incana), Barungi (Quercus dilatata), Chan (Rhododendron arboreum), Horse Chestnut/ Bankhor (Aesculus indica), Ash (Fraxinus hookeri), Maple (Acer oblongum), Poplar (Populus ciliata) and Shrubs: Artemisia (Artemisia maritima), Ephedra (Ephedra nebrodensis), Jangli badam (Prunus padus), Daphne, Phut (Lonicera japonica), Astragalus, Unab (Zizyphus sativa). These forests are managed through Shelters Wood silviculture system.

2.5.

Himalayan moist Temperate Forest

These are evergreen forests of conifers occasionally mixed with oaks and broadleaved species. These forests occur in Azad Kashmir, Murree, part of district Abbottabad, Mansehra, Sawat, some tribal areas (Hazara and Malakand civil division) and Naran Kaghan valleys at an elevation ranging from 1700 to 3350 m above the sea level. These forests extend into dry temperate and occasionally into sub-Alpine forests. Winters are long and cold with snow and hail storms and summers are short mild and moist. Mean annual temperatures and precipitation is around 12°C and 650 to 1500 mm. Vegetation is characterized by a small number of dominant species mainly conifers but good canopy cover. Trees height between 25 to 50 m and stem girth may rise to 4.5 m. These forests are considered as the most productive forests of the country. On flat ground with deep soils and in depression areas, deciduous broad-leaved forest is also found that are subject to extent of lopping, grazing and cleaning for cultivation. In open patches grass vegetation covers the forest soil. Vegetation include species like Conifers: Kail (Pinus wallichiana,), Deodar (Cedrus deodara), Spruce (Picea smithiana), Fir /Partal (Abies pindrow), Barmi (Taxus bacata), Broadleaved: White oak (Quercus incana), Barungi (Quercus dilatata), Brown oak (Quercus semicarpifolia), Chan (Rhododendron arboreum), Horse Chestnut/ Bankhor (Aesculus indica), Ash (Fraxinus hookeri), Maple (Acer oblongum) and Shrubs: Kainthi (Indigofera oblongifolia), Phut (Lonicera japonica), Jangli gulab (Rosa moschata), Desmodium, Black berry (Rubus lasiocarpus), Guchh (Viburnum nervosum), Strobilanthus. Due consideration is given to soil and water conservation in these forests as they constitute major portion of the Mangla and Terbela lake watershed. These forests receive heavy monsoon rains in the summers as well as heavy snowfall in winters, which is typical to these moist temperate zones. Forests are managed under Shelter wood silviculture system.

2.6.

Subtropical Chir Pine Forest

Subtropical Pine forests are mainly located in Kashmir, Abbottabad, Mansehra, Ghoragali (Muree Hills), Margla Hills, and Kahuta at an elevation from 920 to 1700 m. These occupied regions have hot and moist summer with severe winter with some snowfall. Rainfall is received mainly during Monsoon season and means

22

Forest Types of Pakistan

annual temperature and precipitation ranges around 15-20°C and 700-1500 mm respectively. These forests are composed of pure strand of Chir pine that comprises of almost even-aged individuals. However, in depression as well as flat areas evergreen oaks and some deciduous species are also found. Tree growth is reasonably good with average tree height up to 36 m and average stem girth up to 2.5-3.5 m. Forest fire is relatively common in these forests especially in the months of May-June due to heavy needle fall that are full of oils and resins conducive to fire catching. Vegetation structure consists of Conifer: Single coniferous species Chir (Pinus roxburghii) that is completely dominant and Broad leaved species: Walnut (Juglans regia), Oak (Quercus incana), Pear (Pyrus pashia), Chan (Rhododendron arboreum), Kangar (Pistacia integerrima), Jaman (Syzygium cumini) andAnar (Punica granatum). Subtropical Pine Forests are generally managed through Shelter wood Silvicultural System.

2.7.

Sub-tropical Broad Leaved Evergreen Scrub Forest

These forests are found throughout the country at suitable elevation especially in the Foot Hills of Murree, Margalla Hills (Islamabad), Pothowar Region, Kalachitta Hills (Attock), Salt Range (Jehlum), and Suleiman Mountain Range. Mostly occur below the Subtropical Chir pine forest at an elevation of 460 to 920 m mostly along the foothills and lower slopes of Himalayas. Hot and long summers and a definite cool short winter characterize the climate. Long and dry months are common features of these forests. Mean annual temperatures ranges from 20-25°C where summer temperature may rise to 40°C. Mean annual precipitation ranges from 250750 mm. Terrain of these forests is stony and difficult. Forest merges upwards with sub-tropical Chir Pine forest and downwards with the Tropical thorn forests. Species present are xerophytic with thorns and small evergreen leaves mostly broad leaved. The typical species include Kao and Phulai, the two species occurring in mixed or pure form and the shrub Sanatta that is particularly abundant in most degraded areas. Total area of these forests is estimated to be 1,108,826 ha (Table 2.1). These forests are useful for small timber, fuel wood and forage purposes. Scrub forests are also suitable for controlled grazing and browsing however during monsoon profuse growth of grasses and herbs are found that are highly suitable for grazing. Along with other species as mentioned above, large dimension Pistacia trees are also common in moist pockets as well as higher elevations. Vegetation include Trees: Phulai (Acacia modesta), Kau (Olea ferruginea), Ber (Zizyphus mauritiana), Lahura (Ticoma undulata) and Shrubs: Snatha (Dodonaea viscosa), Kanir (Nerium odorum), Pataki (Gymnosporia royleana), Granda (Carrissa spinarum), Kangar (Pistacia integerima). Due to harsh and unpredictable climate, these forests are mostly managed for soil and water conservation under Selection wood sylvicultural system.

F. Rasheed, S. Yaqoob and HM Ahmad

2.8.

23

Dry Tropical Thorn Forests

This forest type occurs throughout the Indus plains except the driest regions. The vegetation is dominated by short and predominantly xerophytic species that are mostly leguminous in nature with small leaves. The species composition varies from evergreen to deciduous mixture depending upon the geographical location. Climate is dry and hot in these forests. Mean annual temperature ranges from 2026°C with the hottest months of June where temperature may rise to 51°C in some areas. Mean annual rainfall is from 120 to 500mm with large temporal variations from year to year. The major tree species found in these forests are Prosopis cineraria (Jhand), Capparis decidua (Karir, Karil), Zizyphus mauritiana (Ber), Tamarix aphylla (Farash) and Salvadora oleoides (Pilu, wan) along with large number of shrubs species with individuals of all sizes. Heavy grazing and browsing is a major problem in these forests that result in the tree climax at short stature especially for the palatable species. Edaphic and other biotic factors also contribute to the poor state of trees in these forests where salinity, water scarcity and soil shallowness is becoming more intense due to climate change. Average height of trees is between 20 to 30 ft. Prior to the extension of agricultural lands the forest area extended from the foothills of the Himalayas and low-hills in the south-west Punjab plains and Balochistan to the Arabian sea. The climax species of these forests depends upon the various soil properties like soil textures, type and depth that vary from region to region. Resultantly, climax species are Salvadora oleoides, Capparis decidua, Tamarix aphylla and Prosopis cineraria, which grow on a wide range of soils. These forests are the home of many important endemic wildlife species as well as many migratory species. Theseforests provide ideal habitat to these migrated wildlife species according to their need of food and shelter during extreme winters. Vegetation include species of trees like Trees: Van (Salvadora oleoides), Kikar (Acacia nilotica), (Acacia senegal), (Acacia jacquemontii), Jand (Prosopis cineraria), Frash (Tamarix aphylla), Phulai (Acacia modesta), Lahura (Ticoma undulate), Ber (Zizyphus mauritiana), Sohanjna (Moringa oleifera), Shrubs: Van (Salvadora persica), Karir (Capparis decidua), Mallah (Zizyphus nummularia), Phog (Calligonum polygnoides), Khar (Haloxylon recurvum), Lana (Sueda fruiticosa), Lani (Salsola foetida), Ak (Calotropis procera) and grasses: Dhamman (Cenchrus ciliaris), Malai (Panicum antidotale), Lamb (Aristida depressa), Chhimber (Eleusine flagellifera), Gorkha (Lasiuruss cindicus). Along with climatic extremes and heavy grazing and browsing, illegal cutting is also of major concern in these forests.

2.9.

Tropical Littoral and Swamp Forest / Mangrove (Coastal) Forest

These forests are located on the narrow belts along the muddy coasts of the Arabian Sea around Karachi and along the coast of Gawader. Mean annual rainfall is between 150 – 200 mm that has an important effect on soil salinity regulation rather

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Forest Types of Pakistan

than bringing additional moisture. Single specie Timar (Avicennia marina) dominates this forest type 95% which is evergreen in nature. These forests are dense with a very low average tree height, often between 10 to15 ft and branchy and bushy in nature. Terrain is difficult to access because soft mud, accessible parts over utilized for grazing and lopping and fire wood collection. Roots produce aerial out-growths (finger like structure from the soil called Pneumatophores) for the exchange of gases. Viviparous germination is dominant where seed germinate on the mother plant before shedding These forests are not important from timber point of view but are basically protected forests as they provide habitat, protection and feed to aquatic wildlife and marine animals such as prawns, shrimps, fish, turtle, etc. They also protect coast line of country from strong tidal erosion and sea storm. Forest is inundated twice a day by the sea water during high tides. The water and soil within Mangrove ecosystem have high salt contents. Soil is water logged and poorly oxygenated. Species present in this forest type are Timar (Avicennia marina), Kirriri (Ceriops tagal), Kamri (Rhizophora mucronata). This forest reserve is seventh largest coastal forest in the world and is managed under Selection Wood Silvicultural System.

2.10. Man Made Irrigated Forest Plantations Irrigated forest plantations spread over the plains of Pakistan i.e. Changa Manga in Distt. Kasur, Chichawatni in Distt. Sahiwal, Pirowal in Distt. Khanewal, Duffar in Distt. Gujrat, Kundian in Distt. Mianwali etc. These plantations spread over the plains of Pakistan covering an area of nearly 203,785 ha (Table 2.1), out of which 50% is stocked (productive). Size of each plantation varies 300 acres to 30000 acres, for example Changa Manga Plantation spread over 12510 acres as it was planted in 1866. Few examples of these man-made irrigated forest plantations are (i) Changa Manga Forest Plantation, (ii) Chichawatni Forest Plantation, (iii) Kamalia Forest Plantation, (iv) Duffar Forest Plantation, (v)Pirowal Forest Plantation, (vi) Lal Sohanra National Park, (vii) Machu Forest Plantation (viii) Kundian Forest Plantation. Mostly these plantations were established in Agroecological zones of Punjab and Sindh (sub-tropical climate) where canal water was available. Originally, these plantations were established to provide fire wood for railways engines. However, after coal discovery, these forests were managed for providing high quality timber for furniture, sports goods and for providing recreational facilities. Species in these plantations include Shisham (Dalbergia sissoo), Mulberry (Morus alba), Babul (Acacia arabica), Desi Kikar (Acacia nilotica), Simal (Bombax ceiba), Bakain (Melia azedarach), Neem (Azadirachta indica), Sufeda (Eccalyptus camaldulensis), Siris (Albizzia lebbek), Willow (Salix tetrasperma), Poplar (Populus deltoides). These forests are managed under clear felling system and coppice with standard silvicultural system for producing high quality large timber as well as small timber and fuel wood.

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2.11. Riverine (Bela) Forest The forests also known as Bela Forests occur along the river Indus and it five major tributaries and in the flood plains. Total estimated area under these forests is about 218994 ha (Table 2.1). The climate is generally sub-tropical dry however the soil is moist, deep, sandy/silty and alluvial that is good for tree growth. The forests are irrigated by the flood water that spills over the river banks during Monsoon season of July, August and September. The intensity of this spill over may vary from year to year, therefore the width of this flooded belt varies from 1 to 15 Km. these forests are dense with tall tree that may rise to 12-15 m. The major tree species found in these forests is Babul (Accacia arabica). These forests are fast growing due to water availability through flood spills and seepage and produces good quality timber. Forest food is generally covered with heavy grass growth and serves as a good source for local grazing and browsing animals. High biodiversity of flora is one of the key features of these forests however this wealth is under several biotic and abiotic pressures and getting restricted within the protective boundaries. Regeneration in these forests is mainly through artificial means. Vegetation found in these forest include tree species like Shisham (Dalbergia sissoo), Kikar (Acacia nilotica), Jand (Prosopis cineraria), Frash (Tamarix dioca), (Tamarix articulata), Van (Salvadora oleoides) and Poplar (Populus deltoides), (Populus euphratica) and grasses like Grasses: Sarkanda (Saccharum munja), Kai (Saccharum spontaneum), Dib (Typha elepantina). Riverine forests are managed according to clear felling silvicultural system as well as with artificial seed spreading

2.12. Agro–Forest / Farm Forest Agro-forestry is a component of social forestry. Social forestry is planting of trees on farmlands and in urban areas along roads, canals, railway tracks, in schools, colleges, universities, hospitals, airports, cantonments, on waste lands, on saline and water logged areas. Whereas agro-forestry is growing together of woody vegetation and farm crops on the same piece of land either side by side or one after the other in the best interest of site and man. Agro-Forestry is being practiced all over Pakistan especially in plain areas of the country. Generally, under agro-forestry, trees are planted in lines along field boundaries, inter planting is done along with the farm crops or in compact blocks without farm crops. Contribution of farm forests for timber production is already 5 to 9 times more than that of state forests as, 60% of total demand of timber and 90% of total demand of fire wood is fulfilled by these forests (Government of Pakistan 2009). Trees growing in lines on farm lands grow fast because less competition among trees as compared to trees growing in natural forests/compact plantations. Farm trees also get some share of water and nutrients from farm crops. Still, there is lot of potential that is untapped where timber and fuel wood production from farm lands can be easily increased by 8 times. Ecological conditions of the area, availability of water, nature of farm crops and market

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Forest Types of Pakistan

demand must be evaluated before choosing tree species for agro-forestry. However, tree species selected for a particular farm should have following properties: i.

Preferably be a fast growing

ii.

Must have a short rotation age

iii. Should produce straight/erect stem iv. Canopy must not be dense or crown should preferably beconical or columnar as it will cast less shade v.

Species must have deep root system

vi. Preferably be deciduous in nature and finally vii. Wood should be of high market value. Agro-forestry system is an integrated land use approach (including various combinations of agriculture and forestry) for obtaining maximum possible benefits from a unit area of land. Different agro-forestry systems are applied in different areas of Pakistan for example Agri-silviculture system, Silvi-pastoral system, Agrisilvi-pastoral system. Tree species that are being planted on include shisham (Dalbergia sissoo), Kikar (Acacia nilotica), Sufeda (Eucalyptus camaldulensis), siris (Albizzia lebbek), poplar (Populus deltoides), neem (Azadirachta indica), bakain (Melia azedarach), simal (Bombax ceiba), sohanjna (Moringa oleifera), pipal (Ficus religiosa), burgad (Ficus benghalensis). These species also include fruit trees like mango (Mangifera indica), jaman (Syzygium cumini), guava (Psidium guajava), ber (Zizyphus mauritiana) and mulberry (Morus alba).

2.13. Linear Plantations Tree planted along the roads, canals and railway tracks are called linear plantations. These Linear plantations are very important from ecological point of view as they act as windbreak, improve environment, reduce noise and environmental pollution, provide timber, fuel wood and forage for local animals. Linear plantations especially along the canal sides are very productive and are commonly regarded as timber mines. As these plantations are mostly in urban areas they are also known as Urban Forestry. The science and art of growing trees in urban and peri-urban areas for obtaining various environmental benefits is known as urban forestry. These plantations have landscape and ornamental values and are planted according to landscape principles and designs. Presently these are planted and managed by government but these plantations should be managed through participatory approach with the involvement of local people and farmers. These plantations need continuous management and protection. Clear felling is strictly prohibited in these plantations, only those trees are harvested which have attain rotation age. Plantation along the Motorway (M-2) is a good example of well-managed linear plantation. Following tree species are prefers under linear plantation:Shisham (Dalbergia sissoo), Kikar (Acacia nilotica), Sufeda (Eucalyptus camaldulensis), Siris (Albizzia lebbek), Poplar (Populus deltoides), Neem (Azadirachta indica), Bakain (Melia azadarech), Mulberry (Morus alba), Simal (Bombex ceiba). Flowering trees that

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are planted includesGul Mohar (Delonix regia), Amaltas (Cassia fistula), Neelam (Jacaranda mimosifolia), Gul-e-Nishter (Erythrina suberosa), Dhak (Butea frondosa), Kachnar (Bauhinia purpurea), Kabli kikar (Parkinsonia aculeata) and Paulownia (Paulownia tomentosa). Foliage ornamental trees include Devil Tree(Alstonia scholaris), Toon (Cedrela toona), Pilkhan (Ficus infectoria), Silver oak (Grevillea robusta), Kangar (Pistacia integerrima), Kanak-champa (Pterospermum acerifolium), Jiaputra (Putranjia roxburghii), Baid-e-Majnoo (Salix babylonica), Baid-e-Laila (Salix tetrasperma), Arjun (Terminalia arjuna).

2.14. Conclusion Pakistan has a wide range of forest reserves but due to variations in the climatic and edaphic factors, the country is still poor in forest resources with only 0.03 ha of forest available per capita, which is declining due to population growth (NIPS 2009). There are number of contributing factor responsible for such decline i.e. inherited a very small forest area since independence, most of the country is arid to semi-arid, receives low precipitation that can support optimum growth. Forest contractors who ruthlessly cut forests for the development of the country that heavily depended on the indigenous wood resources. Ban on timber harvesting in Sept 1993 resulted in decline of legal wood harvesting but illegal harvesting took over and the volumes increase almost en folds as compared to legal harvesting (Fischer et al. 2010). Ever increasing wood demand and supply gap that was 15 million m3 in 1992, increased up to 29.36 million m3 in 2003 and will be 43.97 million m3 by 2018 (Government of Pakistan 1992). Total fuel wood consumption is estimated at 34.95 million m3 in 2011 for the population of 170.52 million3 (Government of Pakistan 2005). Issue of low forest cover and demand and supply gaps can be met by promoting Agro forestry on emergency basis as the country has a lot of potential in this sector. Fast growing and high yielding species must be promoted like teak (Tectona grandis), poplar (Populus spp.) Simble (Bombax ceiba), Eucalyptus spp. and Shisham (Dalbergia sissoo). Plantation for the fuel wood purposes must be encouraged along the roads and railway tracks, along the rivers, canals and drainage channels. Furthermore, steps like credit facilities, subsidized saplings or planting material, expansion of irrigation facilities for the forests, tax exemption on local timber production to encourage private sector. Watershed management and restoration programs can be initiated. This would not only increase our forest area and biodiversity but also supply increase the life of our dams. Finally, the implementation if policies and forest sector reforms remain inadequate (Fischer et al. 2010) and must address the obvious factor of forest degradation like fuel wood/ energy supply issue and illegal commercial harvesting of forest trees.

References FAO (2007). Statistics for APFSOS II - IGF Office, Ministry of Environment, APFSOS II Conference Chiang Mai, Thailand.

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Forest Types of Pakistan

Fischer, K.M., M.H. Khan, A.K. Gandapur, A.L. Rao, R.M. Zarif and H. Marwat (2010). Study on Timber Harvesting in NWFP, Pakistan. Pak-Swiss Integrated Natural Resource Management Project, Swiss Agency for Development and Cooperation. ISBN: 969-9082-02-x. Government of Pakistan (1992). Forestry Sector Management Plan, Ministry of Environment, Government of Pakistan. Government of Pakistan (2005). Supply and Demand of Fuel wood and Timber for Household and Industrial Sectors and Consumption Pattern of Wood and Wood Products in Pakistan, Ministry of Environment, Government of Pakistan. Government of Pakistan (2009). Agricultural Statistics of Pakistan, Government of Pakistan. NIPS (2009). Population growth and its implications. National Institute of Population Studies, Ministry of Population and Welfare, Islamabad, Pakistan. Siddiqui, K.M. (1997). Asia-pacific forestry sector outlook study Working paper series. Working paper no: APFSOS/WP/11. Country report – Pakistan. FAO, Regional Office for Asia and the Pacific, Bangkok, Thiland.

Chapter 3

Tree Anatomy and Physiology S. Gul, Z.S. Siddiqui, A. Noman and F. Rasheed*

Abstract Trees are complex organisms. They originate either from vegetative propagation or through sexually fertilized egg that matures into a seed encased embryo. On planting, seed give rise to one of the nature’s largest living organisms. A tree has three major parts: roots, stem and leaves, which are anatomically different from each other. In this chapter, anatomy of cell, roots, stem and leaves has been described. Related topics like secondary growth, role of cambium, vascular tissues and structure of wood have been discussed. Differences between the wood formation of gymnosperms and angiosperms have been marked out. Water is an important element of life present on the earth. The huge quantity of water loss on every day by trees is a consequence of transpiration that must be reinstated for their growth and survival. In this chapter, importance of water absorption, relation, their interaction with soil and other important aspect of tree physiology like hormonal role and photosynthesis are discussed. Keywords: Tree; cambium; Water; Hormones; Secondary growth.

* S. Gul˧ and Z.S. Siddiqui Department of Botany, University of Karachi, Pakistan ˧ Corresponding author’s e-mail: [email protected]

A. Noman Department of Botany, GC University, Faisalabad, Pakistan. F. Rasheed Department of Forestry and Range Management, University of Agriculture, Faisalabad, Pakistan. Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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3.1.

Tree Anatomy and Physiology

Introduction

Trees are the tallest self-supporting organisms in the world. A tree is generally defined as a woody plant having the height of 15 ft or more and characterized by a single trunk. They live long and grow superior to any other living organism on the Earth; well-defined stems support a crown. Being perennial in naure, their anatomical features are different from other annuals and/or biennials. Coast redwood Sequoiasempervierns (Hyperion) is the world's tallest known living tree, measuring up to 115.61 m (379.3 ft) in height. Treephysiology is the study of natural phenomena operating in the living trees and tree parts. In tree physiology, structure of the cells, tissues and organs are associated with processes and functions. Trees are physiologically alike to other form of plants like biennials/annuals because they are also autotrophic, non mobile, soil dependant for waters and minerals etc. Wood formation and larger heights make trees distinguished from bushes, grasses and/or dwarf plants. Some major physiological phenomena like water absorption, ascent of sap, photosynthesis, transpiration and plant hormones are briefly discussed in this chapter.

3.2.

Tree

A tree consists of three major portions: root, stem or trunk and crown (Figure 3.1). Crown consists of limbs (> wrist thickness), branches (thumb thickness < wrist thickness), twigs (≤ thumb thickness), leaves, flowers, seeds etc. Trunk supports limbs and limbs carry branches and twigs, which, ultimately, support leaves. Leaves are the food manufacturing factories as they contain chlorophyll and the process of photosynthesis occurs therein. Limbs and branches are woody in nature and useful part of a tree to be used for timber or fuel purpose. Distinguish characteristics of crown parts (leaves and seeds) can also be used for tree classification i.e. depending on leaves; tree can be classified as Hardwoods and Softwoods. Softwoods are the Gymnosperms and the Hardwoods are the Angiosperms.

3.3.

Gymnosperms

Gymnosperms or softwoods are also called evergreen since most remain green all the year long. Most of softwoods bear scaly leaves and cones in which seeds are produced, therefore often referred as conifers. Included in softwoods are the genera like Pinus (Pine), Picea (Spruce), Larix (Larch) Abies (Fir), Sequoia (Redwood) and Pseudotsuga (Douglas-fir) etc., In gymnosperm wood, tracheids constitute bulk of axial system. These thick walled treachery elements looks like elongated boxes with rectangular cross section cum tapering upper and lower ends. In spite of thin primary wall, secondary wall is made up of series of layers.

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Fig. 3.1 Major parts of a tree

Usually spirally arranged micro fibrils differ in their orientation among successive wall layers. Often, each layer reverses the direction of spiral winding in adjacent layers. In addition to lignified wall matrix, communication between tracheid takes place by means of bordered pits in radial walls. These pit characteristics e.g. size, number are characteristics in specie or genera. Trachieds produced in spring is generally wider than those of produced in later season. In coniferales, pit torus is considered as chief characteristic that act like a plug (Mauseth 1991). Bars of sanio, thickened areas between pits are another characteristic of conifer wood. In taxus, some Picea spp. and Torreya, secondary wall of tracheid has herical band of thickening. But some conifers also have tertiary wall thickening. Normally, gymnospermic woods lack vessels and fibers. If fibers are present in trachieds, they are found arranged axially along trachieds. Axial parenchyma is rare. Axial resin ducts have been reported in panacea and Cupressacea. The presence of such ducts is used as a taxonomic characteristic. Traumatic ducts found in Cedrus should never be confused with resin ducts. Ray system of gymnosperms consists of parenchymatous cells. Some general radial tracheids have also been reported. Rays are usually unisereate or bisereate. The wall pitting and thickening of ray tracheid may also be important characteristically.

3.4.

Angiosperms

On the contrary, hardwood bears broad leaves that can change color and drop in the mostly in temperate zones. They fall in the dicotyledons class and include species like Quercus (Oaks), Fraxinus (Ash), Acer (Maple), Betula (Birch), and Fagus (Beech) and Populus (Cottonwood and Aspen). Angiospermic or hard wood is composed of multiple types of cells making vast range of wood types. Other than wall pitting, many more and easily observable characteristics are present in this wood type as compared to coniferous wood. Axial system is composed of vessels as major elements while tracheids are sparse. Vessels mainly possess perforation plates for water transport. Fibers and varying amount of axial parenchyma are also present. Fusiform initials are considered as precursors of these cells (Mauseth

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Tree Anatomy and Physiology

1991). Usually fibers are elongated and show intrusive growth. Normally, xylem parenchyma is with somewhat thickened and lignified walls. Mature vessels exhibit extreme diversity in their form. Vessels, fibers and axial parenchyma are arranged in a particular fashion, so that, the clear growth rings can be observed in T.S. of wood. As compared to north, south temperate and mountain species, lowland tropical species do not exhibit growth ring boundaries. Wall thickness has also strong impact on wood hardness. When seen radially, ray cells appear arranged like bricks in a wall. In some species, rather than similar size and proportion, distinctly identifiable differences are present. A cell of a particular size is found generally arranged in regular courses. Rays are more complex than gymnosperms. These may be unisereate or multisereate. Rays are unisereate in Castanea, multisereate, in Fagus, Quercus rays are of two distinct sizes. Rays may have random distribution in TLS or may be arranged in clear horizontal strips in some species. This is a diagnostic difference between families for example Fabaceae or some genera of Elaeagnacae. In diffuse porous wood, vessel may appear size graded according to growth season i.e. wider in early season to narrower in late season while this is opposite in ring porous wood. Viewed in T.S. vessels may be solitary, in pairs or in small groups. Variation is found in arrangement of these groups e.g. tangential groups, oblique chains etc. Chiefly, characteristic appearance of wood is because of variation in vessel distribution. This gets strength often by distribution of axial parenchyma if present.

3.5.

Tree Anatomy

3.5.1. Root Structurally roots can be divided as monocot roots and dicot roots (here, only dicot roots will be discussed) and they can be further divided into two categories. 1. Primary roots 2. Adventitious roots. The functions of the primary roots are to anchor the plant in the soil, to absorb water and also serve as store house of food materials. Adventitious roots are helpful in support the plant body into soil and absorbing soluble substances from soil. Root cap consists of parenchymatous cells. The function of root cap is to give protection and control the movement of root. Epidermis:This layer is consisted of elongated cells without cuticle and stomata. Most of the epidermal cells extend out in tubular unicellular root hairs. Epidermis is also known as Epiblem, Rhizodermis and Piliferous layer (Figure 3.2 and Figure 3.3). Beneath the epidermis is one or multilayer exodermis present whose cell walls can suberized. Cortex:It is consisted of polygonal parenchyma cells. These cells contain starch grains. The roots of dicotyledons, sometimes, exhibit secondary growth and shed their cortex. Various idioblasts and secretory structures are found in the root cortex.

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Endodermis: The inner most distinct layer of the cortex is known as endodermis. It is characterized by the presence of Casparin strips on their anticlinal walls. According to Guttenberg, suberin like materials are found in the strips. Pericycle: The layer next to the endodermis is pericycle. It may be uniseriate or multiseriate. Lateral roots also arise from pericycle cells. It provides outer boundary of the vascular tissues. Vascular system: Phloem strands occur beneath the pericycle. Xylem forms discrete strands alternating with the phloem strands. If xylem is not differentiated in the centre, the centre is occupied by pith. The root shows an exarch xylem, metaxylem occur inward side while proto xylem outward side of vascular cylinder. The phloem is also centripetally differentiated i.e., the protophloem occurring closer to the periphery than the metaphloem. The parenchymatous conjunctive tissue occurs in between xylem and phloem strands. The pith is scanty or absent. Fig. 3.2 Cross Section of Dicot Root

Fig. 3.3 Longitudinal and cross Section of a tree Root Source: Anonymous (2017)

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Tree Anatomy and Physiology

3.5.2. Stem The close association of the stem with the leaves makes the aerial part of the plant axis that is structurally more complex than the root (Figure 3.4). The term shoot, which refers to the stem and leaves are as one system, serves to express this association. The root and stem make a continuous structure called the Axis of the plant. The vascular bundles are continuous from the root to the stem. But the arrangement of vascular bundles is quite different in the two organs. The stems possess collateral bundles with endarch xylem, where as the root possess radial bundles with exarch xylem. Fig. 3.4 Cross Section of a woody stem

Cortex: The region that lies next to the epidermis is the cortex. The innermost layer of the cortex is endodermis. It consists of a single layer of cells which contain numerous starch grains. The part of the cortex situated between the epidermis and endodermis is generally divided into two regions, an outer zone of collenchyma cells and an inner zone of parenchyma cells. Endodermis: The inner most layer of the cortex is the endodermis. The cells are barrel-shaped, elongated and compact in structure. These cells contain starch grain may be termed at starch sheath. Pericycle: The region between the vascular bundles and the cortex is known as the pericycle. It is generally composed of parenchyma and schlerenchyma cells. Vascular bundles: each vascular bundle consists of 3 parts. Xylem are thick walled and occur nearest the centre of stem, while phloem cells are thin walled and occurred towards the peripheral portion of vascular bundle. Between the xylem and phloem cambium layer is present, which is consists of meristematic cells. Cambium cells divided to increase the size of vascular bundles by forming xylem cells on the inner side and phloem cells on the outer side. Xylem: The xylem which is formed by the activity of the cambium is called primary xylem. The xylem formed is nearest the centre of the stem is called protoxylem. The more peripheral part the xylem is known as metaxylem. The xylem is composed of 3 types of cells-Tracheary cells, trachied and vessels, wood fibers and wood parenchyma. The protoxylem is composed largely of annular and

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spiral vessels and parenchyma, while the tracheary elements of the secondary xylem are pitted.

3.5.3. Leaf It isan important component of the plant body. It is engaged in fundamental physiological activities such as respiration, transpiration and photosynthesis. Typically a leaf is a thin, dorsiventral flattened organ, produce above ground. There are two types of leaves (i) isobilateral leaf and (ii) dorsiventral leaf. Leaves are isobilateral if they possess stomata on both surfaces and are dorsiventral if stomata are present only lower surface. Epidermis: It consists of single layered of cells and covered with waxy substance called Cutin. Stomata are found in most abundance in the lower epidermis of the dorsiventral leaf (Figure 3.5). Each stoma remains surrounded by two semi lunar guard cells. The guard cells are living and contain chloroplasts. The guard cells may remain surrounded by two or more accessory cells in addition to epidermis cells. Stomata are found in scattered form.

Fig. 3.5 Cross Section of dicot leaf Mesophyll cells: The tissue of the leaf that lie between upper and lower epidermis and between the veins consists of thin walled parenchyma is known as mesophyll. Mesophyll portion consists of two types one is palisade cells and other one is spongy tissues. Both cells contain chlorophylls therefore take part in photosynthesis process. The palisade tissue may consist of a single or more layers and compactly arranged, while spongy tissue occur lower portion of the mesophyll in the leaf. The spongy tissue is usually composed of loose, irregular, thin walled cells having big intercellular spaces among them. Due to the presence of a large air space in the spongy tissue they are more adaptable to the exchange of gases between the cells and the atmosphere. The function of the midrib and the lateral veins are to strength the leaf. Collenchyma, Schlerenchyma and Parenchyma: In the centre of the upper portion of the mid rib, just below the epidermis, there is usually a group of collenchymas cells which are turgid and give strength to the leaf. Schlerenchyma cells are associated with the vascular tissues of the leaves. They occurred surrounded the

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Tree Anatomy and Physiology

vascular bundle of leaves. Usually these cells are thick walled, dead and lignified. Parenchyma cells occupy the region between collenchymas cells and the central portion of the midrib. These cells give turgidity and strength to the midrib.

3.6.

Secondary or Stem growth

Increase in thickness of stem is due to formation of secondary tissue by activity of vascular cambium is known as secondary growth. This can be prominently observed in dicotyledon and gymnosperms (Mauseth 1991). With passage of time because of primary growth number of leaves and branches increase that in turn elevate transpiration rate so there emerges a need to increase conduction machinery for proper functioning. Under such condition three major requirements of plants are satisfied by secondary growth Secondary growth is considered as one of the most important biological process in tree growth. The final product, Wood, is of prime significance for humans as timber for construction, fuel woods, and for paper manufacturing. It is also environmentally cost-effective renewable energy source (Larson 1994). However, despite the economic and environmental importance, secondary growth has been paid little research interest, mainly because many agricultural products are derived from seeds or roots. Furthermore, the biology of wood formation is surprisingly understudied because of the inherent issues of tree species: long generation time, large size, and scanty of genetically pure lines. a)

Stem is incremented to provide effective conduction of water and assimilate translocation. b) Stem is rendered with rigidity to provide support. c) Stem has phloem tissues that transport photosynthetic assimilates like carbohydrates to all roots for growth purposes.

These benefits are achieved by production of secondary xylem and phloem and lignification of wood vessels to meet increased needs. Following steps are included in secondary growth of perennial woody dicotyledons. During the foremost step, meristematic activity of interfasicular parenchyma joins fasicular cambium strips to each other. So, a complete cambium ring is formed. Division of fusiform initials parallel to the stem surface that results the formation of either xylem inside or Pholem outside is called Periclinical division and radial division of cambium cells that give rise to new cambium cells is termed as Anticlinical division. Cambial cells then start dividing activity and cells to both inner and outer sides are added continuously (Larson 1994). Secondary xylem develops on inner sides (towards pith) while secondary phloem cells are produced on outer side. The derivation of ray initials produce rays. Circumferences of tree ring increase due to addition of secondary xylem toward center. Inhibition of new rays in secondary vascular tissue takes place when new ray initials cut off from fusiform cells during circumference increase. Before differentiation cambial cells divide once or twice periclinally, therefor cambium appears multi layered during peak activity time.

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A cambial zone is formed during growth period by cambial initials (Figure 3.6). The cells are formed to be arranged in radial rows. Initially, cells of this zone widen gradually until acquire attributed of mature xylem and phloem elements. Xylem mature cells are bit longer then phloem mother cells (Bannan 1955). An interesting point is unidirectional cambium present in some conifers i.e. Pinus longeava that produces phloem only (Ewers 1982). During dormant periods, commonly, the multilayered cambial zone generally reduces to few or one cell layer (Fahn and Werker 1972). Fig. 3.6 Cambial zones in dicots

3.6.1. Types of Cambium Based on arrangement of fusiform initials observed tangentially, two types of cambium can be differentiated as described below. a. Storied or stratified cambium: In this type of cambium, horizontal rows of fusiform initials can be observed with their end at approximately same level i.e. Tamarix and Rrobinia. Size of these initials varies between 140 μm to 520 μm (Fahn and Werker 1972). b. Non-storied or non-stratified cambium: Fusiform initials are found overlapping each other in this type. These are longer in length than fusiform initials of storied cambium e.g. 320-2300 μm in dicots. In vessel, less dicots, length has been recorded up to 6200 μm. This is more common type of cambium. Characteristics: Earlier researchers have recorded that both ray and fusiform initials are essentially alike. Accordingly, they possess basic cellular apparatus and membranes like that of typical parenchyma cells. Generally fusiform cells are uninucleate but multinucleate fusiform cells have also been recorded (Iqbal 1981). Active growing cambium cells were reported to have RER, polyribosomes and one or two vacuoles. Mitochondria occur singly. Seasonal changes influence some properties of cambial cells i.e. starch content. In fusiform initial of active cambium cisternae of RER were appeared in association with microfilaments part no such association was found in Ray initials. Life of cambium: A lot of variability is found in arranged functional life of vascular cambium. Diversity in functional life varies among species and even it is

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different in plant parts. For example, in perennial woody plants, cambium of stem survives from time of formation till plant death. In such plants, cambium activity is continuous. In deciduous plant parts, cambium life is comparatively short. Here, all cambial cells mature as vascular tissue (Mauseth 1991).

3.6.2. Cell Division and Growth Periclinal and anticlinal division takes places in cambial cells. Cells divide periclinally more frequently and new cells are added to xylem and phloem. These derivatives constitute radial rows. Cells expand radially during early stage of differentiation (Fahn and Werker 1972). Circumference of xylem cylinder increases due to secondary thickening. Along with this, cambium circumference is also incremented by addition of new cells. Initial in storied cambium undergo longitudinal anticlinal divisions and new fusiform in non-stratified cambium oblique and anticlinal divisions that are followed by intrusive growth resulting in longer cells. Orientation of fusiform initial may be changed both in storied and nonstoried cambium (Wolch 1987). Difference between various degrees of polarity of cambial initials may have connections with determinate polarity of auxin transport. If transport gets blocked, diffusion-dependent flux develops resulting in induction of new polarity. According to Zagroska-Marek and Lutle (1986), orientation of fusiform cells and direction of IAA transport are parallel. In normally growing trees, cells formed after anticlinal divisions of fusiform cells may experience some sort of transformation. Some of newly formed cells grow and convert into new fusiform cells where some mature into abnormal xylem or phloem after losing their generative capacity. Bannan (1962) stated that intensively dividing cambium cells of conifers divide every 4-6 days while apical meristematic cells divided every 8-18 hours. It is further thought that slow division of cambium cells is due to time required for phragmo plasts to reach ends of long cells. Most divisions take place in xylem mother cells as compared to phloem mother cells. Rate of division is also high among xylem cells.

3.6.3. Seasonal Activity of Cambium Continuous activity of cambium normally takes place in many plants of tropical region. Its extent can be imagined from presence of ring less trees in different areas. The percentage of such trees was 75, 43 and 15 in rain forest of India, Amazon basin and Malaysia, respectively (Chandary 1961; Alvin 1964). In warm temperate climates, the percentage of ring less trees are low. During harsh condition, in plants growing in definite seasonal climate, cambium stops its activity. In autumn, later, cambium enters dormant phase until coming spring. On start of spring cambium resume its normal activity. As described earlier cambial activity comprises of two steps in redial expansion of cells and cell division (Figure 3.7). Due to enlargement, radial walls become weak and are peeled off. On later stages, bark may be easily separated due to increased in number of cells in cambium zone. Evidences are in hand that illustrate effect of day length on cambial activity. In Mediterranean region and hot desert, it is possible to find plant with conditional

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cambial activity, periodic cambial activity and intermediates (Liphshitz and Lev yadun 1986). Studies revealed that even some plants were not found in full dormant stage despite winter e.g., Pinus radiate in north island of New Zealand (Barnett 1973); in trees of Eucalyptus camaldulensis that are without dormant period or have short dormancy during July-August, it is very difficult to distinguished between growth rings.

Fig. 3.7 Representation of Cambium activity showing addition of new cells.

3.6.4. Secondary vascular tissues Primary xylem cells are pushed toward center due to production of secondary vascular tissue. These primary xylem bundles can be observed on periphery of pith before its ultimate fire up. Secondary xylem of di-cotyledons comprises of axil/ vertical and horizontal ray system. Ray system consists of radially running files of parenchyma. The ray may be uni seriate (single cell wide) or multi seriate (many cell wide). These rays traverse rays are continuously added to ever accumulating secondary vascular tissue. Bannan (1955) reported that formation of secondary xylem is a methodical developmental progression involving cell division, cell expansion, lignification etc. In secondary xylem production, the cells on the xylem side of the vascular cambium get differentiated by involving a division zone where the xylem mother cells continue to divide, then an expansion zone where the derivatives expand to their final size, next a maturation zone where lignification and secondary cell wall thickening occurs, and finally through an apoptotic zone. The cell division for secondary xylem is initiated in the one or two layers of the cambiumzone. Due to gradual accumulation of secondary vascular tissue, wood is formed that is of characteristic type according to species. Narrow, peripheral and functional part is sap wood while major central nonfunctional portion is Heart wood. Chemical change in heart wood cells may result as a consequence of tannin and lignin deposition. Tylosis may take place due to migration of adjacent parenchyma cell to vessels. Due to seasonal activity of cambium spring wood (with loose and widely dispersed tracheal element) and autumn wood is produced (narrow closely packed

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Tree Anatomy and Physiology

tracheal element). Difference of spring and autumn wood can be easily observed in form of annual rings. Like secondary xylem, secondary phloem also consists of horizontal and vertical system (Iqbal 1981). Ray characteristics are almost same like that of rays in secondary xylem layer of secondary phloem in circumference and never become very thick. Pervious year secondary phloem is often peeled off with bark. Outward stress rupture epidermis and cortex too. The radial fusiform cell of the secondary phloem in conifers and dicots are comprised of different cell type’s i.e.  fibres, parenchyma and sieve cells or sieve elements and companion cells (in dicots). These cell types are arranged speciesspecific sequences along radii of the cell files. The sequences are duplicated in adjacent files and leads to tangential bands of same cell type (Kollman and Cote 1968). cell production plus determination are events which occur simultaneously across the radial files. The repeating blocks of cells may establish functional units of phloem tissue, and the integral cells probably have precise configurations of symplasmic connections cum mechano-structural properties (Chandary 1961).

3.6.5. Bark or Rhytidome Phellogen activity may be periodic, seasonal or annual. With increasing age, new cork cambium cells arise in deep layers. Thus, push older tissues to outer side. Older periderm outer to newly formed cork cambium of new periderm is called bark or rhytidome. Bark is sloughed off in large pieces or patches of various sizes. It is likely that the vascular cambium cells might have come off with the bark tissue when it was separated from the xylem tissue (Arteca 1996).

3.6.6. Root Secondary Growth A root experiencing secondary growth shows massive girth increases owing to the action of the vascular cambium. Root thickness also increases like due to secondary vascular tissue formation. Similarly, xylem and phloem elements are produced on inner and outer sides respectively. Within exception of monocots and herbaceous dicots, this growth is common in di-cotyledons and gymnosperms. Primarily, cambium parenchyma within vascular bundle become meristematic which later joined by inter fascicular cambium to form cambium ring. This cambium ring is wavy in outline in beginning but outline varies in different roots because of number of proto-xylem ridges. Vascular cambium is not well differentiated into fusiform and ray initials. This also undergoes periclinal divisions to contribute cells to inner and outer sides. Endodermal diameter and no. of endodermal cells amplify dramatically in the region of secondary growth. Anticlinal divisions in cambium ultimately increase circumferences. Rays produce by root vascular cambium are wider than that of stem rays.

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3.7.

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Structure of Wood

Wood is the ultimate product of secondary growth. Adequate diversity is found among plant species as far as wood is concerned. Wood may be storied or nonstoried depending upon the source from which it is being derived i.e. storied cambium or non-storied cambium (Fahn and Werker 1972).

3.7.1. Growth Layers Cambial activity in temperate areas is usually periodic and yields a growth layer. In transverse section (T.S.) of stem and roots, these layers be definite rings known as growth rings. In plant with definite seasonal growth or when growth takes place during a season growth layer is called annual layer and growth ring may be termed as annual ring respectively. Periclinical division of a fusiform initials results in the formation of two cells. One of which remains meristematic and the other becomes either a Xylem cell or Pholem cell. The mother cell then may begin to expand radially of may itself divide one or more times before developing into a mature Xylem or Pholem. Maturation of new xylem cells involves diameter growth and increase in length followed by thickening of cell wall and finally lignification. Following general steps are involved in the periclinical division. a) fusiform initial starts to divide as chromosomes split, separate, and then migrate to opposite ends of the cell. In (b), a cell plate begins to form and becomes a new cell wall at (c). Both cells begin to grow in diameter (d) and length (e). The innermost cell becomes part of the xylem, pushing outward the other portion that remains part of the cambium. In (f), the cycle begins again. Fig. 3.8 Wood demonstration Source: Andrews (2012)

Wood is produced in an inconstant environment and is subjected to developmental control, xylem cells are formed that are of different shape, size, cell wall structure, composition and texture (Fahn and Werker 1972). In plants that have experienced

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Tree Anatomy and Physiology

bad environmental condition like stress, disease etc. and growth is interrupted but resumed later, an additional or second growth layer may be observed in wood. Such layer is called false annual ring and the two or more rings formed are termed as multiple annual ring. Generally, spring is reckoned as the best for plant growth. High assimilation rate in spring directly relates with necessity of bulk quantity of water. Therefore, vessels formed during spring have more diameter than routine vessels to facilitate water transport. Such wood has no fibrous element or very little and called spring wood (Figure 3.8). During summer growth rate generally drops and few vessels with little diameter are produced. This wood possesses more fiber and is dark in color. This is known as summer wood or late wood. Due to reduced rate of assimilation in summer, denser xylem is formed, later on, separation of early wood and late wood takes place with a sharp line describing limits of both wood types produce. Approximate age of trees can be estimated by counting the number of growth rings. In areas where seasonal variation is absent, annual rings are not formed in plants. These can be more conveniently viewed in deciduous and evergreen plants (Mauseth 1991).

3.7.2. Sap Wood and Heart Wood Secondary xylem elements are very specialized in their function. Tracheary elements that are without protoplast are particularly related with water movement and the living cells perform storage function and remain active during peak activity time of xylem. Outer portion of secondary xylem comprises of living cell and is actively engaged in water movement. This part is termed as sap wood or Albernum. This is light color region when inner part of xylem ceases its function and cell start dying. Protoplast disintegration and removal of cell sap along with lose of reserve material accompany cell death process. Therefore, inner, dark color portion consisting of non-functional element is demarked named as heart wood or Ourmen. In some tree species vessels get blocked by tyloses. In the later phase, parenchymal cell walls become heavily lignified. Sum substance e.g. oil, resins, gums form in cells and polymerization color substances developed in heart wood (Fahn and Werker 1972). With special reference to gymnosperm due to rigidity of pit membrane, tours close pit aperture and reduce its function in water conduction. Tours in sapwood is composed of pectin mainly but cellulose and hemicellulose too. But in heart wood, tori become lignified. The changes make heart wood resistant to decay. Presence of dark color substances make it easily recognizable from rest. Different authors have elaborated heart wood formation as result of changes with ageing of sapwood cells. According to Barnett (1973), heart wood formation can be considered as a developmental process of tree like other phase of plant development. He thought heart wood formation as regulatory process for keeping sap wood amount at optimum level. Histological, fundamental differences can be observed between wood of dicot and gymnosperms particularly conifers. Wood of dicot is called as hard wood and that of gymnosperm is called soft wood. The degree of hardness or softness of both wood types should not be confused with these terms.

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Secondary xylem of gymnosperms is simpler and homogenous then that of angiosperm. With exception of grelates, absence of vessels is a major difference between angiosperm and gymnosperm wood and parenchyma are relatively in small amount in gymnosperms. Rays of gymnosperm are mostly homocelluler. Resim ducts develop in large number of gymnosperms. The wood having pores is called porous wood whereas wood not having pores is termed as non-porous wood. Based on distribution of pores, porous wood may be of following types Ring porous wood: In this type earl wood vessels are large than late wood and vessels are of unequal diameter i.e. Acer populous. Diffused porous wood: Vessels are approximately equal diameter constitute this type of wood. This vessel can be found uniformly distributed throughout i.e. Malus, Juglans.

3.7.3. Chemical Components of Wood Wood is a carbohydrate composed principally of carbon, hydrogen, and oxygen. Table 3.1 details the typical chemical composition of wood and shows carbon to be the dominant element on a basis. In addition, wood contains inorganic compounds that remain after high-temperature combustion in the presence of abundant oxygen. Such residues are known as ash. Table 3.1 Elemental composition of wood Elements Carbon Hydrogen Nitrogen Ash

Dry weight (%) 49 6 Slight amount 0.1

The elemental constituents of wood are combined into several organic compounds: cellulose, hemicellulose and lignin. Table 3.2 shows the approximate percent of dry weight of each in hardwood and softwood. Cellulose, perhaps the most important component of wood, constitutes slightly less than one-half the weight of both hardwoods and softwoods. The proportion of lignin and hemicellulose varies widely among species and between the hardwood and softwood groups. Table 3.2 Organic constituents of wood Type Hardwood Softwood

Cellulose 40-44 40-44

Hemicellulose 15-35 20-32

Lignin 18-25 25-35

Note: Pectins and starch commonly compose approximately 6% of the dry weight. Source: Kolimann and Cote (1968)

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3.8.

Tree Anatomy and Physiology

The Absorption of Water in Trees

Tree functioning is an important aspect for forestry. This chapter deals with the basic concepts regarding the important functions of trees. Soil-water relation is an integral part of the forest tree survival. Starting with absorption, plants need to utilize water effectively for their survival. Water absorption, ascent of sap, fluid movement, photosynthesis and loss of water (transpiration) are important tree process for proper growth. and functioning. The large quantity of water loss daily by trees is a consequence of transpiration that must be restored for their growth and survival. This is done by the continuous absorption of water from their roots. Therefore, the absorbing organ, soil environment, the mechanism and factors of absorption of water in trees need to be carefully understood. Tree roots serve a variety of functions including anchorage and absorption of water and nutrients. Roots not only absorb moisture and minerals but also transfer them to above ground parts. These are often called feeder roots. The branching of the roots guarantees that a large area of the soil can be tapped for water absorption. These roots offer the framework for the rooting system and are different for each tree species. Generally, the direction of this framework is horizontal and radial. The depth to which roots penetrate the soil varies with species and greatly affected by various factors. Tree roots rarely grow below four feet because the upper few feet of the soil usually are enriched with water, oxygen, minerals, and optimum temperature. Horizontal root spread is one of the important mechanisms to overcome soil compaction. In addition, some of the trees have slender like outgrowths called root hairs to increase the surface area of roots for the increment of nutrient and water uptake, especially in deciduous trees.

3.8.1. Mechanism of Water Absorption The force which brings about the absorption of water transmitted to the roots is basically created by the leaves through a mechanism called as transpiration. However, large extent of water is required to maintain tree growth which is s acquired chiefly from the soil. Two sorts of water absorption mechanisms often occur independently which are discussed as below; Passive Mechanism: Plant exposed to environment, transpiring aerial surfaces develop a powerful transpiration force therefore xylem elements in the root have a negative pressure. These negative pressure is not only restricted to the transportation of water across the cortical cells but also facilitate the water movement towards the peripheral root hairs. Active Mechanism: In natural environment, the actively growing cells of the roots uptake and hoard mineral nutrients from the soil. The absorbed mineral is quickly diffused in the cells and move towards xylem elements. For minerals absorption, transportation and xylem loading, substantial amount of energy is required. Due to minerals loading in the xylem cells, a diffusion pressure deficit (DPD) gradient is created between the soil solution and xylem sap which behave as the motive force

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for water flow into roots through passive osmosis. In this phenomenon, water uptake in roots does not require energy, however, the mineral accumulation which develop the force for water uptake, needs energy therefore it is called as osmotically active process.

3.8.2. Factors Affecting the Rate of Absorption Water absorption in soil is usually hindered by low moisture content, slow root growth, inappropriate soil aeration, low soil temperature and a concentrated soil solution or amalgamations of these factors. There are some attributes which manipulate the water absorption in roots; Soil moisture: As dehydration continues in soil the rate of water absorption by tree roots declines because of resistance to water flow in soil and within the tree as well as loss of soil-root interaction. In soil, capillary movement of water from moist to dry region in moist soil at equal or below field capacity is very slow. In moist soil, resistance to water movement is low since lesser forces are required to move water through water-filled pores. Though, as the soil began to moist the resistance to water movement increases until reach the saturation point. In tree, resistance to water movement also increases as the soil continues to dry up, partially because of greater tension on water in the conducting elements in stems. Usually, the hindrance in water movement from soil to root surfaces is smaller than the resistance to radial movement in roots, however as the soil dries, resistance to water movement increases and the driving force reduces. Transpiration: The rate of water absorption is mainly regulated by the rate of transpiration. However, throughout the day the transpiration rate is greater than the absorption rate of the plant. Consequently, trees keep dehydrating throughout the day, predominantly on hot and sunny days. At night, however, when the rates of both transpiration and absorption are low, the rate of absorption of soil water is greater than the transpiration rate. Subsequently, trees tend to fill-up with water during the night moisture of the soil. Soil aeration: Undevelopedsoil aeration in flattened or flooded soils usually decreases the roots capacity for absorbing water by preventing root development and elongation, encouraging roots decay, and overwhelming mycorrhizal development. Since root growth is lessened more than leaf growth by poor soil aeration; the trivial root system cannot sufficiently absorb water quick enough to refill the water moved out in transpiration, causing dehydration of tree crowns. Several flood tolerant tree species can develop adventitious roots which can adopt physiologically for loss of much of the original root system. For instance, the flood tolerant Betula nigra shaped several adventitious roots after flooding, whereas the intolerant Betula papyrifera did not produce. Many trees are modified root systems by the mycorrhizal development, formed by subsequent invasion of young roots by hyphae of certain fungi. In mycorrhizal association, the tree supplies vital metabolites that are benefited to the fungus. In reply, fungus increases water absorption and nutrients by increasing the root area

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and the root system. Indeed, soil volume is exploited by a mycorrhizal root which may be up to ten times greater than non-mycorrhizal root. Certain evidence indicates that mycorrhizae enhanced drought tolerance of woody plants in arid regions. Mycorrhizae are chiefly beneficial to trees growing in poorly developed soils. Insufficient soil aeration reduces the roots ability for water absorbing and nutrients by preventing mycorrhizal development. Mycorrhizal fungi like to grow in strongly aerobic condition; hence poor soil aeration reduces mycorrhizal associations in trees. In flattened soils mycorrhizae, may be found only in the topmost layers whereas in non-flattened soils they found in much greater depths of depression. Soil temperature: Water absorption is abridged by low soil temperatures. It decreases the roots’ permeability directly and increasing the water viscosity indirectly. When soil temperature falls from 25 to 5°C, the resistance in water flow via roots is approximately double. Moreover, low temperature ranges (25-5°C) in soil also restrict water absorption by hindering root extension. Decreasing root permeability, increasing water viscosity and inhibiting root growth are the few consequences of low temperature in soil. As soon asstems temperature drop down to a few degrees less 0°C, the water in the xylem elements may solidify, stopping water movement to the top even though some root parts are in unfrozen soil. The eventual result of these environments is desiccation on the top of the tree; subsequently leaves shedding are taken place. The range of freezing injury is affected by the freezing time in the soil, depth of frozen soil, snow depth, air moisture and the wind speed. Concentration of soil solution: Unexpected experience of tree roots to high melting salt concentrations or amount of fertilizers in the soil water may cut off absorption due to osmotic effects which results in the dehydration on the top of the tree. Later, a tree may be exposed to physiological drought even sufficient amount soil water is available. Tree with roots subjected to progressively increasing melting salt concentrations do not desiccate as quickly as those with roots quickly exposed to concentrated salt solutions. Reduction in water absorption in the saline soils may also be related to shrinkage of root permeability by dehydration, increased suberization, and root growth inhibition. High amount of salt in the soil may also damage young feeder roots, particularly those of trees growing on sandy soils, further reducing water absorption. Growing root system (Root growth): Continuous root development into wet soil zones is imperative for sufficient water absorption to substitute the water lost through transpiration and thus avoid leaves dehydration. Therefore, trees with deeply penetrating, well branched, and speedily growing roots absorb water most efficiently. In drought environment, high root-shoot (R:S) ratio is predominantly important for growth and survival of trees. Transplantation of evergreens with simple roots, or even with a root ball of soil, suffers physiological shock since their ability to absorb water is suddenly and greatly reduced at a time once high rates of transpiration continued. Loss of roots is often related to dehydration of uprooted trees because they usually lose water

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quicker than they can substitute it by absorption. Therefore, transplantation will depend chiefly on the capability of roots to start growing quickly and establish close contact with the soil beyond the root ball in order to absorb suitable amounts of water.

3.9.

Ascent of Sap

Water is necessary for plants to perform their metabolic activities. It is absorbed from the soil with the help of roots and is supplied to the leaves. Large quantities of absorbed water in trees cover very large distance against the gravitational force. This upward movement of water is calledascent of sap. How does water moves upward is roughly demonstrated in given flow chart (Figure3.9). Fig. 3.9 Flow chart showing water pathways from root to leaf in tree

It is important to know the translocation of water (or ascent of sap) because some of the trees are very tall such as Australian eucalyptus and Sequoia semipervians in which water moves to much great height like 400ft. or more.

3.9.1. Path of Water Water from the soil enters the root hair and is transferred to the adjacent cortex due to the osmosis and diffusion pressure deficit (DPD), the process continues till it reaches the pericycle through endodermis. The upward movement starts when water moves to xylem from pericycle. The water column extends upto the leaf xylem through root xylem and stem xylem. For the continuous flow of water, xylem column must be unbroken. Cohesive forces of water molecules give the tensile strength which required remaining intact with the column. This is how the water pushed up in tall trees. In addition, some trees have evolved bordered pits which allow water to in or out from this column established pressure along the side wall of the cells. The pit membrane is a type of primary cell wall therefore it is reasonably flexible to respond the change in pressure by opening or closing the border on the pit.

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3.9.2. Mechanism Ascent of sap can be easily explained in herbs or in small trees but in tall trees like Eucalyptus and some conifers where water reaches a height of about hundreds of meters, in fact, becomes a problem. There are many forces which help in the ascent of sap. Based on these forces several theories have been put forward to explain the mechanism of ascent of sap. For convenient these are divided into the following main categories: A. Vital force theories B. Root pressure theory C. Physical force theory A. Vital force theories According to these theories the ascent of sap is under the control of vital activities of the stem cells. Several works have supported this view. Two theories are explained this as follow: a)

Pumping action or Relay pump theory: Godlewski (1884) advocated this theory. According to him the living cells of xylem are responsible for the ascent of sap. He suggested that rhythmic or alternate changes in the osmotic pressure of xylem parenchyma are responsible for upward movement. These rhythmic changes bring about a pumping action of water in an upward direction. b) Pulsation theory: Another strong advocate of vital force theory was Bose (1923). He found that the pulsatory mechanism is responsible for the upward movement. Bose suggested that is an alternate contraction and expansion occurs in living cortical cells nearer to the xylem that develops vital force called pulsatory force. He demonstrated the pulsatory mechanism in living cells by means of electric probe needle while working with Desmodium plant.

Because some experiments performed by different workers, the vital force theories were rejected. The main reasons for the rejection of these theories were: i.

After killing the living cells by poison or heat the ascent of sap continues in the stem through xylem.

ii.

There was no correlation between pulsatory activity and ascent of sap.

iii. Many workers could not repeat the experiments. B. Root pressure According to this theory a hydrostatic pressure is built within the root system due to the absorption of large amount of water through roots, called Root Pressure. In all plants this pressure forces the water upward all along the length of stem. It is believed that some plants develop root pressure under favorable conditions, usually roots develop 2 atm pressures but very rarely it reaches 4 to 6 atm. It is known that

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1 atm root pressure can push water upto 15 feet only. Consequently, 6atm root pressure can support the water rise to the altitude of just 75 feet and not more than this. Generally, it has been observed that numerous tall plants do not display any sort of root pressure. However, root pressure that establish in some kinds of plants is likely to occur when there is surplus water and high relative humidity in the atmosphere. Now it has become clear that the force responsible for the upward movement of water is not developed by root pressure but by something else. C. Physical force theories According to physical force theories the dead cells are responsible for the ascent of sap. There are several theories given by different researchers, a few are discussed here: a)

Imbibitions theory: In 1868, it was proposed that imbibitional force is generated in the wall of xylem which causes the water to rise through the wall of the xylem. The upward movement of water by imbibitions is very slow but it generates sufficient pressure to carry water to any distance. It was supported by Sachs (1878). It is found that water moves through the lumen of the xylem therefore this theory is rejected. b) Capillary force theory: This theory proposed that tracheids and vessels of the xylem work as capillary tubes and water rise in the adjoining tubes of xylem due to the capillary force. There are many objections to this theory: i.

A free surface is required for capillary action which is not possible in xylem.

ii.

To raise the water in tall trees a high magnitude is required.

iii. Plant anatomy speaks against the law of capillary. c)

Cohesion and transpiration pull: This theory is based on cohesive (attraction between similar molecules) and adhesive (attraction between different molecules) property of water. It was proposed by Dixon and Jolly (1894) and has been modified to understand some observations that were not explained before. This theory is also called suction force theory and is supported by notable scientists like Kramer and Kozlowski (1960).

The moisture content is the most significant aspect that activates this process. At 50% Relative Humidity the negative pressure generates diffusion pressure deficit (DPD) gradient. This DPD produces a most influential force for the quick exclusion of water from leaves into the air that creates one directional pull by water containing xylem columns. The dragging force on water containing xylem columns is called Transpiration Pull or Suction Pressure. Water adheres with the xylem cells due to adhesive force whereas due to cohesive forces water gets united to provide tensile strength to keep the column intact. Transpiration pull and cohesive force between water molecules, both these forces when work together becomes so powerful that water rises in the body of plant up to the top of plant within no time. This theory provides the best explanation for the ascent of sap, and is considered as the most successful theory.

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3.10. Photosynthesis Photosynthesis is a key process letting plants, and chiefly trees, to trap the solar energy and converts it into chemical energy (ATP) and reducing power (NADPH) to synthesize sugar. Photosynthesis requires pigment, light, water and carbon dioxide to complete the process. Plant leaves keep resulting carbohydrate in cells in the form of glucose for tree. Photosynthesis characterizes brilliant bio-chemical reactions using six water molecules from roots and six carbon dioxide molecules from the air and produces one molecule of sugar. There would be no life on earth without the photosynthetic process. Generally, photosynthesis means ‘made up of polymers using light’. It is generally anabolic process that occurs within chloroplasts. These organelles are placed in the cytoplasm containing green coloring matter called chlorophyll. In photosynthesis, water has been absorbed by the tree roots and moved toward the leaves where it finds the layers of chlorophyll. In the meantime, carbon dioxide from the air is taken into leaves via stomata (leaf pores) and exposed to sun-light and a very important bio-chemical reaction materializes. Subsequently water molecules are broken down into oxygen and hydrogen combines with carbon dioxide in the chlorophyll (reaction center) to synthesize sugar. Additionally, an important byproduct of this chemical reaction is remaining oxygen that leaf releases back into the atmosphere. Released oxygen becomes an integral part of the air we breathe though the glucose is transported to the other parts of the tree as nourishment. From the photosynthesis, high amount of oxygen comes from the tree. Therefore, tree contribute substantial role for the maintenance of damaged environment Biochemical equation for this process is: 6 carbon dioxide molecules + 6 water molecules +sun-light → glucose + 6 molecules of oxygen 6 CO2 + 6H2O + hv (light energy) → C6H12O6 + 6O2 Many developments happen in a leaf, however none of them are significant than photosynthesis and the resulting biomass production. It has been observed that through photosynthesis, the solar energy is trapped in leaf structure and made accessible to other living things. Excluding some types of bacteria, photosynthesis is the only metabolic reaction in which organic compounds are produced from inorganic substances, with subsequent energy storage. Unluckily, approximately 80 percent of the earth's total photosynthesis is made in the ocean and mostly inaccessible to living creatures on the land. Therefore, stress is constantly on terrestrial plants to retain the pace. Entire sugar production on land plants is likely to be 40 billion tons in a year and much more than sufficient to sustain every living terrestrial organism at present. Mainly in photosynthesis light energy is first trapped by accessory pigment like carotenoids called trapping of light energy. Later it is transferred to reaction center to cause excitation chlorophyll molecules. Energy release from the excited

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chlorophyll molecule is utilized in the synthesis chemical energy. Later chemical energy is required for the carboxylation, reduction and regeneration process of dark reaction. In a forest, height of the tree plays substantial role to receive considerable amount of solar radiation which ultimately effect on the production of biomass as an product of the photosynthesis. How does plant utilizes the solar energy and its incorporation in the process of carbon fixation in tress can be illustrated as in Figure 3.10

Fig. 3.10 Light and dark reactions during photosynthesis in tree leaves

3.11. Loss of Water by Transpiration In trees water is absorbed primarily by their roots and evaporation of water occurs through the stomatal openings called transpiration.

3.11.1. Why do Trees Transpire? Transpiration occurs due to the following reasons: •

Cooling: As soon as water evaporates fromthe leaf cell, some amount of energy is given out from the leaf cell. In this process energy is utilized to break hydrogen (H) bonds between water molecules; the energy used is converted to highly energetic gas molecules which are then released into the atmosphere and cools the tree.

•

Accessing nutrients uptake: Transpiration enhances nutrient uptake from the surrounding soil as the water that pass in the root contains many important soluble nutrients crucial for plant growth.

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•

Carbon dioxide entry: During transpiration, stomatal opening not only allowing water molecules to move out from the leave but also let carbon dioxide (CO2) to enter. Unluckily, much more water given out from the leaf than CO2 enters for three motives: i.

CO2 is larger molecules in size than H2O and so they change to their target rapidly.

ii.

CO2 is merely 0.036% of the total air so the concentration for H2O moving from a hydrated leaf into a dry air is much larger than the gradient for CO2 entry into the plant.

iii. CO2 has a relatively greater distance to reach its destination in the chloroplast from the air than H2O which merely must move from the leaf surface to the air. This irregular exchange of H2O and CO2 leads to a variation. The higher stomatal opening causes much easier opportunity for CO2 to enter the leaf to initiate photosynthesis; nevertheless, this greater opening (stomata) will also let the leaf to lose bulk amounts of water and face the threat of drought stress. However, those plants that can retain their stomata marginally open will lose smaller amount of H2O molecules in place of every CO2 molecule that move in and will have better water use efficiency (WUE). Plants with greater WUE showed better ability to survive when available moisture in the soil is low

3.11.2. How Fast does Water Move through Plants? Rate of transpiration depend on two major factors which are discussed as under: •

Solar Radiation: The solar radiation is the driving force for transpiration. The difference in the amount of water (water potential) in soil and the plant surrounding creates a gradient, allowing water to flow in the direction of regions with less water. Water loss from the leaf surface into the drier atmosphere creates a suction pulling water up through the xylem tubes and water is sucked out of the soil by root hairs. The dry air around the plant creating larger the pulling force which result in rapid transpiration rate. Osmotic pressure and capillary rise assists water movement by transpiration pull.

•

Resistances: Three main resistances of evaporation in plants include stomata, cuticle, and boundary layer resistance. Transpiration rate will be slower when the resistance to water movement is greater.

3.11.3. Factors Affecting Transpiration Rate Transpiration is supported by two significant factors including plant parameters and environmental conditions.

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3.11.4. Plant Leaf Attributes Several factors effect transpiration rates comprising leaf number shape, size, stomata, and waxiness of the leaf surfaces. These leaf characteristics aid plants control transpiration rate by reducing water flow out of the plant. •

Stomata: They are small breathing pores in the leaf that permit gaseous interchange where water vapor and CO2 enter the plant leaves. Guard cells regulate stomatal opening and closing. Plants control water loss via transpiration by opening and closing stomata. Once stomata are exposed to sunlight, transpiration rates increase; as soon as they are closed, transpiration rates decrease. Diurnal variation is affected by transpiration rate mainly due to stomatal response. Normally stomata are open in the day and closed during night. Normally transpiration cannot go beyond evaporation and under ideal conditions transpiration may attain 95% of evaporation. In the mid of winter, transpiration from deciduous trees is less than 15% of evaporation and when deciduous trees lose their leaves it nearly stops.

•

Boundary layer: It is a delicate layer of static air enclosing the leaf surface. When transpiration occurs, water vapors exit from the stomata reach the atmosphere through this layer where the water vapor will be vanished by moving air. Layers located on edges increase as leaf size increases causing substantial reduction in transpiration rates.

•

Cuticle: It is waxy and hydrophobic layer present on all above-ground tissueof a plant and serves as barrier that water cannot move through it very easily. The thicker the cuticle layer on a leaf surface, the slower the transpiration rate. Conifer needles are more efficient at retaining moisture than broadleaf trees because they have stiff, waxy leaves (needles) with small stomata that are buried in the leaf surface that is why conifers are found in drier and colder environments where water supplies are restricted.

•

Leaf area: Greater leaf area is responsible to increases transpiration rate. It was examined that at the uppermost part of the canopy, transpiration is higher than near to ground level. An exposed canopy eases transpiration compared to a closed canopy. Isolated tree has a greater transpiration rate than a tree in a forest surrounded by other trees.

•

Environmental conditions: Some environmental conditions accelerate transpiration rate while others have modified the plant’s capability to regulate water loss.

•

Relative humidity: It is the quantity of moisture in the air related to the quantity of moisture that air could keep at a given temperature. A turgid leaf would have a relative humidity near 100%, just like an atmosphere on a rainy day. When relative humidity (RH) is less, the air holds less moisture and increasing the transpiration rate. Higher the RH, more the moisture in atmosphere and there will be less transpiration.

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•

Soil water: The soil water is the main source of water for transpiration which is comes from the soil. It is important to have sufficient amount of available soil water for transpiration. Plants with suitable soil moisture will usually transpire at greater rates since soil delivers the water to move via plant. If the soil is dry, leaves will droop and wilt plants cannot continue to transpire anymore.

•

Solar radiation: Intensity of solar radiation is also a major factor that influences the rate of transpiration. Transpiration is greatest during the mid-day when maximum solar radiation is available and nearly stops during the mid-night. It was clearly observed that trees have to increased transpiration rate with increased temperatures and sunlight intensity. If it gets too hot, though, transpiration will shut down.

•

Sunlight: Light and CO2 becomes available to plant when stomata are open in the light so that becomes accessible for the photosynthesis. In dark, stomata are closed in most plants. At low light intensity at morning can cause stomata to open and they can access CO2 for photosynthesis as soon as the sunrays hit their leaves. Stomata are most sensitive to blue light, the light component prevailing at sunrise.

•

Wind: Wind velocity can change rates of transpiration by removing the boundary layer- immobile layer of water molecules enclosing the leaf surface. Wind velocity accelerates the water movement from the leaf surface when it decreases the boundary layer, the reason for that the path for water to access the atmosphere becomes shorter.

3.11.5. How Transpiration Occurs? The water movement via plant is called the transpiration stream. The water movement during this pathway is initiated at the root epidermis and progressed symplastically and apoplastically to the endodermis and remains in the root’s vascular cylinder. The endodermal transport proteins accumulate the water and mineral solution then push them up to the xylem of each root, stem, and the leaf of the plant. In fact, in the leaf, the soil solution covers the cells in the mesophyll apoplastically, vanishes into the gas spaces among the cells, and given out from the leaf into the air via stomata. •

Root pressure: The water influx into roots is not constant throughout the length of a root. Increased secondary metabolites deposition (suberization) in mature parts of the root resist water uptake through the endodermis. In fact, water consumption is inadequate to just before the cell elongation area at the tips of the root However, the key fact is that the transporter proteins in endodermis allowing root to accumulate minerals by means of active transport. This process utilized much sugar but markedly produces a more concentrated mineral solution exclusively from the vascular cylinder of the root. Osmotic potential is the process that causes water flow along with minerals and this can develop pressure within the vascular cylinder if the transpiration rate is relatively slower. The pressure that grows at the base of the xylem can drive water up to that column.

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One manifestation of root pressure is guttation. A shoot often exudes a drop of liquid from the xylem is called guttation. Osmosis driven water uptake can pressurize the vascular cylinder (0.05 to 0.5 MPa) and can push xylem sap up several centimeters to perhaps a meter. Sometime, root pressure is also noticeable on leaves. In high humidity, chilling temperature, and lesser light duration, root pressure can thrust xylem sap through leaf mesophyll in and out from few relatively larger pores in the leaves called hydathodes. •

Capillarity helps water to climb up the xylem: Capillary tube in xylem has function of bonding of the liquid to the cell wall of the xylem, and keep holding (cohesion) of the water molecules to each other that let water to climb up to the xylem (Figure 3.11).

•

Cohesion and cavitation: The water in the xylem column spreads from the root xylem through stem into the xylem of the leaf. All xylem column must be attached each other for the continuous flow water. As water is flown upto a high tree, the strength of tensile is desirable to retain the column constant. Cohesion of water particles is the real cause of tensile strength. Further, several trees have developed a bordered pits; anticavitation tool. Laterally the side of the cells walls in xylem these bordered pits allow water to pass in or exit the column which is based on pressure and so on. The pit membrane is really a primary cell wall that is convincingly flexible. As soon as pressure varies in a tracheid, the membrane act in response by either terminating the border on the pit or opening the border on the pit. The regulated plug for the border is denoted as torus.

•

Evaporation from the intercellular spaces ofleaves pulls water up to the xylem: Water is evaporated from the mesophyll cells of the leaf into the humid air inside the leaf that eliminates water from the top of the water column in the xylem (A closer look has been presented in the Figure 3.11. to see the route of water in leaf and the pull which is regulated by capillary action in small pits on the cell wall surface). In large trees this process produced force that is well enough to lift the water against the gravitational force. This evaporation pull shouldn’t be undervalued.

Fig. 3.11 Leaf anatomy showing the evaporation of water in leaf air spaces where it is diffused through stomatal pore

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3.11.6. A Closer Look of Leaf Anatomy Water evaporates into the internal environment i.e. spongy parenchyma of the leaf then it moves out to relatively less humid environment outside through stomatal opening as shown in the figure 3.12. Arrows have a “wiggly” edge because they goes through the epidermis by means of stomata. The wiggly edges showed a resistance to the movement of water which is produced by the tiny stomatal opening and the outer layer of dead air (Figure 3.12). The rapid movement of water from internal atmosphere to external environment is determined by these two factors. The function of stomatal pore size and the thickness of outer layer is to regulate the rate of transpiration as discussed earlier. Fig. 3.12 Mechanism of transpiration

The water potential in plant tissue is the measure of energy required to pull the water from one place to another, the more negative value of water potential cause stronger pull of water even against the gravity of the earth. Transpiration flow is explained by water potential and four components namely root pressure “push”, capillarity “climb”, evaporation “pull” and properties of water (osmosis, adhesion and cohesion). The sap present in xylem is a dilute solution containing minerals and its composition is almost same throughout the plant height. The potential of gravitation elevates 0.1 MPa in xylem tissue for each 30 feet in height. Australian Eucalyptus at 492 feet was the tallest ever known tree. The pulling force of water to this tree is pressure potential which is needed to nullify the frictional resistance of perforation plates etc hence stronger vacuum is needed for the upward movement of water in a large tree.

3.11.7. Regulation of Stomatal Aperture The turgid living cells that surround the vascular bundle i.e. bundle sheath, help in the loading of monosaccharide to the phloem tissues whereas unloading of water

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from xylem vessels. This water is pulled form these turgid cells and takes the apoplastic route and bathed the mesophyll cells. The apoplast fluid get concentrated after the evaporation and the diffusion of sugar from the cells of bundle sheath. The pressure potential is somewhat negative because water is being drawn through the pits from this non-cellular tract. The evaporated water from the apoplastic fluid diffused into the intercellular spaces in mesophyll of leaf. Now these intercellular spaces have low water potential than the apoplastic solution and higher humidity than the outer atmosphere of the leaf. Hence this situation in enough to derive the evaporation process or to remove the surplus water to the outside of the leaf. The outer environment is dryer as compared to the leaf’s internal environment. Difference in water potential provides the force to drive the movement of water vapors to outside the air through stomata.

3.12. Plant Hormone and Plant Signaling Molecules Hormones mediate the intercellular communication and are produced in smaller quantities, like tiny messengers communicating around. They are also called as signaling molecules. It is thought that plant growth and development is regulated by five kinds of hormones which are as follows: •

Auxin

•

Cytokinins

•

Gibberellins

•

Abscisic acid

•

Ethylene

3.12.1. Auxin It was discovered because of Charles Darwin and his son’s observations in 1880s. They inspected that canary grass (Phalaris canariensis) coleoptiles twisted towards light, if the coleoptiles are covered with non-transparent foil then the coleoptiles didn’t bend. From this they concluded that the coleoptiles tip of this grass respond to the light. Various experiments have been conducted to observe the growth of modifying compound that was produced at the tip of the coleoptiles transported to the subapical zone and caused elongation of cell. The compound causing these changes was reported by F.G Went in 1926 and isolated in 1934 and named Auxin. Indole Acetic Acid (IAA) is produced in most metabolic active meristematic region. It is synthesized from the amino acid typtophan and there were two pathways in plants but Indole 3-Pyruvate (IPA) route appears to be major one (Davies 1995). Many investigators suggested that the auxin stimulates the cell division, cell elongation, xylem and phloem differentiation and growth of floral tissues. Further it was observed that auxin stimulates the lateral root development and initiation of root on stem cutting in tissue culture, production of ethylene at high concentrations (Raven 1992). The supply of auxin from apical region check

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the growth of lateral buds and induce the bending against the light and gravity. Auxin delay senescence (aging) in leaf can inhibit / promote abscission (detachment) process in ripened fruit and old leaves via stimulation of ethylene. In some plants, it can also delay the fruit ripening or induce the fruit setting. With the company of ethylene auxin promotes the development of gynoecium in dioecious flower and flowering in some plants (Mauseth 1991; Salisbury and Ross 1992; Taiz and Zeiger 2010).

3.12.2. Cytokinins Cytokinins (CKs) are known to be produced in roots, embryos and fruits, or in active part of the growing tissue. The fate regarding the relative proportion of auxin to cytokinins controls that where cells will develop i.e. higher level of cytokinins promotes the emergence of shoot whereas higher concentration of auxin induces the development of roots. In addition to that cytokinins perform many other things, for instance they delay the senescence by destructing older proteins and increase in the concentration of newer proteins. Many horticulturalists and shop keepers utilize this property to keep the freshness of flowers and leaves by spraying the cytokinins. All the naturally occurring cytokinins are adenine derivatives. In addition, free base CKs are also found as the riboside (ribose sugars is attached at position 9 on the ring) and as ribotide (ribose sugar moiety is esterifies with phosphoric acid at its 5 position). Originally it is present in coconut milk and corn grain (zeatin). In 1940s their effects using coconut milk was first discovered by Folke skoog. Some workers reported that the effectiveness of cytokinins depends upon its type and plants species (Mauseth 1991; Raven 1992; Salisbury and Ross 1992; Davies 1995). CKs induces cell division (as its name indicates: Cyto = cell; Kinesis = division), cause leaf expansion by cell elongation, ensuring stomatal opening in some plants, stimulate the chlorophyll biosynthesis, growth of lateral bud-release apical dominance and in tissue culture stimulates the morphogenesis i.e. shoot initiation and bud formation.

3.12.3. Gibberellins Gibberellins are the class of hormones produces wide variety of effects. The Gibberellin was named after its discovery in a fungus called Giberella fujikuroi (a pathogenic fungus of rice seedling). It is also known as gibberellic acid (GA) and is a group of chemicals that encourage the cell division and cell elongation. They are classified on their discovery, structure and functions as GA1, GA2, GA3 and so on (GAn). Recently 136 different types of GAs are identified from bacteria, fungi and plants. GA3 was first among the gibberellins to be structurally characterized. Chemically they are 19 - 20 carbon containing compound gathered into four or five cyclic rings. GAs initially synthesized through mevalonic acid pathway from acetyle CoA. Moreover, GAs is not only prevalent in flowering and non-flowering plants but also in ferns. GA produced in the actively growing tissues of the shoot, developing and germinating seed as well. However young root produced gibberellins in not

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confirmed yet. Some evidence showed that plant leaves is the main source of gibberellin synthesis (Salisbury and Ross 1992; Sponsel 1995). Active GAs involved in several physiological processes. These processes and their effects depend on the type of GA and the plant species. Gibberellin stimulates the physiological processes including stem elongation, flowering in long day plants, breaks the seed dormancy, mobilize seed reserves, stimulates the germination by the production of important enzyme (amylase), prompt the production of androecium in dioecious plants, induces parthenocarpy or seedless fruit, hinder the aging process in leaves and in some fruits as well (Mauseth 1991; Raven 1992; Salisbury and Ross 1992; Davies 1995).

3.12.4. Abscisic Acid Abscisic acid is a natural growth inhibitor originally involved in abscission. It is ubiquitously present in plants and is 15 carbon containing compound i.e. sesquiterpenoid which is produced through mevalonic pathway in plastids including chloroplast. The production of abscisic acid (ABA) in increased under drought, saline and freezing environments. The biosynthesis of ABA takes place via the production of carotenoids indirectly. In late 19th century (1963), Fredrick Addicott with his coworker recognized and characterized when they were studying those compounds which are involved in the abscission process in cotton fruits. The two compounds were separated named as abscising type 1 and abscising type II. Recently abscisin II is known as abscisic acid. In the meantime, the other two groups also discovered this compound. These two groups were led by Philip Wareing and Van Steveninck seperately and were working on bud dormancy in woody plants and abscission mechanism of lupine flowers and fruits. Plant biologists agreed to name this chemical compound as abscisic acid (Salisbury and Ross 1992). As the name indicate abscisic derived from the “abscise” which means to cut off or fall away. Scientists believed that ABA is involved in the in the abscission of leaves and fruits. Later, it was observed that other harmones are mainly involved in abscission process. ABA sometimes called as stress hormone because most of its functions are inhibitory however ABA promote some of the functions in plants (Salisbury and Ross 1992; Arteca 1996). During water shortage (drought) ABA synthesis increased and it stimulate many inhibitory actions including the closing of stomata, inhibit shoot growth, maintenance of dormancy, and induce transcription of gene for proteinase inhibitors against the wound which is involved in defence against the pathogens (Davies 1995; Taiz and Zeiger 2010).

3.12.5. Ethylene Ethylene is a class of phyto-hormone usually found in gaseous state and it is the only member of its class. Ethylene is naturally occurring plant hormones and has simple chemical arrangement. It is ubiquitously synthesized in all angiosperm plants and is typically ascribed with fruit ripening and other physiological response.

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In 1864, gas outflow from the street-lights displayed growth inhibition, plants twisting, and abnormal thickening in stems (Salisbury and Ross 1992; Arteca 1996). In early 19th century (1901), Dimitry Neljubow a Russian scientist reported that the active constituent in the outflow was ethylene. Later, Doubt (1917) uncovered that ethylene stimulates abscission. After that, in 1934, another scientist Gane reported that plants produce ethylene. In 1935, Crocker suggested that fruit ripening and plant growth inhibition was caused by ethylene. To date, ethylene is now known regarding many other physiological roles in plant as well. Ethylene is produced in all higher plants from the precursor methionine (an amino acid). Ethylene production is varied with the kind of plant tissue, plant species, and the developmental stage of the plant. Generally, ethylene is synthesized from ana amin acid methionine in a three-main step (Salisbury and Ross 1992; McKeon et al. 1995). For instance, Adenosine tri phosphate (ATP) is an important component in the ethylene synthesis from methionine. For instance water are combined with methionine in presence of ATP which results in loss of the three phosphates and Sadenosyl methionine (SAM). Later, enzyme amino-cyclopropane carboxylic acid synthase (ACC-synthase) expedites the synthesis of ACC from SAM. For the completion of ethylene synthesis, oxygen is then obligatory for Acc oxidation by an enzyme called ethylene forming enzyme (EFE). The regulation regarding ethylene production has received substantial investigation. Study regarding ethylene is not only observed around the synthesis of auxin, respiration, and dehydration but also dealt with fruit-ripening. Enzyme ACC synthase plays key role in limiting ethylene synthesis and that is why this enzyme is utilized in biotechnology to delay fruit ripening in Lycopersicum esculantum (tomatoe) called as flavor saver (Klee and Lanahan 1995; Taiz and Zieger 2010). It was observed that ethylene break the dormancy, enhance plant growth and development. Ethylene may play substantial role in adventitious root formation, encourages leaf and fruit abscission, flower induction, femaleness inductionin dioecious flowers, accelerate flower opening, (Mauseth 1991; Salisbury and Ross 1992; Raven 1992; Davies 1995; Lamber et al. 2009; Taiz and Zeiger 2010)

3.13. Conclusion Anatomy of a tree is different from monocots. Being perennial in nature, cells of all the parts of trees are continuously in activity and they remain active for long times. Anatomical difference between the trees at various levels i.e bark, seeds, leaves, stem color, flowers and fruits, are their characteristic features and may be the result of long environmental adaptations. Water absorption, transpiration and their interaction with soil is an important aspect of tree physiology. As water moves on within the plant it carries substantial amount of mineral to produce metabolically active substrates. In last few decades, due to climatic changes not only affected small but there is also substantial effect on tree physiology. Moreover, in plant water relationship, plant anatomy and soil characteristic cannot be ruled out.

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Acknowledgements Prof. Dr. Raiha Qadri and Mrs. Robina Iqbal, Department of Botany, University of Karachi are highly acknowledged for providing original figures and improving the technical quality of this chapter.

References Addicott, F.T., J.L. Lyon, K. Ohkuma, W.E. Thiessen, H.R. Carns, O.E. Smith, J.W. Cornforth, B.V. Milborrow, G. Ryback and P.F. Wareing (1968). Abscisic acid: A new name for abscisin II (dormin). Science 159:1493. Alvin, P.T. (1964). Tree growth and periodicity in tropical climates. In: Zimmermann, M.H. (ed). The Formation of Wood in Forest Rrees. Academic press, New York, pp. 479-95. Andrews (2012). Plant growth. http://hbio6gbs1112.blogspot.com/2012_03_01_archive.html. Accessed on 27 July 2017. Anonymous (2017). The Robinson Library. http://www.robinsonlibrary.com/science/botany/anatomy/roots.htm. Accessed on 27 July 2017. Arteca, R. (1996). Plant Growth Substances: Principles and Applications. New York: Chapman & Hall. pp. 241-285. Bannan, M. W. (1962). The vascular cambium and tree ring development. In: Kozlowski, T.T. (ed). Tree Growth. Ronald press, New York, pp.3-21 Bannan, M.W. (1955). The vascular cambium and radial growth in Thuja occidentalis L. Can. J. Bot. 33:113-38. Barnett, J. R. (1973). Seasonal variations in the ultra stricture of the cambium in Newzeland grown Pinus radiate D. Don. Ann. Bot. 37: 1005-11. Bose J.C. (1923). The Physiology of the Ascent of Sap. London: Longmans, Green and Co Publishers, London, UK. Chandary, K. A. (1961). Growth rings in tropical trees and taxonomy. Abstract 280. 10th Pacific Science Congress. Pacific Science Association, Honolulu, Hawaii. Crocker, W., A. E. Hitchcock and P.W. Zimmerman (1935). Similarities in the effects of ethylene and the plant auxins. Contrib. Boyce Thompson Insti. 7:231-248. Davies, P.J. (1995). Plant Hormones: Physiology, Biochemistry and Molecular Biology. Springer Netherlands. Kluwer Academic Publishers. pp. 1-12 Dixon, H. and J. Joly (1895). On the Ascent of Sap. Philos. Trans. R. Soc. Lond. B. Biol. Sci. 186: 563–576. Doubt, S.L. (1917). The response of plants to illuminating gas. Bot. Gaz. 63:209224. Ewers, F. W. (1982). Secondary growth in needle leaves of Pinus longaeva (Bristlecone pipe) and other conifrs: quantitative data. Am. J. Bot. 69:15521559.

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Fahn, A. and E. Werker (1972). Anatomical mechanisms of seed dispersal. In: Kozlowski, T.T. (ed). Seed Biology. Academic Press, New York. Gane, R. (1934). Production of ethylene by some ripening fruits. Nature 134:1008. Godlewski, E. (1884). Zur Theorie der Wasserbewegung in den Pflanzen. Jarb. Wiss. Bot. 15: 569-630. Iqbal, M. (1981). A decade of research in plant anatomy (1971-80). Aligarh Muslim University, India. Klee, H.J. and M.B. Lanahan (1995). Transgenic plants in hormone biology. In Davied P.J. (ed). PlantHormones: Physiology, Biochemistry and Molecular Biology. Davies, P.J. (ed). Kluwer Academic Publishers, Springer Netherlands), pp. 340–353. Kollman, F.F.P. and Jr. W.A. Cote (1968). Principle of Wood Science and Technology, Volume I. Solid Wood Springer-Verlag. NewYork. Pp. 57-65. Kramer P.J. and T.T. Kozlowski (1960). Physiology of Trees. Nature McGraw-Hill Book Co., Inc., New York. Lambers, H., F.S. Chapin and T.L. Pons (2009). Plant Physiological Ecology.Spiner-Verlag NY. USA Larson, P.R (198). The concept of cambium. In: Baas, P. (ed). New Perspectives in Wood Anatomy. Martinus NIjhoff/Dr. W. Junk publishers, The Hague, pp.85121. Liphshitz, N. And S. Lev-Yadun (1986). Cambial activity of evergreen seasonal dimorphic around the Mediterranean. IAWA Bull.7:145-153. Mauseth, J.D. (1991). Botany: An Introduction to Plant Biology. Philadelphia: Saunders. pp. 348-415. McKeon, T. A., J.C. Fernandez-Maculet and S.F. Yang (1995). Biosynthesis and metabolism of ethylene. In Davied P.J. (ed). PlantHormones: Physiology, Biochemistry and Molecular Biology. Davies, P.J. (ed). Kluwer Academic Publishers, Springer Netherlands). pp.118-139. Neljubow, D.N. (1901). Uber die horizontale nutation der stengel von Pisum sativum und einiger anderen. Pflanzen Beitrage und Botanik Zentralblatt 10:128-139. Raven, P.H., R.F. Evert and S.E. Eichhorn (1992). Biology of Plants. New York: Worth. 545-572 pp. Sachs J. (1878). Ueber die Anordnung der Zellen in jüngsten Pflanzentheilen. Arb Bot Inst Wurzburg 2: 46-173 Salisbury, F.B. and C.W. Ross (1992). Plant Physiology. Belmont, CA: Wadsworth. Pp. 357-407, 531-548. Sponsel, V.M. (1995). Gibberellin biosynthesis and metabolism. In Davied P.J. (ed). PlantHormones: Physiology, Biochemistry and Molecular Biology. Davies, P.J. (ed). Kluwer Academic Publishers, Springer Netherlands). pp. 6697. Taiz, L. and E. Zeiger (2010). Plant Physiology. 5th Edition. Sinauer Associate Inc. USA. Wloch, W. (1987). Transition areas in the domain patterns of storied cambium of Tilia cordata Mill. Acta Soc. Bot. Pol. 56:645-665.

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Zagorska-marker, B. And C.H.A. Little (1986). Control of fusiform initial orientation in the vascular cambium of Abies balsamea stem by indol-3ylacetic acid. Can. J. Bot. 64: 1120-1128.

Chapter 4

Forest Ecology M. Abdullah, T.H. Khan and M. Rafay*

Abstract Human actions are supporting the destruction process in earth and are transforming the interactions among forests, land and water resources. Thus, forest ecosystems are continually changing and degrading with the passage of time. This conversion, induced by external factors is mainly defined by those internal ecosystem processes, which are essential for conservation of biodiversity. It is imperative to conserve all biome types as each hold several unique kinds of life forms. Preserving the various forest types is indispensable for the sustainable maintenance of earth ecosystem. The study of ecological methods is essential in dealing forest’s resources because it states interactions that linkage biotic systems, of which human beings are primary component, with physical system on which they rely. The aim of ecosystem science is to incorporate information from the studies of interactions among individuals, populations, communities and their abiotic environment, as well as changes in their relationships. The flow of the energy and material by organisms and physical environment formulate a framework for understanding the variety of forms and working of earth’s biological and physical processes. There is a rising indebtedness that a systematic understanding of forest ecosystem is crucial to manage the biodiversity, water resources and in regulating the atmospheric composition, that governs the Earth’s climate. By educating the peoples about the

* M. Abdullah Cholistan Institute of Desert Studies, The Islamia University of Bahawalpur, Pakistan. For correspondance: [email protected]

T.H. Khan and M. Rafay Department of Forestry, Range and Wildlife Management, The Islamia University of Bahawalpur, Pakistan. Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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results of human activities, a good considerate to conserve the earth’s forest biomes can be obtained. The forest zones, which have been damaged, mostly will never recoup their original shapes, however conservancy will support to save them away from getting worsen. Key words: Earth; Forest; Ecology; Autecology; Synecology; Ecosystems

4.1.

Introduction

The term ecology was first used by Ernst Haeckel in 1866. Ancient Greek philosophers Aristotle and Hippocrates set the bases of ecology in their studies about the natural history. Then current thought of ecology converted into a science that is more rigorous in late 19th century. The word ecology has been formed from two Greek words (oikos-home and logos-the study). Therefore, ecology is defined as the study of an organism at its natural home. The two senses of ecology are widely used such as: i.

Andrewartha (1961) defined ecology “The scientific study of abundance and distribution of the organisms”

ii.

Odum (1971) stated ecology “The study of relationships of organisms or groups of organisms with their environment”

At the developmental stage of ecology, there has been controversy between different schools of thoughts. To remove the barriers, ecology needs to be defined in a way that favors the common opinion. Therefore, a group of ecologists mutually approved a definition in the Institute of Ecosystem Studies, Millbrook, New York (Kemp 1992): which is described as “Ecology deals with the scientific study of processes effecting the abundance and distribution of organisms, interactions of organisms, and the transformation and flux of energy and matter” •

Basic ecological concepts revolve around the four principles

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The ecological system is wide and comprises of interactions of its components.

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This interrelated system encompasses both abiotic and biotic constituents.

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The system in ecology has a control on energy flow as well as nutrients flow.

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Energy from solar governs over the flow of all the energy and nutrients.

Ecology has a broader scope and encompasses an extensive range of interacting levels, covering from micro-level (cell) to planetary scale (biosphere). There are numerous applications of ecology such as in natural resource management (agriculture, forestry, rangelands and fisheries), conservation biology, community health, city planning (urban ecology), human social interactions (human ecology), basic and applied sciences etc. Resources and organisms constitute the ecosystem that form the biophysical feedback mechanism, which control practices related to nonliving and living elements of the planet. Ecosystem endure life assisting tasks

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and create natural capitals like biomass productivity (fuel, fiber, medicines and food), regulating the climate, water filtration, biogeochemical cycles, flood protection, erosion control, soil formation, and many other natural processes of scientific, economic, and historical values (Buchsbaum et al. 1972). Ecology covers a wide range of allied disciplines and various scientists like physiologists, geneticists, taxonomists, ecologist etc. concentrate on respective aspects of ecosystems. In the subsequent discussion, description of different subdisciplines of ecology has been provided. •

Physiological ecology- refers to environmental factors, which affect the physiology of organisms.

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Population ecology- deals with the distribution, dynamics, and structure of populations.

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Community ecology- describes the interactions among individuals and populations of different species.

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Evolutionary ecology- is defined as the studies of the evolutionary histories of species and their mutual relations.

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Landscape ecology- is the study of improvement in the relationships among ecological processes in environment and ecosystem.

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Ecosystem ecology- deals with mass balancing of elements and their interactions. The fluxes of elements are mainly attached to each other, and often one limiting element controls the flux of other elements.

The study of ecosystem should exploit all the approaches defined above to know the complexity, ecological processes and provide useful information for managers. In all aspects of ecology, the convergence of information, different approaches and disciplines lead to major breakthroughs in the understanding of an ecosystem (Kulhavý et al. 2014).

4.2.

Concept of Ecosystem

A British ecologist named Tansley (1935) in his publication initially used the word “ecosystem”. This word is derived from a Greek word; Eco means "Environment" System means, "Complex coordinates unit”. Tansley created the idea to focus on the significance of transfers of elements between environment and their organisms. In nature, numerous communities of organisms live together and cooperate with each other along with their environment as an ecological component. Ecosystem is considered as a community of living organisms (animal, plant and microbes) in combination with nonliving elements of the environment (soil, air and water), cooperating as a system. It is an efficient component of nature about the complex interaction of abiotic (non-living) and biotic (living) factors e.g. forest is a good example of an ecosystem. Ecosystems have been classified as follows:

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a)

Man-made ecosystems i.

Depend upon solar energy-e.g. aquaculture ponds and agricultural fields

ii.

Depend upon fossil fuel e.g. industrial and urban ecosystems

b) Natural ecosystems i.

Depend on solar radiations e.g. forests, grasslands, deserts oceans and rivers. They afford fuel, food, fodder and medicines

ii.

Depend on solar radiations and energy subsidies (other sources) such as rain, tides and wind, e.g., tidal estuaries and tropical rain forests

4.2.1. Forest, Forest Ecology and Forest Ecosystem a)

Forests can be defined as native or local segments of landscapes where ecological and biological processes and conditions are controlled by the trees. Trees are mostly large, perennial long-lived plants also categorized by a large woody stem and extensive root system. The longevity and size of trees make them able to govern other plants by commandeering soil, light and other resources. This allows trees to regulate the important ecological functions, to govern the habitats for animals, microbes and other plants, and perform a role in defining the wealth of other organisms in forest. Thus, trees regulate the soil developmental processes, hydrological cycle, microclimate, and the ecological features of streams in forest ecosystem. b) Forest ecology is a very diverse and essential branch of ecology that deals with tree species and environment. It is the systematic study of interrelated patterns, processes, flora, fauna and ecosystems in the forests. A forest ecosystem is a piece of natural woodland comprising of animals, plants and microorganisms (biotic part) working with all non-living (abiotic part) factors in the environment. Forests are examined at different structural levels, from the individual organism to the ecosystem. However, as the term forest includes an area inhabited by more than one tree, forest ecology most often focuses on the level of the population, community and ecosystem. However, the presence of trees makes forest ecosystem and their study distinctive in various ways. c) Forest ecosystem refers to an area of the landscape; differ in size from a local stand to a whole continent, where the functions, structure, interactions, complexity and patterns of change with time are controlled by trees (Perry et al.2008).

4.2.2. Key Attributes of Forest Ecosystem There are five key attributes of forest ecosystem

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Structure The basic structural components of forest ecosystems are dead and living components like animals, plants, soils microbes, organized in vertical and horizontal patterns. The physical environment involves the soil, atmosphere and geological substrates. Microclimate and topography are also essential ecosystem components, but are not structural parts in the strict sense.

ii.

Function In forest ecosystem, interaction of living and dead organisms along abiotic environment leads in the combining of physical (light) or chemical energy with soil chemical nutrients, geological substrate, and water to make the organic molecules, which form the living organisms. The energy for the formation of these molecules in the forest ecosystem is mostly provided by photosynthesis process. The raw resources for their productions are delivered by the flow of different nutrients in the ecosystem.

iii. Complexity Forest ecosystems are considered by the composite groupings of various life forms, from lichens and bryophytes to different types of shrubs and herbs, to climbers and trees. Dead animals and plants material carries the energy for varied microbes and animals, which help to decay the organic material and make available the nutrients again for uptake by microbes and living plants. The relations between the dead organic matter, living organisms, and the physical environment contribute to the complexity of ecosystems. iv. Interaction between components A basic feature of a forest ecosystem is the relationship among the structural components. For example, soils influence the plants and plants affect the soil development. Climate affects the vegetation and soil development process, but plants transform local climate to create microclimate. Vegetation can affect regional climatic features and vegetation at global level performs a key role in global climate. Microbes and animals influence the plants, and then plants largely determine which microbes and animals will be affecting them. v.

Change over time In ecosystems; nothing is as sure as change. Just as plants grow up, mature and inevitably die, ecosystems suffer renewal because of ecosystem disruption. Ecosystems grow and mature, and are ultimately disturbed and the renewal process is repeated. This change with the passage of time is essential to the ecosystems and in many cases, is a necessary condition for long-term stability of historical ranges of variations in their function, complexity, structure, and interactions of their components (Waring and Running 1996).

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Fig. 4.1 Describing the components and processes of forest ecosystems. Source: Modified from Kemp (1992)

4.3.

Components and Processes of Forest Ecosystems

4.3.1. Components of Forest Ecosystems A forest ecosystem comprises of living and non-living components. Organisms (plants, animals, algae, bacteria and fungi) make the organic or living portion of the ecosystem. The physical environment (air, light, water, temperature, soil, minerals and climate) creates the non-living portion. The word ‘environment’ denotes specially to the nonliving portion of the ecosystem. The living portions of an ecosystem are called the biotic components and the non-living portions are the abiotic components (figure 4.1). Both components cooperate with each other to sustain the ecosystem. A forest ecosystem is a functional part of nature covering complex relationship among its abiotic (non-living) and biotic (living) components. Details of two components are as under (Schulze et al. 2005; Smith and Robert 2012). 4.3.1.1. Abiotic Components (Nonliving) Abiotic (Nonliving) components of a forest ecosystem comprise all chemical and physical factors that affect the living organisms e.g. air, soil, water, rocks etc. Hence, it is an accumulation of inorganic and organic elements found in an

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ecosystem. Several climatic factors, which influence the function of ecosystem, are also a part of this. The abiotic components are vital for the biosphere because life cannot occur without water, sunlight, air and minerals. The nonliving component can be classified into subsequent three groups a)

Physical factors: Physical factors consist of temperature, sunlight, rainfall, humidity and air pressure. These factors limit and sustain the development of organisms in an ecosystem. b) Inorganic substances: Inorganic substances contain oxygen, carbon dioxide, nitrogen, phosphorus, sulphur, soil, water, rocks and other minerals. c) Organic compounds: Organic compounds include lipids, carbohydrates, proteins and humic materials. They are the structure masses of living systems; therefore, make a linkage among abiotic and biotic components.

The organisms of forests ecosystem are adjusted to distinctive physical environment of the forest habitat. These essential abiotic factors comprise water, sunlight, soil, wind and temperature. i. Sunlight The sun supplies warmth, light and energy for almost all forest ecosystems on the earth. Sunlight commands the photosynthesis in plants that are the core producers in maximum terrestrial ecosystems. Inside a forest, very less sunlight extents up to the forest floor than spread on the tops of the trees. This variable amount of sunlight generates diverse microhabitats. In aquatic environment, sunshine gives the energy for photosynthetic producers such as algae. ii. Water Water is necessary for all the organisms on earth. In forest ecosystem, water plays crucial role for survival and in response, ecosystem maintains the hydrological cycle. Plants are much adapted which save them from losing too much water and drying out e.g. Trees of Pine have needle-shaped leaves along with waxy coating. This shape of leaves lessen the quantity of water that vaporizes into air. Similarly, aquatic organisms also maintain their water loss and water uptake; otherwise, their cells may rupture due to osmosis. iii. Temperature Temperature is a very important component of forest ecosystem. Mostly the living organisms survive within a narrow range of temperatures, from around 0°C to 50°C. A small number of organisms can keep an active metabolism below 0°C, and most organisms’ enzyme stop working and lose shape above 50°C. However, extraordinary adaptations permit certain species to survive at extreme temperatures. Several species of prokaryotes can flourish in hot springs as hot as 80°C and nearby deep-sea vents that are even hotter.

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iv. Soil In forest ecosystem, soil is an essential component, which affects the growth and distribution of vegetation. The combination of abiotic components (wind, ice, and rain) and the activities of living things (plants, microorganisms and earthworms) on the rocks and minerals of Earth’s crust produce soil. The soil structure and chemical composition in an ecosystem determine the types of plants that can grow there. Similarly, in aquatic ecosystems the features of the underlying sand or rock define the types of plants and algae that can grow there. v. Wind Wind influences the activities and distribution of organisms in numerous ways. Winds control movement of rain and clouds on the earth. Wind also stirs up water in lakes, streams and ponds, making the currents, which result in bringing up nutrients from the bottom. Several land plants rely on winds for the dispersal of their seeds and pollen. 4.3.1.2. Biotic Components (Living Components) Biotic components (living organisms) in a forest ecosystem can be categorized as producers (autotrophs) or consumers (heterotrophs) depending upon their food sources. a)

Producers (autotrophs, i.e. self-feeders) can synthesize organic nutrients, which they need, by using the simple inorganic compounds from environment: for example, terrestrial green plants on land surface and small algae in aquatic ecosystem make their food thru photosynthesis. The green plants produce the food for the whole ecosystem by photosynthesis. These plants are also called as autotrophs, because as they take carbon dioxide from air, absorb water and nutrients from soil, and capture solar energy for photosynthesis. b) Consumers (heterotrophs, i.e. other feeders) are those living organisms that cannot synthesize their own food but directly or indirectly depend on producers for food. They are called heterotrophs and they eat food produced by autotrophs. Consumers, based on their food preferences and food habits, can be further classified into three broad categories. i.

Herbivores: In food chain, herbivores are stated as primary consumers. They are plant eaters and feed directly on plants e.g. deer, rabbits, cattle, etc.

ii.

Carnivores: They are meat eaters and they feed on herbivores (primary consumers) therefore known as secondary consumers e.g. lions, tigers etc.

iii. Omnivores: Those organisms, which depend upon plants and animals for their feed e.g. human, pigs, sparrows, etc. c)

Decomposersare called saprotrophs. They are commonly fungi and bacteria, which feed on decayed and dead organic matter of animals and plants by releasing enzymes outside their body on the decaying matter.

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They perform a very significant role in reprocessing of nutrients in the forest environment. They are also called detritus feeders or detrivores. Decomposers digest and breakdown the complex organic molecules of dead organic matter (detritus) into simple inorganic compounds. In response, they absorb the soluble nutrients as food e.g. fungi, bacteria and mites. Regarding forest ecosystem components, abiotic factors decide where a species is able to live, however, biotic factors often govern the species success. Numerous key biotic factors comprise different interactions among individuals. Mostly individuals are in competition with members of their own species as well as with other species. Living components depend upon an ecosystem for food, water, and air as well as other things they need for their survival. In return, living things influence the ecosystem in which they live. Plants are an important source of food and as biotic factor in forest ecosystems affect other biotic and abiotic components. The types of plants found in a specific ecosystem will also determine the types of animals that can survive there (Seymour and Hunter 1999).

4.3.2. Processes of Forest Ecosystems Ecosystems are multifaceted dynamic systems, which perform numerous functions (Figure 4.1). There are few different processes that are fundamental in all the forest ecosystems (Odum and Barrett 2004; Thomas and Packham 2007). 4.3.2.1. Energy Flow through Ecosystem In forest ecosystem, the major part of energy comes from sunlight by which plants synthesize food. During photosynthesis, plants transform light energy into chemical energy, which assist in the growth of branches, leaves, fruits, seeds, and wood. Herbivores obtain energy by consuming plants, carnivores by consuming other animals, and decomposers by the decay of animals and plants. In decomposition process, nutrients become accessible to soil fauna and flora, and then energy is released to environment. No part of the energy used by animals comes back to plants; this whole process is referred as energy flow. This conversion of energy from plants to animals also contributes to the dynamic nature of a forest ecosystem. Forest ecosystems are functioning by using the sun energy in the process of photosynthesis. The leaves of green plants absorb the solar energy and transform hydrogen, carbon, and oxygen into simple sugar form. That is again transformed into complex compounds such as cellulose, which is key constituent of wood fiber. A mature forest ecosystem yields many tons of sugar and various other compounds per acre each year. When a tree dies, it starts to decompose and microorganisms that decompose leaves, twigs and wood, consume some of the stored energy. As energy comes from sun and flows through an ecosystem, certain form of energy is lost to environment in heat form at each level during decomposition and metabolism (Figure 4.2).

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Fig. 4.2 Showing the process of energy flow through a forest ecosystem 4.3.2.2. Food Chain and Food Web In each ecosystem, food chain is made up of producers, consumers, and decomposers. In forest ecosystems, producers can be trees, shrubs etc. but consumers are the components of ecosystem that depend on other components for their food. Every time an animal consumes another organism, ultimately energy moves to the consumer. For example, foxes, deer, rabbits, hawks, owls, snakes, insects and spiders are the examples of consumers in a forest ecosystem. There are three categories of consumers in ecosystem i.e. herbivores, carnivores, and omnivores. The decomposers are part of ecosystem, which survive on dead organisms and convert them into simple forms that are source of energy. Decomposers comprise of fungi, bacteria and mushrooms. Ultimately, producers, consumers and decomposers build different food chains. In an ecosystem, there are more than one food chains for the organisms as every organism eat more than one type of foods or eaten by more than one kind of predators. Arrays of interactions develop out the complex system of overlapping and interconnecting food chains in an ecosystem is known as food web. In an ecosystem, there can be many food chains and the combination of many food chains is called as food web. Food webs present accurate models of energy flow through an ecosystem. Flow of energy in an ecosystem occurs through food chains, by transferring the energy from one organism to another (Figure 4.3).

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Fig. 4.3 Difference between Food chain and Food web in a forest ecosystem. Source: Modified from Odum and Barrett (2005)

4.3.2.3. Trophic Level In a forest ecosystem, trophic level is a phase of food chain occupied by an organism. Every stage of food chain is regarded as trophic level. From each trophic level, organisms get their energy whereas those organisms who share a trophic level obtain energy from the same point. The quantity of energy passing through the trophic levels reduces successively. At each stage in a food chain or web, energy got by organism is used to endure itself and remaining is passed on succeeding trophic level. In ecosystems, trophic levels are not linear however; they are interconnected and form a food web. e.g. (Grasses→ Grasshopper → Frog → Snake → Eagle) (Figure 4.3) Every point in food chain is named as trophic level. In above example grasses represent the 1st, and eagle represents the 5th trophic level. Similarly, trophic levelscan be categorized from level 1 with plants to level 5 with predators, are numbered successively as shown in Figure 4.4. i.

Trophic level 1: At level 1 plant and algae exist which create their own food and are named as primary producers.

ii.

Trophic level 2: In this level, herbivores are present which consume plants and are named as primary consumers.

iii. Trophic level 3: Carnivores at level 3 eat herbivores and are named as secondary consumers. iv. Trophic level 4: This level includes the carnivores, which eat other carnivores and are named as tertiary consumers.

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v.

Trophic level 5: At level 5 apex predators are present which have no predators and found at the top of food chain.

Fig. 4.4 Description of Trophic levels in a forest ecosystem

4.3.2.4. Ecological Pyramid An ecological pyramid is also known as energy pyramid or trophic pyramid. It is basically a graphical illustration which is designed to demonstrate biomass production at each trophic level in a forest ecosystem. They are pyramidal in shape and the producer is at the base of the pyramid and makes the first trophic level in food chain whereas later levels of the pyramid symbolize the herbivore, carnivore and top carnivore levels respectively. The ecological pyramids are of three different forms: i.

Pyramid of number: This characterizes the relationship among the number of producers, herbivores and carnivores at succeeding trophic levels. It describes the number of organisms at each trophic level. For instance, in a forest ecosystem the number of producers (trees, shrubs, herbs) are in large number than the number of herbivores (deer, antelopes, elephants) and the carnivores (lion and tiger). In some cases, the pyramid of number can be reversed, i.e. herbivores are larger in number than primary producers (e.g. many insects feed on a single tree).

ii.

Pyramid of biomass: It refers to total standing biomass at each trophic level. Standing biomassrepresentsthe mass of the living material at any given time. It is expressed in gram/unit area or kilo cal/unit area. Mostly in terrestrial ecosystems pyramid of biomass is upright. Total biomass of producers will be highest and further biomass would go on decreasing from producers to top carnivores.

iii. Pyramid of energy: This shows the total quantity of energy at each trophic level. Energy is denoted in terms of rate like cal/unit area/unit time or kcal/unit area /unit time. Energy pyramids are not inverted. The maximum amount of energy occurs at the base of the pyramid whereas

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minimum amount of energy is found at the top of the pyramid (Figure 4.5). Fig. 4.5 Illustrating the ecological pyramid in a forest ecosystem. Source: Modified from Odum (1971)

4.3.2.5. Biogeochemical Cycles Biogeochemical cycleis a path overwhich chemical substances travel through both bioticand abiotic parts of the Earth. It is a cyclic sequenceof changes, which comes again to starting point andcan be repeated. The main biogeochemical cycles contain nitrogen cycle, phosphorus cycle, oxygen cycle, sulphur cycle, carbon cycle and water cycle. In a forest ecosystem, energy flow is linear however, nutrients flow is cyclic. The nutrients cycle from dead residues of the organisms back to soil by decomposers and absorbed again from soil by roots of plants which passes on to herbivores and carnivores. This cycled movement of the nutrients is necessary for life and called nutrient cycle or biogeochemical (Bio=living, geo=rock, chemical=element) cycle. The whole earth is a sealed system i.e. nutrients are neither exported nor imported from this biosphere. The word “biogeochemical” states that geological, chemical and biological factors are involved in it. Biogeochemical cycle always includes hot equilibrium status: stability in the cycling of the elements and whole balance may involve universal scale. As biogeochemical cycle defines the movements of matters on the entire sphere, their study is inherently multidisciplinary. 4.3.2.6. Ecosystem Productivity The measurement of productivity enables us to determine the rate of photosynthesis and increase in biomass of a forest ecosystem. Yet, all natural activities in plants finally depend on solar energy whereas solar radiation alone does not control the gross primary production. All plant types need water, soil nutrients, carbon dioxide and sunlight for the process of photosynthesis. It also depends on moisture, temperature, and nutrients availability. Temperature governs the metabolism rate in plants, which in turn regulates the photosynthesis procedure. The optimum temperatures for production range from 15°C to 25°C i.e. optimal range of photosynthesis. Water is a main prerequisite for photosynthesis and the leading chemical element of most plant cells. In dry areas, there is a linear rise in net primary production with increase in availability of water. The productivity of

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plants, particularly at the local scale, can be governed by the availability of nutrients. Nearly 20 to 30 elements are regarded crucial for plant growth and metabolism. These necessary nutrients are sometimes assembled into two types: micronutrients and macronutrients. Plants use the macronutrients for the manufacture of structural molecules and for constructing a range of organic molecules used in metabolic processes. There are only two macronutrients used by plants that exist in less concentration for plant uptake: phosphorus and nitrogen. When limiting, these two nutrients regulate the quantity of plant production that can take place. Plants need micronutrients in minor quantities for the making of less common organic molecules or as ions to catalyze certain metabolic processes. Generally, micronutrients are abundantly viable and do not lower the plant productivity. 4.3.2.7. Ecosystem Equilibrium Forest ecosystems have capacity of maintaining their equilibrium condition. This self-regulation of ecosystem is known as homeostasis. There are numerous factors: like climate, species introduction, and species extinction that can change the equilibrium on which an ecosystem fluctuates. The climate change can affect the dominant plant species and better-matched plants might move into the area. Resultantly, dominant plants become extinct and the organisms that once depended on these plants will also become extinct or be forced to change their behavior. Consequently, a new equilibrium will be developed. Ecosystems continuously change with the passage of time. The series of ecosystem changes are known as ecological succession. Succession occurs when one community gradually replaces the other community with the changes in the environment. As succession in a community continues, it’s finally becomes a climax community. The community becomes ecologically stable unless disturbed by some unusual event. Forest succession is a systematic change as the plants grow taller, larger, and compete with other plants for nutrients, light, water and destroying them. In ecosystem disturbance is expected to occur certainly in the form of fire, disease, insect, flood, wind, and other natural actions. Several common forest operations cause natural disorder to certain extent. Usually, disturbances open up the canopy of forests and permitting setting up of fresh plants. However, in many of our forests disturbances like roads, dams, logging, fire, and prescribed burning due to human influence have negative effects. When disruption arises over the massive forest areas, more time is needed for regaining and to maintain the equilibrium.

4.4.

Factors Sffecting Tree Growth

Like every organism on the earth, trees are strongly influenced by different environmental factors. Environmental factors comprise everything other than plants, which influence the plant life. Hence, the basic information about interrelationship between trees and environment is indispensable. Trees differ markedly from each other in their distribution, growth, adaptation, phenology, regeneration, etc. These changes in trees can often be associated with prevailing environment. The factors affecting tree growth in the field can be broadly studied under two approaches mentioned as below (Gurevitch et al. 2006).

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Autecology approach

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Synecology approach

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4.4.1. Autecology Approach (auto-self, logy-knowledge) Autecology deals with the ecology of an individual species and its population therefore, termed as "species ecology". It also studies the individual organism including its life histories, behavior, adaptations with its environment comprising all the parameters of ecological importance. Autecology is the level of integration between the environment and the individual species. Autecology mostly involves the discussion about the environmental factors. Environment is a complex of various factors, which interact not only with organisms but also among themselves. Each factor consists of three levels, minimum level is one below which tree cannot survive. Optimum level is the best for tree growth and the maximum level is one above which tree cannot survive. The importance of these factors keeps on changing and depends upon the type of tree species, their growth and season of the year etc. In return, trees also affect these factors. Environmental factors can be classified into followings categories (Kimmins 2004). 1) 2) 3) 4) 5)

Climatic factors Water factors Topographic factors Edaphic factors Biotic factors

1. Climatic factors Climatic factors involve precipitation, humidity, light temperature and wind. These factors affect the life processes as of plants and are undoubtedly most important than all other factors. The above mentioned climatic factors are discussed one by one as below: a)

Precipitation directly and indirectly influences the trees by atmospheric humidity and water contents in the soil. In atmosphere, water vapors on cooling condenses to form clouds, which on further cooling forms the rain, snow, hail, dew, etc. Rainfall- rainfall refers to the drops of water that come down from the clouds, when water vapors in clouds condenses around dust particles, they form tiny droplets that ultimately get too big for the cloud to hold so they fall and grow larger as they accumulate more water on their way down. Whereas, drizzle consists of smaller droplets of water that slowly move toward the earth surface. Hail- hail is formed when water droplets repeatedly descent through cold area in the atmosphere, consequently, freezing the water in the shapes of balls which may be of significant weight and size. It exerts severe harm to the plants particularly to the small seedlings.

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Snow- snow is another form of precipitation, which not only acts as shield to check evapotranspiration from the soil and plants but on melting it also enters the soil directly as rain does and entertain as a source of water. Dew- dew is formed when water vapors in air meets cold surfaces, moisture condenses on the surface in the form of small droplets of water called as dew. When the above mentioned all forms comes down on the earth they are named as precipitation. Area receiving high precipitation is always considered as the area with dense tall vegetation. Therefore, years of abundant rainfall are also regarded as the years of abundant forest growth rate. Total amount, intensity, form and frequency of precipitation all control the survival and growth of trees species. b) Temperature is an important climatic factor because it controls the several physiological functions in plants. Plant metabolic processes are high at certain temperature called optimum but low at minimum and maximum temperature. Both very high and low temperature has negative effect on the growth of plants. Plants significantly vary in temperature tolerance not only from species to species but also within same species in different seasons of the year. Overall, there are insignificant metabolic functions at temperature higher than 40°C or below 0°C. Temperature along with combination of moisture define the over-all distribution of vegetation. Vegetation is mainly described by the heat. Thus, the plants, which grow in cold climate, cannot grow in hot climates and vice versa. Trees are usually more sensitive to temperature extremes at their early growth periods and temperature extremes are more severe near the ground surface. However, provision of mulch, moisture and shelter can decrease the temperature extremities near soil surface. Plants can be classified based on the temperature requirements such as; i.

Megatherm- Plants which live in the high temperature throughout the year e.g. equator and tropical region rain forest

ii.

Mesotherm- Plants that favor high temperature in summer alternating low temperature in winter e.g. deciduous forest of tropical and subtropical zones

iii. Microtherm- Plants that found in the temperate and high altitude (upto12000 ft.) e.g. mixed coniferous forest iv. Hekiskotherm- Plants of arctic and alpine zones with low temperature (above 12000 ft.) e.g. alpine vegetation c)

Humidity: In atmosphere, humidity always exists in the form of invisible suspension of water vapors. Normally, the water holding capacity increases with the rise in the temperature. Relative humidity is influenced by atmospheric pressure, exposure, wind, vegetation and presence of water contents in the soil. In an unsaturated or dry condition, the water vapor concentration of the air is commonly stated as relative humidity. In plants

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transpiration and absorption of water is directly related with the relative humidity in the atmosphere. Lesser the relative humidity in air, higher the rate of transpiration and absorption of water by plants. Humidity is also dependent upon the blowing or still wind. Blowing wind supports to enhance the transpiration rate by removal of moisture-laden air from around the stomata of the transpiring plants. The atmosphere is assumed to be saturated when the atmosphere contains the maximum possible amount of water vapors at specific pressure and temperature. On the other hand, if the temperature of the saturated atmosphere is lowered, the ability of holding water vapors falls and consequently, some water condenses as rain, snow or dew. d) Wind: Air in motion is called wind. It plays significant role in the movement of gases, water vapors and small soil particles in environment. The wind action as an ecological factor may be direct or indirect. The direct effects of wind are usually obvious in the region where high wind velocities occur. Violent and strong winds may cause flattering of herbaceous plants to the ground, referred as lodging. Strong winds also carry and move the soil particles that cause a scratchy action on the tender braches and leaves of various plants. Indirect effects of wind are physiological which involve influence on the transpiration rate in plants. Strong winds accelerate the transpiration rate in plants and plants fail to maintain internal water balance consequently suffer desiccation. Wind velocity increases with an increase in height above the soil surface so that large plants are more prone to high rate of transpiration than smaller ones. e) Light: Light is considered as a factor of great ecological importance in the environment. It is mainly used for the synthesis of food by green pigment in plants. Out of the total sun energy, reaching to the earth only 2 % is utilized during photosynthesis process and almost 10% is used in various physiological functions. In plants, the stored chemical energy in the food is used for numerous other biochemical activities. The requirement of different light periods by plants is referred as photoperiod. Based on photoperiod, the plants are categorized as short day and long day plants. However, the plants that show slight response to the day length are called day neutral plants. Plants can also be categorized according to the relative requirements of sunlight or shade. Those plants that develop finest in full sunlight are known as heliophytes and those that develop at less light intensities are known as sciophytes. There are some facultative heliophytes, which grow well in less amount of light but can also develop fine in full sunlight. Correspondingly there are some heliophytes that grow good in sunlight but can also fairly grow in shade are called as facultative sciophytes. However, there are distinct morphological and anatomical variations between the leaves of plants growing in sun and in shade and even between sun exposed leaves and shade exposed leaves of same plants.

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2. Water factors Among all the environmental factors that affect the distribution and growth of plants, water is known as most vital for all the life processes. Water encompasses almost 70% of earth surface and found in lakes, streams, ponds and oceans. In nature, water moves in circular fashion called hydrological cycle. For all the physiological processes like photosynthesis, transpiration and translocation of food material water is very important. Water also plays significant role in pollination, fertilization processes in flowers and dispersal of flowers and seeds. Maximum plants have adjusted in nature according to the amount of moisture available to them. On the basis of habitats, plants have modified themselves morphologically and anatomically and accordingly they are classified as i.

Hydropytes- plants growing in water reservoirs like ponds, lakes, streams or rivers.

ii.

Amphibiophytes- moisture loving plants, which grow on very moist and swampy places i.e. on the side of pond ditches, rivers, etc.

iii. Mesopytes- plants which grow in habitats, which are neither dry nor wet, and temperature of the air is neither too high nor too low. iv. Xerophytes- plants living in xeric habitats where there is scarcity of water, found in arid region, on rocks, sandy soil and steep slopes. 3. Topographic factors Topographic or physiographic factors include the form, behavior and structure of earth surface such as hills and their slopes, elevations, aspects, valleys and coastal areas. In prevailing climatic conditions of an area, topographic factors have a great influence on the vegetation. It affects the growth of plants in two ways: by producing the variations in local climate and by changing the edaphic factors of the area. Forms of land and direction of sloppy faces have strong indirect effects on the growth of trees. Altitude, slope and aspects are main constituents of lands configuration. These features have very strong modifying effect on the temperature, duration of growing season, soil moisture and precipitation. Major components of physiographic factors are discussed here under: a)

Altitude- It describes the height of a certain area from sea level. As we move towards higher altitude, climatic variations become more and more severe and vegetation also changes. Altitude tends to create contrasting local climates. b) Slope- Slope isalso a topographical factor that effects the variations in the habitats. Slope of the ground influences the distribution of vegetation by affecting the insolation, soil stability, movement of water as well as level of water. c) Aspect- Aspect or exposure of mountains towards sun is another physiographic factor. Sometime quite different vegetation is perceived on the two aspects of the mountains.

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4. Edaphic factors Edaphic factors are very important like other environmental factors for the growth of plants. Climatic factors are of utmost importance in determining the characteristics of vegetation over extensive areas but within general climatic zones, edaphic factors are also essential for the local differences in vegetation. Plants grow in the soil, which provides the nutrients for them, and also act as reservoir of water for the plants. However, most plants grow well where soil pore spaces are not exclusively occupied by either water or air. Warming (1895) has categorized the plants on the basis of soil types. He characterized the plants found on acid soil as Oxylophytes, on saline soil as Halophytes, on sand as Psammophytes, on rock surface as Lithophytes and in rock crevices as Chasmophytes. The main components of soil affecting the plant growth are discussed as follows a)

Soil texture-Relative proportion of soil particle sizes is referred as soil texture. It indirectly affects plants by producing the variations in soil water and soil air. The water amount available to the plants from soil is determined largely by the texture of soil. b) Soil structure-Soil structures are formed when the merging of individual soil particles occurs with the help of soil colloids into various forms, shapes and sizes (1-10mm in diameter). Aggregation of soil is very important with the increase in the fineness of texture. More the degree of aggregation in soil the more favorable the soil for growth of plants. Aggregations make soil permeable to water; assist heat transfer, and increase aeration and water holding capacity. c) Soil organic matter-It is dead remains of plants in soil, which is lightweight and less radically mixed with other soil components. Organic matter makes the soil porous and increases the percolation, aeration and absorption of water, therefore, organic matter is a pool of nutrients and oxygen that is essential for plant growth. d) Soil organisms-Soil microorganisms are mainly responsible for decomposition of organic material and making it available to the plants. The large soil organisms are responsible for significant mixing and weathering of soil. Nitrogen fixing organisms are directly responsible for soil fertility, improving soil structure, aggregate stability, and fertility, and as whole affect the soil environment and the plant growth. e) Soil water-It is essential in order to meet the water requirements of plants. Soil water also acts as solvent through which necessary minerals and salts are absorbed by plants in dissolved state. It compensates the continuous loss of water from plant during transpiration. Both shortage and excess of water in soil are harmful for the plant growth. Precipitation (rain, snow & hail) is the ultimate source of water to soil but rain act as the principal source. f) Soil air-It mostly inhibits the pore spaces among the soil particles. Oxygen is required for the respiration of roots and other underground parts of the plants. Soil air is significant to the plants since seed germination and

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microbial activities within soil depend upon it. Many seeds will not germinate unless soil is aerated. It is also essential for the respiration of micro and macro organism of the soil that is important for decomposition of plants and animals thus improving the soil fertility. g) Soil temperature-The temperature is a factor of vital concern for plant growth. The amount of the heat that is absorbed into the soil is controlled by climate, altitude, aspect of the land, soil color and vegetation coverage. Plant growths as well as biological and chemical functions are greatly influenced by the soil temperature. Soil temperature also regulates the soil air to some extent. Functional activity of root decreases as the temperature change from an optimum degree. 5. Biotic factors Biotic factors determine the relations among plants, between plants and animals, and soil micro flora and fauna. In biotic factors, most important one is the effect of man on the plants. Trees are continuously influenced by other trees, crops, weeds, insects and man. They are seriously exposed to these factors at the seedling stages. Fungi, bacteria, virus, nematodes and other soil microbes act as main agents who alter the chemical and physical properties of soil, increase or decrease soil fertility, which has great influence on the growth of vegetation. Some soil microbes live in close association with plants, both benefiting from each other and mycorrhizas are the good example of such symbiosis. It has been noted that mycorrhiza also plays an essential role for successful growth of many plant species. Grazing animals disturb the plants by making the injury or by complete removal of species mainly at the seedlings stages. By trampling grazing animals harmfully influence the aeration of soil, rendering it compact and hard and finally making it unfit for plant growth. Mechanical, chemical and biological warfare and regular use of pesticides, herbicides and weedicides by man have also exhibited great role in the devastation of vegetation. Modifications made by fire are another biotic factor due to human activities if small areas are affected by surface fire the vegetation normally return to normal state though long and severe crown fire may destroy all plants and animals as well as soil humus and seeds.

4.4.2. Synecology Approach Synecology is called as the "ecology of communities". It deals with the study of communities; their compositions, behaviour and their relationship to the environment e.g. study of a forest in which Eucalyptus tree grows or grassland in which animals graze. A forest is a relatively stable and complete system of interacting biotic community and abiotic environment as its components. Synecology approach generally includes the discussion on following components (Kimmins 2004). 1. Nature of plant communities Plant community is the sum of total plants in an area growing on sand dunes, bare rocks, flats plains, or in water. Plant community is also referred as an aggregation of individuals with mutual relationships among themselves and environment.

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Mutual relationships in the individuals of community are comprised of all the direct or indirect effects that the organisms have upon each other, the most significant of which is competition. Based on the soil and environment, a forest consists of various kinds of plants i.e. huge tree, large shrub, small shrub and ground flora, etc. Existence of lower layer depends upon the shade of the trees above them, which make them to adapt as the undergrowth whereas if the plant has to survive for long time they have to adapt themselves in their habitat. Climate of an area determines the types of the plants that may survive there, thus vegetation types like grasslands or forest is a product of complex of climatic factors, consequently, climate of region can also be assessed from vegetation types. 2. Development of plant communities Development of plant communities in a barren area includes different stages like migration, ecesis, aggregation, competition, reaction and stabilization. a)

Migration: The bare areas which are free from the seeds or other propagules involves the migration of pioneers i.e. the movement of germules, seeds, and spores etc. from their original areas into new sites. The factors effecting the migration are dispersing agents, mobility, distance and topography. Plants may be classified based on their part distribution e.g. i-plant distributed, ii-spore distributed, iii-fruit distributed, iv-seed distributed, v-offshot distributed. Besides the dispersal mechanism of plants the possibility of migration also depends upon the dispersing means e.g. man, animals, water, and wind. b) Ecesis: The process of propagule growth and their adjustment in the new area is called ecesis. It involves three main phases i.e. germination, growth and reproduction. When seed does not germinate immediately after detaching from parent plant is said to be in dormant stage. This stage may prolong to a period of few weeks, months or even years. Suitable depth at which seed is sown is main condition for the successful germination. At seedling stage when the plant just started to live on its own it has to face very severe competition among themselves and with other species. If the ecesis has to be successful, seedling must grow, establish and reproduce in the neighboring habitats also. c) Aggregation: When the plants have established themselves in new habitat, they try to dominate the area by the same species and develop in the form of colonies is called as aggregation. Aggregation may be simple or mixed. Simple aggregation is the grouping and growing of seedlings around the parent plants. Mixed aggregation is the slow spreading and intermingling of the neighboring plants also with other species due to the process of migration. d) Competition: The simple and mixed aggregation leads to the competition. Competition always arises when two plants demand for nutrients, light or water more than the supply. It is the general charisma of the all plant communities. If the competition is within species, and make same demands upon the same supply at same time is called intraspecific

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e)

f)

competition. When the competition is between different species, it is called interspecific competition. A dominant plant does not compete with secondary dominant one, undershrub, herbs or ground flora because each layer and each species have different requirements of nutrients, water, light, space and with the passage of time each plant adjust itself to prevailing conditions. Reaction: When a plant community adjusted itself to a new habitat; it applies certain effects on its surroundings and nearby plants is called as reaction. Several reactions are the direct outcomes of the plants activities like decrease in water by absorption and increase of humidity due to transpiration. Death and decay of plants or plant organs leads to the integration of sufficient organic matter into the soil, therefore, changing the chemical and physical properties of soil. Stabilization: A series of progressive reactions produced by a series of plant communities in an area is called as succession. Each step of succession is known as sere. Reactions of each sere, generally produce conditions favorable to new invaders, which succeed the previous one and become the dominant, the new invaders with the passage of time produce a new reaction favorable to another community. Eventually times come when no reaction is possible and habitat cannot be reformed more. At this stage, a stable community comes into existence and become more or less balanced with the climate.

3. Mutualism and Symbiosis It is a relationship between two or more species, when both species get mutual benefits. Similar relations among species are also known as cooperation. Mutualism might be categorized in terms of closeness of association, the closest being symbiosis, that is often confused with mutualism. In the interaction, one or both species may be obligate, means they cannot survive in short or long term without the other species. In parasitism, the profits of the relationship only occur to one organism whereas other is spoiled. Competition has harmful influence on both companions, but there are also associations, which are helpful to both sides called mutualism. It may be a loose association or one in which both allies are completely dependent on each other. The word symbiosisis to define the latter state. There are some examples of mutualism and symbiosis such as relations between fungi or bacteria and higher plants that can be just a close relation. Leguminous plants mostly have root nodules with nitrogen fixing bacteria. There are several plantfungus relations i.e. mycorrhiza fungus survives either in root tissues or thoroughly cover it and sends fungal threads into soil. A nearly whole interdependence between two organisms may be present during pollination among plants and animals. The plants offer nectar to insects or birds that come to flowers and transfer the pollens from one flower to another. The relationship is commonly very close, that both pollinator and flower form distinct structures to select specific partners. For seed dispersal, numerous plants are again dependent on animals to which they provide food to appeal them. The seeds of fleshy fruits have a solid covering to protect them from the enzymes in the

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digestive system of animals whereas some seeds pass through animal guts to breakdown dormancy. Animal to animal mutual relationships are generally a bit looser than the examples considered so far. For example, cattle egrets accompany with cattle and get benefit by eating insects disturbed by cattle. The cattle will get help from the warning of the egrets when a predator approaches. Further birds eat ticks and other parasites from the skin of herbivores, from which the mutual assistance are clear. 4. Biodiversity Biodiversity is expressed as the degree of variations of life. It is the abundance and diversity of life form processes, functions, and structures of plants and animals and other living organisms in the ecosystem. Biologists mostly describe the biodiversity as the sum of all genes, species, and ecosystems in an area. It can discuss about genetic variations, species variations, and ecosystem variations in an area or biome. Therefore, biodiversity might be explained at the level of genes, species, communities, and ecosystems. Each biodiversity level has three parts: structural diversity, compositional diversity and functional diversity. The variations in habitats and species diversity are mostly used as indicators of health of ecosystems. Terrestrial biodiversity inclines to be maximum at low latitudes around equator that might be due to the effect of hot climate and high-level primary production. Young forests commonly have more number of individual species as compared to mature forests. However, old forests sustain some species, which cannot stay alive in younger forests due to more complex habitat requirements of species. The features of older forest contain decaying logs, trees, shrubs, and often a multilayered canopy that supports dwellers communities. Biodiversity need to be understood in the perspective of scale and level of biological associations. Generally, managing biodiversity at landscape level is most reasonable which is producing diversity of various habitats over a vast geographic area and offer the long-term ecological benefits. There are three traditional levels around which biodiversity has been documented i.e. genetic diversity, species diversity, and ecosystem diversity. a)

Species diversity is the effective number of various species, which are present in an assemblage of individuals. It involves two components, species evenness and species richness. Species richness refers to the simple count of species, while species evenness tells how equal the abundances of species are. Localized species richness at a particular place is called alpha diversity, but biotic community often changes in a traverse of the landscape and creating locally different habitats within a forest: beta diversity measures the extent of such change along a gradient. Gamma diversityis similar to alpha diversity but is a measure of species richness across a range of habitats within a larger geographical area, which may include forests and other types of vegetation. b) Ecosystem diversity is the diversity of an area at ecosystem level. This term varies from biodiversity as it discusses the variations in species rather than at ecosystem. Ecosystem diversity can also denote to the variability

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c)

of ecosystems present in biosphere, variety of species and ecological processes found in various physical settings. Genetic diversity is defined as the biodiversity level, which deals with total number of genetic features in the genetic makeup of a species. Genetic diversity helps the populations to adjust into the changing environments. With more variation, it is more likely that few members of population will have variations of alleles, which are suitable for environment. These individuals are more likely to live and produce offspring and population will continue for generations’ due to success of these individuals.

5. Distribution and Abundance Distribution of species means the range of conditions in which species exist; and abundance is number of species, which occur within that range, this is also population size. To describe distribution, we can start with all surviving species in world and ask ourselves why in any area we discover only a small number of them. There are many factors responsible for this. Geographical obstructions stop numerous species from reaching regions where they might be able to survive. This of course is associated to the dispersal way of the organism in question. Geographical separation is best understood on islands, but large rivers or mountains can act as barriers and isolated areas of a certain habitat in between other habitats can be viewed as islands too. In case of diseases, safety actions such as confinement are essential to prevent them from spreading into new areas. Only those organisms that are adjusted to the climatic conditions and for which all basic requirements are fulfilled can survive. However, a large number of them will not be present due to competition. It is exposed by the fact that in garden several plants that would not survive otherwise can be grown-up when weeding eradicates the competitors. Even among those species that can find a niche without serious competitors, certain will not survive in an area due of parasites and predators. The last two factors also affect the abundance of the species present. Roughly speaking the quantity of existing food controls the carrying capacity, the maximum number of organism that can occur. If the circumstances are positive, every population can develop speedily at a high growth rate. Generally, most of the young’s (or seeds for plants) will not survive and territorial performance inclines to control the numbers by keeping them at a balanced value. 6. Succession The series of ecosystem changes are also known as ecological succession. In analyzing forest communities, various patterns of plant growth arise; one of these is called as succession. It is rather predictable and often lengthy system in which one community replaces another ending at climax community that is self-perpetuating. There are two types of succession primary succession and secondary succession. Primary succession occurs in areas that are devoid of any life and secondary succession occurs where the living community has been partially or completely damaged. As succession in a community continues, it finally becomes a climax

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community. This community is ecologically stable except disturbed by some unusual events. All the animals and plants exist in specific environment to which they are specially adjusted. As the changes occur in environmental conditions, the species of plants and animals also reveal changes. The process through which communities of plants progressively change with the passage of time is termed as succession. The first stage of succession is bare land that may take several years to reach final climax stage. Once a forest is at climax stage, the process of succession starts to stop. At climax stage forest community is constant, comprising of trees, which only preserve themselves, and can sustain for several hundred years. To demonstrate the various stages of succession, firstly the changes start to appear following the abandonment of a cultivated area. The first plant species to grow in the field are grasses and weeds and are named as pioneer species. In next three to five years, several small trees can be found there. These tree species are hardy and are capable to survive with full sunlight and changes in weather condition. As trees settle in the area, they start to provide the shade to other vegetation. Pioneer weeds and grasses are not able to survive with extra shade and are gradually replaced with shadetolerant species of grasses and weeds. After 10 to 15 years, shrubs and young trees in the field converted into dominant species. At this stage, grasses and weeds have been excluded because of the reducing amounts of sunlight. Finally, individual trees develop well beyond the shrubs level, reach sexual maturity and produce seeds. Afterwards many years the cultivated field transformed into a green forestland. However, in nature, plant communities are continually changing. Long-lived hardwood species shade the forest floor and small changes are observable, as these species remained intact to make environment that satisfy their requirements. This forest field is now regarded as climax community and remains in this condition until a distressing force such as hurricane, human effects or fire causes the succession to start again. A forest ecosystem has much tolerance that involves the maximum and minimum environmental conditions compulsory for an organism to live. In this tolerance, various adaptations are established to support species, to contest positively and sustain in ecosystem. Though succession is considered as well-organized process but viewing at the overall ecosystem one may find several variations in this system. Changes in successional process come for a number of reasons i.e. microclimate, soil condition and disturbances. This variety of habitats can be found in several natural ecosystems (Figure 4.6). 7. Survival In forest ecosystem not all the tree seedlings that have regenerated and established themselves in an area essentially live, grow and reach maturity, several of them die during the process of development. The phenomenon in which many individuals that remained safe from death and reaches maturity is called survival. Foresters are highly concerned in the surviving individual’s tree seedlings because these set up our future final crop and profit. Surviving individuals of different populations follow the three basic schemes of survivals;

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a)

Less survival at early age (very high early mortality) and high survival at intermediate and late age. Usually trees adopt this process of growth.

Fig. 4.6 Showing the different stages of secession in forest ecosystem Source: Walter (2015)

b) Almost uniform rate of survival (nearly uniform rate of mortality) during the several growth stages. Marine organism generally follows this growth pattern. c) Very high survival in early and intermediate age (very low mortality) and low survival at advanced age. Human population in advanced countries adopt this pattern In nature, there are groupings of above any two or all three patterns for different populations. Species characteristics and environmental factors regulate the choice of survival pattern. As specified earlier, trees follow the first growth pattern. Therefore, all silvicultural and protective efforts should be focused on the initial years of forest seedlings in order to help the young seedlings and saplings. Once the saplings reach pole stage these are more or less completely safe from most different destructive agencies. Hazards and risk are commonly high only in initial years of growth. Ecological studies in this way may help in selecting suitable actions at proper time in order to promote or depress the particular population.

4.5.

Biomes of the World

4.5.1. Meaning of Biome Biomes are called "the world's major communities, classified based on dominant vegetation and described by the adaptation of organisms to specific environmental conditions. A biome is considered as the largest division of the biosphere. Biomes are explained by their biotic (living) and abiotic (non-living) components. The term biome is a short form of biological home. There is no unity between the scientists as far as the classification and definition of biome is concerned. Biome can also be described as a vast natural ecosystem where we analyze the total collection of animals and plants communities. All the biota has least common features and all the

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areas of biomes are defined with more or less similar environmental conditions. However, a biome contains both animals and plant communities but commonly known and named based on its dominant vegetation, that usually makes the maximum biomass (Pomeroy et al. 1988).

4.5.2. Factors Effecting Biomes Several factors influence the location, size, and character of biomes. Main factors are as follow • • • • • • • • •

Length of day light and darkness Length of growing season Mean temperature as well as differences in temperature Precipitation which consist of total amount, variations over intensity and time Wind flow which includes speed, duration, frequency and direction Slope Soil types Drainage Animal and plant species

4.5.3. Classification of Biomes An ultimate classification (Table 4.1) of biomes is 1) Terrestrial biomes (land) 2) Aquatic biomes (comprising marine biomes and freshwater biomes) There are two key bases of classifying biomes, which are discussed as below a. Based on climate with emphasis on moisture availability Biomes are classified by moisture availability to plants ranging from abundant (forest biome) to almost scarce (desert biome). However, in each biome, temperature differs much from low to high latitude and from low to high altitude. Therefore, there is a need to sub-divide each biome into further sub-types. But according to this grouping, there are four major types of biomes: i.

Forest biome

ii.

Savanna biome

iii. Grassland biome iv. Desert biome b. Based on climate and vegetation This classification describes a close relationship between the climatic types of the world and the world distributional patterns of plants and animals. As vegetation and climate have close relationship, the world is divided into several biomes types.

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Table 4.1: Classification of biomes based on climate and vegetation Biomes of first order (Based on climatic zones)

Biomes of second order (Based on vegetation)

Biomes of third order (Combination of climate and vegetation)

1. Tropical Biome

a. Tropical Forest Biome

i. Evergreen Rain-Forest Biome ii. Semi-evergreen Forest Biome iii. Deciduous Forest Biome iv. Semi-deciduous Forest Biome v. Montane Forest Biome vi. Swamp Forest Biome i. Savanna Forest Biome ii. Savanna Grassland Biome i. Dry and arid desert Biome ii. Semi-arid Biome i. North American Biome ii. Asiatic Biome iii. Mountain Forest Biome i. North American Biome ii. European Biome i. Soviet Steppe Biome ii. North-American Parries Biome iii. Pampa Biome i. Australian Grassland Biome ii. Southern Hemisphere Biome

b. Savanna Biome c. Desert Biome 2. Temperate Biome

a. Boreal Forest Biome (Taiga Forest Biome) b. Temperate Deciduous Forest Biome c. Temperate Grassland Biome d. The Mediterranean Biome e. Warm Temperate Biome

3. Tundra Biome

a. Arctic Tundra Biome b. Alpine Tundra Biome

4.5.4. Description of World’s Major Biomes Biomes are classified in various ways. Five major types of are discussed step wise as below (Whittaker 1975; Pomeroy et al. 1988). 1) 2) 3) 4) 5)

Aquatic Deserts Forests Grasslands Tundra

1. Aquatic Water is considered as mutual linkage among five biomes that form the major portion of biosphere and covering about 75% of the earth surface. Aquatic areas hold several species of animals and plants, consisting of both small and large types. With scarcity of water, maximum life forms would not be able to sustain themselves and earth would be an abandoned place. The aquatic biome can be categorized into two basic regions, marine and freshwater. a. Freshwater regions Freshwater is determined as having less salts contents, normally lower than 1%. Animals and plants in freshwater areas are settled to less salt concentration and would not be able to live in regions of high salts content. There are various kinds of freshwater regions e.g. ponds and lakes, streams and rivers, and wetlands. The characteristics of these three zones are described as below.

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Ponds and Lakes

These regions vary in size from just a few square meters to thousands of square kilometers. Several ponds are seasonal; remain active just for a couple of months however, lakes can occur for hundreds of years or even more. Ponds and lakes can have less diversity of species as they are often separated from one another and from other water sources like oceans and rivers. Temperature fluctuates in lakes and ponds seasonally. In summer season, temperature may vary from 4°C near bottom to 22°C at the top level. In winter, temperature at bottom can be 4°C whereas at the top is 0°C. In between the two layers, there is a narrow zone named thermocline where temperature of water fluctuates promptly. However, during spring and fall seasons, there is a mixing of top and bottom layers due to wind, which make the almost constant water temperature about 4°C. ii.

Streams and Rivers

They are water bodies, which are flowing in one side direction. Streams and rivers can exist universally, they originate from headwaters, which might be snowmelt, springs, or even lakes, and move all the way to their mouths, generally another water channels or ocean. The features of a stream or river vary during the flow from the source to mouth. The temperature is lower and water is clean, has more oxygen level at the source than at the mouth. In the mid area of stream or river the width increases and diversity of species increases, several algae and aquatic green plants can be located there. Towards the mouth of river or stream, the water converts to murky due to sedimentation; reducing the amount of oxygen, light and there is less floral diversity. iii. Wetlands Wetlands are defined as the regions of standing water, which support water plants. Swamps, bogs and marshes are all regarded as wetlands. Plants species adjusted to very humid and moist environments are called hydrophytes. These comprise cattails, pond lilies, tamarack, sedges, and black spruce. Wetlands are considered to have maximum species variety as compare to all the ecosystems. Numerous species of birds, reptiles, amphibians and furbearers can be found in wetlands. Wetlands are not regarded as freshwater ecosystems because there are certain salt marshes, which have high salts concentration; these support different species of grasses and animals. b. Marine regions Marine regions comprise of about three-fourths of earth’s surface and consist of coral reefs, estuaries and oceans. Algae from marine areas provide most of world’s oxygen and absorb a massive amount of carbon dioxide from the atmosphere. The loss of seawater by evaporation becomes the source of rainwater for the land. i.

Oceans

Oceans are considered as the biggest among all ecosystems and are huge bodies of water, which covers earth’s surface. Similar to ponds and lakes

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regions, the oceans are divided into different areas: pelagic, abyssal, intertidal, and benthic. These four areas have a vast variety of species. Several authors has describe that oceans comprises of the richest species diversity. ii.

Coral Reefs

They are extensively dispersed in shallow warm waters. Naturally, the major organisms existing in coral reefs areas are corals. Corals are attractive, as they comprise of both algae and tissues of animal polyp. Meanwhile water of reefs incline to be nutritionally poor; corals gain nutrients from algae through photosynthesis and by spreading tentacles to find planktons from water. Beside the corals, the fauna consists of numerous species of invertebrates, microorganisms, octopuses, sea urchins, sea stars and fishes. iii. Estuaries Estuaries are regions where freshwater from rivers or streams combine with the oceans. This intermixing of waters with various salt concentrations produces a very exciting and sole ecosystem. Micro flora such as algae, and macro flora, like seaweeds, marsh grasses, and mangrove trees, can be found there. Estuaries also support different types of fauna, comprising a variety of crabs, worms, waterfowls etc. 2. Deserts Deserts spread over one-fifth area of Earth’s surface and exist where rainfall is lower than 50 cm/year. Mostly deserts are found at low latitudes, such as Sahara of North Africa and deserts of southwestern U.S., Mexico, and Australia. Another type of deserts called cold deserts, exist in the basin and range area of Utah and Nevada and in the region of western Asia. All the deserts contain significant range of particular vegetation, along with specific vertebrate and invertebrate animals. Desert soils normally have ample nutrients, as they need simply water to convert into productive but contain no or less organic material. Hazards are frequent in the form of cold weather, unusual fires and rare but extreme rainfalls. Deserts normally offer little shelter to animals from the sun. Desert biomes can be categorized based on numerous features. There are four major kinds of deserts a) b) c) d)

Hot and Dry Semiarid Coastal Cold

a. Hot and dry desert The main four deserts of this category are found in North America, which are Chihuahuan, Sonoran, Mojave and Great Basin. From outside the U.S. consist of Neotropical (South and Central America), Southern Asian realm, Australian and Ethiopian (Africa). The seasons are mostly warm during the whole year and severe hot in summer. Temperature show daily extremes as atmosphere contains low humidity to stop sun’s rays. Mean annual temperature range from 20-25°C and extreme maximum ranges from 43.5-49°C. Minimum

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temperature occasionally fall up to -18°C. Rainfall is normally very less and occur in small bursts after long rainless phases. Soils are categorized as coursetextured, shallow, rocky or gravely with fair drainage and have no subsurface moisture. The particles of fine sand and dust are blown everywhere and accessibility of canopy is very scarce. Plants are mainly small woody trees and ground laying shrubs. Leaves are completely equipped with water saving features. They incline to be thick, small and coated with a thick layer of cuticle. The animals consist of small carnivores, arachnids, insects, birds and reptiles. They remain inactive in safe hideaways in hot day and come out to feed at dawn, dusk, or at night when desert is cooler. b. Semiarid desert The main deserts of this kind involve the Great Basin, sagebrush of Utah and Montana. They also consist of Nearctic realm (Newfoundland, Greenland, North America, Russia, northern Asia, and Europe). The summer seasons are moderately dry and long, like hot deserts whereas winters commonly carry poor rainfall. The average summer temperature usually range from 21-27°C and does not rise above 38°C whereas temperature in evening is cool at about 10°C. Besides, condensation of dew produced in night cooling may exceed or equal to rainfall received by some deserts. In hot deserts, rainfall is very low and average annual rainfall differs from 2-4 cm. The soil can vary from sandy and fine-textured to lose rock trashes, gravel or sand. In areas with sloppy mountains, soil is rocky, shallow or gravely with fair drainage. In each type, there is no availability of subsurface water. The spiny nature of numerous plants species in semiarid desert protects them from harsh situations. Mostly plants have glossy or silvery leaves, which help them to reflect more radiant energy. These plants also have an unpleasant taste or odor. Naturally, several animals protect themselves in underground burrows where they are isolated from aridity and heat. These animals comprise mammals like rats, rabbits, kangaroo, insects; such as grasshoppers, ants, reptiles; like snakes, lizards while birds such as burrowing owls. c. Coastal desert These deserts are found in moderately cool to warm regions similar to the Nearctic and Neotropical realm. Atacama of Chile is a good example of coastal desert. The winter of coastal deserts is cool followed by long and moderately warm summer. The average temperature in summer varies from 13-24°C; winter temperature is 5°C or below. The maximum annual temperature is about 35°C and the minimum is about -4°C. The maximum annual precipitation over a long period of years has been 37 cm with minimum 5 cm. The soil is categorized as fine-textured along with medium level salts concentration. Its normally have good drainage and porosity. Plants usually have extensive root systems near soil surface therefore; they take benefits of any rainfall. Mostly plants with fleshy and thick leaves or stems can absorb and store large quantities of water for further usage. Certain animals have specific adaptations to survive with desert heat and scarcity of water. Some toads close themselves in burrows with gelatinous secretions and stay inactive up to nine months until

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good rainfall occurs. Some insects lay eggs, which stay inactive until environment is appropriate for hatching. Other fauna comprises reptiles (lizards and snakes), insects, amphibians, birds (golden eagle, great horned owl and bald eagle), and mammals (coyote and badger). d. Cold desert Cold deserts are described by cold winter with snowfall and high rainfall during winter season and occasionally in summer season. They are found in Greenland, Antarctic and Nearctic realm. They are defined by moist, short and moderately warm summer along with long, cold winter. The mean summer temperature ranges from 21-26°C and winter temperature from -2 to 4°C. The mean annual precipitation varies from 15-26 cm and winter receives fair level of snow. The soil is heavy, salty and silty however, it comprises of alluvial fans with relatively porous and good drainage. The plant species are usually scattered and height may range from 15 cm to 122 cm. The mostly plants have spiny leaves and are deciduous. Commonly found animals are kangaroo rats, kangaroo mice, pocket mice, grasshopper mice, antelope ground squirrels and jackrabbits. All of them are burrowers except the jackrabbits. Some lizards also do the burrowing and moving of the soils. Deer’s are only found in the winter season. 3. Forests Today, forests cover about one-third of Earth’s surface, account for two-third of the leaf area of land plants, and hold almost 70% of carbon found in the living things. Forests are becoming the main losses of civilization because human population have increased from past several thousand years, and causing deforestation, pollution in this important biome. Presently forest biomes that are dominated by woody vegetation and trees can be categorized based on various features, with seasonality being most important. Different forest types are found within each of these broad groups. There are three main kinds of forests, classified based on the latitude a) Tropical b) Temperate c) Boreal forests (taiga) a. Tropical forests Tropical forests are described by highest diversity level of the species. They are found around the equator at latitudes 23.5°S and 23.5°N. Key feature of tropical forests is their distinctive seasonality: winter is lacking, and only two seasons exist (dry and rainy). Length of daylight is 12 h and fluctuates slightly. Temperature ranges from 20-25°C and change little during the year. Precipitation occurs uniformly round the year with annual rainfall; beyond 2000 mm. Soil is considered as acidic and nutrient deficient. Decomposition rate is fast and soil is subjected to high leaching. Canopy of tropical forests is continuous and multilayered, allowing the fewer light penetration. Trees are usually 25-35 m tall, along buttressed trunks, mostly evergreen with large

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leaves and shallow root system. In tropical forests, plants like orchids, bromeliads, vines (lianas), ferns, mosses, and palms are present. Fauna comprises of various bats, birds, small mammals, and insects. Unfortunately, more than half of tropical forests have already been damaged. More subdivisions of this category are described by seasonal rainfall distribution i.

Evergreen rainforest- without dry season

ii.

Seasonal rainforest- short dry period in wet tropical region (forest shows seasonal changes as trees undergo developmental changes simultaneously, but general character of vegetation remains same as in evergreen rainforest)

iii. Semi evergreen forest- long dry season (upper tree story comprises of deciduous trees, while lower story is still evergreen) iv. Moist/dry deciduous forest (monsoon)-the length of the dry season increases further as rainfall decreases (all trees are deciduous) b. Temperate forests Temperate forests are found in northeastern Asia, eastern North America, and western and central Europe. This biome is described by well-defined seasons with a distinct winter. Temperate forest are distinguished with moderate climate and growing season of 140-200 days during 4-6 frost-free months. Temperature can range from -30°C to 30°C. Precipitation (75-150 cm) is uniformly dispersed during the year. Soil is productive and developed with decaying material. Canopy of forests is moderately dense that permits the light to enter which promote the well-developed differentiated understory vegetation and faunal variety. Flora is described by 3-4 tree species per square kilometer and contains species such as oak, beech, hickory, hemlock, basswood, cottonwood, maple, elm, willow, and spring flowering herbs. Rabbits, skunks, squirrels, birds, deer, mountain lion, timber wolf, fox, bobcat, and black bear are characterizing fauna. Only isolated leftovers of original temperate forests have remained. Further division of this group is described by the distribution of seasonal rainfall i.

Moist conifer and evergreen broad leave forests-dry summers and wet winters (rainfall in winter and winter is relatively mild)

ii.

Dry conifer forests- less precipitation, at higher elevations

iii. Mediterranean forests- precipitation mostly in winter, less than 1000 mm per year iv. Temperate coniferous- mild winters with high annual precipitation, greater than 2000 mm v.

Temperate broad leaved rainforests- mild, frost-free winters, high precipitation more than 1500 mm and evenly distributed throughout the year

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c. Boreal forests or taiga Taiga or boreal forests are characterized as the biggest terrestrial biomes. They exist between 50 and 60°N latitude and located in broad belt of Eurasia and North America: two-thirds in Siberia with rest in Scandinavia, Canada and Alaska. Seasons are distributed into long, cold, dry winters and short, moist, and moderately warm summers. The duration of the growing season in boreal forests is almost 130 days. Temperature is very low and precipitation occurs mostly in snow form, 40-100 cm annually. Soil is thin, acidic and nutrientpoor. Light penetration through canopy is poor and consequently, understory vegetation is less. Flora contains mostly cold-tolerant evergreen conifers with needle shape leaves, such as fir, pine and spruce. Fauna comprise hawks, woodpeckers, moose, weasel, lynx, bear, wolf, fox, deer, hares, shrews, and bats. Present widespread logging in boreal forests can soon cause their vanishing from earth. 4. Grasslands Grasslands are categorized as the lands that are dominated by grasses rather than large trees or shrubs. In Miocene and Pliocene Epochs, which cover a period of about 25 million years, mountains rose in western North America and produce a continental climate suitable for grasslands. Prehistoric forests have deteriorated and grasslands became common. After the Pleistocene Ice Ages, grasslands stretched out in range as hotter and drier climate prevailed globally. There are two major types of grasslands: a) Tropical grasslands (Savannas) b) Temperate grasslands a. Savanna Savannas are defined as grasslands with dotted individual trees. Savannas of one type or another occupy nearly half surface of Africa and large area of Australia, India and South America. Savannas are occurring in warm climate where annual rainfall ranges from 50.8 to 127 cm per year. Rainfalls occur in six or eight months of the year, followed by long drought periods when fire chances are higher. Savannas, which are formed by climatic conditions, are called climatic savannas. However, savannas, which are made by soil conditions and are not wholly maintained by fire, are referred as edaphic savannas. A third type of savanna, known as derived savanna, is formed because of peoples clearing forestlands for cultivation purposes. The soil of savannas is porous, with speedy drainage and has only a thin layer of humus that provides nutrients to vegetation. The major vegetation comprises of forbs and grasses. Different types of savannas sustain different grasses because of differences in soil and rainfall; normally few types of grasses are more successful than others in a specific area. Savannas are defined by both rainy and dry seasons. Seasonal fires play a key role in the savanna’s biodiversity. A fire is a feast for several animals, such as birds, which come to

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fire sites to eat stick insects, beetles, grasshoppers, mice, and lizards that are driven out by fires. Though dry leaves and stems of grasses are burned by fire, the grasses deep roots remain undamaged. These roots with reserves starch are ready to produce new growth when soil becomes moisten. The dispersed shrubs also survive on food reserves in their roots, however; they wait time to grow above soil. Different from grasses and shrubs, trees survive fire by holding some moisture in their aboveground parts throughout dry season. When the rainfall occurs, the savannas experience a new life at this time. Animals consist of zebras, buffaloes, giraffes, kangaroos, mice, ground squirrels, moles, snakes, beetles, termites, leopards, hyenas, lions etc. There are also some environmental issues concerning the savannas such as overgrazing, poaching, and clearing of the land for cultivation of crops. b. Temperate Grassland Temperate grasslands is defined by having grasses as the dominant species and usually large shrubs and trees are absent. Temperature fluctuates more from summer to winter season and rainfall is low in temperate grasslands as compared to savannas. The main examples are the puszta of Hungary, veldts of South Africa, pampas of Argentina and Uruguay, steppes of former Soviet Union, and prairies of central North America. Temperate grasslands have cold winter and hot summer. Rainfall is moderate and amount of annual rainfall affects the height of vegetation, with tall grasses in wet areas. The soil condition of temperate grasslands is dark and deep with productive upper layer. Numerous species of grasses grows best in a specific grassland environment. The erratic fires, periodic droughts, and grazing by large mammals all stop the woody trees and shrubs from becoming established. However, scarce trees and few non-woody species, also rise among grasses. Precipitation in temperate grasslands commonly happens in early summer and late spring however average annual rainfall is around 50.8 to 88.9 cm. The temperature varies throughout the year and summer temperature can be high over 38°C whereas winter temperatures can be low as -40°C. The fauna consists of zebras, gazelles, rhinoceroses, lions, wolves, wild horses, prairie dogs, mice, coyotes, deer, foxes, badgers, grouses, blackbirds, meadowlarks, quails, sparrows, owls, hawks, snakes, spiders and grasshoppers. There are some environmental issues concerning with temperate grasslands. Few natural prairie areas have remained, mostly have been converted into grazing lands or farms as they are treeless, flat, covered with grass, and have rich soil. Temperate grasslands can be further subdivided. Prairies are grasslands with tall grasses whereas steppes are grasslands with short grasses. Prairie and steppes are similar however, information specified above relates to prairies. Steppes are dry area of grasslands with cold winter and hot summer. Steppes are found in the interior of Europe and North America.

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5. Tundra Tundra is defined as the coldest among all the biomes. It is distinguished for its frost-molded landscape, little precipitation, very low temperature, simple vegetation structure, short growing season and poor nutrients. Dead organic matter acts as a source of nutrients pool. The two main nutrients are phosphorus and nitrogen however, phosphorus is made by precipitation and nitrogen is produced by biological fixation. Tundra is divided into two types: a) Arctic tundra b) Alpine tundra a. Arctic tundra Arctic tundra occurs in northern hemisphere, surrounding North Pole and extending south to the coniferous forests of taiga. The arctic is famous by its cold, desert-like environment where growth period varies from 50 to 60 days. The average winter temperature is -34°C but average summer temperature is 312°C that allows this biome to sustain life. Rainfall can vary in different areas of arctic. A sheet of permanently frozen subsoil named permafrost occurs, comprising of gravel and finer material. There is no deep root system in vegetation of arctic tundra; though, there is diversity of plants, which can withstand cold climate. There are about 1,700 types of plants in arctic and subarctic that includes low shrubs, sedges, liverworts, mosses, and grasses. Plants are usually short and group together to stand with snow and cold temperature during the winter. The artic fauna is very diverse: Herbivorous mammals consist of caribou, voles, lemmings, squirrels and arctic hares. Carnivorous mammals are arctic wolves, foxes, and polar bears. Migratory birds include falcons, sandpipers, ravens, terns, Snowbirds, and gulls. Insects are flies, moths, mosquitoes, and grasshoppers. Fishes include flatfish, cod, trout and salmon. Animals are modified to live in long, cold winter and to breed their young ones quickly in summer. Several animals hibernate in winter due to food deficiency; they also travel to south in winter, as birds do. Amphibians and reptiles are few because of extremely cold temperature. Due of continuous immigration and emigration the population in arctic tundra frequently fluctuates. b. Alpine tundra Alpine tundra comprises mountains all over the world at high altitude where trees cannot grow. The growth season is only for almost 180 days. The temperature at night is generally below freezing point. The soil in alpine tundra is well drained. The plants are like to those of arctic ones and include dwarf trees, tussock grasses, small-leafed shrubs, and heaths. Animals in alpine tundra are also well adjusted for example Mammals were mountain goats, sheep, elk, Birds consisted grouse like birds, Insects included beetles, grasshoppers, butterflies, etc.

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4.5.5. The Importance and Conservation of Biomes Over the past few decades, the increasing human actions have quickly damaged several ecological habitats in entire world. It is essential to conserve all kinds of biomes, as each comprises several distinctive forms of life (fauna and flora). However, the constant heavy misuse of certain biomes, such as forest and aquatic biomes may have consequences that are more critical. Forests are very significant because they are homes of maximum diverse biotic communities of the biosphere. Within these biomes, there exist potential medicinal and several thousands of undiscovered and unseen species of plants and animals. In addition, forests have a universal climate-buffering capacity, so their damage may lead large-scale changes in worldwide climate. The day-by-day increased demand for homes, industry, paper, and other wood products have hindered the conservation process. More recently, peoples have started to understand that logging has devastated much of the forests in the whole world. Judicious use of forests and struggles to regrow trees has assisted to slow down depletion process of these plant populations. From few years, this forests destruction has been occurring at an alarming rate. Public awareness to this misuse has aided to lessen the problem somewhat; however, numerous challenges are still to be faced. Aquatic biomes are also very significant, they support life, and numerous species live in it for all or part of their lives. Freshwater biomes are source of water for drinking and for crop irrigation purposes. The world’s oceans have even more influence on the global climate than forests. Pollution and overfishing have threatened to make the oceans into ecologically damaged regions. By educating peoples about the results of human activities, we can all gain a good understanding to preserve the earth’s natural biomes. Unfortunately, the zones, which have been damaged the most, will never recover their original forms, but protection and management will support to keep them from becoming worsen (Olson et al. 2001).

4.6.

Conclusion

The ecosystem approach describes the ecological understanding of resources for long-term sustainability of ecosystem and provision of important ecosystem services to the society. Forest ecosystems are directly influenced by the actions like land conversion, resource harvest and indirectly impacted by human induced changes in atmosphere, soil and hydrology. Since human actions intensely affect the earth ecosystems, it is required that we should also take the responsibility for their protection and conservation. An essential component of that responsibility must be to decrease the rate and extent of global changes in biotic and abiotic components. Recent development must be consisting of an increased ability to handle the environmental and natural limiting factors. This increased power to control should be accompanied by a better sense of responsibility for the forests conservation. The understanding of ecology is extremely interdisciplinary, based on many aspects like hydrology, climatology, ecology, and geology that contribute efforts to conserve earth forests. Ecosystem ecology states interactions among organisms and their environment as an integrated system, which control the pools and fluxes of energy and materials through ecological system. From last few years,

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it has become increasingly clear to the world's population, that conservation of floral diversity in a broader sense is compulsory. Several plants species that have not been used for any purpose but can become important sources of food or medicine, if analysis is carried out. However, the destruction of forest ecosystems on a universal scale is such that several species will wipe out before they have been investigated scientifically. Forest ecosystems have to necessarily conserve the diversity in nature. Maintaining forests is necessary to regulate the water flow of whole earth system. Dynamic management of all forest ecosystems is compulsory to maintain ecosystems functions in response of anthropogenic changes and to sustain the provision of goods and services that humans receive. Ecosystem management confesses the impact of our inability to forecast future circumstances with certainty. The basic principle behind ecosystem management is that peoples are vital components of regional systems and planning for sustainable future need solutions, which are economically, ecologically and culturally justifiable. Maintaining the forest ecosystems diversity in nature is of prime importance. We are however at beginning stage to understand the consequences of these forest ecosystem changes. Mostly peoples get benefits from common natural resources such as forests and grazing lands but no one cares to look after them. For several human activities, there are always short-term benefits to few peoples, whereas there is a long-term cost to the environment and consequently to the community at large. Alas, there is only one earth, therefore we should be very cautious not to destroy its natural resources (Anonymous 2010, 2012).

References Andrewartha, H. G. (1961). Introduction to the Study of Animal Populations. Univ. Of Charles Darwin reformierte Descendenz-Theorie. 2 vols. Reimer, Berlin. Chicago Press, Chicago. pp. 281. Anonymous (2010). Global Forest Resources Assessment 2010. Main report. FAO Forestry Paper 163. FAO, Rome. pp. 378. Anonymous (2012). State of the World´s Forests 2012. Food and Agriculture Organization of the United Nations (FAO), Rome. pp. 60. Buchsbaum, R., and M. Buschbaum (1972). Basic Ecology. Boxwood Press. Pacific Grove, CA. Gurevitch, J., S.M. Scheiner and G.A. Fox (2006). The Ecology of Plants. 2nd Edition, Sinauer Associates, Sunderland, USA. Kemp W.M. (1992). The ecosystem approach: Its use and abuse. In: Likens G.E. Edition, Excellence in Ecology, Vol. 3, Ecology Institute, Oldendorf/Luhe, Germany. pp. 166. Kimmins, J.P. (2004). Forest Ecology: a foundation for sustainable forest management and environmental ethics in forestry. 3rd Edition, Prentice Hall, Upper Saddle River, NJ, USA. Kulhavý, J., S. Josef, M. Ladislav (2014). Forest Ecology. Mendel University in Brno. Brno, Czech Republic. Odum, E.P. and G.W. Barrett (2005). Fundamentals of Ecology. Brooks/Cole. Belmont, CA. USA. pp. 598.

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Odum E. and G. W. Barrett (2004). Fundamentals of Ecology. 5th Cengage Learning. Boston, Massachusetts, USA. pp. 624.

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Edition,

Odum, E.P (1971). Fundamentals of Ecology. 3rd Edition, W. B. Saunders Co., Philadelphia. USA. pp. 574. Olson, D.M. (2001). Terrestrial ecoregions of the world: A new map of life on Earth. BioSci. 51:933–938. Perry, D.A, R.A. Oren, and S.C. Hart (2008). Forest Ecosystems. 2nd Edition, Johns Hopkins University Press. Baltimore, USA. Pomeroy, L.R. and J.A. James (1988). Concepts of Ecosystem Ecology. SpringerVerlag, New York, USA. Schulze, E., E. Beck and K.M. Hohenstein (2005). Plant Ecology. Springer, Berlin, Germany. Seymour, R.S. and M.L. Hunter (1999). Principles of ecological forestry. In: Hunter, M.L. (ed). Managing Biodiversity in Forest Ecosystems. Cambridge University Press. UK. pp. 22-62. Smith, T.M. and R.L. Smith (2012). Elements of Ecology. 8th Edition, Benjamin Cummings, Boston, USA. Tansley, A.G. (1935). The use and abuse of vegetational terms and concepts. Ecology 16 (3): 284–307. Thomas, P.A. and J.R. Packham (2007). Ecology of Woodlands and Forests: Description, Dynamics and Diversity. Cambridge University Press. UK. Walter, T. (2015). Introduction to geography. http://www.geo.hunter.cuny.edu/tbw/ncc/Notes/chap4.wc/vegetation /plant.succession.jpg. Accessed on 27 July 2017. Waring, R.H. and S.W. Running (1996). Forest ecosystems: analysis at multiple scales. 3rd Edition, Elsevier Academic Press, Amsterdam, Netherlands. Warming, E. (1895). Plantesamfund - Grundtræk af den økologiske Plantegeografi. P.G. Philipsens Forlag, Kjøbenhavn. pp. 3-6. Whittaker, R.H. (1975). Communities and Ecosystems. MacMillan Publishing Company, New York, USA.

Chapter 5

Raising of Forest Nursery M. Asif, M.T. Siddiqui and S.H. Dogar*

Abstract Natural regeneration is a very slow process and can be assisted and/or promoted through artificial regeneration. Nursery plays a key role in the success of afforestation and artificial regeneration of forests. Healthy seedlings of nursery can only lead to dense forest with desired features. Objectives of nursery raising can be either the introduction of exotic species or promotion of threatened native species in an area. For some tree species, nursery raising is essential due to their slow growth and severe competition. Afforestation of problematic and marginal lands is impossible without nursery raised seedlings. There are several types of nurseries depending upon type of planting material, size and irrigation. Before establishing a nursery, suitable type should be selected depending upon our objectives. Suitable site selection with ample supply of water is a determinant factor in the successful establishment of nursery. Care should be provided to nursery plants to protect them from diseases and pests. Key words: Nursery; Tools; Trees; Seedlings; Forests.

* M. Asif˧ and M.T. Siddiqui Department of Forestry and Range Management, University of Agriculture, Faisalabad, ˧ Corresponding author’s e-mail: [email protected]

S.H. Dogar Department of Forestry, Wildlife and Fisheries, Government of Punjab, Pakistan. Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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5.1.

Introduction

Nursery is a place where seedlings, cuttings and grafts are raised with care before transplanting (BCFT 1953). It comprises of nursery beds, paths irrigated channels etc. To make afforestation/reforestation successful a well stocked and managed nursery is a prerequisite. Besides all the other biotic and a biotic factors the principle failures reasons can be traced back through these poorly managed nurseries. Ultimately, the planting material produced in these nurseries is not up to the mark and due this reason although millions of plants are planted of the whole, the percentage of survival and success is not satisfactory (Sheikh 2003). Therefore, it is of great importance that maximum attention must be paid to raise nurseries on scientific basis.

5.2.

Objectives of Nursery

Establishment of forest has got an important place in artificial regeneration (Chaudhry 1994). Following are important objectives for which a forest nursery is generally made: 1) Some important species do not produce seed every year. So, the plantations of these species can be raised only by sowing all available seeds in the nursery to prepare seedlings to be planted out each year. 2) Some species have slow growth rate and if the seeds of these species are sown directly/naturally, the seedlings are most likely to be suppressed by weeds and ultimately killed. Therefore, slow growing species are generally raised in nursery and ultimately after attaining desirable plant height, planted elsewhere. 3) Success of linear plantations heavily depends on planting healthy, tall and sturdy plants which can be obtained only from nursery. 4) For some species, raising tree plantations by direct sowing are not so successful when raised by transplanting their seedlings. In such cases, nursery is an essential part of artificial regeneration. 5) To introduce exotic species raising nursery is the best option 6) Planting of nursery grown plants is the best method of artificial regeneration on problematic sites. 7) Failure of plantations have to be replaced either for the year of planting or during the next year. Sowing done in the patches/gaps is liable to be unsuccessful because of suppression from weeds and cannot catch up the growth as from, original sowing. Therefore, replacement of causalities is always done by planting nursery grown plants or stumps.

5.3.

Types of Forest Nursery

The nurseries may be of several types (Figure 5.1). Some important types of nurseries found in Pakistan are as under:

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5.3.1. Based on Use (Time Span) On the basis of use or time span, nurseries can be further divided into: •

Temporary Nursery

•

Permanent Nursery

Temporary Nursery These are the nurseries which are raised to supply planting stock for a shorter period of time, normally near to the area to be regenerated. These nurseries don’t have the permanent infrastructure. Salient Features: These nurseries are established near to the regeneration areas These are maintained for only a shorter period of time These are normally smaller in size and extent Generally maintained for only few species No permanent infra structure is developed Less capital is required for these nurseries. TemporaryNursery

Permanent Nursery

Fig. 5.1 Nurseries division on the base of time span

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Permanent Nursery These are the nurseries which are established to supply planting stock for a longer period of time with development of permanent infrastructure. Salient Features These nurseries are established/run for a considerable period of time These are normally large in size and extent Maintained for a large number of tree species Permanent infra structure is developed

5.3.2. Large no of Labor is Engaged for a Longer Period of Time, etc. based on Nature of Use On the basis of nature of beds, nurseries can be further divided into: •

Seedling Nursery

•

Transplant Nursery

Seedling Nursery It is the nursery in which seedlings are raised and hence no transplanting is done (Figure 5.2). In these seedlings are raised directly at final destination and hence there is no need to transplant them elsewhere. Time and cost effective nurseries. Normally raised by consumers themselves Transplant Nursery It is the nursery in which seedlings are transplanted in preparation for afforestation of an area. Sometimes these are also called pricking out beds. Seedling Nursery

Transplant Nursery

Fig. 5.2 Nurseries division on the base of use. In these nurseries seedlings are raised purely to be transplanted elsewhere. Seedlings can be raised in pots or in beds

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These can be permanent or temporary in nature

5.3.3. Based on Irrigation On the basis of irrigation (Figure 5.3), nurseries can be further divided into: •

Dry Nursery

•

Wet Nursery

Dry Nursery It is the nursery which is managed without any artificial means of irrigation water. Salient Features These are established in rain fed areas. No proper lay out is carried out for irrigation. These are normally temporary in nature Wet Nursery It is the nursery which is managed by the artificial means of irrigation water during dry spells. These nurseries can be established in any suitable area with proper availability of irrigation water. Proper irrigation plan is laid out with the development of permanent infrastructure in these nurseries. These are the nurseries found normally throughout the world. These are permanent in nature but can be temporary. Dry Nursery

Wet Nursery

Fig. 5.3 Nurseries division on the base of irrigation.

5.3.4. Based on Type of Planting Material On the basis of planting material (Figure 5.4) nurseries can be further divided into: •

Bed Nursery

•

Potted/Polythene bag Nursery

•

Bed Nursery

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There are two types of bed nursery which are: •

Raised bed nursery This type of nursery is established when large number of plants are required (about ten thousand).

•

Trench-berm nursery This type of nursery is established in irrigated plantations for providing planting stock in Government forests and to provide people and raised on any number of acres. e.g Shisham, Siris etc.

•

Potted/Polythene bag Nursery In this type of nursery, the planting material is raised in pots or in polythene bags of various sizes. e.g., Kikar, Eucalyptus

Before taking up the task of a nursery establishment some important considerations must be taken into account. Following are the few important points: Bed Nursery

P-Bag Nursery

Fig. 5.4 Nurseries division on type of planting material.

5.4.

Establishment of Forest Nursery

5.4.1. Prior Considerations Before taking up the task of a nursery establishment some important considerations must be considered. Following are the few important points: Estimates of Nursery operations and Cost •

Cost of site clearance

•

Demarcation of the nursery area

•

After demarcation fencing of the nursery area and leveling

•

Basic tools/implements required to carry out various operations

•

Preparation of soil mixture

•

Collection of seed

•

Raising of nursery

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Sowing and planting operations

•

Use of the latest technology available

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Basic Requirements To execute various nursery operations as mentioned above following basic requirements must be given due consideration: •

It is always recommended to have the exact estimates, availability of labor and expenditure to be incurred to carry out various nursery operations right from the start to the sale of product for the successful nursery business

•

It is recommended to have exact idea of basic planting material production in terms of its compatibility and number according to the selected site

5.4.2. Establishing Nursery There are numerous factors which are to be considered while establishing the forest nursery (Duryea and Landis 1984). Some of the important factors are as under: 1) Site selection: Selection of suitable site is a basic requirement for establishing the good nursery. Site should easily accessible for carriage of planting material and irrigation supply should be available as well. Moreover, the area of nursery depends upon: •

Species to be grown

•

Quantity of stock

•

Availability of labor

2) Fencing the Nursery: This practice normally depends upon the type of nursery. For example, cattle and game proof fences along with live fences are used in permanent nurseries. This is on one of the most important practice to protect nursery plant from biological pests. 3) Layout of Nursery: This is one of the most important steps as far as forest nursery establishment is concerned. For this following key points are taken into account: •

Provision of Irrigation water

•

Paths are to be carved

•

Provision of a store

4) Preparation of Beds: Following operations are done for the preparation of beds: •

Proper size of the beds must be decided according to the area available.

•

Type of beds must be decided, depending upon the conditions of the site/area, species to be grown and type of the nursery.

•

Preparation of soil in terms of digging up to proper depth, removal of pebbles/stones, roots and other wastes etc.

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5) Miscellaneous Operations: Other operations include: •

Collected seeds must be healthy and sufficient to raise the required amount of planting stock.

•

Timely sowing of seeds in nursery beds/pots.

•

Protective measures must be taken at proper time (including weeding, hoeing, pricking, root pruning, shifting, shading, use of pesticides against biological pest and hardening of planting stock before transplanting etc.)

•

Proper irrigation at proper time

•

Maintaining the fertility of nursery soils

5.5.

Equipments Used in Nursery

Sr. Tool 1 Rose Can/Water Can

Uses Diagram This is used for watering the nursery. Fine spray of water should be used for watering nursery of small sized seeds

2

Digging Fork

This has prongs of 20 cm long fitted to a wooden handle. This is used for uprooting plants, rooted cuttings, harvesting of tubers etc., without damaging the root system or tubers.

3

Spade

A long wooden handled tool used for digging, shoveling soil, compost and other materials etc.

4

Dibbler

This is wooden or metallic implement used to make planting holes.

M. Asif, M.T. Siddiqui and S.H. Dogar Sr. Tool 5 Lopper

Uses Diagram A tool used to cut small branches of trees.

6

Shovel

This is a curved steel plate attached to a wooden handle and used for transferring soil, manure etc.

7

Garden Rake

This is used for leveling lands and collecting weeds. The rake consists of a number of nail like projections from a crow bar provided with long handle

8

Hand Trowel

This is used for making holes for planting seedlings and small plants. This is also useful for removing surface weeds in nursery beds.

9

Secateur

This is used for cutting small shoots to regulate shoot growth in fruit trees/forest trees.

10 Budding or Grafting knife

This knife is used for budding and grafting. This has two blades in which one is with ivory edge used for lifting the bark in budding operation. For sifting the soil to be used for the filling of polythene bags etc.

11 Sieve

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Sr. Tool 12 Water Pipe

Uses Diagram For the irrigation of polythene bags and other plants

13 Wheel Barrow

Used for the transport of soil, filled pots, tool and seedlings etc.

14 Germination Tray Used for germinating the small quantity of seed

5.6.

Important Nursery Diseases and their Control

5.6.1. Damping Off This disease is caused by soil-inhabiting fungi that are facultative parasites. Most of them cause damage in pines seedling belongs to genera Pythium, Rhizoctonia and Fusarium. Sowing in summer with abundant soil moisture and alkaline in nature helps to favors this disease. Symptoms: Damping off is characterized by early decay and death of seedlings with soft and succulent stem. Hyphae of the fungus spread through the soil and penetrate the tender epidermis of the succulent tissues of the plant stem (Figure 5.5). There are two types of this disease i.e. pre-emergence damping off and post emergence damping off. In pre emergence damping off, the seeds are decayed or killed by the damping off organisms before the emergence from soil. With the post emergence, the seedlings are attacked after they have appeared above ground/germination. The fungi spread rapidly in the tissue, especially, in the roots and the seedlings either wilt completely or suddenly fall over before wilting. A bed of seedlings may be completely wiped out within few days.

Pre-emergence Damping off Fig. 5.5 Damping off nursery plants.

Post-emergence Damping off

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Prevention and Control: Avoid heavy or excessive watering and keep seed beds well ventilated. The fungi caused damping off reproduce and spread fast under humid conditions. • • • • • •

Thinning of heavy plants should be made Plants should not be under complete shadow. Proper weeding of the nursery is essential. Proper drainage Avoid excessive use of nitrogen fertilizer Use of Bordeaux mixtures

5.6.2. Rodents and their Control Major rodents have been presented in the Figure 5.6 and describe below: 1) Porcupine: Porcupine causes serious damage to nursery and regeneration areas at night and lives in earthen holes (burrows). It damages almost all types of nurseries. Roots and bark of trees are the favorite food of this pest. Fumigation of burrows is normally done with Aluminum Phosphide or Fostoxin tablets at the rate of 5 tablets/burrow and it is plugged with grasses/thorny bushes and soil etc. 2) Field rats: These also cause damage to nursery and young plants. Nine types of field rats are found in Pakistan. These make serious damage to the roots of plants due to this plants health is affected and the chances of termite attack are increased to many folds as well. Field rats are controlled by using the fumigation of burrows with Aluminum Phosphide tablets at the rate of 1 tablet/hole and then plugging this with soil and grasses etc. These pests are also controlled by baiting of various rodenticides. For more effective results, the tablets must be rolled in piece of cloth, then dip in water before putting it into the burrow. 3) Termite: Termite normally attack on young plants but this also can damage the seedling in the nursery as well. Chloropyrifos is commonly used at the ratio of one liter/acre, through flood irrigation by mixing this pesticide in water, drop by drop at the inlet of water. 4) Defoliator: Defoliators usually attack nursery seedlings as well as regeneration areas and causes serious damage to the plants. Organophosphate spray is normally used to control this pest. The doze of 0.5 liter/acre with the ratio of 1:160 is used in water as spray.

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5) Parcupine

Field Rat

Termite

Defoliator

Fig. 5.6 Some pests of nursery plants.

5.7.

Nursery Record

To adopt nursery profession and run this business successfully, the record regarding nursery raising must be maintained on scientific basis. Following is the basic information to be recorded to raise the nursery: Name of the Nursery 1 Name of Forest Guard (managing nursery) 2 Name of Forester 3 Total Area 4 Net used Area (for beds) 5 Net Area (for making paths etc) 6

No of coolies/Labour

7 8

Source of irrigation water Source of seed collected

Source: Modified from Hafeez (1996).

9

Date of sowing (Species wise)

10 No of beds for potted nursery 11 No. of raised beds Germination % (Species wise) 13 Total no of plants available for planting (Species wise) 14 Cost (Of various operations performed to establish a nursery, right from the start to the sale of planting stock)

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Distribution Record Record keeping regarding distribution of plants is as under: Name of the Nursery: Season: Name of Forest Guard: Date Species Rate

No of plants

Name and address of recipient

Purpose/Remarks

Source: Modified from Hafeez (1996)

5.8.

Important Information Regarding Nursery Raising

Sr.

Scientific name

1 3

Acacia nilotica Acacia modesta

Local name Time for seed availability Kikar December-January Phulai November-Jan

Acer oblongum

…..

Agave, various species

Keora

Aegle marmelos

Bael

Albizzia lebbek

Siris

Albizzia procera

Safed siris

Bouhenia variegata

Kachnar

Bischoffia javanica

Bishop wood

Bombax ceiba

Simal

Broussonetia papyrifera Butea frondosa Capparis aphylla

Paper mulberry Dhak Karir

How to grow

Direct sowing after hot water treatment Soak the seed for 12-24 hours in cold water and sow direct on site November-Jan Raise plants in pots and transplant when about 1 foot high Poles usually in hot Transplant root suckers or remove tiny water bulbils from poles, plant them on ridged nursery beds and finally transplant when seedlings are over 1 foot high May-June Sow seeds in pots and transplant 2 years old plants. Use seeds from the fruit collected off the tree Dec-Jan Direct sowing on ridged beds or along berms of trenches Feb-May Direct sowing on ridged beds or along berms of trenches May-June Direct sowing as well as transplanting. Use fresh seeds. Transplant in 2nd year. Weeding essential Dec-Jan Sow seed in March inboxes or nursery beds using porous soil. Transplant in July-Aug April-May Direct sowing along berm of trenches. Avoid stiff clay or shallow rocky soil. June-Aug Direct sowing

May-June April-May

Use fresh seed for direct sowing Direct sowing soak the fruit in cold water for 12 hours prior to sowing

118 Sr.

Raising of Forest Nursery Scientific name

Local name Time for seed availability Amaltas April-May

How to grow

Sohanjna

May-June

Morus alba

Tut

May

Parkinsonia aculeata Pistacia integrrima Platanus orientalis Pongamia glabra

…..

June-July

Kangar

June-Oct

Chinar

Nov-Dec

…..

April-May

Prosopis cineraria

Jand

May-June

By direct sowing, transplanting and propagation from cuttings Easily propagated either by direct seeding or by root or shoot cutting Transplant one year old seedlings raised through seed Transplant one year old plants raised through seed From branching cutting as well as from seed Easily raised from seed or by cutting as well, transplant after one year By direct sowing or transplanting one year old stock. Break the pods and soak in cold water before sowing By direct sowing or transplanting one year old stock. Break the pods and soak in cold water before sowing

Cassia fistula

Casuarina equisetifolia Cedrela toona

Celtis australis

Dalbergia sissoo Dodonea viscosa Eucalyptus camaldulesis Syzygium cumini

Ficus benghalensis Ficus infectoria Ficus religiosa

Gliditschia triacanthos Gmelina arborea Mangifera indica

Melia azedarach Millingtonia hortensis Moringa oleifera

By transplanting 3 months to one year old plants. Weeding required. Poor germination, Use fresh seeds. Beef wood June and December Use fresh seed for direct sowing , to grow seedlings Toon May-June Transplant one year old seedlings raised from seed and can be raised through cutting as well. Khirk June-Sep Sow seeds in the nursery in Feb-March and transplant in the following rainy season Tali Dec-Jan By direct sowing as well as stumpplanting, preferably the later Sanatha May-June Direct sowing Sufeda Aug-Sep Use 1 foot high seedling raised from direct sowing Jamon July Direct sowing, regular watering, weeding and some side shade required in early stages Bohar Dec-Jan and April- Transplant seedlings raised in pots or May plant large cuttings 6-8 feet long with buds. Palakh Dec-Jan and April- Use 1 foot high seedling raised from May direct sowing Pipal April-May Raise stock through seed in pots or boxes in ordinary garden soil and transplant 1-2 feet high seedling Dozakh Winter months Transplant one year old seedlings, raised through seed Kumhar June Easily raised both by direct sowing or by transplanting one year old seedlings Aam July Easily raised from seed either by sowing on site or transplanting nursery raised grafted plants Bakain Winter months Direct sowing or transplanting of 6 months – 1 year old plant Walaiti nim Summer By planting root suckers

Prosopis juliflora Mesquite

May-June

M. Asif, M.T. Siddiqui and S.H. Dogar Sr.

Scientific name Putranjiva roxburghii

Salix babylonica

Local name Time for seed availability Putanjan Jan-Feb

Majnun

Mau-June

Salix tetrasperma Laila

Winter months

Sapium sebiferum Makhan

Nov-Jan

Schinus molle

Kali mirch

Hot weather

Sterculia diversifolia Tamarix aphlla

…..

Aug-Sep

Farash

August

Tamarix dioica

Pilchi

Aug-Sep

Terminalia arjuna Arjan

April-May

Thevetia neriifolia Peeli Kaner October Zizyphus Ber Winter months mauritiana

Bauhinia , various species Crataeva religiosa Dendrocalamus striclus

Kachnar etc. Barna

Dec-March

Bans

June

Erythrina suberosa Ficus glomerata

…..

June-July

Gular

April-June

Ficus palmata

Phagwara

May-Oct

Mallotus philippinensis Phyllanthus emblica Punica granatum Sapinus mukorossi Terminalia belerica

Kamila

March-May

Amla

Winter months

Anar Ritha

July-Oct Oct-Jan

Bahera

Nove-Feb

Acer caesium

Mandar

July-Oct

Acer pictum

Mandar

July-Oct

June

119 How to grow Sow fruit stones in nursery in april. Keep the beds well watered and weeded. Transplant in next rainy season Easily raised from seeds and cutting. Use 3-4 feet long cutting Easily raised from seeds and cutting. Use 3-4 feet long cutting By direct sowing, by transplanting or by cutting By direct sowing , Transplant one year old seedlings By direct sowing, Transplant 2-3 years old plants Propagated from cuttings. Transplant in 2nd year Propagated from cuttings. Transplant in 2nd year By direct sowing after formal treatment, Transplant 6-12 month old plants before the tap root become too long Direct sowing of seed or by cutting. By direct sowing after formal treatment or transplanting one year old plants. Cultivated varieties are propagated by grafting on the wild stock Direct sowing or transplant. Soil loosening and weeding is helpful Raised by seed, Transplant 1-2 year old plants Sow seed under shades and transplant 2-3 year old plants leaving only 9-12 inches above collar Branch cutting Raised by seed, Transplant one year old plants Raised by seed, and through cutting Transplant 1 year old plants Raised by seed, and through cutting Transplant 1 year old seedling Sow seeds in nursery in March and transplant in the following rainy season Raised through seeds or cuttings By direct sowing or planting of cuttings Sow nuts or whole fruit in the nursery in March and transplant during following rains Sow seeds in Feb-March in light soil and transplant 2-3 year old plants Sow seeds in Feb-March in light soil and transplant 2-3 year old plants

120 Sr.

Raising of Forest Nursery Scientific name Aesculus indica

Local name Time for seed availability Banakhor October

Cedrela serrate Cedrus deodara

Drawi Diar

July_Aug Oct-Nov

Cupressus torulosa

Devidiar

April-Oct

Juglans regia

Akhrot

September

Pinus wallichiana Kail Pinus roxburghii

Chil

Sep-Nov May-June

Populus deltoides Poplar

June

Populus ciliata

Palach

June

Quercus dilatata

Moru

October

Quercus incana

Rein, Ban

Dec-Jan

Robinia pseudoacacia

Robinia

September

How to grow Sow seeds in nursery to 18” × 18” and transplant 2 year old plants Transplant 1-2 year old seedlings Easily raised by direct sowing in November or by transplanting 3 year old plants Sow seed in boxes in light porous soil. Prick out in nursery beds to wider spacing for 2 years and transplant in the third year By direct sowing or by transplanting 12 year old plants. Nuts to be buried about 2” deep in the soil By direct sowing, for transplanting 2-3 year old plants are used By direct sowing, for transplanting 1-2 year old plants are used Easily raised from branch cutting planted direct on site or first rooted in the nursery. Take cuttings in Feb, size 12”-18” long, 1”-2” inches in girth Easily raised from branch cutting planted direct on site or first rooted in the nursery. Take cuttings in Feb, size 12”-18” long, 1”-2” inches in girth By direct sowing or transplanting 2 year nursery raised seedlings. By direct sowing or transplanting 2 year nursery raised seedlings. Sow seeds in spring and not in rains and transplant 1-2 old plant

References BCFT (1953). British Common Wealth Forest Terminology, Part-I. The Empire Forestry Assosiation, London.UK. Chaudhry, Z. (1994). Forest diseases and their control. In: Ashraf, M.M. and I. Ahmad (ed). A handbook of Forestry. Pakistan Agricultural Research Council, Islamabad, Pakistan. pp-177. Duryea, M.L. and T.D. Landis (1984). Forest Nursery Mannual: Production of bare root seedlings. Martinus Nijhoff/Dr. W. Jank Publishers, The Hague, Netherlands. pp 385. Hafeez, S. M. (1996). Forest Nursery Mannual. Punjab Forestry Research Intitute, Gattwala, Faisalabad, Pakistan. Sagwal, S.S. (1999). A Textbook of Silviculture. Kalyani Publishers, New Delhi, India. pp. 18. Sheikh, M.I. (2003). A handbook on Social Forestry. Punjab Forestry Research Intitute, Gattwala, Faisalabad, Pakistan. pp 49.

Chapter 6

Forestry and Ecotourism Z.H. Khan and R.A. Khan*

Abstract Pakistan is a land of contrasts, therefore, got high prospects for the developments of eco-tourism in the country. Due to diverse climatic conditions, topographies and soil types, the area accommodates various forest covers, rangelands and agricultural areas. The Alpine ranges, temperate tropical and subtropical forests of Northern area are famous for their unique wildlife species of deer, pheasants and reptiles. Since the population pressure is increasing, thus, there is huge burden on natural resources leading to the exploitation of forest covers, range resources and farmlands for food and other life requirements. Wildlife parks, safari parks, game sanctuaries and game reserves have been created to save the wilderness environment and the related wildlife resources, which provide excellent opportunities of recreation/eco-tourism to residents and foreign gests. Five major rives passing through middle of the country, associated dams, lakes and wetlands harbor grate variety of fish, ducks, geese, storks, egrets and cranes visiting Pakistan for over wintering. World’s most famous mountain peaks, glaciers and snow covered mountains along with their associated cultures have got attraction as tourism sites and recreational spots thus invite millions of naturalists for all over. Our heritage sites with their rich historical background are worth seeing from ecotourism development point of view. Though in the flourishing stage but the industry of eco-tourism has strong prospects for future developments and if properly restructured, funded and managed on scientific lines can serve backbone for the economy of Pakistan.

* Z.H. Khan and R.A. Khan˧ Department of Forestry and Range Management, University of Agriculture, Faisalabad, Pakistan. ˧ Corresponding author’s e-mail: [email protected]

Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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Keywords: Tourism; Forestry; Entertainment; Climate; economy.

6.1.

Introduction

According to the International Ecotourism Society (TIES-1990), ecotourism is defined as “Responsible travel to natural area that conserves the environment and improves wellbeing of the local people”. The Ecotourism Society of Pakistan (ESP) defines the ecotourism as “A travel activity that ensures direct financial support to local people where tourism activities are being generated and enjoyed” (Anonymous 2012; 2013). The importance of ecotourism has been recognized internationally as well as locally almost in the same manner. It basically involves the visiting of national and international community (travelers/eco-tourists) to undisturbed natural areas without degrading the local environment. Another important component of ecotourism is the economic welfare of local people, which is considered as its integral part. Local people as host are the most important stakeholders of ecotourism industry, so, the travelers must respect local cultures at their destinations. Moreover, along with other developments, a part of the income generated through tourist activities must be spent for the wellbeing of people belonging to ecotourism communities. Similarly, successive development and improvement steps are important to generate interests of local people. Instead of scatted and unplanned development, the government agencies should construct hotels, tourist resorts and create other related facilities at selected sites to properly accommodate tourism activities. Another vital aspect of ecotourism is the conservation of natural environment which should not be disturbed, damaged or degraded at any cost to operate the ecological aspect of ecotourism in the real sense. To ensure all this, the concerned stakeholders especially the travelers and local peoples should be educated and made aware of the significance of environment and nature conservation for ecotourism. Necessary information about all important tourism spots should be published in the form of booklets to guide the nature lovers and tourists, and the same information be made available on the country ecotourism website to facilitate international tourists (Raza 2001; Mock and Neil 1996). Since 1980, the ecotourism has been considered a significant enterprise by environmentalists who are cautious and concerned to save, preserve and conserve all the components of environment as gift of nature for the coming generations. The concerned naturalists always stress upon the sustainability of such fragile environmental sites and natural areas. From forester point of view, ecotourism means traveling and visiting of forests having wildlife, lakes, rivers, mountains and many other worth seeing natural places located in there. No doubt, forests are the best places of recreation, leisure and pleasure for the nature loving tourists. The word “ecotourism” has been derived from tourism. It nullifies the conventional negative impacts of tourism activities on local environment and helps in conserving the cultural transition of the local dweller communities. Conservation of environment means the conservation of climates, sites, soils, waters, heritages and biodiversity along with raising the living standard of local peoples. It is generally

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said that overall affect of sustainable tourism is positive and the peoples associated with ecotourism should be generously nature loving. A renowned ecologist and eco-tourist Martha Honey gives an elaborated definition of ecotourism. She has enlisted seven important characteristics of ecotourism given as under: 1) It involves traveling to natural destinations. 2) It helps minimizing negative impacts of the travels. 3) It enhances the environmental awareness among local as well as the international travelers. 4) It provides direct financial benefits to local peoples living at the tourist spots 5) It ensures financial benefits to countries for the conservation of natural tourist spots. 6) It guarantees the respect of local culture by the visiting tourists. 7) It supports human rights and democratic movements of local communities. 8) It provides opportunities for constructive use of leisure time and helps in knowledge development. Ecotourism is considered as an industry for foreign exchange earning and generating income for local people. Pakistan is land of diverse cultures, people and landscapes thus have tremendous scope for local and international ecotourism. In Pakistan, tourism has been stated by “Lonely Planet” magazine and the industry has attracted 1 million tourists during 2012.

6.2.

Ecotourism Development in Pakistan and Worldwide

Pakistan is a land of diverse cultures and traditions. It has beautiful landscapes and natural resources. Its heritage sites, plains, deserts, rivers, mountains, glaciers, lakes, wetlands, forests, wildlife and other renewable resources are unique in the world. The country posses four distinct seasons on account of its topographic diversity which help in the production of a wide range of farm commodities in the farm of cereal crops, fiber, fodder, fruit, vegetables and many other useful byproducts. The existing variety of natural resources and the environmental conditions reflect tremendous scope of ecotourism development in Pakistan. Following natural resources have a lot of potential for the promotion of ecotourism in Pakistan (Eja et al. 2009). Forestry and ecotourism are very important and integral components affected by local environmental conditions. Forest is considered the main stay of ecotourism development and promotion all over the world. This is also fact that these days ecotourism is considered as the biggest industry for income generation. The United States of America generates $ 3 billion dollars from visitors/tourists every year. This earning is mainly based upon the people visiting forests, national parks, lakes and sea shores of the country. Accordingly, ecotourism has been

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considered as the main economic hub of many other countries like China, Hong Kang, Nepal, and Switzerland etc. It was estimated that during 1998, there were 157 to 236 million international eco-tourists worldwide and the number of visitors moved to zoos to watch wildlife species were estimated to be from 79 to 157 million. Global value of ecotourism during 1998 was estimated as high as 1 trillion US dollars. Due to vide range of beautiful landscapes, variety of forest covers, wetlands and diversity of related wildlife, Pakistan have tremendous potential and scope for the development and promotion of ecotourism in the country (Raza 2001). The importance of travel and tourism to global economy has been increasing during the past decade. It is now arising as the major contributor to global economic development. It generates more than US $3.4 trillion in gross output and employees more than 200 million people worldwide. It invests more than US $ 693billion per annum in new facilities and equipments and, US $655 billion in direct and indirect taxes each year. The World Economic Outlook (WEO) presents that worldwide GDP growth is estimated at 3.2% for 2003 and 4.1% for 2004 in this industry (Anonymous 2013).

6.2.1. Climate of Pakistan Climate plays a key role in the biodiversity of flora and fauna. Climate in the country varies from could alpine zone (northern mountains) in the North to the hot coastal belt in South. More than 90% of the area has the subtropical dry climate including arid and semi arid zone (Chapter 2). From annual rainfall point of view, there are two types of climate found in the country especially in the Indus basin i.e. Monsoon and Mediterranean climate. Lower Indus plain has subtropical and tropical climate. Northern areas of KPK (Khyber Pakthoon Khah Province) have alpine climate that changes into moist temperate in Swat, Mansehra, Hazara, Malakand and Abottabad. Whereas at the same elevation of 6500-11000 m on Eastern side, moist temperate climate becomes dry temperate and cover Diamir, Chitral, Dir, Wazirestan and Northern Baluchistan. Subtropical climate supports broad-leaved evergreen forest in the upper parts of Punjab and broad-leaved deciduous forest in the Indus plains consisting of lower Punjab and upper Sindh. Coastal belts of the inundated delta of Indus River along Arabian Sea have the unique mangrove forest. Alpine regions are surrounded by mountainous ranges of Karakorum, Himalayas and Hindukush and have alpine climate. This area has prolonged winter with no or very short summer. Snowfall is the distinguishable feature of this region and tree growth is confined up to timberline at an elevation of 12000 to 13000 feet. These climatic and ecological zones have rich biodiversity of fauna and flora to attract the eco-tourists and accommodate innumerable destination spots which can be utilized for the promotion of ecotourism in the country (Mock and Nile 1996; Siddiqui 1997).

6.2.2. Mountains of Pakistan Pakistan has world’s famous mountains ranges consisting of Karakorum, Himalayas and Hindu Kush. Five of the 14 highest peaks of the world above 8000

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m height lie in the Karakorum and Giglit Baltistan region which are considered as a part of the Great Himalaya Range. Pakistan is also famous for being the home of the world’s second highest mountain peak K-2. This mountain range extends up to North and Northwestern parts of Baluchistan province and surrounds its capital i.e. Quetta. In addition, there is another famous mountain range, the Koh-e-Suleman (3480 m high) that extends up to the province of Sindh and joins Kirthar hills. The highest mountain peaks of Karakorum, Himalaya and Hindu Kush are K2, Nanga Perbat and Tirchmir which are located at the height of 8611 m, 8125 m and 7708 m respectively with the ranking of 2nd, 9th and 33th highest peaks in the world. Most of the high peaks lie in the Gilgit Baltistan with few exceptions which are located at more than 700 m in the Hindu Kush mountain range. No doubt many eco-tourists all over the world are attracted and fascinated by these highest mountains ranges but they cannot touch the highest peaks being very difficult to climb. Since hiking is tedious and dangerous sport therefore needs training and skill for enjoyment. All these mountains have unlimited opportunities of ecotourism. Table 6.1 Glimpse of the highest peaks is given in the following table Name K2 Nanga Parbat Gasherbrum I Broad peak Gasherbrum II

Height (m) 8611 8126 8080 8051 8035

Location Karakorum Himalaya Baltoro Karakorum Baltoro Karakorum Baltoro Karakorum

Rank (Pak) 1 2 3 4 5

Rank (world) 2 9 11 12 13

The listed mountain ranges in table 6.1 have famous and attractive hill stations like Muree, Sugran, Naran, Kaghan, Ziarrat, Kalam and Swat. By virtue of their natural beauty, these regions are serving as diverse recreational spots thus thousands of visitors/eco-tourists to enjoy this area especially during summer and winter seasons (Israr et al. 2009, 2010).

6.2.3. Glaciers Glaciers of Pakistan are the symbols of ecotourism. These vary in size and cover the Northern mountains ranges of Karakorum, Himalayas and Hindukush. These glaciers encompass an area of about 17000 km2 which is around 15% of the mountainous regions. The total length of glacier in Karakorum mountain range is more than 6160 km2. According to an estimate, 37% of the Karakorum region is covered under the glaciated ice. Most famous glaciers like Siachin, Biafo, Baltoro, Batura and Hispar covers an area of 75, 63, 62, 58, and 53 km2 respectively and lie in the Karakorum mountainous range. According to the estimates by conservationists, there are 120 major glaciers and numerous smaller glaciers in the Northern highlands of Pakistan and in addition many others still needs to be explored and documented. The referred glaciers are the biggest bodies of glaciated ice found anywhere in the world and are asset for ecotourism. Gradual melting of these glaciers continues

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water flow and feed more than 60 large and small rivers as well as feed the famous dams of Terbela, Mangla and Warsak in Pakistan. Water of these glaciers is in fact a source of life for the people and is highly important for economy of the country. From recreational point of view, these glaciers are important for tourists and attract visitors from allover the world thus help in the development and promotion of ecotourism in Pakistan (Eja et al. 2009).

6.2.4. Lakes Due to their natural beauty and clean water local lakes are considered excellent touristic sites. All these natural and man-made lakes/reservoirs also have an appealing aesthetic value. Mancher Lake in Sindh province is the biggest natural water body in Pakistan and the largest lake in South Asia. It spreads over an area of more than 160 km2. The other highest lake of Pakistan is the Rush Lake which is 25th highest lake of the world located at an altitude of 4700 m. The second highest lake of the country is Karambar Lake located at an elevation of 4272 m and is ranked 31st highest lake in the world. Some other beautiful natural and man-made lakes found in the provinces are Ansoo Lake, Attabad Lake, Borith Lake and Deliputsar Lake. In addition, there are hundreds of small lakes and water reservoirs which serve as wintering grounds for millions of migratory water fowls seasonally visiting Pakistan. The major migratory birds include swans, goose, ducks, cranes, egrets and cormorants. These water bodies also accommodate local wetland species and provide active spots fishing. These lakes house great biodiversity of flora and fauna and help promoting ecotourism in the country. Thousands of local and foreign tourists visit these lakes to enjoy boating, fishing and waterfowl shooting each year (Qureshi 1998; Robert 2000).

6.2.5. Forests The natural forests, irrigated forest plantations and scatted tree covers are highly important for the stability of environment and help in reducing pollution. Tree covers represent variations in the landscape and help in the conservation of biodiversity of fauna, flora in the relevant ecosystems. There is acute shortage of forest cover in Pakistan in comparison with the international standard (25% of the total area of the country). Forest cover of the country is about 4.28 million hectares, which constitutes 4.9% of the total geographical area of Pakistan. This is far below the international standard of forest cover area (20-25%) for maintaining an ecological equilibrium. Keeping in view the forest area of countries at global level, Pakistan occupies the much lower position in the world. Current position of forest resources in the country are not only alarming to meet the wood requirements of the nation but lacking control on pollution, increasing environmental hazards and posing threats to wildlife conservation (Qureshi 1998).

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Table 6.2 Land utilization statistics of Pakistan and AJK. Land use 1 2 3 4 5 6 7

Geographical area Forest area Not available for cultivation Cultivable waste Cultivated area Reported area (2+3+4+5) Area not classified

KPK (Mha) 10.17

Punjab (Mha) 20.63

Sindh Baluchistan NA AJK (Mha) (Mha) (Mha) (Mha) 14.09 34.72 7.04 1.33

1.40

0.57

0.65

0.29

0.95

0.42

4.05

3.19

6.13

11.16

N.A

0.71

1.04

1.86

1.26

4.69

N.A

0.03

1.92

11.99

5.68

1.66

N.A

0.17

8.41

17.61

13.72

17.80

0.95

1.33

1.76

3.02

0.37

16.92

6.09

Total (Mha) 87.98 4.38 (4.9%) 25.24 (28.7%) 8.88 (10.1%) 21.42 (24.3%) 59.82 (68%) 28.16 (32%)

Source: Raza (2001)

Table 6.3 Wood production, requirement and deficiency in Pakistan. Years 1975-86 2000 1987 2000

Types of production Timber Fuel Timber Fuel

Wood production 1.33 Mm3 3.00 Mm3 13.33 Mm3 15.84 Mm3

Wood requirement 2.08 Mm3 4.11 Mm3 39.36 Mm3 61.01 Mm3

Wood deficiency 0.74Mm3 1.11 Mm3 26.16 Mm3 45.17 Mm3

Source: Quraishi (1998)

Deficiency of timber and fuel wood as shown in table 6.3 is steadily increasing for the last few years and is still in progress. The factual position is that state managed forests provide only 14% and 10% of the total timber and fuel wood needs and rangelands supports about 40% of the total livestock. Due to diversity vegetation covers and related wildlife species, these areas provide massive opportunities for tourists and play a vital role in the promotion of ecotourism.

6.2.6. National Wildlife and Safari Parks National wildlife and Safari parks created for the conservation of national biodiversity are the other important segment of ecotourism. There are almost 27 national parks located in the forest lands and spread all over the country. These include 5 National Parks of Gilgit Baltistan, 8 of AJK, 5 of KPK, 6 of Punjab one in Sindh and 2 in Baluchistan. In addition, the Safari park, game reserves, wildlife sanctuaries have been developed in these areas. These are the best centers for studying fauna and flora found under typical climatic and ecological zones. All the forests possess numerous picnic and recreational destinations rich in wildlife species, diversity of tree covers and fascinating landscapes thus attract tourists from all over the world. The Tourism Department is launching different development

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schemes for the welfare of local host communities in the areas to promote ecotourism in the country. The forest covers found on highly erected mountains of Karakorum, Himalaya, Hindu Kush mountainous ranges provide beautiful habitats for wildlife. These mountains have snow covered peaks and beautiful milky glaciers which present a unique blend of trees, shrubs, grasses and a wide range of variety flora and fauna thus very rich in biodiversity and landscape. Among these forests, there is an attractive network of rivers, streams, lakes and wetland where very beautiful and rare migratory waterfowls come for overwintering from Siberia. In short, the fascinating green sceneries, attractive environment, natural beauty required for ecotourism are all available in these forests thus have tremendous potential/scope for ecotourism. The government is providing all kinds of recreational facilities, resorts, hotels, motels, restaurants, rest houses and shops to facilitate the visitors for shopping, boarding and lodging. Very attractive handicrafts and dress shops representing different cultures of the regions and provinces are developed to show that Pakistan is land of diverse peoples, and traditions. More than one million local and foreign eco-tourists visit Murree hill station located 65 km in the North of Islamabad (Anonymous 2013).

6.2.7. Wildlife Breeding Centers and Zoos Diversity of wildlife is an integral component of any ecosystem. The sites having rich and diverse wildlife species are considered more attractive for ecotourism development. Such sites are found all over the country extending from Alpine Forests to coastal region of Arabian Sea. The province of KPK and Gilgit Bultistan is famous for its mighty mountain ranges of Karakorum, Himalayas and Hindu Kush. Due to high altitude and dangerous topographic characteristics, these areas are difficult to be exploited by hunter and poachers. Provincial governments have imposed complete ban on the harvesting forest trees therefore most of the wildlife habitats are undisturbed. Resultantly, these mountainous ranges maintain diverse fauna and flora contributing to richness of biodiversity. Famous local wildlife species found in these mountains are Snow Leopard, Markhor, Black Bear, and Rhesus Monkey etc. Among birds Monal Pheasants, Cheer Pheasant, Koklas Pheasant Kleje Pheasant, Chokar Partridge, See-see Partridge are the famous species. In the plains of Pakistan, water bodies like canals, rivers, manmade dams, lakes, marshy areas and costal belts provide good habitats to different wetland species of waterfowls, fish, frog, tortoise, turtles, dolphins and crocodiles. In short, Pakistan has wide variety of wildlife found in the forests, deserts, pastures, agricultural fields and wetlands. From conservation point of view, many of the native wildlife species are kept in zoos, wildlife/safari parks, breeding center, game reserves, sanctuaries and national parks developed under the control of Forest and Wildlife Department (Table 6.4). Tourism Department has created different picnic spots, recreational areas, hiking tracks, motels and other related facilities at attractive natural sites to attract eco-tourist locally and from all parts of the world.

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Table 6.4 List of zoos, safari parks, breeding center, game reserves, sanctuaries, wildlife parks, national parks and Public Zoos Zoos

Aviaries

Aquaria Wildlife Parks

Breeding Centers

Bhalwalpur zoo, Bhawalpur, Punjab. Hyderabad zoo, hydrabad, Sindh. Islamabad zoo, Islamabad Karachi zoo, Karachi Sindh Landhi, Korangi zoo, Karachi, Sindh Animal theme Parks Jungle world (forestry jungle kingdom) Rawalpindi, Punjab Kund Park, Nowshera KPK Lake view park, Islamabad Safari Parks Jallo wildlife park, Lahore, Punjab Karachi safari park, Karachi, Sindh Lahore Zoo and Safari park, Punjab (Formerly Lahore wildlife parks) also called woodland wildlife park Rawalpindi. Changa Manga vulture center Lahore (Punjab) Dhodial Pheasantry. (Mansehra K.P.K) Karachi walk through aviary (Karachi Sindh) Lahore walk through aviary (Lahore Punjab) Lake view park aviary (Islamabad Federal Capital) Lakki Murwat crane center (K.P.K) Saidpur Hatchary (Islamabad Federal Capital) Cliften Fish aquarium (Karachi Sindh) Karachi Munipal aquarium (Karachi Sindh) Landhi Korangi aquarium (Karachi Sindh) Attock wildlife park (Attock Punjab) Bhawal Nagar wildlife park (Bhawal Nagar Punjab) Bhagal wildlife park (Toba Take Singh Punjab) Changa Manga wildlife park (Lahore Punjab) Jallo wildlife park (Lahore Punjab) Kamalia wildlife park (Toba Take Singh Punjab) Lalazar wildlife park (Abbottabad K.P.K) Dera Ghazi Khan wildlife park (Dera Ghazi Khan Punjab) Gatwala wildlife park (Faisalabad Punjab) Perowal wildlife park (Khanewal Punjab) Raheem Yar Khan wildlife park (R.Y.K. Punjab) Sulemanki wildlife park (Okara Punjab) Vehari wildlife park (Vehari Punjab) Changa Manga breeding center (Lahore Punjab) Faisalabad breeding center (Faisalabad Punjab) Jallo breeding center (Lahore Punjab) Rawalpindi breeding center (Rawalpindi Punjab)

Source: Anonynous (2017)

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6.2.8. World Heritage Sites In Pakistan, ecotourism potential is yet to be exploited as it has beautiful natural resources and world heritage sites which can help to flourish this industry here in the coming years. The country with its diverse culture, people and landscapes has attracted one million eco-tourists in 2012. During 2009, the travel and tourists competitiveness report of World Economic Forum ranked Pakistan at 25th position for its world heritage sites. Thus it can be rightly said that there are bright prospects of ecotourism in Pakistan. The country’s heritage sites consisting of the ruins of Indus valley civilization such as Mohanjo Daro, Harappa, and Taxila, to the Himalayan hill stations attract tourists from all over the world. Pakistan is famous to have several mountain peaks over 7000 m as described in detail under previous headings, which attract thousands of adventures and mountain hikers from within Pakistan and from the world over. The North part of Pakistan has many old fortresses of ancient architecture and the beautiful Hunza and Chitral Valleys. It is also home to small Pre-Islamic Kalash Community. The romance of the historic KPK province is timeless and legendary. The Punjab province has the site of famous Alexander’s battle on the Jhelum River and the historic city Lahore. Lahore; the Capital of Punjab is also famous for many Moghal architectures such as Badshahi Mosque, Shalimar Garden, Tomb of Jhanger and the Lahore fort. Before the global economic crisis, Pakistan was receiving more than 5,000,000 tourists annually. This number came down to minimum since 2008 due to local instability and religious extremism. Many countries have declared Pakistan as unsafe and dangerous country for tourists. The five sites viz. Taxila, Lahore, Karakorum Highway, Karimabad and Lake Saiful Maluk are the valuable heritage assets of Pakistan. The Prime Minster of Pakistan launched the “Pakistan marketing campaign in 2007” to promote tourist visits to unique and varying cultural heritages. This campaign involved various events throughout the year including fun fairs and religious festivals, regional sporting events, various arts and craft shows, folk festivals and opening of several historical museums. All five provinces of the country viz. Punjab, Sind, K.P.K, Baluchistan and Gilgit Blistan, and the three territories viz Capital Territory of Istamabad, federally administrated Tribal Areas and Azad Jammu and Kashmir (AJK) are the centers of various religions settlements present there long before the creation of Pakistan. The cultural and physical diversityhas made the country a paradise for tourists, foreign travelers and adventurists. Pakistan encompasses six major heritage sites recognized as UNESCO’S world heritage sites which include (Anonymous 2017): 1) 2) 3) 4) 5) 6)

Archaeological ruins at Mohengo Daro of the Indus valley civilization Fist century Buddhist ruins at Tokht-i-Bahi at Saha-i-Bahlol The ruins of Texla from the Gandhara civilization The Lahore Fort and Shalimar Garden in Lahore Historic monuments of the ancients city at Thatta The ancient fort of Rohtas

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On the basis of research, conducted by the Ministry of Tourism, Pakistan in 2004, seventeen more sites have been recognized as world heritage by UNESCO are asunder: 1) Badshahi Mosque, Lahore built in 1673 during Mughal Empire. 2) Wazir Khan Mosque, Lahore built in 1635 by Wazir Khan. He was very famous “tabib” (Doctor/Surgeon) who did an important operation of the foot of the most beloved wife of Jahangir operation successfully. Tabib was given prize worth of billion dollars and he spent this huge amount to construct the mosque which became famous after his name. 3) Tombs of Jahangir, Asif Khan and Akbari Sarai Lahore and Mausoleum built in 1627 4) Hiran Minar and Tank, Sheikhupura, built by Moghal empior, Jahangir in 1606 5) Tomb of Shah Rukne Alam, a famous sufi of Multan 6) Ranikot Fort-Dadu, one of the longest forts in the world. 7) Shah Jahan mosque built in 1647 8) Chank Handi Karachi tombs built during Moghal empire 9) Mohrgarh-Baluchistan one of the oldest Neolithic ruins and archeological sites. 10) Rehman Dheri Ismail Khan historical ruins of Indus valley civilization 11) Harrapa Punjab historical ruins of Bronze age 12) Rani Ghat K.P.K archeological remains of Buddhist monastic complex 13) Monsehra Rock edicts 14) Shahbaz Garhi rock edicts Mardan 15) Baltit fort Hunza valley of Tibetan style fort built in 13th century BC 16) Tomb of Bibi Jawindi Bahaal Halim and Ustaad mosque of Jalal-ud-Din in Bukhar 17) Port of Banbhore archaeological site of historical port city on the Indus river In addition, several other buildings constructed before the creation of Pakistan show different cultures and religious attachments existed that time. Actually, this was the result of various wars led to several dynastic and tribes ruling the land. They left various landmarks behind them which have become national icon and valuable tourist sites. Some are given as under: 1) 2) 3) 4) 5) 6)

Faisalabad clock tower and the eight bazaars Altit fort in Hunza valley 17th and 18th century tombs of Talpur Mirs Faiz Mohal of Talpur Mirs Samadhi of Ranjit Singh Moghal built tomb of Asif Khan

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7) Empress market built during the rule of the British empire 8) The tomb of Qutb-ud-Din Aibak, the first sultan of Delhi and founder of the slave dynasty 9) Mohatta palace built in 1927 10) 18th contury Omer Hayat mahal 11) 19th century Italian Chatean Noor palace 12) Drawar fort 13) Moghal built Hiran Minar 14) One of the oldest salt mines in Asia Khewra Salt Mines 15) The 3000 BC built fort of kot DIJI and Faiz mohal in Khair Pur 16) 16th century built fort at Sakardu During post independence time, Pakistan retained/improved its heritage by constructing various artistic sites to commemorate its independence by blending the styles from the past. Some of these are: 1) 2) 3) 4) 5) 6) 7)

6.3.

Mannar-e- Pakistan in Lahore Faisal mosque in Islamabad The mausoleum of the founder of Pakistan, Muhammad Ali Jinnah Bab-e-Pakistan. A memorial site for the victims of the independence Pakistan mausoleum in Islamabad The mausoleum of Allama Muhammad Iqbal. A national poet of Pakistan Islam summit minaret to commutate Islamic summit held in Lahore during 1974.

Role of Forests

Since forests serve in multidirectional ways therefore mutual relationship between forests and ecotourism is highly significant. No doubt, in any country, ecotourism cannot be promoted without developing forests. Presently despite meager forest cover, this renewable resource is playing a vital role in the national economy. Forests give direct and indirect benefits to the people.

6.3.1. Role of Forests in Ecotourism The forests protect the nature against degradation. Besides glorifying the natural beauty, these forests moderate the climate and enhance rainfall in the area. From wildlife point of view, the forest covers provide attractive habitats in the form of safe nesting, breeding feeding, drinking sites and escape covers, thus ensure sustainability of biodiversity in the area. All such multidimensional wildlife habitats are attractive destination for the visitors, tourists and onlookers to enjoy their leisure time in peaceful environment. All types of forest cover and the connected landscapes provide recreational facilities to the people thus play significant role in the development of ecotourism industry.

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These forests have good capacity and scope of ecotourism promotion. Take an example of Juniper forests of Baluchistan, which are considered as world heritage. These are the second oldest forests of the world found at the elevation of 20003000 meters. These are more than 3000 years old. The historical and physical facts about these forests are unique to be considered from ecotourism point of view. Similarly, the mangrove forests of the country are unique in nature and considered a valuable asset for ecotourism in the country. Many other valuable aspects of these forests include aesthetic value, different blooming seasons, tree byproduct and aromatic/colorful leaves which fascinate the eco-tourists.

6.3.2. Ecotourism and Forest Management It is highly important that forests, rangelands and other vegetation covers be properly managed to make them attractive for tourists. The respective departments be trained and funded to manage the forests and related picnic points, study sites, tourist resorts, hoping centers wildlife parks to enhance tourism activities and numbers visitors. Roads should be built and suitable parking sites be given to facilitate the eco-tourists. Local tourism department should be strengthened to supervise the development work, cleanliness and security measures to be in line with the required facilities for updating touristic sites. One should have clear concept of forest management to use these areas for ecotourism and other related purposes. Forests are the communities of flora and fauna where the woody vegetation is dominant as compared to other groups of vegetation and animal life. Forest vegetation is composed of many groups of plants, which succeed to exist after a long process of competition and succession under favorable conditions of soil. The succession changes in vegetation lead to the existence of most stable plant community. Being living entities, plant communities act and react with soil and environmental during this process of succession. A harmonious relationship is evolved and ultimately a climax type of plant community settles which shows the perfect balance with the environment. Sound forest management means the maximum procurement of woody and non-woody forest products and services on sustained basis without any damage to the other prevailing sources in the forest area. The basic need of forest management is not only to maintain dense stands in the natural and manmade forests but also to increase and manage them for future growing prospects. The conservation and developmental approaches of forest sustainability are very important for ensuring regeneration and afforestation. Due to growing population, Over cutting, harvesting and exploitation of forest resources has become a common practice in the country and should be discouraged in all respects. The importance of regeneration and afforestation through natural and artificial means has increased many folds. where as the rate of annual deforestation is much more. As afforestation and regeneration falls much short of the requirement therefore it may take years to add another one million ha in the forest cover. Forest experts have pointed out that it is highly desirable that afforestation programmed should be accelerated as part of forest management by removing physical, legal and financial constraints. Attitude of policy makers and planners to

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give low priority to forestry program in the economic planning should be changed. With the help of sound forest management, production of wood per unit area from irrigated plantations and natural mountain forests could be increased manifold. Second important point of forest management is the protection of growing stock. Forests are damaged through lopping and illicit cutting. Attack of insects, diseases, wild animals, fires and livestock herds also cause a lot of damage to forest cover. These factors also cause serious damage to seedlings. In fact, many of these are the socioeconomic problems because of people residing in and around forests who cut trees for timber, fuel, fodder and plough forest lands illegally. The major reason of this kind damage is because of the absence of burning fuel and fodders for their livestock.

6.3.3. Social Forestry and Ecotourism Social forestry is a type of participatory forestry that is considered imperative for the increase tree cover in the country (Chapter 9). In such forestry practices, common man directly take part in forestation activates like soil preparation, tree planting, post planting care and tree harvesting. Social forestry focuses on the common interest of associated communities. It is raising and managing trees for the benefits of common people. Community forestry, commercial forestry, Farm forestry, participatory forestry, rehabilitation forestry, amenity forestry are the synonymous terms describing social forestry. For ecotourism, practice of amenity forestry is considered more important because these forestry exercises are carried out for maintaining beautiful and attractive landscape through ornamental forest trees to arrange recreational pleasure for local visitors and eco-tourists. The significance social forestry in eco-tourism as income generating industry cannot be under estimated in Pakistan. Ecotourism is a worldwide phenomenon that touches the highest and deepest aspiration of associated people. It is also an important element of socio economic and political development in many countries. Take an example of USA where revenue generated by ecotourism mainly comes from the visitors of national park and the income generation has reached up to 3 billion US $ a year. For the development and promotion of ecotourism in Pakistan, we should take strategic steps to resolve the root causes of environmental degradation by ensuring a significant increase in the existing vegetative cover of the country.

6.4.

Socioeconomic and Environmental Impact of Ecotourism

Socio economic and environmental impacts of ecotourism are positive for any country. Eco-travelers and the host people are social components of ecotourism industry. Whereas, economic development for the promotion of ecotourism in the form of constructing approach roads, hotels, restaurants, resorts, establishments of minimarkets, availing means of communication in the area will have economic impacts on local ecotourism development. Similarly, the conservation of natural

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fauna and flora and preservation of landscape beauty will definitely leave healthy environmental impacts on ecotourism activities. In fact, man itself is the key figure responsible for positive and negative socioeconomic and environmental impacts on ecotourism. Ecotourism is not only an economical enterprise but also a very important social activity because people of different regions and provinces of the country with different cultures, traditions and even habits have chance to see and meet the foreigners from all over the world. This reflects the social impacts of ecotourism. Nature loving eco-tourists and hosts are the basic stakeholders of ecotourism, which affect each other significantly. For example, the residents of villages located in the forests or outside generally belong to very poor community. Due to miserable poverty, they harvest timber for fuel wood for domestic purposes thus seriously damage forests. They do illegal shooting and trapping the mammals, birds and other wildlife. Such activities do irreparable damage to ecosystem and withhold to get socio-economic benefits from the ecotourism. Though it is bigger industry that can help in fetching a significant amount of foreign exchange for the socioeconomic development but do to terrorist activity, numbers of eco-tourists visiting the country are declining fast. Therefore, especial attention be paid on this issue and better understanding of the concept of ecotourism be introduced to enlarge eco-tourism activities in Pakistan.

6.5.

Ecotourism Trends and Challenges

In Pakistan, tourism industry is in the take off position thus faces on certain challenges, which are summarized as the fallowing. 1) Pakistan is a home of diverse people, cultures, traditions, heritage and sizable biodiversity thus attracts several tourists every year. Because ecotourism is still in the growing phase with brighter prospects therefore requires more investments and funds. Building of road toward all attractive tourist spots, organization of recreational/residential facilities and provision of required protection of the guests during field movement are important aspects to be taken care. 2) In the past, no serious attention was given on ecotourism department. This kind of odd attitude may damage the marketing of ecotourism and led to large decline in number of travelers to Pakistan. The position needs to be rectified for ecotourism and the sites development in the country. 3) Sizable investment and innovations in ecotourism industry is required for development of this industry. This negligence has led to depreciate several eco tourist sites over time. In the annual budgets, less priority is being given to ecotourism which needs to be reconsidered and improved in comparison with other department for the development and promotion of this industry in Pakistan. 4) Weak travel facilities, low/hardly trained staff position and marketing effectiveness needs to corrected and improved on priority basis, and the

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5)

6)

7)

8)

9)

6.6.

same was pointed out during 2008- by world economic forum travel and tourism competitiveness report (TTCR). The report ranked Pakistan on 103 out of 124 countries with respect to ecotourism. Though work has been done by Ecotourism Department of Pakistan on introducing the Ecotourism Industry through Website but it still needs a lot of improvement. This is age speed, people use internet for getting any tourism related information. Unfortunately, our related websites are hardly upgraded and improved with time thus adversely affecting the enterprise. It needs special attention of the department Higher rates of boarding/lodging, un-controlled prices of utility items, food adulteration and high rent of hotel rooms are discouraging for economists and helping to drop their number. This aspect needs well thought reforms to facilitate the enterprise connected people. Lack of security measure during touring, horrifying news through print/electronic media and the actual mishaps are playing negative role for the development and promotion of eco-tourism. Suitable steps need to be taken to rectify the situation in support of this industry. Though printed materials about worth seeing places and sites are available on the website for the guidance of tourists but it lacks comprehensive information and needs revisions as per latest information. Private agencies are more actively involved in arranging tours for eco-tourists but charge a lot without any renationalization of expenditures. The related government agencies must take steps to correct the situation in favor of comprehensive development of tourism website, improvement of transport facilities, online booking of hotels, management of security risks and on solving other connected issues. Research based interventions are highly important to upgrade the ecotourism facilities and to enhance tourism activities in the country. This can be made possible by creating an active research wing in the local ecotourism department by involving graduate and post graduate research students from different universities. The eco-tourism research outcomes should then be translated into recommendations to be implemented in letter and sprit for the up gradation of the department and its related facilities to the international standards.

Conclusion

It is quite evident that ecotourism is directly linked with forests, wildlife, environment and nature. Ultimately any disturbance related to these assets may adversely affect the flourishing of industry ecotourism. Human interventions and natural calamities are the main forces which can play destructive role for tourism management. Thought there no control on natural phenomenon, however their impacts can be controlled and minimized by taking suitable measures timely. Similarly, negative role of human being can be managed by training exercises and improvement of education facilities in local communities.

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Decrease in forest cover affect the overall environment of an area. It increases temperature, induces erosion, forces out the wildlife species thus have negative impacts on ecotourism. Severe damages in forest cover results in green house effect and led to major climatic changes. These climatic problems damage the overall environment of the area. Decreased rain fall and led to rise in temperature, cause doughtiness and increase chances of forest fire. It is reported during 2009 that the environmental degradation is causing loss of Rs. 365 billion per year in Pakistan. Improvement in forest covers, management of the available forest lands through controlling timber mafia is the task to be addressed to make the ecotourism progressive. Improvement in the infrastructure, staff position, mobility, updating security measures and enhancing budget allocations are highly important steps for the development and improvement of Tourism Department. This needs substantives efforts at government level to make this enterprise a successive and profitable industry in Pakistan.

References Anonymous (2012). A consultancy report for the World Conservation Union, (IUCN), Islamabad, Pakistan. Anonymous (2013). Ecotourism Society of Pakistan. Tourism industry crumbling in Pakistan. www.ecotourism.org.pk. Anonymous (2017). Wildlife of Pakistan. http/www.wildlife of Pakistan.com. Accssed on 28 July 2017. Eja, E.L., J.E Out, and A.U. Michael (2009). Socioeconomic implication of ecotourism development in plateau state, Niger. J. Sustain. Develop. Afr. 11 (3): 246-264. Israr, M., H. Khan, N. Ahmad, M.M. Shafi, S. Baig, M. Rehman, and N. Muhammad (2010). Role of local food and handicrafts in raising ecotourism in the northern areas of Pakistan. Sar. J. Agric. 26 (1): 119-124. Israr, M., S.M. Shaukat, M.M. Shafi, N. Ahmad, S. Baig and M. Nasir (2009). Role of host community in promotion of ecotourism in the northern areas of Pakistan. Sar. J. Agric. 25 (4): 629-634. Mock, J. and K.O. Neil (1996). Survey of ecotourism potential in Pakistan’s biodiversity project area (Chitral and Northern area): A consultancy report for the World Conservation Union, (IUCN), Islamabad, Pakistan Quraishi, M.A.A. (1998). Basics of Forestry and Allied Sciences. A-One Publishers Lahore, Pakistan. pp 310. Raza, S.B. (2001). Comprehensive Forestry. Publishers Emporium, Lahore, Pakistan. pp. 524. Robert, T.J. (2000). Pakistan Natural Wonders. Oxford University Press, Karachi Pakistan. Siddiqui, K.M. (1997). Forestry and Environment. Pakistan Forest Institute Peshawar, Pakistan. pp. 21-27.

Chapter 7

Tree Plantation in Problem Soils A.R. Awan and K. Mahmood*

Abstract Being a non-renewable resource, soil holds vital position to all primary production systems. Various factors such as fast rate of population growth, modern trade and industry development, changes in land use trends, environmental pollution and climate change have led to different types of soil degradation. Land based resources like cultivable land, range and forest lands have experienced excessive pressure due to unprecedented population growth in developing countries. Challenge of the present era is to utilize degraded soils in such scientific way as to not only halt further land degradation but also to improve their productivity. This chapter focuses on extent and forms of land degradation in problem soils, the phenomenon involved in their formation and remedial measures to mitigate the ill effects to improve socio-economic conditions of rural communities in degraded poor soils through successful tree plantation. Keywords: Soils; Degradation; Fertility; Afforestation; Forestry.

7.1.

Introduction

Over the long time, soil has been considered as an interminable resource for recurrent agricultural production. However, contradictory to this concept, soil needs to be regarded as preious source and must be conserved, utilized and managed with due consideration since exceptionally slow formation rate i.e., it takes about 100-

* A.R. Awan and K. Mahmood˧ Nuclear Institute for Agriculture and Biology, Faisalabad, Pakistan. ˧ Corresponding author’s e-mail: [email protected]

Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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400 years cm-1 of top soil development. In developed countries, most of the agricultural practices are implemented on the soils suitable for specific intensive farming purpose in present era. Due to this trend and because of steadily rising productivity of soils, most of European Union Commission (EUC) countries and USA have even been able to reduce their cultivated area. However, the state of affairs in the developing countries is in marked contrast to aforementioned situation. In these countries, good soils are scarce and consequently agricultural productivity is low. Recent advancement in agricultural technologies may lead to further enhance the productivity of these ‘better soils’ to a considerable extent. In these areas, the farmers depending on limited land resources with low productivity face various socio-economic problems. Population pressure in developing countries has forced the communities to bring ‘problem soils’ under cultivation. It has been estimated that worldwide food production will requisite to be boosted by about 38% by 2025 and 57% by 2050 (Wild 2003; Aslam 2002) if food supply to human beings is maintained at current consumption levels. On grounds, cultivable lands are already under plough and further addition of new land tracts in food production systems on mass scale seems infrequently possible. Hence, the trend of bringing the problem soils under plough is ascending progressively. Presently, much of the agriculture in these countries is practiced on the soils that are unsuitable or only marginally suitable. In such soils, different constraints to plant growth and development reduce farm production to considerable extent. Prominent constraints include aridity, waterlogging, acidity, alkalinity, salinity, presence of disproportionate extents of clay, sand and gravel in the soil. Contemporary needs and future predictions strongly advocate that the want to produce extra food, fiber and woody stuff for ever-increasing world population will make compulsory use of brackish and marginal quality water as well as poor land resources (Bouwer 2000; Gupta and Abrol 2000). This is particularly more pertinent to the under developed countries located in arid and semi-arid regions of the world where soil degradation is common phenomenon (Qadir and Oster 2004). Need of the time is to develop locally adapted farming systems or appropriate management techniques for problem soils for achieving better farm productivity. The objective, therefore, must be spiraling in crop yield per unit area of land rather than extension of cultivated area. Deliberate exertions are obligatory to improve productivity of existing lands. While reviewing various techniques available for utilization of problem soils, we hope to contribute to a well-thought understanding about the complications encountered, the risks and threats involved and future prospects when such poor soils are used for tree plantation.

7.1.1. How do Problem Soils Develop? Soil is the upper portion of the earth's shell where lithosphere (rocks), hydrosphere (water), atmosphere (air) and biosphere (micro-organisms) interpenetrate to form pedosphere. In fact, it is a more complex medium than air and water.

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Soils being natural entities exist in a wide range of diverse forms and are, undeniably, the multifarious systems till documented to science. In broader sense, soils, being composed of organic and inorganic components enriched with microorganisms, act as medium which supports life. A ‘normal soil’ or farm area develops into a ‘problem soil’ or area when shortage or excess of any or some environmental factors prohibit plant establishment and severely retard their growth. Such factors vary from one locality to another and can be any one of the numerous environmental (climatic, edaphic or biotic) factors. Different malpractices such as overgrazing, deforestation, faulty agricultural cultivation schemes and elimination of vegetative cover or hedgerows can intensify the formation of problem soils.

7.1.2. Extent of Problem Soils Many kinds of problem soils exist in the world, each of them hindering agricultural activities in one way or another. According to one estimate, 4900 M ha in the tropic regions, two-third of the total land area, is categorized as ‘wasteland’ (King and Chandler 1997). Another estimation shows that about 15% of total land area of the world is subjected to different forms of land degradation like soil erosion and salinization (Wild 2003). Examples of such soils include the acid savannas of South America which were formed by transfiguring tropical rainforests into animal and crop husbandry production systems, uninhibited shifting cultivation tracts (with severe erosion) in southeastern Asia and Africa, and widespread stretches of salt-affected soils in Indo-Gangetic grasslands of the Indian subcontinent. Similarly, flawed agricultural and land management practices result in formation of problem soils on gigantic scale every year.

7.2.

Types of Problem Soils

Different types of problem soils are discussed below.

7.2.1. Salt-Affected Soils Salt-affected soils are those in which either the salt contents of lower horizons concentrate in or on the soil surface or normal proportion of various cations and anions present in the soil is disturbed in a big way by excess or shortage of certain ions. Such soils are found in arid and semi-arid regions of the world where precipitation is relatively deficient to meet evaporative requirements of the plants growing there. Consequently, inorganic salts are not leached from the soil, but are amassed in soil profile. This re-distribution of salts in soil profile is generally caused by rise of water table accompanied by intensive evaporation from the surface.

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Table 7.1 Different characteristics of salt-affected soils Characteristics Electrical conductivity (dS m-1) at 25oC Soil pH Sodium adsorption ratio (SAR) Exchangeable sodium percentage (ESP) Cations

Saline soils ≥4

Sodic soils ≤4

Saline-sodic soils ≥4

≤ 8.5 ≤15

8.5-10.5 ≤15

8.5-8.10 ≤15

≤15

≤15

≤15

Na+

Na+

Anions Soil structure Water permeability

Cl-, SO4-2 Flocculated Equal to normal soil

Predominantly Na+ CO3-2, HCO3-2 Dispersed Low permeability

Dispersed Permeability not a problem

The saline water moves up through capillaries and evaporates into the atmosphere while leaving the salts on soil surface. These salts are frequently seen in the form of thin white crust in the saline areas. The crust is quite conspicuous during winter. In some cases, the percentage of exchangeable sodium (ESP) exceeds 15 which results in the destruction of soil structure (deflocculation). Salient features of different categories of salt-affected soils are given in Table 7.1. Salt-affected soils are widespread all over the earth planet. Due to uninterrupted accumulation of salts in soil, millions of hectares of arable land have become unfit for cultivation round the globe (Flagella et al. 2002). According to another estimate, 932 M ha or almost 10% of land surface of the globe is subjected to saltinduced soil degradation i.e. salinity and sodicity (Szabolcs 1989) and damage to agricultural productivity is about 25-60% of world’s irrigated land (Suarez and Rhoades 1991) as shown in Table 7.2. According to FAO (2008), about 800M ha of land all over the world is salt-affected (both saline and sodic soils) equal to 6% of the world’s land area. Table 7.2 Overall distribution of saline and sodic soils in the world Continent North America Central America South America Africa South Asia North and Central Asia Southeast Asia Europe Australia Total Source: Szabolcs (1989)

Saline 6.2 2.0 69.4 53.5 83.3 91.6 20.0 7.8 17.4 351.5

Area (M ha) Sodic 9.6 59.6 27.0 1.8 120.1 22.9 340.0 581.0

Total 15.8 2.0 129.0 80.5 85.1 211.7 20.0 30.7 357.4 932.2

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In Pakistan, it has been estimated that about 6.8 million hectares land is affected with varying degrees of salinity (Khan 1998). The crux of the problem is saltaffected and/or waterlogged farmland resulting from faulty irrigation system/practices. Salt-affected soils are further subdivided in three categories namely saline, sodic and saline-sodic soils. These subtypes are discussed in detail in following sections. 7.2.1.1. Saline soil These soils are defined as soils which have electrical conductivity of the saturation extract (ECe) of 4 or greater than 4 dS m-1 and an ESP of lower than 15. The pH of saturated paste (pHs) is less than 8.5. These soils are comprised of abundant amounts of soluble salts which inhibit germination and growth of the plants. Sodium (Na+) is not the dominant soluble cation in these soils and seldom comprises 50% of the soluble cations. Chloride and sulphate are the principal anions. Such soils may contain slightly soluble salts such as gypsum and lime. These soils are flocculated and their permeability is either greater than or equal to that of similar normal soils. Calcium chloride and magnesium chloride, being highly hygroscopic absorb atmospheric moisture keeping the soil surface moist and making it look dark in color. In order to reclaim these soils, no amendment is obligatory. 7.2.1.2. Sodic Soils Soils containing sufficient exchangeable sodium which damagingly disrupts their properties as well as plant growth are called sodic soils. Their ESP is ≥15 but ECe is less than 4 dS m-1. Generally, pH ranges between 8.5 and 10.5. Since these soils are generally dispersed, soil drainage and aeration are poor. Because of their dispersed condition, it becomes difficult to maintain a soil tilth favorable for seed germination, seedling emergence and plant growth. It also becomes difficult to replenish the water supply in the root zone by irrigation. Organic matter present in soil solution in dispersed and dissolved form may be deposited on the soil surface after the evaporation of soil solution. This phenomenon grounds darkening of the soil surface as generally observed. For this reason, these soils are also termed as ‘black alkali soils’. Application of amendments to such soils is essential to replace the excessive exchangeable sodium during reclamation. 7.2.1.3. Saline-Sodic Soils These soils containing both extraordinary levels of soluble salts as well as exchangeable sodium in ample quantity to hamper the germination and growth of most crop plants are called saline-sodic soils. Such soils are the result of both progressions of salination and sodication. Soluble salts present in saline-sodic soils affect plant growth directly, while exchanageable sodium affects it both indirectly by degrading soil properties and directly though adverse effects of Na+ on plants. Soluble salts tend to flocculate the soil particles, while exchangeable sodium tends to disperse the soil and thus decrease its permeability to water and air. Saline-sodic soils have an ESP of 15 or more and an ECe of ≥ 4 dS m-1. The pH depends on the dominance of either soluble salts or exchangeable sodium. If soil properties are dominantly affected by exchangeable sodium, the pHs of saline-sodic soils will be

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greater than 8.5 and the soils have low permeability. On the other hand, if soil properties are dominantly affected by soluble salts, the pHs will be less than 8.5 and the soils will be permeable. Therefore, pH is not a good criterion for the cataloging of salt-affected soils, especially those of saline-sodic soils. If such soils are leached in the absence of gypsum (CaSO4.2H2O), soil properties may alter distinctly and become alike to those of sodic soils. Generally, the soil pH also goes up. Therefore, the application of amendments like gypsum is essential for the effective reclamation of such soils.

7.2.2. Waterlogged Soils Waterloggingis said to a condition that all small and large soil pores are filled with water and create anaerobic condition in the soil. In fact, water is limiting gas diffusion in the soil under waterlogged conditions. It is the inundation of the soil by groundwater ample to inhibit or impede plant growth. It is a soil disorder when functions of roots of the plants are impaired due to absence of oxygen which ultimately results in ceiling in plant’s capability to take up nutrients and conduct the course of photosynthesis properly. As water amasses in the soil persistently without reasonable infiltration, it results to increase the water table level of the soil, and eventually leads to the waterlogging. Similarly, if water accrues in a particular region, salts and minerals present in soil also get liquefied in water and move to upper soil horizons which forms white salty deposits on soil surface and leads to salinity hazard. Due to lack or reduced availability of oxygen and buildup of toxins, antagonistic effects of waterlogging on plant growth and development are observed. Oxygen inadequacy prevents aerobic respiration of plants which fallouts in grave energy shortage and eventually death of plants. Waterlogging can also lessen the accessibility of some vital nutrients, e.g. nitrogen, and increase the availability of certain nutrients to toxic level. Waterlogging has been affecting about millions of people around the world leading to a large scale damages of crops, employment, livelihoods and economy. The intensity of waterlogging is variable and depends on season, general slope and soil porosity, etc. Productivity of most crops is adversely affected up to fifty per cent in waterlogged land as compared to normal land, e.g. South Asia, Sub-continent (Singh et al. 2011).

7.2.3. Clayey Soils Soils that contain a high percentage of fine particles like silicates of aluminum, iron, magnesium and colloidal substance (over 35% of the total weight) with large surface are categorized as clayey soils. These soils are dark brown with a red to orange coloration (Figure 7.1). These soils develop in situ by weathering of parent rocks. They have high field capacity, tend to become sticky and plastic when wet and harden to something resembling concrete in dry condition. Wet clayey soils are also heavy and tend to swell from the added moisture but when dry, they shrink and settle. These soils impede the flow of water, meaning it absorbs water slowly and

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then retains it for a long time. Generally, the top layer can bake into a hard, concrete-like crust which cracks. These soils are generally poorly aerated. Soils having clayey texture within soil profile occur widely throughout the world. The main areas of their occurrence are Australia (70 M ha), India (60-80 M ha), Sudan (50 M ha) but areas of considerable extent (≥ 10 M ha) include China, USA, Ethiopia and Chad. Fig.7.1 A view of clayey soil

Plants growing in clayey soils have to face difficulty because their plantlets or roots are incapable to infiltrate through hard, dry soil. Due to high adsorptive capacity of clay, irrigation water having even a trivial but recurrent addition of Na+ is plentiful to cause deflocculation of soil particles which is a very detrimental phenomenon for annihilation of soil structure and leading to reduced plant productivity. Addition of organic matter to clayey soils is an operative technique of improving growth conditions. Establishment of vegetative cover and presence of litter/organic matter will prevent evaporation from soil surface and will, therefore, minimize the development of crevices and fissures. The addition of humus and the activity of subterranean fauna will improve the soil structure that will result into easier root penetration, better aeration and better drainage. Such a soil will eventually become highly productive because of permanent woody vegetation.

7.2.4. Water-Eroded Soils Water erosion is form of erosion where detachment and removal of soil material materializes with water. Every single specific soil owns natural erosion rate. Generally, a soil with sandy or clayey texture is less susceptible to erosion as compared to loam or silt loam. It has also been observed that sandy soils which are formed with material weathered from decomposed granitic rock are exceedingly erodible. Soils originated from rock leftovers or having biological scabs on their

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surface are protected from the impact of raindrops. Generally, naked soil between the plants is most liable to erosion. The ocular signs used to recognize past erosion include: naked soil and roots, modifications in thickness of topsoil, disclosure of subsoil at land surface, rills, head cuttings, cutting in gullies, sediment in streams, curtailed plant growth, abridged soil aggregates and soil surface solidity and reduced water infiltration. The plants that grow in water-eroded sites should face any one or some of the following problems. 1) The soil is unstable and the plants are continuously subjected to either exposure of their root system as a result of erosion or burial of their shoots due to sediment deposition. 2) Shoots and leaves are subjected to mechanical damage by high velocity water currents. 3) Newly exposed sub-soil horizons are not as suitable as top soil with respect to many factors such as nutrient and water holding capacity, soil structure and porosity etc. Addition of organic matter binds stable soil aggregates and helps to check erosion, enhances infiltration, and lowers runoff rate.

7.2.5. Wind-Eroded Soils Soils are composed of sand, silt and clay particles. Individual soil particles usually need to be less than one mm to be relocated by wind. Individual clay particles have an average diameter of 0.001 mm but they commonly bunch together in aggregate forms which are too weighty to be relocated by wind. Individual particles of sand, silt, clay and organic matter are most defenseless to exclusion by wind erosion. Hence, in deserts and coastal areas, strong winds blow recurrently to cause soil erosion. The plants that grow in such situation have to face some or all of the following problems. 1) The plants are continuously faced with either exposure of their root system due to blowing away of sand or burial of their shoots due to deposition of new sand. 2) Moving sand particles cause mechanical damage to tender shoots and foliage. 3) The transpiratory load is extremely high. 4) Light intensity tends to be very high due to its reflection from shining sand surface. 5) Water holding capacity of sandy soil is very low which leads to water deficiency for most of the time. In arid and semi-arid regions of the world, wind erosion is a prevalent phenomenon and light textured soils with a limited vegetative cover are subjected to severe

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destruction. Continental distribution of soils affected by wind erosion has been presented in Table 7.3. Wind erosion is primarily caused by overgrazing (60%), followed by mismanagement in agricultural practices (16%) and over exploitation of vegetative cover for domestic usage (16%). Deforestation (8%) is considered as fourth causal element foremost to wind erosion. Wind erosion depreciates soil quality by amending soil properties important for optimal plant growth and output. Wind erosion is a common cause of land degradation in the arid and semi-arid grazing lands which eventually leads to desertification. Substantial wind erosion happens when strong winds blow over light-textured soils which have been ruthlessly grazed and browsed during drought periods. As a result of wind erosion, dunes are persistently moving; hence roads and tracks are covered by itinerant sands in moments. Soil fertility is reduced as a result of loss of plant nutrients which are concerted on fine soil particles and organic matter contents in the topsoil. This reduces the soil’s capability to support prolific pastures and endure rich biodiversity. Hence, we may establish that soil erosion is the most widespread form of soil degradation. As per estimate, total land area a5ffected by erosion is 1047 M ha; out of which 751 M ha by water erosion and 296 M ha is rigorously affected by wind erosion (Oldeman 1994; Scherr 1999) as shown in Table 7.3. Table 7.3 Global extent of water and wind erosion Continent/region Africa Asia South America Central America North America Europe Oceania World

Land area affected by severe erosion (M ha) Water erosion Wind erosion Total 169 98 267 317 90 407 77 16 93 45 5 50 46 32 78 93 39 132 4 16 20 751 296 1047

Total as percent of total land use 16 15 6 25 7 17 3 12

Source: Oldeman (1994)

7.3.

Tree Species Suitable for Plantation in Problem Soils

A plantation is defined as an extended, artificially-established forest, farm or estate where tree crops are grown. Tree planting is carried out in different parts of the world; however, planting strategies may be unlike widely across nations, regions and among individual afforestation enterprises. Intentions of tree plantation may include production of lumber, fuel wood and forage; erosion control, watershed protection, wildlife habitat improvement, riparian shield creation, improvement of

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stocking or composition in open woodlands, Christmas tree production, shelterbelt establishment, energy conservation and land scape remodeling. Therefore, efforts must be made to make plantation at the right time of the year and choose a suitable tree for the region, climate, and space keeping in view the objectives of the plantation being raised. Selection of trees and shrubs for establishment of any plantation should be site specific i.e., it must be based on capability of the plant to withstand biotic and abiotic stresses and be suitable as per climatic conditions of site, region or locality. It is better to use native species if these are capable to serve the same objectives like exotic species. It is because acceptability of local plant species is normally better among communities. Depending upon the severity of the problem in soils, there are several options for establishing vegetation or changing the type of vegetation. Use of perennial woody plants has the advantage of reducing annual maintenance costs and their deeper-rooted habit will assist with water management which is the key to restore land productivity. Information regarding the ability of various trees, shrubs and bushes to withstand ecological conditions are given in the following guidelines.

7.3.1. Tree Species for Salt-Affected and Waterlogged Soils Tree species most suitable for salt-affected areas lying in subtropical climate include Eucalyptus camaldulensis, E. tereticornis, Acacia nilotica and Prosopis juliflora. Certain tree species have adjusted to waterlogging environments by emerging root air channels called as aerenchyma and adventitious (nodal) roots. Examples of such plants are Casuarina obesa and Eucalyptus camaldulensis. Some temperate tree species like poplar and willow can also withstand waterlogging. Other species include Azadirachta indica, Albizia lebbeck, Casuarina equisetifolia, Leucaena leucocephala, Phoenix dactylifera, Salvadora oleoides, Syzigium cumunii, Zizyphus spp., Sesbania aculeata, Acacia ampliceps, Prosopis chilensis, Eucalyptus striaticalyx, Prosopis cineraria, Casuarina glauca, Prosopis tamarogo etc.

7.3.2. Tree Species for Waterlogged Soils Plants suitable for waterlogged soils include Acacia nilotica, Albizia lebbeck, Azadirachta indica, Casuarina equisetifolia, Broussonettia papyrifera, Eucalyptus camaldulensis, Leucaena leucocephala, Phoenix dactylifera, Prosopis juliflora, Salvadora oleoides, Syzigium cumunii, Tamarix aphylla, Zizyphus spp., Ficus religiosa, Populus euramericana, Terminalia arjuna, Sesbania aegyptica, Tamarix dioica. A brief chart of woody plants is given in Table 7.4 showing their site specificity.

7.3.3. Tree Species for Clayey Soils Acacia nilotica, Acacia modesta, Tamarix aphylla, Tecoma undulata, Pongamia pinnata, Zizyphus mauratiana, etc.

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7.3.4. Tree Species for Wind-Eroded Soils Acacia jacqumontii, Calligonum polygonoidies, Prosopis spicegera, Salvadora oleoides, Tamarix aphylla, Tecoma undulata, Broussonettia papyrifera, Albizia lebbek, Azadirachta indica, Casuarina equisetifolia, Eucalyptus camaldulensis, Leucaena leucocephala, Phoenix dactylifera, Prosopis juliflora, Salvadora oleoides, Syzigium cumunii, Zizyphus spp., Ficus religiosa, Populus euramericana, Terminalia arjuna, Sesbania aegyptica, Tamarix dioica.

7.3.5. Tree Species for Water-Eroded Soils Cordia myxa, Dalbergia sissoo, Ficus bengalensis, Morus alba, Prosopis spicegera, Robinia pseudoacacia, Salix tetrasperma, Bombax ceiba, Tamarix aphylla, Vitex negundu, Zizyphus mauratiana. Table 7.4 Rating of specific trees and shrub species to root-zone salinity, sodicity and waterlogging Species Acacia ampliceps A. nilotica A. saligna A. stenophylla A. tortilis Ailanthus excelsa Albizia lebbeck A. procera Azadirachta indica Butea monosperma Casuarina equisetifolia C.glauca C. obese Conocarpous lancifloius Dalbergia sissoo Eucalyptus camaldulensis E. citriodora E. tereticornis Leucaena leucocephala Parkinsonia aculeata Pongamia pinnata Prosopis juliflora Tamarix aphylla Tamarix aculeate Terminalia arjuna Zizyphus jujuba

Salinity Severe Moderate Moderate Severe Moderate High Moderate Moderate Moderate Moderate High High/Severe Moderate Moderate Moderate/High Moderate Moderate/High Low/Moderate Moderate Moderate Severe Severe Severe High High

Source: Extended from Marcar and Khanna (1997)

Sodicity Severe High Moderate Severe Moderate Moderate Moderate High High Moderate/High High Moderate/High High Moderate/High High High Moderate/High -

Waterlogging No Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes

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7.4.

Methods/Techniques for Tree Plantation on Problem Soils

Planting of a tree is not as simple as just digging a hole and throwing the tree in it. In order to make successful plantation, one must take special care for better survival of the trees planted. A suitably planted tree or shrub can withstand more stressed conditions and need much less managing care than one planted incorrectly. Therefore, successful tree establishing includes a chain of steps, each one reliant upon the others. These strides comprise: scheduling, site preparation, choosing and gathering planting stock, caring for the nursery stock, planting techniques and plantation upkeep. Thus, adoption of proper planting techniques for making plantation in problem soils cannot be overemphasized.

7.4.1. Planting Methods in Problem Soils There are two basic tree planting methods which may be adopted for plantation in problem soils depending on prevalent conditions. 1) Hand planting: It is apposite method when plantation is to be carried out with a minor number of seedlings or if the situate is not helpful to equipment maneuver. Hand tools used for tree planting include auger, planting bars, spades, shovels and other apparatuses which help for digging holes for the planting stock. 2) Machine Planting: It can facilitate the task of planting trees on large scale. Specially designed tree planters are available in advanced countries for planting on tougher sites. Such planters can plant 500 to 1,000 or more trees per hour. Adoption of site-specific planting techniques for problem soils ensures successful afforestation. Therefore, while decisive about planting techniques, one should think through about the on-site condition, nursery raising, the plant's drainage provisions and the convenience of irrigation water facility. The plant should be precisely apposite to the locality, or the site should be modified to explicitly fit the plant. Appropriate planting technique also minimizes water, fertilizer and pesticide use. Various techniques which may be valuable for successful plantations in problem soils are discussed here-under.

7.4.2. Tree Planting Techniques for Salt-Affected Soils Regarding modification of planting techniques, the following points should be kept in view. 1) Use of large vigorous plants: Entire plant with a ball of earth or potted plants be selected. Shoot or root cutting, etc. must be avoided. 2) Pit planting having following modifications should be adopted. a. Top 8-10 cm of saline surface soil be removed from planting site and should not be used for filling the pit.

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b.

3)

4)

5) 6)

Relatively large pits, i.e. 1 meter diameter x 1.25 m depth should be dug. c. If possible, powdered gypsum, farm yard manure and/or coarse sand should be mixed with dug-out soil and this mixture be used for filling the pit. The surface of the filled pit should be 15 cm below the soil surface to avoid accumulation of salts. d. It is better to cover the pit surface with 5-8 cm layer of coarse sand or litter. The layer would cut off evaporation and prevent salt accumulation on pit surface. e. A ridge should be provided around every pit to prevent surface run-off saline water from bringing salts into the pit. Fresh water should be provided at short regular intervals during the initial stages. Later on, watering intervals may be increased along with an increase in its intensity. Plants should be rigorously protected from climatic and biotic stresses such as frost, hot dry winds, extreme solar radiation, extremely high temperature of soil surface, trampling and browsing etc. Most plants can overcome one problem (salinity, drought, waterlogging, etc.) at a time, however, fail to survive when these are faced with two or more problems simultaneously. One should, therefore, try to minimize the number and intensity of problems. Fluctuations of surface soil temperature should, for example, be moderated by providing a little mulch and keeping the soil moist. If there is heavy deposition of salts, it is better not to undertake any planting on large scale unless supported by research and experience. If salinity and alkalinity are found coupled with high water table, deep drains should be provided much before planting as a vital part of site preparation.

7.4.3. Tree Planting Techniques for Waterlogged Soils Regarding planting techniques, the following points should be kept in view. 1) Mounds or ridges of appropriate size (one meter high) should be made to increase the distance between plant roots and water table. The young plants can, therefore, grow unabated in their early life. During later growth stages, roots strike the water table, they are able to survive there as a result of acclimatization (adjustment). Although it sounds funny, water will have to be provided to the young plants growing at the top of mounds or ridges during the first few months. 2) Relatively large and vigorous plants should be used. Entire plants with or without ball of earth should be preferred. 3) Tree planting should proceed from least-affected to most-affected areas. In first phase, one should plant to encircle the most-affected area by planting trees on least affected peripheral area that surrounds it from all sides. With

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passage of time, the most-affected area will become smaller and smaller in size because of water consumption by trees. In the second phase, the trees should be planted further towards the center on newly but partly reclaimed area. The tree planting thus continues to advance and the entire area gets reclaimed within a few years.

7.4.4. Tree Planting Techniques for Clayey Soils The following points should be kept in view while undertaking any planting in such an area. 1) Suitable hardy, drought resistant, fast growing species with deep root system should be preferred. 2) Large sized plants with intact root system should be used. Potted plants or the ones with balls of earth may be preferred. 3) Necessary pruning of branches should be done just prior to or after planting in order to improve root shoot ratio. 4) A large pit of 1 m diameter and 1.25 m depth should be dug. One should make sure that hard pan is broken. This will increase the depth of available soil. 5) The pit should be filled with a mixture of soil, coarse sand or gravel and organic manure. Sand is, however, most important component. This will improve the aeration and drainage and will minimize crevices and fissures. 6) An 8 cm thick layer of pure sand or fine gravel should be provided at the surface of each pit. This will cut down evaporation loss of soil water and make available more water. 7) In areas of low rainfall, interplant spacing should be increased and each plant should be provided with a little watershed of its own. If properly done, this practice alone can increase the available water supply equivalent to 3-4 times of natural precipitation. 8) In order to increase the water supply, the watershed should be compacted and weeds should be removed. The size of watershed will depend on water requirement of plants, annual precipitation and rate of water infiltration. 9) The plants should be particularly protected against hot dry winds, drought, trampling and browsing etc.

7.4.5. Tree Planting Techniques for Water-Eroded Soils Biological solution to this problem has two components: a selection of suitable species and modification of planting method. Regarding the selection of suitable species, one should first of all know the desired qualities that make a species suitable for this purpose. The following characteristics are important. 1) A very extensive and fibrous root system that firmly binds the soil or sand particles and thus prevents erosion.

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2) Ability to produce profuse adventitious root system from nodes and buds that effectively utilizes newly deposited sediments. 3) Elastic shoot and leathery leaves that bend easily and resist mechanical damaged due to water currents. 4) Perennial, fast growing, drought resistant and spreading type plants should be preferred to give complete and permanent vegetative cover in the shortest possible time. It is easy to select suitable species for this purpose from our local flora. As far as modification of planting methods and strategy of planting are concerned, one should keep the following points in view. 1) Planting should be done along contour at low spacing. 2) Continuous, discontinuous trenches, ridges or trough pits may be used for planting. Their choice depends upon the amount, intensity of rainfall and water holding capacity of soil. 3) All spots and stretches having more than 15% slope should always remain under woody or grass vegetation. The remaining area may be terraced and brought under cultivation for farm crops. 4) Gullies be plugged at their heads to begin with and later along their course by driving posts of green branches which can sprout and developing new root system of their own and by filling space in between with brush wood and stones. Gully floor should be planted with grass or paved with stones. 5) Stream banks can be consolidated by driving live posts which are capable of sprouting and developing roots. In between posts, fast growing shrubs (Vitex negundu), bushes (Impomoea carnia) and grasses (Saccharum spontaneum) may be planted. Brush wood may also be placed in between posts. All above mentioned operations reduce the water velocity and lead to accelerated sediment deposition and raising of stream bank. These operations may be carried out in such a way that water is directed to flow in a permanent predestined course. 6) Once the stream bank or eroded soil has been consolidated, it should be brought to productive use by planting suitable fruit or timber trees.

7.4.6. Tree Planting Techniques for Wind-Eroded Soils In order to grow tree plants successfully in wind-eroded sites, a plant should have qualities like drought resistant, fast growing and spreading type, extensive and deep root system that will hold together loose sand particles, capable of producing new adventitious root system from various nodes and buds in order to overcome the problem of sand deposition and elastic shoots and thick bark or epidermis in order to avoid mechanical damage of wind and wind borne particles. Fortunately, it is not difficult to select some species from our local flora, in Pakistan, that have most of the above mentioned qualities. 1) Perennial herbs, grasses and bushes should be planted as a first step, which should be followed by planting of shrubs and trees. Large-sized entire

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2) 3) 4) 5) 6)

saplings with ball of earth or with biodegradable baskets made from Typha angustifolia, Phoenix dactylifera, Nannorrhops ritchienana or punched polythene bags should be used. Planting should be first concentrated on exposed windward sites. Loose soil should be stabilized on highly exposed spots by the use of organic mulches and spray of suitable adhesives. Planting should be done in the beginning of rainy season and at a time when strong winds have subsided. The interplant spacing should be kept to a minimum. Traditional cultural operations such as weeding, cleaning, thinning and pruning should be avoided.

In case of avenue plants or otherwise where hand watering or trickle irrigation is to be done, small earthen jugs (with lids at the top and a minute pore at the base) may be buried close to the tree sapling. This ensures minimum loss of water through evaporation/percolation and leads to maximum uptake by the roots.

7.5.

Biomass Productivity, Economics and SocioEconomic Impact of Plantations

7.5.1. Biomass Productivity Small-scale timber plantations established on such problem soils provide an excellent opportunity to develop an enterprise that market wood as timber and fuelwood for enhanced wood, forage and other beneficial products. Figures (7.2a7.2d) show impressive growth of different tree plantation established on saltaffected soils at Biosaline Research Station, Pakka Anna, NIAB, Faisalabad. Certain tree crops compatible to specific site conditions may be more productive in such environments like growing of Eucalyptus in waterlogged soils. The major benefit of growing trees is the production of wood of different categories and other by-products. Quantitative estimation of above ground biomass is important to measure productivity potential of different tree plantations for their economic viability. Growth and biomass productivity potential on of some trees grown in salt-affected soils is given in Table 7.5 which show that certain tree species like Prosopis juliflora, Acacia nilotica, Casuarina equisetifolia and Terminalia arjuna have good growth potential on problem soils as experienced in India and Pakistan. Fuel wood, charcoal and timber produced from such soils can be utilized for all types of applications just like wood formed from fertile soils without any alteration. Wood produced from poor soil soils can also be utilized for pulp and paper production without any disinclination. Table 7.6 presents the feasibility plan for founding of a small paper mill in regions appropriate for Eucalyptus plantation which will support its marketing, help ranchers to boost their income and lessening unemployment ratio as well as expenditure incurred on import of paper.

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a

b

c

d

Fig. 7.2 View of tree plantations (a: Eucalyptus camaldulensis, b: Azadirachta indica, c: Prosopis juliflora, and d: Acacia ampliceps on salt-affected soil at Biosaline Research Station, Pakka Anna, NIAB, Faisalabad.

7.5.2. Economic Perspective In addition to ecological conditions, various economic factors also strongly influence the community regarding tree plantation on problem soils. These factors include opportunity cost for various factors of production, access to the market for inputs and outputs, risk and access to credit and profitability etc. Financial analysis of several plantations has revealed that raising of Eucalyptus and Acacia plantations on mass scale are financially workable and striking to farming community in degraded soils. In certain cases, farming of Acacia is more striking as compared to Eucalyptus (if Eucalyptus is sold as fuel wood) as shown in Table 7.7. This table shows that growing of Acacia niloticaand Eucalyptus camaldulensis is financially viable at low prices for farmers in problem soils. Various research

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endeavors conducted on community benefits and costs of Eucalyptus plantations, likewise, aid to the hypothesis that tree crops grown-up for wood must be constrained to marginal lands. Major emphasis should be laid on production of these two species being producers of wood with multiple uses. Table 7.5 Biomass appraisal of trees afterwards 10 years of planting on saline soils Tree species Terminalia arjuna Azadirachta indica Prosopis juliflora Pongamia pinnata Casuarina equisetifolia Prosopis alba Acacia nilotica Eucalyptus tereticornis Pithecellobium dulce Cassia siamea

Biomass (kg tree-1) 90.75 48.25 140.03 67.93 104.48 69.15 123.64 80.14 84.15 58.10

Total biomass (Mg ha-1) 52.95 26.62 70.27 36.69 53.11 39.12 63.09 39.67 40.45 24.36

Source: Singh et al. (2011)

Table 7.6 Growth rate of Eucalyptus camaldulensis at various spacing in Pakistan Age of tree (years) 4 6 8

Spacing (m)

Growth rate (m3 ha-1 yr-1)

Land area (ha) required for annual supply of a pulp mill

1.5 x 1.5 3.0 x 1.8 3.0 x 3.0 1.5 x 1.5 3.0 x 1.8 3.0 x 3.0 1.5 x 1.5 3.0 x 1.8 3.0 x 3.0

35.6 28.5 21.4 30.3 24.4 17.6 25.3 16.5 17.5

5541 6918 9240 5622 6984 9660 6249 9567 9015

Source: Aslam et al. (2002).

Similarly, Table 7.8 shows net economic returns obtained through raising tree plantations of different tree species on salt-affected soil which was previously unproductive. Eucalyptus camaldulensisand Acacia niloticafetched higher prices/financial benefits as compared to other tree species. In order to make such programs economically feasible, effort should be made to establish these tree plantations ‘site-specific’ on the basis of marketing of the produce. For example, an area planted with Eucalyptus away from pulp mill would fetch fewer prices for wood due to transportation cost. Both the species have the capability to grow in diverse agro-ecological zones and their wood is also of multiple usages.

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Table 7.7 Sensitivity test of financial analysis of various tree plantations Wood commodities Eucalyptus camaldulensis Acacia nilotica Albizia spp. Pongamia pinnata Leucaena spp. Terminalia arjuna Prosopis cineraria Tamarix aphylla

Benefit cost ratio @16% mark up 1.02:1 1.15:1 1.06:1 0.98:1 1.08:1 1.00:1 0.62:1 0.64:1

Internal Rate of Return (IRR) 6.7% 20.6% -1.2% 15.4% 17.8% 16.2% 3.2% 4.4%

Source: Shahid et al. (2002)

Table 7.8 Biomass productivity, growth and gross monetary return of different species on saline-sodic soils Species

Leucaena leucocephala Acacia nilotica Parkinsonia aculeata Albizia lebbeck Eucalyptus camaldulensis Tamarix aphylla* Prosopis cineraria

Timber production (11 years old plantation) Main stem weight Main stem length (kg plant-1) (m) 90 7.32 150 7.32 38 2.44 99 6.10 203 7.92 35 4.57 52 4.27

Gross return PKR y-1 6,000 10,000 1,400 6,600 16,107 3,182 3,467

*Growth after 5.5 years Source: Aslam et al. (2002)

7.5.3. Socio-Economic Impact Perennial woody plantations established in problem soils can deliver manifold environmental, economic and social benefits to the community if such plantations are appropriately planned and included into multiple land use ventures. Generally, tree plantations always exist in our social and cultural set up depending upon the occupants of the region before the plantation was established, and the residents who arrived after the plantation was well established. In order to evade adverse effects of tree plantation on society and natural environment and make it cost-effective, each plantation needs to be designed for its peculiar social, cultural, and ecological background. As plantation field work and related activities depend on local labor, it should be preferred to uphold the structure of local community in a way that provision of steady supply of reliable workers is ensured. Hence, more the plantation is unified into day-to-day economic and societal life of the community is desirable to the joint benefit of both the community and the plantation; and the plantation is more likely to succeed in the long run. Adopting another technique, tree establishment can be further enhanced through interplanting of agricultural

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crops during initial years of plantations. Thus, agroforestry practices also support the plantations as well as local community by contributing food and/or cash crops. Plantation of suitable tree species on problem soils can be assistance to the village people through providing firewood and small timber, thus reducing pressure on natural forests. These plantations may also act as a safeguard against fiscal crisis for countless poor farmers alive on the land unsuitable to practicable agriculture. These plantations may also assist to increase job opportunities in planting as well as in downstream industries.

7.6.

Conclusion

The ever-increasing demand for food, feed, energy and raw materials warrants urgency for proper exploitation of the under-utilized ‘so-called degraded’ land resources. It is emphasized that existing reclamation practices / technologies may be adopted on a mass scale by the farmers to utilize poor/degraded soils for successful tree plantations. Despite disagreement over the exact extent and rate of land degradation, state-of-the-art scientific assessments demonstrate urgent attention for proper utilization of such soils for higher productivity. Option for establishment of tree plantations while utilizing diverse plant genetic resources may lead to proper utilization for poor degraded soils. Various stress tolerant tree plants are capable to generate better economic returns. So, it seems realistic that instead of capitalizing more and more on reclamation programs, poor ranchers can decide for low-cost practices of growing tree plantations on their infertile land means. Thus, judicious use of the poor soils through improved production systems with people’s participation is the way to turn ‘problem soils’ into ‘productive soils’ with tangible economic and ecological benefits. To maintain long-standing community compulsions to afforestation schemes, it is imperious to have secured timber remunerations, improving civic business skills and safeguarding cost-effective investment plans.

References Aslam, M. (2002). Salt-affected soils: options for rehabilitation. Pak. J. Soil Sci. 21: 119-126. Aslam, Z., A.R. Awan, M.A.A. Qureshi, T. Mahmood, M.I. Haq, A.K. Chaudhry and K.A. Malik (2002). Growth, ion uptake, agro-industrial uses and environmental implications of Eucalyptus camaldulensis in saline systems. In: Ahmed, R. and K. A. Malik (ed). Prospects for Saline Agriculture, Kluwer Academic Publishers. Pp. 277-285. Bouwer, H. (2000). Integrated water management: emerging issues and challenges. Agric. Water Manage. 45: 217–228. FAO (2008). Land and plant nutrition management service. Food and Agricultural Organization. Rome, Italy. http://www.fao.org/ag/agl/agll/spush/.

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Flagella, Z., V. Cantore, M.M. Giuliani, E. Tarantio and A. De-Caro (2002). Crop salt tolerance: physiological, yield and quality aspects. Rec. Res. Dev. Plant Biol. 2: 155-186. Gupta, R.K. and I.P. Abrol (2000). Salinity build-up and changes in the rice–wheat system of the Indo-Gangetic Plains. Exp. Agric. 36: 273-284. King, F. and L.T. Chandler (1997). The Wasted Lands. ICRAF, Worl Agroforestry Center, Nairobi, Kenya. Khan, G.S. (1998). Soil salinity/sodicity status of Pakistan. Soil Survey of Pakistan, Lahore, Pakistan. pp. 59. Marcar, N. E. and P. K. Khanna (1997). Reforestation of salt-affected and acid soils. In: Nambiar, E.K.S. and A. Brown (ed). Management of Soil, Nutrients and Water in Tropical Plantation Forests. ACIAR Monograph No. 43, Canberra, Australia, p. 481-525. Oldeman, L.R. (1994). The global extent of soil degradation. In: Greenland, D.J. and I. Szabolcs (ed). Soil Resilience and Sustainable Land Use. Wallingford: CAB International. pp. 99–118. Qadir, M. and J.D. Oster (2004). Crop and irrigation management strategies for saline-sodic soils and waters aimed at environmentally sustainable agriculture. Sci. Total Environ. 323: 1–19. Scherr, S. (1999). Soil degradation: a threat to developing country food security by 2020. IFRI Food, Agric. and Environment Discussion Paper 27, Washington, DC. 63 pp. Shahid, S.A., H. Rehman and M. Afzal (2002). Economic option for agricultural production in saline areas of Pakistan. Pak. Econ. & Social Review, XL-II: 89120. Singh, Y.P., G. Singh and D.K. Sharma (2011). Ameliorative effect of multipurpose tree species grown on sodic soils of Indo-Gangetic alluvial plains of India. Arid Land Res. Manage.25: 55-74. Suarez, D.L. and J.D. Rhoades (1991). Soil salinity. In: Nierenberg, W.A. (ed). Encyclopedia of Earth System Science. Academic Press, USA. pp. 251258. Szabolcs, I. (1989). Salt-Affected Soils. Bosa Raton. FI. CRC Press. Wild, A. (2003). Soils, Land and Food: managing the land during the twenty-first century. Cambridge University Press, Cambridge, UK.

Chapter 8

Forest Diseases and Protection S. Dawar, I. Ahmad and M. Tariq*

Abstract This chapter deals with the forest diseases and their management strategies. Pakistan is blessed with number of plant species including trees; however, forests are declining rapidly. Major cause of deforestation is the cutting down of trees followed by the diseases caused by pathogens. Both ornamental and forest tree species are susceptible to these pathogens. Both man-made forest plantations and naturally occurring forests suffer from these diseases, especially, the diseases caused by fungi. Most of the fungi attacking on trees are host-specific, which limit the spread of diseases to other non-host species, but such fungi greatly damage the orchards bearing economically important trees mainly of same host species (fruit trees and trees cultivated for timber). In forest plantations and orchards, if one tree is attacked by the fungal pathogen, other trees are likely to suffer. In the current chapter, a brief introduction about forests is given, followed by describing economically important diseases. Care has been taken while suggesting disease control strategies. Keeping in view the high cost and intensive labor involvement, it is difficult to control or manage the forest diseases. Therefore, we have mentioned

* S. Dawar Department of Botany, University of Karachi, Pakistan. For correspondance: [email protected]

I. Ahmad Department of Forestry and Range Management, University of Agriculture, Faisalabad, Pakistan. M. Tariq MAHQ Biological Research Centre, University of Karachi, Pakistan. Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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only those disease management practices and remedial measures which have some practical implications. Keywords: Dieback; Forest trees; Wood rot; Fungal diseases, Leaf spot, Powdery mildew.

8.1.

Introduction

Forests are vital to mankind and are essential for life on Earth, as they support biodiversity. Trees releases oxygen by the process of photosynthesis and takes in carbon dioxide, thus giving the life fresh oxygen to breath and provides home to a variety of animals, birds and other organisms. The wood obtained from forest trees is mainly used by man in multiple ways. Generally, the wood of forests is used as timber, lumber, fuel, for the manufacturing of paper, wood extracts and the leaves of trees are used in medicines, cosmetics etc. while some species of trees are religiously important (Anonymous 1999). Forests also bring rainfall and prevent from soil erosion; the trees keep the water bed of land under control. Trees also provide food, fruits and shade to animals, birds and human beings. In general, forest referred to the area in which there is a dense population of trees. Due to severe deforestation, man has promoted social forestry i.e agroforestry, community forestry, urban forestry, irrigated forest plantations etc. Pakistan is fortunate which blessed with large number of tree species; however, according to a survey by World Bank and FAO, the total area of Pakistan under forest has declined to 2.2% during 2010, which is very alarming situation (Anonymous 2014a; FAO 2014; Khan 2014). There is much plantation of trees and shrubs within the country on roadsides, parks, homes and orchards; however, such plantation is not considered as forests. Trees like Lannea spp. (Kamlai), Bombax ceiba (Semal), Acacia catechu (Kath), Pinus wallichiana (Kail), Pinus roxburgii (chir pine), Cedrus deodara (deodar, diar), Quercus incana (rin), Q. dilatata, Q. semecarpifolia, Abies pindrow (partal), Pinus gerardiana (chilghoza), Quercus ilex, Junipers macropoda, Salix spp., (willow, baid), Ephedra spp., (asmania), Ficus religiosa (peepul), Platanus orientalis (chinar) Eucalyptus spp., Dalbergia sissoo (shisham), Acacia nilotica (kikar), Populus spp. (poplar), Morus alba (mulberry), Azadirachta indica (neem), Capparis decidua (karir), Prosopis spp. (Jhand), Berberis (sumbal) Ziziphus mauritiana (beri), Tamarix aphylla (farash), Salvadora oleoides (pilu) etc are commonly found in different forest types of Pakistan (Orwa et al. 2009). These trees are sometimes susceptible to diseases caused by pests, fungi in particular. Fungal plants pathogens like powdery mildew, sooty mold, leaf scorch, die back, anthracnose, stem rust, broom rust, smuts, root rot, root-infecting vascular wilts, stem decays, cankers etc are the common diseases found in forest trees. These fungal pathogens not only produce diseases but cause considerable damage to economy of the country as well. Some of the diseases commonly found in Pakistan on trees in general; and forest trees in particular are described below:

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8.2.

163

Powdery Mildew Disease

Powdery mildew is one of the most common, widespread and easily recognizable plant disease; infecting about 10, 000 plants species of 1600 genera (Cooper 2002; Anonymous 2007). Wide host range makes powdery mildew an economically important disease. Fungi causing powdery mildew are obligate, host specific parasites which attack the plants during warm, dry and humid weather (Newman and Pottorff 2013). Fungi belonging to the order Erysiphales are responsible for producing powdery mildew disease (Table 8.1). Powdery mildew seldom kills their hosts, however, the pathogens utilize the nutrients of hosts, reduce photosynthesis, increase transpiration, respiration rate and reduce the yields upto 20 – 40 % (Agrios 2005).

8.2.1. Disease Distribution Kulkarni (1924) reported this disease for the first time in India. Bertus (1946) reported from West Indies, Dyer (1947) from South Africa, Fieds (1945) from United States (California), Landaeta and Figueroa (1963) from Venezuela and Boesewinkel (1980) from New Zealand. All these first reports of powdery mildew diseases were on mango trees. Erper et al. (2010) reported powdery mildew (Phyllactiniafraxini) for the first time from Turkey on Ash tree (Fraxinus excelsior) present along road sides. Lee (2012) reported powdery mildew (Erysiphe arcuata) on lance leaf coreopsis (Coreopsis lanceolata) for the first time from Korea. Lee et al. (2011) reported E. quercicola causing powdery mildew on ubame oak in Korea. In Pakistan, it is known to attack 70 different plant species (Anonymous 2007). Species of Phyllactinia, Erysiphe, Leveillula, Podosphaera, Uncinula, Microsphaera and Oidium etc are responsible for causing powdery mildew on wide host range of forest and ornamental trees (Table 8.1). Table 8.1 Host range of powdery mildew disease Causal organisms Phyllactinia dalbergia

Erysiphe acacia Microstroma acacia Phyllactinia gutlata, P. suffulta Microsphaera extensa Oidium eucalypti, Erysiphe cichoracearum Uncinula salicis Uncinula adunca Uncinula aceris Erysiphe largerstroemiae

Hosts Betula, Fraxinus, Alnus, Quercus, Carpinus, Fagus, Xanthoxylum, Castanea, Magnolia, Acer, Celastrus, Ulmus, Mulberry, Juglans regia, Morus alba, Pyrus communis, P. pashia, Celtisaustralis, Dalbergia sissoo Acacia catechu Acacia catechu Morus alba, Dalbergia sissoo, Salix tetrasperma, Alnus nitida Quercus ilex Eucalyptus spp Populus ciliata, Salix daphnoides, S. julacea, S. caprea, S. cinerea, S. viminalis, S. babylonica Salix alba, S. triandra, S. caprea Acer pseudoplatanus, A. oblongum Lagerstroemia lanceolata

164 Pleochaeta polychaeta Uncinula tectonae Erysiphe sikkimensis Uncinula polychaeta Phyllactinia mespili

Forest Diseases and Protection Celtis australis Tectona grandis (Teak) Castanopsis tribuloides Celtis australis Cotoniaster bacillaris

Source: Khan (1989)

8.2.2. Disease Symptoms Powdery mildew produces similar symptoms on all host plant species. Spots or patches of white to grayish, powder like growth of fungus can be seen on upper surfaces of leaves. The powdery mildew fungi in general, produce chasmothecia (cleistothecia), which are first white but later turn yellow-brown and finally black. The disease symptoms first appear on lower (older) leaves of plants and spread towards the upper leaves, causing chlorosis around the infected areas (Wegulo 2010). Commonly stunting and distortion of leaves, buds, growing tips and fruits are observed on infected trees (Hartman 2008) [Figure 8.1]. Fig. 8.1 Powdery mildew of Neem Tree

8.2.3. Disease Description Powdery mildew fungi over winters survive as dormant mycelium in dead leaves, buds and other parts of living host tissue etc. Powdery mildew fungi produce spores both sexual and asexual, depending upon the type of fungi. The spores germinate giving rise to hypha, which grows on the surface of the host plant. Powdery mildews typically grow superficially and produce appressoria that help in attachment of mycelia to plant surfaces. Haustoria, which are specialized outgrowth, arise and penetrate the cell wall of host to obtain nutrients. The asexual spores or conidia are produced in chain, which can be easily blown by wind and can infect host of the specific type only. For example, powdery mildew of maple trees will infect only other maple trees or members of the same genus. The sexual stage produces cleistothecia (chasmothecia) which releases ascospores.

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Appendages are produced on the surface of cleistothecia which is a characteristic feature of this group (Cooper 2002).

8.2.4. Disease Management Disease can be managed by the following methods (Cooper 2002; Agrios 2005; Hartman 2008; Wegulo 2010). •

Disease prefers warm humid temperature for development. The mycelium or conidia die due to excessive water, therefore, watering the plants directly or washing the infected leaves or high rainfall may reduce this disease, however, excess water may help other pathogens by making the plants susceptible.

•

These fungi over winters in folded leaves and fallen leaf litter and other parts of plants tissues. Removal of leaf litter and other debris is recommended near the tree trunks or seedling beds. pruning and cutting of trees are helpful. Properly discard the pruned branches or cuttings, especially branches showing powdery mildew symptoms should be burnt to eliminate the disease.

•

For agronomically important trees, resistant cultivars should be used. Much work is needed in this regard, as more and more resistant cultivars are required nowadays.

•

Commercially available systemic fungicides can be used to reduce the disease; however, such fungicides can be applied only to the forests which are man-made, for naturally occurring forests like the ones growing on mountains, application of fungicide on such a large scale would be practically impossible.

8.3.

Leaf Spot Disease

Leaf spot is a common descriptive term used for several diseases affecting the foliate of various ornamental and forest trees. Most leaf spots are caused by fungal pathogens however; bacteria or insects can also become the reason for leaf spots. Leaf spot disease does not kill the plant, fully established trees can tolerate complete defoliation (defoliation occurs because infected leaves shed due to necrosis); however young seedlings or newly emerging may suffer because of defoliation. Species of Alternaria, Ascochyta, Cercospora, Ciborinia, Coccomyces, Coniothyrium, Coryneum, Cristulariella, Cylindrosporium, Discochora (Guignardia), Elsinoe (Anamorph: Sphaceloma), Entomosporium (telomorph: Diplocarpon), Gloeosporium (various synonyms), Gnomonia (Stegophora), Hendersonia, Marssonina, Microstroma, Monochaetia, Mycosphaerella, Phyllosticta, Physalospora, Rhytisma, Septogloeum, Septoria, Taphrinia, Tubakia (synonym: Actinopette), Venturia, Blumeriella, Colletotrichum etc are some causal agents of leaf spots on wide variety of hosts throughout the world (Table 8.2). These genera include more than 1000 species of fungi which are capable of producing disease (Pataky 1998; Douglas 2012; Anonymous 2014b).

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Table 8.2 Host range and causal organisms of leaf spot disease Causal organisms Cercospora sissoo, Septogloeum dalbergiae Septogloeum sp Physalospora acacia Calonectria theae Mycosphaerella dalbergia Endodothella albizziae Calonectria theae Phleosetpora cassia, Cylindrosporium cassia, Colletotrichum lindemuthianum, Cercospora angustata Mycosphaerella mori Cercospora bombacina Ascochyta quercus Glomerella cingulate Corynespora cassiecola Drapenopeziza popularum Cladosporium herbarum Helotium epiphyllum, Phiala subhyalina Mycosphaerella skimiae Polystigma ochraceum Pestalotia guepinia Phyllostictina artocarpina Colletotrichum arjunae, Sphaceloma terminaliae Phyllachora bambusae, P. malabarensis, P. shiraiana Microxyphium artocarpi Ravenelia hansfordii Fusarium roseum Cercospora simarubaciensis Pestalotiopsis versicolor Microthyrium juniper, Trimmatostroma juniper

Hosts Morus alba, Poplar, Eucalyptus, Melia azedarach Acacia arabica (Babul) Acacia dealbata, A. catechu, A. cyanophylla Acacia decurrens, A. melanoxylon, A. mearnsii, A. dealbata Dalbergia sissoo Albizzia odorastissima Albizzia falcate, A. lophantha Cassia fistula

Morus alba, M. nigra Salmalia malabarica Quercus ilex Juglans regia (Walnut) Eucalyptus grandis (Sufaida) Populus nigra Populus tremuloides Acer oblongum (Maples) Aesculus glabra (Indian horse chestnut) Prunus cornuta (Kalakath) Largerstroemia lanceolata Artocarpus heterophyllus Terminalia arjuna, T. bellerica, T. chebula, Bamboosa tulda, B. arundinacea Acacia auriculaeformis Accia ferruginea Aegle marmelos Alianthus excels Anogeissus latifolia Juniperus polycarpos

Source: Khan (1989)

8.3.1. Disease Distribution Cercospora species cause leaf spot of Dalbergia sissoo, Morus alba, Populus, and Eucalyptus spp. (Spaulding 1961). In Pakistan, Mycosphaerella dalbergia also

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produces leaf spot on Shisham (Ahmad 1956). M. marksii is reported on Morus alba from Australia, UK, Canada, Pakistan, India, Tanzania, and Uganda (Khan 1989). Phillips (1994) reported Mycosphaerella spp as causal agent of crinkle leaf disease in Morus alba. Aulographina eucalypti causes corky leaf disease on adult and juvenile leaves. Pseudocercospora eucalyptorum causes leaf spot on adult leaves, while Septoria pulcherrima infects both young and adult leaves in Eucalyptus spp.

8.3.2. Disease Symptoms Presence of spots on leaves is a major symptom of this disease. Leaf spot disease develops as small, scattered, and circular to oval dead areas in the leaves. The spots are generally brown, black, tan, yellow, gray or purple in color, while some spots develop color at their margins or might have concentric rings at their margins. Some spots are raised, shiny or coal black, while others may drop over leaving behind a small hole. Spots may combine to form a blotch. The spots or blotches which are angular referred to as anthracnose. Hence, the color and size of spots depends upon the pathogen producing the disease. Spots produced by fungal pathogen may have fruiting bodies known as pycnidia, acervuli, or perithecia. Heavily infected leaves may turn yellow or brown, and finally sloughs off (Pataky 1998; Douglas 2012) [Figure 8.2 ]. Fig. 8.2 Cercospora Leaf Spot

8.3.3. Disease Description The fungal pathogen over winters survives in fallen leaves or in infected buds, fruits, twigs and in branches. From early spring to summer, microscopic spores are produced in tremendous numbers on the surface of the leaves or in the speck-sized fungal fruiting bodies. When spores are mature, they are spread due to air current or water splashes. Cool weather, light, frequent rains, high humidity, heavy dew and crowded plantation favors the growth of disease. In the presence of susceptible host and free water, the spores germinate and produce infection in new hosts; hence several generations of pathogens produce in one growing season. The extended periods of cool and moist weather favor the development of leaf spots. As the leaf

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spot pathogens are host specific, spores of one host plant can not infect other nearby plant species present but infection can develop in multiple host species at the same time, due to similar growth requirements of the pathogens (Pataky 1998; Douglas 2012).

8.3.4. Disease Management Disease can be managed by taking following methods (Pataky 1998; Douglas 2012). •

Most trees tolerate leaf spots with little or no apparent damage. If the host plant is properly established infected trees can survive complete defoliation. The tree will re-leaf and chances for the new leaves would be disease free.

•

Remove infected leaves, branches and twigs or fruits of trees as the inoculum may over-winter in them. Also prune the trees regularly to allow proper ventilation and sunlight.

•

Properly remove the debris present near tree trunk. The fallen leaves, twigs or any other debris present around should be carefully dumped away.

•

Avoid close plantation of trees. Clean, well spaced and properly ventilated plantations provided by plenty of sunlight generally give rise to into healthy trees.

•

Avoid over head watering to keep the foliage dry. Watering the trees during early hours in the morning is recommended.

•

Once the trees develop leaf spot disease, use of fungicide is ineffective because spray can not cure the infected leaves. Spraying should be done before the development of disease.

•

Use of resistant cultivars, as the pathogen is host specific, cultivation of non-host species may help in reducing the disease.

Leaf Spot of Eucalyptus Species Eucalyptus spp., are world’s most important and widely planted forest species, used as a source of timber, pulp, firewood, charcoal, honey production, ornamental foliage, shelter and environmental rehabilitation (Turnbull 2000; Sedgley 1997). Leaf spot of Eucalyptus species is caused by Cryptosporiopsis eucalypti, Aulographina eucalypti, Coniella spp., Microsphaeropsis spp., Pseudocercospora eucalyptorum, Cylindrocladium spp., and Mycosphaerella spp and their anamorphs like Phaeophleospora spp (Park et al. 2000; Table 8.2). The fungi are commonly found on the lower crowns of young trees, coppice shoots causing leaf spots of varying shapes and sizes according to the host and environmental conditions.

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8.3.5. Disease Distribution This disease is found in Brazil, New Zealand, Vietnam, Japan, Sri Lanka, Australia, India, Indonesia, Tasmania, Argentina, South Africa, Sabah, Taiwan and Thialand. (Sankaran et al. 1995; Yuan 1999; Old et al. 2002).

a

b

c

Fig. 8.3 Leaf spot by (a) Microsphaeropsis (b) Coniella fragariae (c) Pseudocercospora spp.

8.3.6. Disease Symptoms Fungi cause different symptoms according to the host and environment. Dark brown corky leaf spots with elongated or branched fruiting bodies known as hysterothecia are formed which are open by longitudinal slit (Aulographina eucalypti). Reddish-brown lesions are formed by Coniella fragariae. This fungus partially curls the leaf as the tissue desiccates. However, prominent black pycnidia are embedded in lesions and extrude vast numbers of dark brown to black spheroidal conidia on the lesion surface. Infected leaf showed profused angular spots and the tufts of conidiophores bearing needle shaped septate conidia (Pseudocercospora eucalyptorum). Leaves of Eucalyptus grandis showed large brown lesions with raised purple margins. Few pycnidia are produced which are easily seen by naked eye. These pycnidia are embedded in leaf surface and extrude small dark brownish black ellipsoidal conidia which are thick walled (Microsphaeropsis). In case of Cryptosporiopsis eucalypti leaf spots produce on both side of leaves which are vary in size, shape and color. Fungus proliferates by producing a vast number of spores from conidiomata that develop on infected leaves and shoot (Old et al. 2003) [Figure 8.3].

8.3.7. Disease Description Variation occurs in the causal agents of leaf spot like A. eucalypti is an obligate parasite while Coniella spp., have wide host ranges and to invade the leaves, they require leaf damage or prior infection by other pathogens. They are favored by moist climates and mostly occur on the lower crowns of Eucalyptus (Old et al. 2003). Auglographina eucalypti grew slowly in culture and penetrated in leaves

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through appressoria and the fungus produce both surface and sub-cuticular colonizing hyphae. Sporophores formed on the lesion surface and this lesion disturbs the photosynthesis process of healthy parts of infected leaves (Wall and Keane 1984).

8.3.8. Disease Management No control measures are acceptable with these fungi except for the elimination from provenance or clonal trials (Old et al. 2003).

8.4.

Wood Rot Fungi

Members of polyporaceae family called as wood rotting fungi which include Polyporus, Trametes, Coriolus, Poria, Polystictus, Nigroporus, Pycnoporus, Rigidoporus, Fomes, Daedalea, Globifomes, Cryptoporus, Heterobasidion and Lenzites. Wood decay process is mainly due to microorganism, plant species and microhabitat within substrate. This is due to conidial ascomycetes causing soft rot, basidiomycetes causing white rot and brown rot (Table 8.3). The main features of genera include fruiting body with a cap, well developed, simple or branched stipe, dimitic hyphal system with arboriform skeleton-binding hyphae, smooth basidiospores, cystida in hymenium are absent. Fruiting bodies in Polyporaceae species may resemble crusts, shelves or mushrooms. When young, the basidiocarps may be soft but at maturity they become tough, leathery, woody or corky. Few species have lamellate hymenium and mouth of tubes which contain basidia may be circular, angular or elongated (Alexopoulos et al. 1996).

8.4.1. Disease Distribution The disease is common in Pakistan, India, Southern United States, Canada, North Asia, Australia, Europe, Ireland, Britain. Eighteen species of the genus are restricted to North America which includes Nigroporus, Fomes, Pycnoporus, Rigidoporus, Poria (Gilbertson and Ryvarden 1987). P. tomentosus is widespread on conifers in the temperate zone which causes butt rot whereas mortality of white and black spruce is most common in Northern America. In Asia, P. tomentosus is foundin the Himalayas of northern India (Bakshi 1971).

8.4.2. Disease Symptoms Polypores species attacks living plant tissues and are serious parasites. Heterobasidion annosum invades stands of pines that have been thinned. It colonizes the surfaces of the freshly cut stumps and spread to the other trees by way of natural root grafts. Infected trees due to wind throw may die outright [Figure 8.4a, b].

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Fig: 8.4a Decay of Pinus tree by Polypores fungi (Picture taken from Ayubia National Park)

All members of polyporaceae produce shelf like or hoof-shaped fruiting bodies which are hard woody structure produced on the sides of dead or dying trees and stumps. Fruiting bodies produced a new hymenophore layer over the old one each year. P. tomentosus attacks on trees and causes outright mortality, premature windfall, growth slowdown and butt cull. Fungus causes weakening of root system which increases the susceptibility of a tree to windfall said to be greatest damage of fungus. Continuous killing of roots by P. tomentosus over a period of years results in reduction of tree height and diameter increment (Whitney 1962). Fungus might reach to several meters up to the stem in black and white spruce resulting in volume loss of affected trees. Fig. 8.4b Polypores wood decay (Picture taken from Ayubia National Park)

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8.4.3. Disease Description Basidiocarp of Polyporesis stipitate and annual. According to Dube (1990), fruiting bodies degenerate when the single layer of tubes is exhausted. The hyphae survive inside the trees and next year, the fruiting bodies again form. In P. tuberaster, fruiting bodies are bracket or fan shape and produce large underground sclerotiumlike structure which in warm and moistened place gives rise to several centrallystalked, funnel-shaped fruiting bodies. Fan shape fruiting bodies of some of the species of Polyporus attached laterally to tree trunks by short stalks. Septate dikaryotic hyphae cause discoloration and decay of wood. Infection of P. tomentosus occurs from below ground i.e. by root contacts in which mycelium grow from a diseased root onto a healthy root (Myren and Patton 1971; Whitney 1962). According to Ouellette et al. (1971), dead and deformed roots resulting from the poor planting practices lead to infection. The diseased roots remain in soil for at least 15 to 20 years resulting in the death of host. The inoculum in the old remaining roots leads to infect succeeding generations of trees. Both basidiospores and mycelium within a woody substrate can spread the disease over long distance by wind (Whitney 1962; 1966). In wet years, abundance of sporophores are produced and millions of basidiospores are produced under a wide range of climatic conditions (Bohaychuk and Whitney 1973). Table 8.3 Host range and causal organisms of wood rot disease Causal organisms Polyporus sulphurens P. squamosus P. schweintzii P. glomerata P. tomentosus Cryptoporus volvatus

Hosts Wood rot of oaks Heart rot of elms Butt-end rot of several trees Wood decay of red maple Butt rot of conifers, white pocket root rot of Pinus strobus Conifers

Source: Dube (1990)

8.4.4. Disease Management •

Disease can be managed by the following methods.

•

Urea, creosote and liquid borate can be used to prevent spore germination of H. Annosum. Dry borax granules sprinkled directly on the stumps showed much better control of the disease.

•

Liquid suspension of Phlebiopsis gigantea should be applied to the stumps.

•

Fungal fruiting structures on trees should be removed properly at the first sign of infection.

•

Deformation of roots in planting techniques should be avoided.

•

There is no direct control for disease caused by P. tomentosus, infected trees stands should be cut as soon as possible. Those trees showing above

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ground symptoms, cutting will not prevent spread of fungus to the remaining trees (Agrios, 2005).

8.5.

Sooty Mold on Trees

Sooty mold is a general term applied to the black, sooty mass that appears on certain plants. Sooty mold is basically fungal species having black mycelium, which grows on honeydew secreted by insects. Sooty mold is not a disease; instead it is an aesthetic problem. Sooty mold not only infects trees, but also infects small plants, stuff like fences, or umbrella or surface of anything kept in the open air. Fungi that most commonly causes sooty mold include the genera Capnodium, Fumago and Scorias (Table 8.4). Less common genera include Antennariella, Aureobasidium and Limacinula (Nameth et al. 1996; Lamborn 2009; Laemmlen 2011).

8.5.1. Disease Distribution Sooty mold is probably present throughout the world. Trees like, Abies spp. (Fir), Acer spp. (Maple), Alnus spp. (Alder), Camellia spp. (Camellia), Carya spp. (Hickory), Citrus spp. (lemon, orange), Fagus spp. (Beech), Fraxinus spp. (Ash), Ilex spp. (Holly), Juglans spp. (walnut), Juniperus spp. (juniper), Malus spp. (apple, crabapple), Picea spp. (Spruce), Pinus spp. (pine), Populus spp. (poplar), Prunus spp. (Plum, cherry, peach), Quercus spp. (oak), Salix spp. (willow), Viburnum spp. (viburnum) etc., are more likely to develop sooty mold fungi because of honeydew producing insects (Nameth et al. 1996; Lamborn 2009; Laemmlen 2011). Table 8.4 Causal organisms and host range of sooty mold disease Causal organisms Meliola spp Meliola bambusicola Fumigo vagans Popularia sphaerosperma Rosellinia congesta Capnodiastrum stylosporium Meliola palmicola Meliola geniculata Meliola similina Astrinella pinastri

Host Shorea robusta Bambusa spp Bambusa spp, Calotropis spp Bambusa bambos Bambusa spp Trema orientalis Phoenix sylvestris Lannea coromandelina Hollarrhena antidysenterica Pinus wallichiana (Kail)

Source: Khan (1989)

8.5.2. Disease Symptoms Sooty molds gives the appearance of black layer of soot present on the surface of leaves. Sooty mold appears on trees when insects like aphids, mealy bugs, leaf hoppers, Psyllids, soft scales and white flies are present in the nearby vicinity or on trees.

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8.5.3. Disease Description The insects both adults and juveniles suck sap from plants as their source of nutrition, however they can’t digest it completely, so they excrete out the excess sap in the form of honeydew. Honeydew is a sweet, sticky liquid which is consumed by several ant species. The sooty mold fungi present in the air develop on honeydew. The sooty mold does not infect the leaves or plants, but due to excessive growth of fungal mycelium, the passage of sunlight blocks from reaching the leaves surface. As plant produce their nutrient through photosynthesis, the mycelium growing on leaf surface prevent photosynthesis and respiration making leaf weak and finally it falls off. The species of sooty mold present on certain plant are determined by the combination of environment, host and insect species (Nameth et al. 1996; Lamborn 2009; Laemmlen 2011) [Figure 8.5]. Fig. 8.5 Sooty mold on tree leaves

8.5.4. Disease Management Disease can be managed by the following methods (Lamborn 2009; Laemmlen 2011). • • •

•

Growth of sooty mold depends upon the presence of honeydew secreting insects. Eliminating such insects will ultimately eliminate sooty mold. Sooty mold can be easily removed by applying water with full pressure. Heavy rain can also remove the black soot. Use of chemical insecticides or Neem oil can be effective for the control of insects; however, insecticides should be applied after proper identification of insects producing honeydew. Pruning and cutting the affected parts can be helpful in some cases.

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Rust of Trees

Rusts are among the most common fungal diseases of the ornamental as well as forest trees. Rust diseases are caused by the fungi which belong to the phylum basidiomycota. All the rust producing fungi are obligate parasite and to some extent host specific. The fungal pathogens generally produce spores of five types and complete their life cycles on two hosts, however, some may complete their life cycle on one host. Rust infection occurs on almost all tree species however, certain trees like poplar, willow; birch, plum, pinus, Salix, Betula spp, Eucalyptus spp., ash, maple etc. Rust fungi reduce plant vigor and in extreme cases can kill the host. Cronartium ribicola (white pine blister rust), Puccinia psidii (Eucalyptus rust), Melampsora (poplar tree rust), Melampsora (willow tree rust), Melampsoridium betulinum (birch rust), Tranzschelia pruni-spinosae var. discolor (plum tree rust), Gymnosporangium juniper-virginianae (Cedar-apple rust), Cronartium comandrae (Comandra blister rust), Melampsorella caryophyllacearum (fir broom rust) etc., are some examples of rust pathogens (Anonymous 2014c) (Table 8.5). Table 8.5 Host range and causal organisms of rust disease Causal organisms Uredo sissoo Maravelia achroa Ravenelia sessilis R. clemensiae R. japonica Hapalophragmiopsis ponderosa Ravenelia tandonii Ravenelia franesianae R. formosana R. spegazziniana R. esculenta R. deformans Uromyces phyllodiorum U. bisporum Cerotelium fici Phakopsora zizyphivulgaris Melampsora pinitorqua, M. populnea Melampsora ciliate, M. populnea Melampsora amygdalinae Melampsora caprearum Melampsora epitea Pucciniastrum aceris Pucciniastrum areolatum Melampsoridium hiratsukan

Hosts Dalbergia sissoo Dalbergia sissoo, D. latifolia Albizzia lebbek A. procera A. odoratissima Acacia leucophloea Acacia catechu (Khair) Acacia franesiana A. franesiana A. franesiana, A. decurens A. eburnean A. Arabica A. dealbata A. dealbata Ficus elastic, F. glomerata, F. religiosa, Morus alba, M. nigra Ziziphus jujube (Berry), Z. oxyphylla, Z. mummularia, Z. sativa Populus alba (Sufaida) Populus ciliate Salix triandra, S. alba Salix caprea, S. cinerea Salix babylonica, S. hastate, S. alba, S. cinerea, S. viminalis, S. acutifolia, S. caprea Acer caesium, A. mono, A. pictum Prunus cornuta Alnus nitida

176 Olivea tectonae Uredo artocarpi Dendrocalamus strictus, Oxytenanthera abyssinica Gymnosporangium clavariiforme Gymnosporangium cunninghamianum

Forest Diseases and Protection

Tectona grandis Artocarpus chaplasha Randia dumatorum, R. brandissi, R. candolleana Bambosa spp Juniperus communis Cupressus torulosa

8.6.1. Disease Distribution Generally, all the plant species throughout the world suffer due to rust infection. In Pakistan, it is reported to cause white pine blister rust (Khan 1989).

8.6.2. Disease Symptoms The pathogens produce lesion like pustules on the under surface of leaves. The pustules contain spores which are yellow, orange, brown, etc in color according to the pathogen species, thus giving the disease its name “rust”. Wet conditions and high humidity or rain favors the growth of pathogen; however, this disease grows well during summer season. Presence of secondary host makes the economically important plants/trees more susceptible to the disease. For example, white pine blister rust fungus completes its life cycle in 5 stages and on two different hosts, while western gall rust fungus completes its life cycle on one host (Anonymous 2011; Anonymous 2014c) [Figure 8.6]. Fig. 8.6 White Pine Blister Rust.

8.6.3. Disease Description The pustules present on leaves burst on maturation releasing the spores in the air. The spores, if susceptible host is present nearby, lands on host plant. The spores germinate and produce haustoria which penetrate the living host cells and drive its nutrients from it. In case of white pine blister rust, one host is pine while other (or alternate/secondary) host is goose berry plant (Ribes spp.). The disease can not spread from pine to pine but is transmitted to white pine by from Ribes trees.

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Seedlings and young trees of white pine are more susceptible and thus infected trees dies more rapidly (Anonymous 2011, 2014c).

8.6.4. Disease Management Disease can be managed by the following methods (Anonymous 2014d). •

Removing of infected plant parts and pruning of trees can help in reducing the infection. Elimination of secondary/alternate host reduces the disease but do not eradicate it.

•

Use of chemical fungicides can also be helpful in the reduction of disease in silviculture.

•

Use of resistant cultivars in case of orchard trees and gardens can be helpful. For naturally occurring forest trees obviously, this method will be un-applicable.

•

Crop rotation in case of orchards or garden trees is a good but expensive method of management. For naturally occurring forest trees this method has no practical implication.

•

There should be proper spacing between trees. The pruned trees parts and infected seedlings/trees should be discard away from susceptible host. It is better to burn the infected parts like leaves, branches, twigs etc to eliminate the spores.

8.7.

Juniper Blight

Juniper forests are found in Ziarat and Loralai districts of province Baluchistan in Pakistan, are one of the world largest, slow growing and long lived forest, also referred to as ‘Living Forest Fossils’. Juniper forest provides essential oils, berries for flavoring, bark for roofing, grazing pastures and are used for the cure of kidney and many other diseases (Sarangzai et al. 2010). Juniper forests suffer from different fungal diseases like leaf blight caused by Didymascella thujina, tip blight by Coryneum berckmannii, juniper blight by Phomopsis juniperovora. These fungi infect susceptible wound and cause extensive damage (Moore, 1976). a) Juniper Phomopsis blight The causal agent of disease is Phomopsis juniperovora andthis disease commonly occurs on eastern red cedar and other species of junipers and affects the Chinese and common junipers (Table 8.6).

8.7.1. Disease Distribution Fungus causing blight disease is widespread in the United States, Pakistan and some countries of Asia (Sarangzai et al. 2010).

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Table 8.6 Host range and causal organisms of juniper diseases Causal organisms Phomopsis juniperovora Didymascella thujina Sclerophoma pythiophila Coryneum berckmannii Arceuthobium oxycedri, A. juniperprocera, A. azoricum Cercospora sequoiae

Hosts Juniperus sabina, Juniperus scopulorum Arbor-vitae Pines, Douglas-fir, Eastern Thuja orientalis Junpierus excels Eastern red cedar

8.7.2. Disease Symptoms Healthy hosts are infected from spores of diseased juniper plants in the fall but the symptoms are not seen until late winter or early spring. First symptom noted as browning of needle tips when disease invades young vulnerable tissue. Yellowgreen new shoots begin to turn red brown and slowly die from fungal disease. After the infection progress, inward, small lesions are formed at the tip of branches. These lesions are less than one centimeter in diameter, results in death of the entire branch. Repeated blighting results in abnormal bunching called as witches broom.

8.7.3. Disease Description Blight disease infects Juniperus sabina, Juniperus scopulorum and other rocky mountain juniper plants besides attacking red cedar. This blight disease only infects young leaves and branches. However mature juniper plants are usually immune to infection. The fungus reproduces by conidia which are produced in pycnidia. In wet and rainy periods (optimal germination temperature range between 24-28°C), conidia releases from the pycnidia and spread to healthy tissue due to rain splash. Spores germinate and infecting immature needles of trees. Viable spores are produced by P. juniperovora within 3 weeks of infection for reinfection. Fungus forming pycnidia in dry shoots for upto two years after the death of tissues (Peterson and Hidges 1982). Secondary inoculum will continue to spread infection in favourable environmental conditions.

8.7.4. Disease Management •

Plants with yellow or grey discoloration on needles and necrotic areas on branches and stems should be removed in healthy juniper seedlings (Peterson et al. 1965).

•

Avoid plantation in poorly drained or heavily shaded and prolonged moisture areas.

•

When planting provide proper spacing for air movement to prevent the germination of fungi.

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•

Pruning should be carried out during dry weather. Diseased plant waste should be disposed by burning.

•

Spray with fungicide like propiconazole or mancozeb, combination of zinc, manganese and ethylene bisdithiocarbamate will be helpful in preventing the disease development (Peterson and Hidges 1982).

b) Juniper tip blight This juniper disease is caused by Phomopsis juniperovora, Kabatina juniperi, Sclerophoma pythiophila. Despite of juniper, white cedar, cypress, false-cypress and arborvitae are also susceptible to P. juniperovora while S. pythiophila also cause disease on pines, Douglas-fir and Eastern (Table 8.6).

8.7.5. Disease Distribution Disease is common in Pakistan and New York (Sarangzai et al. 2010).

8.7.6. Disease Symptoms The disease starts to show up on lower branches. Infected foliage changed from normal green to reddish brown color and may dropped resulting in unsightly masses of grey stems. Death of entire plant may result where P. juniperovora and K. Juniperi are involved while S. pythiophila does not kill whole plants. Dieback symptoms appear on shoot tips and continue towards the main stem. Leaves near tip turned brown in late spring and the fruiting bodies of the fungus was observed as tiny black bodies on the lower surface of the infected foliage (Moore 1976).

8.7.7. Disease Description P. juniperovora attacks young succulent shoot tips and enter to plants through wounds and cause infection throughout summer while K. Juniperi attacks one year old growth in the fall, enter to plant through wounds and symptoms appears in early spring. However, S. pythiophila attacks shoots which become weakened due to winter injury. In the wet weather, these fungi spread throughout the shrub within few years or less. These three fungi killed twigs and bark on the shrub, fruiting bodies of fungi develop in spring and in wet weather many spores are released which are capable of causing new infections.

8.7.8. Disease Management •

Pruning of infected twigs and branches and pruned items should be burned.

•

Plantation should be in proper spacing for good ventilation.

•

Sterilize the tools used for cutting by using 10% bleach and water solution.

•

Use of fungicide like potassium biocarbonate or propiconazole is available for treating Phomopsis. Some researchers suggested spray of copper

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sulphate in the month of October and November for the prevention of disease (Grant 2015).

8.8.

Chestnut Blight Disease (Cryphonectria parasitica)

Causal agent of chestnut disease is Cryphonectria parasitica. List of causal agents and host of blight diseases are presented in Table 8.7. Oak tree is most susceptible to this disease. Young trees are not usually affected by blight. The primary host of the disease is American chestnut. However, fungus also attacks and causes minor injury to maple, sumac and hickory trees. Fungus enters trees through wounds, furrows and cracks of mature bark. Table 8.7 Causal agents and host range of blight disease Causal organisms Glomerella cingulata, Phyllosticta sissoo, Colletotrichum dalbergia, Phomopsis dalbergia, Phyllachora dalbergia, Phyllachora spissa Physalospora eucalypti Colletotrichum gloeosporioides Endothia parasitica Cercospora sequoia, Keithia thujina

Hosts Dalbergia sissoo

Eucalyptus globules, E. citriodora Alstonia schorlaris Castania sativa Cupressus torulosa

Source: Khan (1989)

8.8.1. Disease Distribution Blight disease is present in the entire range of host and moved to the areas of planted chestnut far away from the native range. However, disease is present in North America, Europe, China, Japan (Sarfaraz 1999; Anagnostakis 2007).

8.8.2. Disease Symptoms Appearance of numerous cankers on branches and stem. Wilting and yellowing starts on the foliage of infected branches and the bark starts to spilt and dies in patches. The plant cells in the affected areas gradually die. Browning also starts under the bark where cambium layer is present and reddish orange masses of fungal spores are visible on the bark near the cankers. Spores of fungi spread rapidly by animal and splashing rain to other healthy trees.

8.8.3. Disease Description C. parasitica is a member of ascomycetes which infects any part of the trunk or limbs and enter through wounds. Once the fungus penetrates bark, produces canker and reaches down to the vascular cambium and functional xylem and phloem. By this transport of nutrients and water are blocked above and below the canker (Smith 2012). Leaves turn brown and eventually stem above the canker dies. Fungus produces two types of spores, ascospores (cause black vase-like structure called

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perithecia) and conidia (ooze out of round fruiting bodies called pycnidia after rain).

8.8.4. Disease Management There is no cure for the chestnut blight disease but the research is still being conducted to find an effective way to eradicate the disease (Smith, 2012; Sarfaraz, 1999). •

Research is being conducted on isolating resistant varieties.

•

Development of hypo-virulent (lesser virulence) fungal strains which when applied to the cankers promotes healing in infected trees and attacking the causal agent of the disease.

8.9.

Shisham (Dalbergia sissoo) dieback

Dieback and decline is a periodic event characterized by premature loss of tree health and stand vitality (Clatterbuck 2006). The illness and mortality of trees are caused by number of reasons which seems to be inexplicable but most of the problems in trees are caused by human disturbances especially to the environment which lead to mortality (Lowman 1991). Different terms like dieback, stand level dieback and canopy level dieback have been used in the literature according to conditions. It is difficult to determine or diagnose the exact cause of dieback or decline as compared to other diseases, because it is a complex issue and may differ from place to place (Manion 1991). The exact cause of the dieback is still not clear and there are many controversial reports (Bakhshi 1974) because different factors including biotic and abiotic factors were found associated with forest and especially with shisham dieback (Sharma et al. 2000). Aslam (2004) stated that the intensity and causes of dieback varied from region to region in Pakistan. Forestry experts and pathologists have estimated that the high death rate of D. sissoo was due to several pathological, entomological, silvicultural, edaphic and age factors (Sah et al. 2003). Afzal et al. (2006) identified the two major causes of D. sissoo dieback: according to them the primary cause was physiological drought, lopping and over maturity, whereas the second was attack by pathogens. A wide range of fungi have been reported from shisham trees showing symptoms of dieback, leading to the involvement of pathogens being considered the most likely cause of the problem (Bakshi 1954). Different pathogens isolated from the D. sissoo trees include Botryodiplodia theobromae, Fusarium solani, F. oxysporum, F. dimarium, F. semitectum, Pestalotia spp., Curvularia spp., Drechserla spp., Chaetomium spp., Cystospora spp., Colletotrichum gloeosporioides, Ganoderma spp., Phialophora spp., Phialocephala spp., Dothiorella spp,. and Oomycota species like Phytophthora cinnamomi (Dargan et al. 2002) (Table 8.7). Similarly different fungal and other pathogens including F. solani, B. theobromae, Ceratocystis maginecans, Ganoderma lucidum, Phytophthora cinnamomi, Rhizoctonia solani, Alternaria alternata, Curvularia lunata, Aspergillus flavus, A. niger and Colletotrichum gloeosporioides have been

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identified from different parts of Punjab province (Rehman et al. 2006; Al Adawai et al. 2013)). Ceraocystis fimbriata fungus was also isolated from diseased shisham trees for the first time in Pakistan (Poussio et al. 2010). However, F. solani and B. theobromae have been considered as the major factor responsible for the dieback of D. sissoo (Bajwa and Mukhtar 2006; Rajput et al. 2008; 2010; Ahmad and Siddiqui 2013).

8.9.1. Disease Distribution for Dalbergia sissoo Shisham (Dalbergia sissooRoxb. Ex DC) is native to Nepal (Bajwa and Mukhtar 2006; Idrees et al. 2006). This species belongs to family Fabaceae (sub-family Papillionaceae) and genus Dalbergia (Southon 1994), which contains 100 species in Asia, America and Australia (Thothathn 1987). History reveales that this tree was grown about 2500 years ago (White 1994; Kumar and Rai 2002) and is an internationally known timber species of rosewood genus. This species has great importance as fuel, shade and shelter wood and is locally known as “tally”. It is found in Afghanistan, Bangladesh, Bhutan, India, Nepal and Pakistan. It is also found in the cultivated tracts of tropical and sub-tropical regions of Africa, Asia, Kenya, Maustius, Nigeria, Palestine, South Africa, Sri Lanka and Zimbabwe ( Afzal et al. 2006). Being a multipurpose tree it had greatly contributed in the socioeconomic development of the South Asian region (Khan 2000; Bajwa and Mukhtar 2006; Kausar et al. 2009). It is a moderately fast growing tree with an average growth rates of 3.7 m/year, 5 m in 3 years, 11 m in 5 years and 15 m in 10 years have been recorded in favorable environmental conditions. Its rotation age varies from 30 to 60 years. Flower color varies from pale white to dull yellow and pods on an average have 1-4 seeds and number of seeds varies from 4500055000/kg (Orwa et al. 2009). Dalbergia sissoo is an important timber tree of Pakistan (Bajwa and Mukhtar 2006) and was introduced in Pakistan almost 150 years ago (Afzal et al. 2006). Its growth is commonly found along the foothills of Himalayan mountains. Normally it extends from the Indus valley up to Attock district but does not dominate in this area (Champion et al. 1965). In Pakistan, it is widely planted along canal banks, along agronomic crops in agricultural fields and as well as on road sides, canopy gaps, disturbed sites and forest margins (Sharmaet al. 2000; Rajput et al. 2008; Kausar et al. 2009). It is also used for fuel, shade, shelter, soil stabilization and for the control of erosion. It has been considered an important tree for agro-forestry practices because it increased the soil fertility and played an important role in safeguarding the environment (Stewart and Flinn 1984; Sharma et al. 2000; Kausar et al. 2009). Dieback of forest trees has been identified as a major problem in different parts of the Indian subcontinent (Shukla 2002). D. sissoo (Shisham) an important species of the subcontinent has suffered from dieback, wilt and many other pathological problems (Sah et al. 2003) and in the past few decades dieback of D. sissoo is a serious threat affecting millions of trees in South Asia (Vogel et al. 2011). Bakhshi (1954) reported the disease for the first time in the forest stands of Utter Pardesh, India. History of D. sissoo decline due to dieback in Pakistan goes back to the early

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period of 1900s, but regular research on this very important problem was carried out in 1956 in Khanewal irrigated plantation (Khan 1989). The widespread incidence of shisham dieback was reported in 1998 in central irrigated tract of Punjab, Pakistan (Naz 2002). During this period about 70% shisham trees were affected by dieback disease (Khan 1999). This disease has also been recorded in different agro-ecological zones of Punjab with different severity levels (Bajwa and Mukhtar 2006). Table 8.8. Causal organisms and host range of die back disease of forest trees Causal organisms Polyporus gilvus

Botryosphaeria stevensii, Cryptosphaeria ramulosa, Microdiplodia phyllodiorum, Cytosporella lignicola, Aposphaeria lignicola, Rhytidhystereum rufulum, Phoma hennigsi Corticium salmonicolor, C. solani Hendersonula toruloidea Daldinia eschscholzii Nectria cinnabarina Hendersonula toruloidea Phomopsis salmalia Diplodiella tamaricina, Pilidiella tamaricina, Sirococcus tamaricis, Valsaria tamaricis, Teichospora obducens, Massarina dubia, M. epileuca Bulgaria inquinans Glomerella cingulata Botryosphaeria ribes Hendersonia populina Valsa salicina Nectria cinnabarina, N. ditissima, N. galigena Diaporthe eres Cytospora stenospora Dothiorella Largerstroemiae Corticium salmonicolor Trichosporium vesiculosum Source: Khan (1989)

Hosts Dalbergia sissoo, Quercus, Prunus, Dalbergia latifolia, Shorea robusta, Cedrela toona, Pterocarpus marsupium, Albizzia lebbek, A. procera, Cassia fistula, Acacia arabica, Mangifera indica Acacia Arabica

Albizzia falcate Morus alba (Mulberry) Morus alba Melia azedarach (Bakain) Melia azedarach, Azadirachta indica (Neem) Bombax cieba (Semul) Tamarix articulata (Tamarisk)

Quercus leucotrichophora Juglans regia (Walnut) Populus nigra Populus ciliate Salix alba, S. viminalis Acer spp Prunus cornuta Alnus nitida Lagerstroemia lanceolata Artocarpus chaplasha, A. heterophyllus Casuarina equisetifolia, C. muricata

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8.9.2. Disease Symptoms Heatwole and Lowman (1986) stated that several stages are involved in a complete tree dieback which starts from a full healthy tree, then twigs and leaves starts to die. Most of the branches become dry but some remain healthy near ground prior to death of the whole tree. Change in colour and wilting of crown also indicate the symptoms of the disease (Tantauet al. 2005). Two stages have been observed in D. sissoo dieback, first was yellowing of leaves, resulting in foliage death, whereas in the second stage, branches become bare after shedding the leaves and ultimately the death of diseased and wilted trees within few months (Sharma et al. 2000). The same fact was also verified by Kumar and Rai (2002). Khan (2000) describing the prominent symptoms of shisham dieback in Pakistan further added that dieback started from the thinning of leaves and crowns progressed downwards and in the final stages crowns were flat and stag headed [Figure 8.7]. Fig. 8.9 Diseased Shisham Tree

8.9.3. Disease Description The problem is caused by number of factors like mechanical injury by wind, frost, drought or attack by a destructive pathogen or insect but without any identification of causal organism or factor. This ultimately disturbs the physiological functions of twigs and branches of trees to start dieback which may leads to the death of entire plant (Ciesla and Donaubauer 1994). Dieback has been considered a diverse disease of forests by different forest pathologists. In this situation trees are affected by different environmental factors and finally tree tissues are invaded by pathogens which lead to the death of tree (Housten 1967; 1992; Manion 1991).

8.9.4. Disease Management Following remedial and curative measures have been suggested by different researchers and foresters (Khan et al. 1965). •

Proper silvicultural practices e.g pruning, thinning etc. suggested by forestry experts should be followed.

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•

Diseased and dead trees affected by dieback should be removed immediately.

•

Trees should be harvested at proper rotation age, as older trees are more susceptible to disease as compared to younger plants. It will reduce further spread of infection and termites.

•

Only good quality seeds collected from resistant plus trees should be used for raising new plantations.

•

Fungicides should be used as seed treatment.

•

Asexual propagation method (cuttings) should be promoted, as in the past less disease appeared in vegetatively produced plants as compared to sexually raised plants.

•

Fungicides like Bavistin (carbendazim) and captaf (captan) can be effective in reduction of disease.

8.10. Key to Major Tree Diseases A key to major tree diseases has been given in Table 8.9. Table 8.9 Key to tree diseases Leaf diseases

Disease Name Leaf spots Powdery mildews Rust Needle cast/Blight

Stem diseases

Heart Rots

Root diseases

Vascular wilts Root Rots

Causal Organism Fungi (Cercospora spp., Alternaria spp., Colletitrichum spp., Septogloeum spp., Phyllosticta spp., and Septoria spp.) Erysiphales (Mildew fungi) Melamspora epitea (Fungus) Lophodermium pinastri and Dothistroma pini Phellinus pini (red ring rot of conifers), Pyrofomes demodofii (Juniper heart rot), Fomes badius (Acacias), Fomes fomentarius (Walnut) Fusarium oxysporum Ganoderma lucidum, Fomes annosus, Armillaria mellea, Polyporus schweinitzii

Source: Chaudhry (1994)

8.11. Conclusion Diseases like powdery mildew, rust etc are pathogenic and if remain unchecked, the diseases can be fatal to plants. Trees are gigantic, healthy and have more tolerance towards pathogens but constant attack due to fungal pathogens or insects may damage a healthy, fully established tree. By taking little care, many diseases can be avoided. Use of pesticides do not cure the disease, however it may prevent the further spread of disease. But in case of forest trees or road side ornamental trees,

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spraying trees with expensive pesticides is near to impossible for developing countries like Pakistan. Hence, alternate methods should be found to cure or prevent tree diseases. More research work is needed to be done in this aspect so that we can have a proper data regarding forest diseases and their prevention in Pakistan

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Aslam, M. (2004). Brief on mango killer or mango quick decline or mango dieback. Ministry of Food, Agriculture and Livestock, Islamabad, Pakistan. Bajwa, R and I. Mukhtar (2006). Incidence of shisham dieback disease in different Agro-ecological zones of the Punjab. Proceedings of the third National Seminar on Shisham dieback, Punjab Forestry Research Institute Faisalabad, 11 May. pp. 89-106. Bakshi, B.K. (1954). Wilt of sisham (Dalbergia sissoo. Roxb.) due to Fusarium solani. Nature. 174: 278–291. Bakshi, B.K. (1971). Indian Polyporaceae. Indian Counc. Agric. Res., New Delhi. 246 p. Bakshi, B.K. (1974). Control of root disease in plantation in reforested stands. Indian Forest. 100: 77-78. Bertus, L.S. (1946). Plant Pathology. Admn. Rep. Dir. Agric. Cylon. D:9-11. Singh (1960). The Mango. Inter. Science Publisher Inc. New York, USA. Boesewinkel, H.J. (1980). The identity of mango in mildew Oidium magniferae. Phytopathol. Zeitschrift. 99: 126-130. Bohaychuk, W.P. and R.D. Whitney (1973). Environmental factors influencing basidiospore discharge in Polyporus tomentosus Fr. Can. J. Bot. 51(4): 801815. Champion, S.H., G. Seth and G. M. Khattak (1965). Forest Types of Pakistan. Pakistan Forest Institute, Peshawar, Pakistan. pp 100. Chaudhry, Z. (1994). Forest diseases and their control. In: Ashraf, M.M. and I. Ahmad (ed). Handbook of Forestry. Pakistan Agricultural Research Council, Islamabad. pp. 177–183. Ciesla, W.M and M.E. Donaubauer (1994). Decline and dieback of trees and forests: a global overview. FAO Forestry Paper 120. FAO, Italy, Rome. pp 90. Clatterbuck, W.K. (2006). Dieback and decline of trees. Publication No. SP 686. Knoxville, University of Tennessee, Agricultural extension service. Cooper, J. (2002). Powdery mildews. WSU Extension. WSU Master Gardener.http://sanjuan.wsu.edu/mastergardeners/documents/PowderyMildews .pdf. Accessed on 06 June 2014. Dargan, J.S., T.K. Gill, P. Verma and K. Lalji (2002). Proceedings regional symposium on mortality of shisham and kikar in northern states of India. March, 3-4. Punjab Agriculture University Ludhiana. pp. 45-49. Douglas, S.M. (2012). Leaf spot diseases of ornamental trees and shrubs. Department of Plant Pathology and Ecology. Connecticut Agricultural Experiment Station. Huntington Street, USA. Dube, H.C. (1990). An introduction to Fungi. 2nd Edition. Vikas Publishing House Pvt. Ltd. Pp. 608. Dyer, R.A. (1947). Protection and classification of plants. Fmg. S. Afr. 22: 269273. Erper, I., G.H. Karaca and M. Turkkan (2010). First report of Phyllactinia fraxini causing powdery mildew on ash in Turkey. New Disease Report. 20: 39. Fieds, W.S. (1945). Summary of the more important plant diseases taken in connection with the insect and plant diseases. Survey in general vicinity of the ports of entry from Jan. 1945. Pl. Dis. Rept. 24: 693-697.

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FAO (2014). Forest Resource Assessment Program. Working paper 14. Food and Agriculture Organization of United Nations, Rome, Italy. Gilbertson, R.L. and L. Ryvarden (1987). North American Polypores, Fungiflora, Oslo, Norway. Grant, B.L. (2015). Juniper twig blight disease: Symptoms and solutions for twig blight on Juniper. Gardening know how. http://www.gardeningknowhow.com/ornamental/shrubs/ juniper/ juniper-twigblight-disease.htm. Accessed on 28 July 2017. Hartman, J. (2008). Dogwood Powdery Mildew. Cooperative Extension Service. University of Kentucky- College of Agriculture. Plant Pathology Fact Sheet. PPFS-OR-W-13. Heatwole, H. and M. Lowman (1986). Dieback, Death of an Australian landscape. Reed Books Pvt. Ltd., Frenchs Forest. pp.150. Houston, D.R. (1967). Dieback and decline of northern hardwoods. Trees. 28:1214. Houston, D.R. (1992). A host-stress-saprogen model for forest dieback-decline diseases. In: Manion and Lachance (ed). Forest Decline Concepts. APS Press, St. Paul, 3-25. Idrees, M., S.Sh. Zaidi, A. Khan, A. Mahmood and A.S. Akhtar (2006). Studies on organisms associated with shisham dieback and their pathogenecity. Proceedings of the third National Seminar on Shisham dieback, Punjab Forestry. Research Institute Faisalabad, 11 May. pp.29-36. Kausar. P., S. Chohan and R. Parveen (2009). Physiological studies on Lasiodiplodia theobromae and Fusarium solani, the cause of shisham decline. Mycopath. 7(1):38-38. Khan, A.H., A.G. Asghar, C.G. Rasul and A. Hamid (1965). Observation on the mortality of shisham (Dalbergia sissooRoxb.) and other trees in the Khanewal plantation. Pak. Forest. 6: 109-120. Khan, A.H. (1989). Pathology of trees. Volume II, University of Agriculture, Faisalabad, Pakistan. Pp. 921. Khan, M.M. (1999). Diagnostic study of shisham dieback in the Punjab. Pak. J. Phytopath. 2(1):106-114. Khan, M.H. (2000). Shiahm dieback in Pakistan and remedial measures. Field Document No. 18. In: Appanah, S., G. Allard and S.M. Amatya (ed). Proceedings Sub Regional seminar on Dieback of sissoo (Dalbergia sissoo), Kathmandu, Nepal, April 25–28, 2000. Forestry Research Support Programme for Asia and Pacific (FORSPA), FAO Regional Office for Asia and Pacific, Bangkok. pp.43-47. Khan, R.S. (2014). Pakistan’s Fast Disappearing Forests. The Express: Tribune. https://tribune.com.pk/story/676010/pakistans-fast-disappearing-forests/. Accessed on 28 July 2017. Kulkarni, G.S. (1924). Report of work done in plant pathology section during the year 1922- 1923. Annual Report of Department of Agriculture, Bombay Presidency for the year 1922-23 1924 pp.167-171. Kumar, A and P. Rai (2002). Status of shisham mortality at Jhansi and nearby areas. Proceedings Regional symposium on mortality of shisham and kikar in

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northeren states of India. March, 3-4, 2002. Punj. Agri. Univ. Ludhiana. pp. 26-28. Laemmlen, F.F. (2011). Pests in Gardens and Landscapes: sooty mold. UC State Wide IPM program. University of California, Davis. Lamborn, A.R. (2009). Black, sooty mold on landscape plants. Baker county extension, University of Florida, Alicia R. Lamborn Environmental Horticulture Agent, Macclenny, FL, USA. Landaeta, A. R. and R.M. Figueroa (1963). The appearance of Oidium or Ash on mango in Venezuela. Rev. Fac. Agron. 3: 40-47. Lee H.B. (2012). First Report of Powdery mildew caused by Erysiphae arcuata on lanceleaf coreopsis (Coreopsis lanceolata) in Korea. Plant Diseas. 96(12): 1827. Lee H.B., C.J. Kim and H.Y. Mun (2011). First report of Erysiphe quercicola causing powdery mildew on ubame oak in Korea. Plant Diseas. 95(11): 77. Lowman, M.D. (1991). The dieback crisis-Tree declines throughout the world. Centre for environmental studies journal, Williams college. Massachusetts, United States. pp.28-31. Manion, P.D. (1991). Tree Disease Concepts. 2nd Edition. Pearson Education Australia. pp. 402. Moore, B. (1976). Leaf-browning and shedding-Arbor-Vitae and Juniper. Ornamentals northwestarchives, Oregon State University, USA. 1(10): 1-2. Myren, D.T. and R.F. Patton (1971). Establishment and spread of Polyporus tomentosus in pine and spruce plantations in Wisconsin. Can. J. Bot. 49:10331040. Nameth S, J. Chatfield and D. Shetlar (1996). Sooty mold on trees and shrubs. Ohio State University. Extension fact sheet. HYG - 3046 - 96. Naz, S. I. (2002). The vanishing shisham tree. The Daily Dawn. 4 Jamuary, Lahore Pakistan. Newman, S. and L.P. Potorff (2013). Powdery Mildews. Colorado State Extension. No. 2. 902. Old, K.M., M.J. Dudzinski, K. Pongpanich, Z.Q. Yuan, P.Q. Thu and N.T. Nguyen (2002). Cryptosporiopsis leaf spot and shoot blight of Eucalypts. Australas. Plant Pathol. 31: 337–344. Old, K.M., M.J. Wingfield and Z.Q. Yuan (2003). A manual of diseases of Eucalyptus in South-East Asia. Center for International Forestry Research, Jakarta, Indonesia. pp. 98. Orwa, C., A. Mutua, R. Kindt, R. Jamnadass and S. Anthony (2009). Agroforestrey Database:a tree reference and selection guide version 4.0 (http://www.worldagroforestry.org/sites/treedbs/treedatabases.asp). Ouellette, G.B., G. Bard and R. Couchon (1971). Self-strangulation of roots: Points of entry of root-rot fungi in the Grand-Mere white spruce plantations. Phytoprotection 53(3): 119-124. Park, R.F., P.J. Keane, M.J. Wingfield and P.W. Crous (2000). Fungal diseases of eucalypt foliage. In: Keane, P.J., G.A. Kile, F.D. Podger and B.N. Brown (ed). Diseases and Pathogens of Eucalyptus, CSIRO, Collingwood, Victoria. pp. 153-239.

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Chapter 9

Agroforestry: Prospects and Challenges W. Nouman*

Abstract Forest can play a vital role in improving Pakistan’s economy being protective layers for watershed areas, maintaining a sustained supply of wood, wood-based and non wood forest products, conserving and improving soil fertility, erosion control, improving food, fodder and fuelwood production. As the forest area of Pakistan is very low from the standard figure i.e., only 2.5%, there is a dire need for introducing such systems and practices which can increase the forest area meeting the nation’s requirements. For this, agroforestry is a better option that cannot only increase forest area but by adopting this system, marginal lands can also be brought under cultivation by incorporating salinity and drought resistant trees into land use system which can bridge the gap between demand and supply of food and fodder for livestock. This chapter describes in detail the important issues, challenges and solutions associated with agroforestry in the light of various examples, case studies and theories. Keywords: Agroforestry; Multipurpose trees; Agrisilviculture; Soil improvement.

* W. Nouman Department of Forestry and Range Management, Bahauddin Zakariya University, Multan, Pakistan. For correspondance: [email protected]

Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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Agroforestry: Prospects and Challenges

Introduction and History of Agroforestry

Trees have an important role to play on earth by fulfilling the basic necessities of all living organisms from micro organisms to animals. The world’s population is assumed to reach at 10 billion by the middle of 21st century (UN 1995) if it continues to grow at the present rate. This upcoming challenge reveals a great demand of food, fiber and shelter to cover social, medical and economical demands of human beings. Trees are also essential for the survival of about 200 million people worldwide by providing wood and income (Ansari and Iftikhar 1985). There is no doubt that agroforestry has been practiced since millennia as an arrangement of traditional land-use systems and practices but in late 1970s, it was evolved as a modern and improved land-use system. It has been a customary practice to grow trees and crops in a combination for getting maximum benefits and intermediate income. Not only in Asia, but it has been practiced in European countries like Finland and Germany as well. Beside this, farmers of tropics and Central America have been regularly involved in growing different tropical trees on their farmlands aiming at obtaining timber benefits, shelter tree crop and windbreaks (Nair 1993). Such examples can also be found in Asia i.e., the farmers practiced agroforestry in Philippine by clearing the forest area for agricultural crop production but leaving a few selected trees to provide a partial canopy or shelter to new crop (Nair 1993). These examples indicate that trees are integral part of cropping system to support agriculture. The change of cropping pattern or the inclusion of tree species into traditional farming system started in 1806 from Burma which was under British Empire at that time. U Pan Hle, a Karen in the Tonze forests of Thararrawaddy Division in Burma, established a plantation of teak through the use of "taungya" (hill cultivation) method and presented it to Sir Dietrich Brandis (Blanford 1958). This system was further spread to other parts of Burma and later it reached South Africa in early times of 1887, India in 1890 and Bengal in 1896 (Raghavan 1960). This is important to mention that teak is not the only species that can be used in agroforestry system, other tree species of multiple benefits can also be used for this purpose. Like the traditional land-use disciplines of agriculture and forestry, agroforestry covers biological, physical and social science disciplines. (Mercer and Miller 1998). Understandably, the biophysical sciences have dominated the first two decades of agroforestry research and development because the interest in agroforestry as a land use emerged from observations of the impacts of non sustainable farming systems on tropical soils and forests (Nair 1996). Concerns over the inadequacy of socioeconomic research in agroforestry began to grow, however, as improved agroforestry systems were transferred from research institutions to rural development projects. As mentioned above, during the 1980s agroforestry became an established focus of international rural development efforts. For example, in 1988 and 1989 ICRAF identified 166 agroforestry projects supported by developmental organizations and government agencies (Miiller and Scherr 1990), and by the early 1990s the US Agency for International Development alone supported 28 agroforestry and technological advances, agroforestry rural development efforts were frequently unsuccessful (Nair 1996).

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More than a decade of discussions on how to protect the world's forests has resulted in substantial changes in the way forests are managed. Policies and programs help to promote sustainable forest management. Forest plantations comprise about 5% of the world's forests. Asia has the largest area of plantations, accounting for 62% of the world’s total. China accounts for 24% of that total and India, 18% (FAO 2000). The area of forest plantations was increased by an average of 3 million hectares per year during the 1990s. Half of this increase was the result of afforestation on land previously under non-forest land use, whereas the other half resulted from conversion of natural forest. In Pakistan, at present about 90% fuel wood and 60% timber comes from farmlands. Thus, agroforestry is playing a vital role in fulfilling our wood requirements. It is estimated that 10% area of our farmlands can be easily brought under tree cover without harming agricultural crops. At present the tree cover on farmlands is only 2%. There are about 300 million trees on farmlands throughout the country with a standing volume of 70 million m3 (Quraishi 1998). The significance of wood produced on farmlands has increased sharply during the last two decades. According to FSMP (Forestry Sector Master Plan) the annual growth of forests and trees was 14.4 million m3 of which 7.7 million m3 (53%) was put on by the farmland trees. The farmlands of the Punjab have about 200 million trees of which 95% are in irrigated areas. These trees are mainly comprised of Dalbergia sissoo (42%), Acacia modesta (20%), Acacia nilotica (11%), Melia azedarach (7%), and Mango (6%). Ber (31%), Acacia modesta (20%), Acacia nilotica (19%) and Dalbergia sissoo (7%) are the predominant species in rainfed areas (Quraishi, 1998). The farmers have long recognized the value of planting trees on fields for sheltering crops, generating wood for self-consumption and commercial sale. Scattered trees have less competition with agricultural crops and they yield tangible benefits at very little cost and efforts. Figure 9.1 manifested that agroforestry is adopted for various purposes. This figure provides a detailed overview of agriculture-forestry interface based on the socioeconomic need of the community. An agroforestry system possesses three main qualities to obtain maximum benefits i.e., productivity (farm income can be increased by enhanced tree products’ output, improvement in crop yield, and optimizing labour efficiency), sustainability (improvement in soil fertility, reclamation of problem soils) and adoptability (introduction of new and improved technologies in agroforestry systems).

9.2.

Agroforestry Systems and Practices

Based upon the concept and definition of agroforestry, different agroforestry types can be observed around us. Based upon ecological, geographical and farming system combinations, different agroforestry systems can be classified. These classifications were made on the basis of findings and reports described by ICRAF and Nair (1987). These reports explain the collection and evaluation of present land-use systems. These reports not only assist in classifying the agroforestry systems but it also provided a detailed and comprehensive database to evaluate the

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strengths and weaknesses of current agroforestry systems and the proposed ones. Reviewing the classification of agroforestry, a common objective can be found in all, which is the essence of agroforestry i.e., “the purposeful growing or deliberate retention of trees with crops and/or animals in interacting combinations for multiple products or benefits from the same management unit” (Nair 1993). Generally, agroforestry systems are classified into three systems on structural basis i.e., agrisilviculture (combination of trees and crops), silvopastoral (combination of pasture, livestock and trees) and agrosilvipastoral (combination of crops, pastures, livestock and trees) (Figure 9.2). A few other classifications are also proposed based on the function, agro-ecological and environmental adoptability, and socioeconomic and management level. These classification criteria are confined only to specific geographical regions. So, here we will discuss only above mentioned three agroforestry systems. It’s a common misunderstanding that growing agriculture crops and trees on the same piece of land is considered as agroforestry. It has been wrongly interpreted somewhere in literature. For a detailed understanding about agroforestry concept, the components should be understood. In an agroforestry system, three components have prime importance i.e., trees, pastures/ livestock and agriculture crops.

Fig 9.1 Special conditions and constraints of Agroforestry Source: Modified from Nair (1993).

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Fig. 9.2 Classification of Agroforestry Systems It is clear from the definition and concept of agroforestry that trees are the main components of each agroforestry system that cannot be deleted. Beside these three agroforestry systems, a few other are also in practice, for example multipurpose woodlots, apiculture (with trees), sericulture (with trees especially mulberry plants) and aquaculture/ fish farming (with trees) (Nair 1985). These systems also improve the socio-economic conditions of community livelihoods but these types do not fall in above mentioned three main agroforestry systems, hence, these are brought under others term. It is important to mention here that a few other sub-divisions are also in practice worldwide that include agrihorticulture (combination of agriculture crops and fruit trees) and agrisilvihorticulture (combination of agriculture crops, timber trees and fruit trees). The application of all these agroforestry systems may vary according to the main and specific objective. For example, fodder and food production, livestock production, timber production, shelterbelts, windbreaks, fuelwood production, soil rehabilitation etc. Agroforestry practices and agroforestry systems are often used synonymously while Nair (1992) differentiate both terms as following. “An agroforestry system is a specific local example of a practice, characterized by environment, plant species and their arrangement, management, and socioeconomic functioning. An agroforestry practice denotes a distinctive arrangement of components in space and time. Although hundreds of agroforestry systems have been recorded, they all consist of about 20 distinct agroforestry practices”. In other words, in a system, more than one practice can be found simultaneously or at different times.

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9.2.1. Trees and Arable Crops (Agrisilviculture) Agroforestry practices mainly consisting of trees and crops growing together are known as agrosilvicultural practices. It includes ‘taungya’. In Taungya, the farmers grow their agricultural crops with young trees either on borders or in between. It’s a common practice in West Africa and savannas as discussed earlier. In these areas, the farmers retain the native trees present on their farmlands and cultivate their crops amongst those trees with the addition of modern technology as hedgerow intercropping cropping or alley cropping. In such system, fast growing and nitrogen fixing tree species are preferred to retain or grow between crop lines which are periodically pruned, thinned and harvested to provide nutrient-rich mulch as fertilizer to the crop. In sloping areas, tree species are planted on contour especially to control soil erosion, improve water infiltration and reduce run-off effects. In this system, following practices have been used in various parts of the world. Some important practices in this system are elaborated here. •

Improved Fallow: In this practice, fast growing, leguminous trees are grown during a fallow period.

•

Taungya: During early stages of plantation, agricultural crops are cultivated among young trees. In this practice, fast growing leguminous trees are used.

•

Alley cropping: Fast growing, leguminous or fodder trees are grown between crops or as hedges.

•

Multipurpose trees (MPTs) on agriculture land: MPTs Trees which can benefit in terms of timber, fuelwood, fruit and fodder are planted on bunds or terraces.

•

Shelterbelts, windbreaks and live fences: tall growing trees are grown along / around agriculture land.

9.2.2. Trees, Livestock and Rangelands/ Pastures (Silvopastoral) Growing trees in combinations with pastures are termed as silvopastoral system. It includes growing and retaining forest trees in pastures to provide food and fodder to livestock and shade or shelter for both human beings and livestock. Tree browsing in silvopastoral system may occur mainly for productive or conservation purposes. For example, in United Kingdom, forest grazing in pastures is allowed periodically to conserve the habitat and retain understory ferns. Such examples have also been reported for Northern Europe, Southern Mediterranean region and Spain. Scattered trees grown or retained in dry tropical pastures contribute to feed cattle in dry seasons while in wetter tropical areas, trees may contribute in improving soil fertility by nitrogen fixation and atmospheric input. Sometimes, agroforestry practices are encouraged without the involvement of pastures i.e., having a direct interaction between trees and livestock. In such practices, trees serve as fodder banks. Fast growing trees with better nutritional qualities are grown which can be harvested at intervals providing fodder to livestock. Moreover, trees are also used in sericulture and apiculture. These both

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systems are also considered under this system but this is the opinion of a few scientists. Some common practices of this system are discussed here. •

Protein banks: Plantation of protein rich and nutritious trees on agriculture land/ pastures/ rangelands for cut-and-carry fodder production.

•

Fodder Tree plantation on rangeland/ pastures: Trees are grown and retained to provide a regular supply of fodder to livestock

9.2.3. Trees, Crops and Livestock (Agrosilvopastoral System) The practical approach of agrosilvopastoral system is to combine tree plantation, agriculture crop production and animal husbandry. This system is especially used to focus on conserving the resources and their efficient utilization with minimum energy losses. Here, a few main practices are mentioned which exist in this system. •

Apiculture: Trees are grown for honey production

•

Sericulture: Preferably, Morus alba is grown for silk worm rearing.

•

Multipurpose woody hedgerows: Fast growing trees with better fodder qualities are grown for livestock grazing/ browsing, mulching, fertilizer, soil conservation, etc.

•

Home-gardening along livestock: Closed, multistory combination of multipurpose trees preferably fruit trees, vegetable crops around homesteads.

9.3.

Importance of Agroforestry in Pakistan

Pakistan’s economy has undergone considerable diversification over the years yet; agriculture is the most important sector of its economy. The cultivated cropped area covers 22.15 million hectares with its present contribution to GDP at 22%. Agriculture accounts for 44.8% of the total employed force of Pakistan (Government of Pakistan 2014). Most importantly 65.9% (Government of Pakistan 2014) of country’s population currently living in rural areas is directly or indirectly dependent on agriculture for their livelihood. Agriculture is the largest source of country’s foreign exchange by serving as base sector for its major industries viz. textile, sugar etc. Consequently, this sector has a substantial effect on the overall growth of GDP of the country. The area under cropping system in Pakistan is 22.15 million hectares (Government of Pakistan 2014) out of which 76% is cultivated area under irrigation (Government of Pakistan 2014). Being an agricultural country, mostly the inhabitants of Pakistan depend on natural resources and fulfill their requirements from agriculture, livestock, poultry, forestry and fisheries. But these resources are not too much to meet the needs of all the people, especially, those living below poverty line. It has been reported that 28.1% of rural population is living below poverty line, who are earning Rs. 878.64 per adult equivalent per month. Therefore, there is a need to justify the necessities of life by generating natural along with income resources.

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Forests can also play an important role in Pakistan’s economy. These are the important sources for protection of land and water resources, particularly in prolonging the lives of dams, reservoirs and the irrigation network of canals. The trees are also essential for maintaining a sustained supply of wood and wood products. Pakistan is a land of great diversity, which has yielded a variety of vegetation. According to FAO report 2000, 3.9 billion hectares or 40 million km2 of the globe is covered with forests which are almost 30 percent of total land area. This corresponds to an average of 0.62 ha (6200 m2) per capita, though this is unevenly distributed. For example, 64 countries with a combined population of 2.0 billion have less than 0.1 ha of forest per capita. This estimate was based on data on forest area reported by 228 countries and territories. Among world regions, Europe (which, for the purpose of this assessment includes the Russian Federation) accounts for one-quarter of total forest area, followed by South America and then North and Central America. South America is the region with the highest percentage of forest cover (almost half of the land area) and Asia is the region with the lowest percentage of forest cover (less than 20% of land area). If a comparison is carried out among Asian countries, India stands first representing 21.6% of its area under forest and China ranked 2nd having 17.5% while Pakistan has only 3.1% or about 1,902,000 hectares of total land area while in 2005 it remained only 2.13%, which is very low as compared other Asian countries (World Bank 2011). The figure of Government of Pakistan is different from above. She reported that the area under forest cover in Pakistan is about 5%, out of which 85% is public forest, including 40 % coniferous and scrub forests on the Northern hills and mountains (Government of Pakistan 2005). The balance is made up of irrigated plantations and Riverain forests along major rivers on the Indus plains, mangrove forests on the Indus delta and trees planted on farmlands. If we consider the official figure of Pakistan, then it is also less than the world forest area, which is 30% of total land. Forest cover is divided into four percentage groups (>70%, 40-69%, 10-39%, 09%), thus the Pakistan lies in the last category i.e., 0-9%. Moreover, it can further be categorized into primary, protected, conserved and production forests (FAO 2000). Trees are being cut at in an unmanaged system i.e., there is no balance between harvesting of trees and regeneration or afforestation activities. Such brutal practice is fashioned due to increasing demands for fuel to meet domestic and industrial needs. Unbalanced harvesting and afforestation activities hamper forest decline rate which is consequently leading towards environmental and land degradation, air pollution, and biodiversity loss. For this, efforts should be undertaken to multipurpose tree plants new and improved varieties of trees and plants that have a good growth rate. It has been reported that Pakistan lost about 214,000 ha forest @ 2.1% deforestation rate only between 2000-2005 which correspond to 43,000 ha/year loss. Pakistan's total deforestation rate from 1990-2000 was 41,000 ha or 1.8% per year. Hence this report shows that the deforestation rate in Pakistan is increasing day by day. This is very alarming figure of a great concern (FAO 2000). Pakistan is forest deficient country with only 0.03 ha as compared to world average of 1 ha per capita (Government of Pakistan 1992), is facing timber and fire wood shortage of about 29 million cubic meters (Government of Pakistan 2005) and our

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forests produce only 32% of fuel wood supply to meet national energy requirements (Government of Pakistan 1992). In a study, it has also been estimated that this shortage of 29 million cubic meters will become 52.6 million cubic meters up to 2018 thus increasing future needs by 23 million cubic meters (Wani 2003). This forest area per capita is declining due to growing population rate at 1.90% annually. According to safe estimates, the annual import bill for pulp, paper and paper products runs into RS 8 billion which is expected to increase many times due to increase in population. The area under public forest cannot be further expanded to keep pace with population growth rate and increasing demands for forest products. The only available option is to increase wood production on private or farmlands so as to meet pulp and paper demand locally to reduce import bill and save foreign exchange. It is estimated that state forests contribute only 14% of timber and 10% of fuel wood whereas 46% of timber and 90% of fuel wood requirements are being met from farmlands (Government of Pakistan 2014). To counter the deficit issues in timber and fuelwood supply, agroforestry is an important practice. It will be discussed in next sections of this chapter that how agroforestry can be helpful in soil conservation, improving soil fertility, erosion control, for improving food, fodder and fuelwood production of the country. Below are some facts demonstrating the role of agroforestry in developed and developing countries. •

Intercropping of Paulownia elongate with cereals is practiced on 3 million hectares in China (Sen 1991).

•

In Henan province of China, agroforestry was introduced in late 1970s. 30 years after initiation of agroforestry practices, two-thirds of the 46,000 ha of farmland were intercropped with Paulowina elongate (Wu and Zhu 1997).

•

In Tabora District of Tanzania, about 1,000 farmers intercropped Acacia crassicarpa with tobacco and maize (Ramadhani et al. 2002).

•

In Uttar Pradesh, India, 30,000 farmers cultivate Populus deltoids on their farms. The average farm size under populous deltoids plantation is 1.3 ha. These plantations support their national match industry and minimize the import cost. (Jain and Singh 2000; Scherr 2004).

•

According to McAdam et al. (1999) ash trees were intercropped with ryegrass pastures at 40 years rotation in United Kingdom. No reduction in ryegrass yield was recorded for first 10 years of rotation.

•

In the Canada, more than 43,000 km of windbreaks has been planted since 1937 which protect 700,000 ha of Canadian prairies.

•

In 1987, approximately 858,000 windbreaks were planted in the United States, especially in the north central and Great Plain areas, covering 281,000 km which protected 546,000 ha (Williams et al. 1997).

•

An increase of 8, 12, 23 and 25% in yield of spring wheat, maize, winter wheat and barley, respectively was recorded by Kort (1988).

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Agroforestry: Prospects and Challenges

Agroforestry on Marginal Lands

Poor physical and chemical quality of soils severely affects the crop growth and productivity (Flowers 2004). A vast area of the world is wasteland due to excessive salts, waterlogging, acidity, alkalinity, or even the presence of sand or gravel in soil (Zhu et al. 1997). Agroforestry practices can be implemented to bring such wasteland under cultivation by imparting different techniques (Munns 2002; Munns and Tester 2008). In general, selection of suitable tree species especially multipurpose trees is the key factor in reclaiming such kind of areas (Cavalcante and Perez 1995). These trees not only provide timber and fuelwood to the farmers but rehabilitate the soil conditions improving its fertility. Detailed discussion can be seen in Chapter No. 14.

9.5.

Agroforestry for Soil Conservation

Agroforestry is a unique, ecologically balanced and sustainable ecosystem. This is greatly to the fact that trees being a woody component offer the most: food, fuel wood, fodder, shade etc. They also minimize nutrient losses as a result of leaching and erosion. The large tap root with wide spreading lateral roots not just provide anchorage but also play an important role in nutrient uptake, absorbing nutrients from the lower strata of the soil. Nutrient cycling is another major aspect whereby the nutrients absorbed by the tree are returned back in form of litter fall, stem flow and decomposition. This again provides nutrients for fresh use to the same trees. Soil microbial associations such as rhizobia with the tree roots improve nutrient uptake especially in the case of nitrogen. Such fast growing species combined with herbaceous crops enhance the soil fertility status and improve the microclimate, improving survival conditions for both plants and animals. The roots of the trees are long to give the tree anchorage and wide to avoid soil erosion. Some trees fix nitrogen and produce nitrates which are essential for plants. The mycorrhizal roots play a vital role in the poor and the dehydrated soil. Productivity and protection of system and soil conservation are certainly most important functions of trees. Though originally equated with control of erosion, soil conservation now associates with maintenance of soil fertility (Young 1987). Moreover, the plantation of trees improves physical and chemical characteristics of soil by adding soil nutrients through leaf litter decomposition. Tree roots uptake soil nutrients below crops’ roots level and make them available by fixation (Hartemink et al. 1996; Allen et al. 2004). In this way, trees can maintain soil organic matter and nutrients but it depends on tree species, planting space, tree age and agroforestry system (Szott et al. 1991; Mohsin et al. 1996; Young 1997). For example, Populus deltoides is considered as a potential multipurpose tree or agroforestry system as it has single and tall stem, fast growth, deep roots and narrow crown which enable less competition with associated crops (Jain and Singh 2000). The researchers have mentioned certain qualities which are necessary for trees to maintain soil status like a high yield, better aboveground biomass production, more nitrogen fixation, dense adventitious roots capable of mycorrhizal association, existence of deep roots, less toxic substances and adequate amount of nutrients.

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There are many mechanisms involved in soil fertility improvement such as compatibility of trees and their suitability to the soil. A leguminous tree fixes nitrogen and improves nutrient status. Leaf litter increases organic content. The organic matter is greatly influenced by the microbial activity in the rhizosphere, which are beneficial for the companion crops. Physical properties such as water holding capacity (WHC), permeability, aggregate stability of soil and soil temperature are some of the more essential aspects. Soil conservation and erosion control through biological measures lend stability to the system and decrease siltation rate in downstream reservoirs. Previous research reports, observations and farmers’ experiences support the hypothesis that the plants improve the soil quality, texture, organic matter and nutrients accumulation. Following points strongly support this concept: •

From ancient times, the farmers have been interested in cultivating their agricultural crops on cleared forest lands.

•

Forest soils have been found with better physical and chemical properties pertaining ample amount of organic matter and essential nutrients in comparison with fallow lands.

•

Being a closed ecosystem, woodlands are preferred for nutrient transfer, storage, and cycling.

•

The best way to reclaim a marginal land or improve the soil fertility on sustainable basis is to incorporate tree cultivation either as compact plantation, linear or alley cropping. It will gradually improve soil organic matter, nutrients accumulation and water holding capacity.

The summarized beneficial effects of agroforestry on soil fertility and productivity are given in Table 9.1. Nutrient cycling includes the conservation of sources and their partitioning between soil and plant within a system. Agroforestry systems have been cited as potential land-use systems for their efficient nutrient cycling which in turn improve soil fertility. As discussed earlier, trees possess deeper root system than other herbaceous plants having the potential to retrieve nutrients from deep soil horizons. Moreover, forest, an undisturbed ecosystem, takes nutrients from the atmosphere, or by nitrogen fixation etc enabling the atmospheric input to soil. Such input of biologically important elements is caused though precipitation. Nitrogen is essential element as first floor contains 2225 kg/ha which is mostly in humus complexes (Young 1987). The amount of nitrogen and potassium is higher in the leaves and fruit of plant than in branches, poles and litter. Leaf fall is an important process as the litter continuously provides the nutrients back to the soil and they keep the cycle in progress. With respect to the nutrient intake, the major part of nutrients is in the leaves of the nutrients. The mechanisms include uptake from lower soil horizon, reduction of leaching to lower horizons, balanced nutrient supply and improvement ratio between available and fixed nutrients for a tree leave biomass production of 4000kg dry matter per ha year. The potential nutrients returns in form of nutrients are of the order of 80-120 kg N, 8-12 kg phosphorus, 40-120 kg potassium, and 20-60 kg calcium. The nutrient uptake in trees is currently

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explained by a hypothesis that trees are most efficient agents than the herbaceous plants in intake of nutrients. Potassium, phosphorus, bases and macronutrients are released by rock weathering particularly in the B/C and C-horizon on to which tree roots often penetrate. The strong gradient in nutrient content, control between top soils and sub soils indicate recycling through litter whereas other processes are also involved. It is important to note here that almost 20-30% of tree total living biomass is present in soil as roots which are constantly adding organic matter to soil through its dead and decaying parts. Table 9.1 Beneficial effects of trees on soil fertility Addition to soil

Reduction of losses from soil Sustainable supply of Protection from soil organic matter to soil erosion: proper planning and management of trees on wind/ water eroded soil can minimize the effects of soil erosion in terms of loss in organic matter Nitrogen fixation Nutrient reclamation: through leguminous soil nutrients which tree roots are deeply deposited in soil horizons are absorbed and uptaken by tree roots Nutrient uptake as trees are more active in uptaking soil nutrients from deep root zones especially in B/C and C horizons Atmospheric input: nutrients dissolved in rainfall and then deposited in soil

Effect on physical properties of soil Improvement of soil physical properties i.e., soil structure, texture, porosity, water holding capacity

Effect on chemical properties of the soil Decrease in soil acidity

Amelioration of soil temperature

Decrease in salinity and sodicity

Effect of shading: by lowering down soil temperature, loss of organic matter through oxidation can be minimzed

The plantation of trees in the agroforestry systems increases soil fertility by improving the physical properties of the soil. Sreemannarayana et al. (1994) studied influence of Albizialebbeck on soil properties with cowpea as intercrop in different seasons and with pruning treatments. The soil organic matter improved over the recorded value. Great improvement in soil fertility was shown by Albizia lebbeck. Karite (Vetellaria paradoxa) and Ner (Parkia bilobosa) were observed in this regard. They showed that the organic matter was rich in the soil under the trees and soil fertility improvement was least in the fallow land and was highest in Albezia lebbeck based system. Induced crop yield are from 0-60%. The study in Rampur (Utter perdesh, India) shows benefit of poplar (Populus deltoides) plantation. The

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litter produced had higher content of N P K. Alley cropping has also proved much beneficial. Soil carbon was found to be 8.7 % higher than sole crop plant. However, C/N ratio decreased. When woody perennials and agricultural crops are together cultivated they improve soil conditions and fertility greatly. The productivity, fertility, and erosion under cassava based agroforestry systems were studied by Gosh et al. (1989). There was increase in the phosphorus and potassium status. Alley cropping also has a significant effect on it. It showed that large biomass could be obtained from this system. In most cases 30% of nitrogen is available; the rest is lost by leaching and gaseous losses Gosh et al. (1989). In leucaena, 50% of N is released in first 25 days. The trees may have negative effects on the crops and soil fertility: if the tree plantation is poorly managed it leads to soil erosion. Similarly shading and spectral quality of light in close proximity may have serious effects on agroforestry and adverse chemical and biological effects may result from acidification, allelopathy, etc. According to a phenomenon, the tree roots and leaves have some substances that hinder crop production regardless of their benefits like benzoic and p-coumaric acids can create a problem if they are present in large quantity in the trees. Application of fertilizers to forest trees in agroforesty is generally a costly process but it suits to the trees of economic values as seen in horticulture based trees. An ideal fertilizer must be cheaper to get a unit of plant food, give high growth response, maintain fertility and physical and chemical properties of soil (Maslekar 1990). Generally, hardwoods require more nutrients than conifers and fast growing trees. Many advanced countries except India have accepted the benefits of fertilizers and it is proved to be better for getting large biomass in short span of time. Significant growth advancements due to the putting of 28 kg N and 15 kg P2O5 per ha were observed in pines (Singh et al. 1981). Krohn (1981) reported that fertilization of eucalyptus seedlings resulted in better tree growth and survival. The effect of phosphoric fertilizers on growth of teak plantation was also beneficial. Ammonium phosphate also proved beneficial for growth and height of teak plants in initial 2 years. In case of SS, a dose of 120 g per plant showed significant effect on height (Singh et al. 1981) Generally, soils brought under agroforestry systems are in poor condition with low nutrient availability, and mismanagement may lead to mortality of trees soon after planting. Supplementary nutrients should be ensured at the critical stage of planting. Fast growing leguminous species ensure increased fertility of soil along with herbaceous cover as this constantly contributes in biomass and organic matter in form of leaf litter. This increases nutritive status and prevents erosion. Any biomass that accumulates is decomposed and liberates nutrients for reuse. Further techniques can be introduced for efficient recycling, soil aspects should be assessed in detail. Any negative effects should be remedied in accordance with expert advice and dealt with immediately.

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9.6.

Agroforestry: Prospects and Challenges

Interventions for Soil and Water Conservation Through Agroforestry System

Soil and water are the most important resources for life. However, ignorance of soil and water conservation measures, improper use of fertilizers, mismanaged irrigation and water practices, mining, and effluents discharge etc. are responsible for land degradation at a massive scale. This leads to the paradox of getting more production from the increasingly scarce resources to meet the requirements of mounting human population. Demographic pressure is the primary cause of land degradation, along with loss in vegetative cover. Shifting cultivated areas may result in further losses of 18million tonnes of soil. Values for tributary river sediments in the region range from 6.0 to 98.4 cum ha-1 per year. Hence agroforestry techniques become crucial for the conservation of soil and water. Water erosion can cause losses of top soil in 130.5 million ha as well as degradation of terrain in 16.4 million ha. Of the total eroded soil, 29% is lost to sea, 61% relocated or transferred to different places, and 10% is sedimented in reservoirs, reducing their capacity by 1-2 % at an annual basis. The erosion rates have reduced the life of reservoirs increasing rates of sedimentation, especially in the catchment areas. If we talk about creating barriers for controlling run-off and soil loss on slopes, the most effective and feasible are the vegetative barriers. Panicum maxicum used as a barrier in maize succeeded in decreasing run off by 28% and erosion by 48% at Dehradun (Bhardwaj and Khola 1999). The barriers also help in redeposition of soil on contours forming bunds or terraces naturally. However, the effectiveness of the barrier also varies according to situation and conditions. For example, in Doon valley run-off was reduced by 18% and soil loss controlled upto 78% on a 4% slope using barriers of native grasses such as Vetiveria zizanioides (Vetiver), Eulaliopsis binata (Bhabar) and Panicum maxicum (Guinea). But the same grasses cannot be universally accepted to achieve the same result or control erosion and run-off in different countries or zones. Apart from grasses, tree species too prove to be an effective control measure. Paired contours and hedgerows consisting of Leucaena leucocaphala (ipil ipil) and Eucalyptus hybrid (Sufeda) can reduce run-off by 40-48% as well as 12.5t ha-1 soil loss in maize on 4% slope. Other suitable grass species include Panicum maxicum, Chrysopogan fulvus, Setaria sphacelata, Saccharum munja, Saccharum spontaneum and Arundo donax. Panicum maxicum reduced soil losses from 45t ha-1 to 6.12t ha-1 in Dehradun (Bhardwaj 1990). Hedgerows are of multipurpose concept. They don’t just reduce soil loss and runoff, but provide fodder too. They also trap soil particles helping to prevent loss of nutrients and finer soil particles. Even small farms can easily raise hedgerows. Grewal (1993) compared agroforestry models for eroded lands stated soil loss to be most negligible when under a Eucalyptus hybrid and Eulaliopsis binata system, soil loss being only 0.07t per ha. Acacia catechu-Pennisetum purpureum was next with loss of 0.24t per ha, and Tectona grandis-Leucaena leucocephala-Eulaliopsis

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binata with loss of 0.43t per ha. Run-off and nutrient losses were reduced too. Eucalyptus trees managed as a sole tree are more effective. Grass cover decreases run off by 73 percent and soil loss by 94 percent. These were further reduced by eucalyptus tree rows. The trees affect the crop yield but this is compensated by tree products (Narain et al. 1998). Local flash floods can be controlled by establishment of vegetative spurs, brushwood check dams, vegetative filters and stream bank lining of native species. This will save a greater portion of land from degradation and erosion (Samra 1994). Leguminous shade trees are of immense importance to tea plants as they provide shade and nitrogen (Tejwani 1994). Shade trees provide 2500-5000 kg leaf litter, 63-126kg N, 18-36kg P2O5, 22-44kg K2O, 32-64kg CaO and 16-32kg MgO ha-1 per year to soil (Gogoi 1976). These trees play a vital role in improving fertility and enhancing production by improving soil nutrient content. Mine spoils, or mining, results in degradation of land by shifting of soil, denudation, reduction in water holding capacity of soils etc. The disturbed land can be reclaimed by establishing forest cover with trees as well as grasses and shrubs. Agroforestry is the ultimate option for such a solution. Species that are indigenous, hardy, with coverage and nitrogen fixation with good economic and social values are preferred. From the western states of Jammu and Kashmir to Himachal Pradesh, about 10 million ha of land are covered by the cold desert as it lies in the Himalayas and Tibetan plateau. (Rai 1996) lying in the rain shadow of mountains and facing severe extremes of cold and dryness, this is a fragile and unstable area. The constant biotic pressure in terms of grazing, fodder and fuel has led to degradation. Faulty land practices and exploitation of tree cover are other reasons. Eucalyptus and poplar clones have been recently introduced in the Kashmir Valley. Other agroforestry species suited to the region are Quercus spp., Bauhinia variegate, Morus cerata, Ulmus wallichiana, Celtis australis etc. A native shrub, Hippophae rhamnoides, is used for both fodder and fuel with promising potential. One ha plantation of the shrub is sufficient to fulfill needs of 20 households. (ICFRE 1993) Integrated watershed management is an essential to reduce run-off, flooding in down-stream area and improved in-situ moisture conservation, hence improving biomass production (Samra 1994). Vegetation in the catchment area helps ground water recharge and rise in water table. Both run-off and soil loss are decreased when watershed areas are incorporated with trees and grasses, or mechanical measures are taken. (Singh et al. 1990) To conclude, agroforestry has the distinctive feature that the land use systems have the potential for both production and conservation. (Young 1986) These include products and services such as conservation of resources, prevention of erosion, increased soil fertility, shade, moisture conservation, recreation, biodiversity, etc. The agroforestry interventions are aimed to increase biomass production, soil amelioration and stabilization of degraded lands. Not only are the needs of fodder, food, fuel wood, fiber satisfied but economic and environmental security is ensured too, leading to sustainable development with steady income sources.

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9.7.

Agroforestry: Prospects and Challenges

Agroforestry for Food Production

Development and well-being of humanity depends on the degree of sustainability of human activities. A sustainable community must be able to balance the socioeconomic development with the production of food and the environment protection. The speedily inflating human population is pushing for greater food requirements, which is in turn, threatening the environment conservation and enlarging the gap between the supply of resources and the demands of basic necessities of life. Since ancient times, people are fulfilling their requirements for food and shelter by depleting natural resources. The scientists and policy makers are encouraging communities to adopt sustainable ways o f harvesting benefits from natural resources without causing any serious environmental concern. Fischer et al. (2009) reported that 12% of total world population (800 million) is undernourished and the policy makers are devising protocols to minimize this figure to its half by 2015. The food security issues can be resolved by imparting various agricultural approaches and technological innovations in current farming system. Currently, a wide array of fruit trees, crops, vegetables, etc. are being practised in agricultural system. however, food shortage threats can be overcome by planting under-utilized forest trees rich in minerals, protein, fiber, etc. (Leakey 1999; FAO 2010; Malézieux 2013). The scientists are working on the domestication of forest trees to provide year around income, food for local communities and feed for livestock.. For this, fruit trees are being utilized as primary option. This said, the significance of wood-based and non-wood based forest products cannot be declined either. A case study in Africa revealed that 90% households cultivate fruit trees. Of these, one fourth of the respondents grew banana, avocado and mango while two third were growing some other fruit species. Likewise, the people of Malawi consume papaya and oranges which are mostly harvested on their own farmlands (Jamnadas et al. 2011). In addition to the provision of food, feed, fruits and nutrients, forest trees offer meaningful aid in sheltering, nourishing and improving agricultural crop systems through means like providing shade for crops that are sciophytic in nature (grows well under shade conditions); shelter and fodder for livestock production and improving soil fertility through litter-fall and extensive adventitious and tap root system (how tree root system benefits soil fertility and crop productivity is discussed in “Role of Agroforestry in Soil Fertility”). Nitrogen fixing trees improve crop yield by improving soil fertility, rain use efficiency of crop plants and better performance under drought conditions (Sileshi et al. 2011). Moreover, these tree species can regulate the climatic factors especially micro ones which can assist agricultural crops to mitigate harsh climatic effects resulting in better growth behaviour and higher yields (Sileshi et al. 2012). In addition to supporting agricultural crops, trees also play their roles in dairy farming by providing, shade, shelter and fodder and supplementary feed. Home gardening has been considered as a viable option to support food requirements of households. Home gardens are preferably a combination of plants, shade trees, fruit bearing trees, shrubs, vines and medicinal plants. In home gardens, tuber crops, medicinal plants and fruit trees are preferred crops since these

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can fulfil the basic needs however, a conspicuous character of a home garden is the dominance of fruit trees like mango, guava, date palm etc. and food providing trees like Moringa oleifera and Sesbania grandiflora which dominate in Asian home gardens. These trees make up the deficiency of local diet providing better nutritious supplements. It has been reported in literature that home gardens support the energy and food requirements of local farming communities substituting vitamins and nutrients’ deficiency (Soemarwoto and Conway 1991). In order to increase the function of agroforestry in food and nutritional security, following recommendations may be considered: •

The present role of agroforestry tree products and services in sustaining food and nutritional security of inhabitants of rural area in different farming systems should be better quantified.

•

The expansion of agroforestry policy should not be restricted to the agricultural or forest sectors only. It should be treated as an individual farming system. Required improvements include selecting suitable tree species and land occupancy, in-depth research o practices and behavior of farmers to grow these trees and the credit of agroforestry as an investment option for food production.

•

Research studies should be focused on investigating food tree domestication options appropriate for meeting smallholders’ needs, and assess complementarity and resilience in agroforestry systems under climate change in the context of other global challenges to food and nutritional security.

9.8.

Agroforestry for Fuelwood Production

Traditional energy sources could not have much consideration in current energy debates, but firewood and charcoal from trees are vital for the endurance and wellbeing of approximately two billion people (FAO 2008). In sub-Saharan Africa, the use of charcoal is increasing speedily, as the value of charcoal industry is supposed to reach about US$ 8 billion in 2007 (World Bank 2011). The charcoal industry is an essential element for food and nutritional safety because it provides both energy and income. As the prices of modern energy sources are increasing, this situation is improbable to change for some time. In developing communities/ in below-the-poverty-line/In communities with inadequate economic means, firewood and charcoal are frequently burnt in open fires or poorly-functioning stoves with considerable release of pollutants (especially from firewood) that may be fatal to human health. Such a condition has already lead to the deaths of more than one million people in a year worldwide. Of these, women stand most victimized since they are in direct contact with cooking activities (Jamnadas et al. 2011). Different tree species exhibit varying fuel quality as mentioned in “Multipurpose Trees MPTs”.

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Agroforestry: Prospects and Challenges

Reduced access and increased prices of wood-based biomass have led to initiatives to promote agroforestry cultivation. The farmers who are involved in agroforestry practices growing their own fuelwood trees need less fuelwood to purchase from market as most of their needs can be fulfilled from their own sources. Moreover, there is less reliance on natural forest stands and requires lesser time in collection. This leaves more time for income-generating activities, especially for women who are usually the major fuelwood collectors (Thorlakson and Neufeldt 2012). Access to cooking fuel provides people with more flexibility in what they can eat, including foods with better nutritional profiles that require more energy to cook. The cultivation of woodlots allows the production of wood that is less harmful when burnt and has higher energy content. The use of better stoves – with greater efficiency – reduces greenhouse gas emissions relative to the energy generated for cooking purposes. Pakistan is an energy deficient country. It has been reported that approximately 54% of national energy demand are covered by electricity conventional energy sources while the utilization of fuelwood, crop residues and dung fulfill the remaining requirements. It is important to mention here that fuel wood trees fulfill 26% of total energy requirements. By now, 95% energy requirements in rural areas are fulfilled by trees while in urban areas, this figure goes to 56% (Zaigham 2004). According to Zaman and Ahmad (2012), total wood consumption of Pakistan would be 59.44 million m3 including timber consumption (16.62 million m3) and fuelwood consumption (42.81 million m3) by 2025 if population is 208.84 million. Currently, per capita fuelwood consumption is estimated at 0.205 m3 while total fuelwood consumption is 34.95 million m3 in Pakistan. Three main sectors are fuelwood consumers i.e., household, commercial (restaurants, hotels, tea shops, bakeris, milk shops etc. and industrial sector (mainly brick and tobacco curing industries). Zaman and Ahmad (2012) reported household sector as the largest fuelwood consumer (81.8%) followed by industrial fuelwood entrepreneurs (14.9%) and commercial sector (3.3%). Out of household sector, 75% households consume fuelwood for cooking purposes, 14% for water heating while the rest (11%) for room heating in winter. Moreover, rural community consume a major part of fuelwood for cooking purpose (90%) while in urban areas, only 10% inhabitants depend on fuelwood (Government of Pakistan 2011). In case of fuelwood consumption by industrial sector, major proportion goes to social ceremonies (27%), khoya production (24%), brick making (20%), charcoal making (8%), tobacco curing (3%) and other industries (18%). Mainly Acacia nilotica(kikar), Acacia modesta (phulai), Dalbergia sisso (shisham), Ziziphus jajuba (ber), Morus alba (mulberry) are used for fuelwood consumption depending upon their calorific values, physical and chemical characteristics. Tree species with minimum moisture percentage are preferred that produce more heat as compared to other species with higher moisture content. The selection of suitable tree species plays a key role in the production and exploitation of fuelwood in an agroforestry system. The selection mainly depends on community preferences, climatic factors, edaphic factors, landholding size, interaction with existing agricultural crops, and market demands. So, it is rather

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difficult to propose a specific fuelwood tree which can address global requirement but a few criteria can be made to select suitable species. •

Adaptation ability to local environmental conditions. In this case, indigenous species are preferred which are of community interest.

•

Continuous pruning can supply unremitting fuelwood but for this, highly branched tree species should be preferred which can endure pollarding and pruning shocks.

•

Multipurpose trees provide a number of useful benefits like branches can be used as fuelwood and leaves can be used as livestock fodder etc.

•

Spineless wood of small diameter is easy to harvest and transport because that can be easily utilized for cooking and heating purposes.

•

TCI (tree-crop interaction) is an important factor while selecting a suitable tree. The species which are compatible with agricultural crops should be preferred.

•

Species with low moisture contents, higher density, and more ash and sulphur content possess good combustion quality.

•

The consumers’ demand is highly influential in selection.

A large number of tree species have been identified as fuelwood crops. Fuelwood markets are dominated by such tree species as Acacia nilotica, Tamarindus indica, Prosopis cineria, Salvadora oliodes and other local species, inspite of the large scale tree planting efforts for fuelwood production by state agencies using exotics such as Leucaena, Casuarina and Eucalyptus. Increasing efforts are being made all over the world to plant new species and improved varieties of trees that have good growth rates as well as have multiple uses. In Pakistan, many efforts are being made for introducing and cultivating fast growing and short rotation trees. The species most favored by farmers are kikar and shisham. They use the wood of these tree species for fuel, shelter, shade and fodder.

9.9.

Multipurpose Trees (MPTs)

Multipurpose trees are defined for their multiple benefits which can be driven from their different parts like food, fruits, nuts, fodder, timber medicines etc. This term is commonly used in agroforestry especially when the farmers are to decide about selection of suitable tree species. No doubt, all trees provide several benefits like soil improvement, shade, shelter etc. but MPTs have greater impact on farming culture because trees are planted not only for one purpose. The farmers are willing to get fodder, timber and fuelwood while planting trees as living fences, shelterbelts or alley cropping. In this part, scientific and local names, family and sub-family, origin, distribution, habitat and ecology of potential trees which can be used in agroforestry systems are given in this table with their uses, specific gravity, calorific values and productivity (Table 9.2).

Acacia senegal

Albizzia lebbek

3

4

LeguminosaeMimosoideae

Kala Sirin, LeguminosaeBlack Siris Mimosoideae

Gum Arabic

Kiker

Acacia nilotica

2

LeguminosaeMimosoideae

Local name FamilySubfamily Katha LeguminosaeMimosoideae

No. Scientific name 1 Acacia catechu

Distribution Habitat & Ecology

Uses

Specific Calorific Gravity Value Subcontinent Malakand, Drought tolerant, grows Fodder, food, 1 5200 Hazara, best on rocky, stony, sandy agriculture kcal/kg Rawalpindi, and loamy soils, required implements, plain areas precipitation is 500-2700 handy tools, of Punjab mm/ year, upto 1200 m timber elevation, -5 to 40 °C Pakistan Sindh, Drought and salinity Fodder, fuel, 0.75 4900 Punjab, tolerant, requires charcol, kcal/kg Balochistan, precipitation 125-1300 mm/ agricultural KPK year, semi arid, subtropical/ implements, tropical climate, 1-45 °C land stabiulization, nitrogen fixing Pakistan Sindh and Drought resistant, usually Fodder, fuel, 3200 Balochistan below 1700 m elevation, charcol, kcal/kg intolerant to waterlogging, agricultural requires precipitation implements, between 200-800 mm/year, land arid to semi-arid, hot stabiulization, subtropical climate, -4-48 nitrogen °C fixing SubSialkot to Well drained and loamy Fodder, fuel, 0.555100 Himalayan Hazara, soils, pH 8.7 to 9.4, apiculture, 0.64 kcal/kg tract Bajaur, Summer precipitation of agricultural Buner, 400-1000mm/yr, subimplements, Malakand humid/sub-tropical/tropical land and plains climate, 4-40 °C, elevation stabilization of sindh & 0-1600 m. Punjab.

Origin

5 m3 /ha/yr

1-4 m3/ha/yr

4-15 m3/ha/yr

4-7 m3/ha/yr

Productivity

212 Agroforestry: Prospects and Challenges

Table 9.2. Multipurpose Trees for Agroforestry

Neem, margosa tree

Azadirachta indica

Bombax cieba

6

7

Simal, Silk Bombaceae Cotton Tree

Meliaciae

Local name FamilySubfamily Sufed Sirin, LeguminosaeWhite Siris Mimosoideae

No. Scientific name 5 Albizzia procera

Distribution Ha bitat & Ecology

Uses

Specific Calorific Gravity Value Central/South Punjab, Prefers moist sites, tolerant Fodder, fuel, 0.69 4800 India, KPK to saline/sodic conditions, apiculture, kcal/kg Bangla desh, summer precipitation of agricultural Burma 500-1000mm/yr, implements, subhumid/warm/subtropical tannin, climate, temperature 1-45 furniture, °C, elevation 0-1200 m. poles & construction. Furniture, 0.68 4990 India, Sindh, Rich loams to nutrient deficient soils that are not fodder, wood kcal/kg Pakistan, Southern carving, Nepal, Punjab, saline or waterlogged (water table >18 m), medicinal, burma, Lower Afghanistan, Balochistan precipitation of 300-1150 oil, tannin, timber and China & Sri mm/yr, arid/hot tropical/subtropical c limate, agricultural Lanka 1-45 °C, prone to frost implements. damage. Pakistan, SubBest in well-drained deep Fuel, 4900 India, Nepal Himala yan alluvial soils, precipitation ornamental, kcal/kg tracts and 750-1700 mm/yr, humid medicinal, eastwards warm subtropical/tropical canoes, from monsoon climate, -5 to 40 furniture, Hazara. °C, elevation of 1000 m, carvings, drought hardy but not frost seed cotton tolerant,. for pillows.

Origin

Diameter growth: 35 cm/ yr

5-18 m 3/ha/yr

10 m 3/ha/yr

Productivity

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Dalbergis sissoo

Shisham, LeguminosaeTahli, Rose Papilionoideae wood

Australia

SubHimalayan tract of the subcontinent

FamilyOrigin Subfamily Leguminosae- Pakistan Caesalpinoideae

10 Eucalyptus Sufeda, Myrtaceae camaldulensis Lachi, Red River Gum

9

No. Scientific Local name name 8 Cassia fistula Amaltas, Indian Laburnum

Plains and hills.

Mostly along river banks and streams, in plains and foothills.

East of Indus, upwards to Himalayas, and throughout plains.

Uses

10-25 m 3/ha/yr

7.7 m 3/ha/yr

5000 kcal/kg

4900 kcal/kg

10-12 m 3/ha/yr

Productivity

Specific Calorific Gravity Value 5164 kcal/kg

Fuel, ornamental, agricultural implements, fine furniture, tool ha ndles, support posts, cart wheels, tannin, medicines 0.85 Frost hardy, dry Fodder, subtropical/dry temperate furniture, climate, well drained fuel, sandy/sandy loam soils, charcoal, railway elevation 900-1500 m, precipitation of 300-2000 carriages, mm/yr, temperature range sports goods, of 0 to 50 °C farm implements and medicinal. Intolerant, frost hardy and Carriages, 0.71 may even tolerate drought, fuel, variety of soils even furnitutre, oil, saline/sodic/waterlogged, charcoal, semi-arid/warm apiculture, hot/subtropical shelterbelt, winter/monsoon climate, pulp & fiber board temperature -5 to 40 °C, elevation of upto 1400m, precipitation of 200-1250 mm/yr.

M oderately shade tolerant, grows on variety of soils, sub-humid cool to subtropical humid warm/tropical climate, precipitation of 500-3000 mm/yr, -5 to 45 °C, prone to frost damage.

Distribution Habitat & Ecology

214 Agroforestry: Prospects and Challenges

Sufeda, Lachi, Mysore hybrid

13 Eucalyptus tereticornis

14 Leucaena Subabul, leucocephala Ipil Ipil

Sufeda, Flooded Box

12 Eucalyptus microtheca

LeguminosaeMimosoideae

Myrtaceae

Myrtaceae

Local name FamilySubfamily Sufeda, Myrtaceae Lemon Scented Gum

No. Scientific name 11 Eucalyptus citriodora

Mexico

Australia

Australia

Plains and foothills.

Plains and hills.

Plains and hills.

Plains and hills.

Australia

Well drained soils, tolerates light frost, grows well in flood plains and swamps, stands dry period upto 7 months, precipitation: 2001000 mm/yr, 0-40 °C and elevation upto 700 m Well drained soils including saline/ sodic/waterlogged soils, frost hardy and drought tolerant, precipitation: 8001500 mm/yr, 0-40 °C, elevation: 1500 m. Tolerant, adaptable growing even on steep and marginal lands, grows in saline and acidic soils, precipitation: 500-1000 mm/yr, 2-45 °C and elevation upto 500 m.

Well drained soils, tolerates dry periods for 5-6months, semi-arid/warm hot/subtropical winter/monsoon, precipitation of 600-900 mm/yr, 5-40 °C, elevation upto 2000 m, tolerates light frost, easily coppiced

Distribution Habitat & Ecology

Origin

4600 kcal/kg

4900 kcal/kg

Specific Calorific Gravity Value 0.78 4800 kcal/kg

Fuel, charcoal, perfume, furniture, shelterbelt, apiculture, fiber board, pulp and tool handles. 0.89 Fuel, poles and fence posts, charcoal, shelterbelt, apiculture & tool handles. Fuel, 0.7 carriages, shelterbelt, furniture, fiber board, erosion control Poles and 0.56 construction, fuel, fodder, apiculture, agricultural implements, furniture and soil stabilization.

Uses

30 m 3/ha/yr

12-25 m 3/ha/yr

5-10 m 3/ha/yr

10-15 m 3/ha/yr

Productivity

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Bakain, Persian Lilac

Sohanjna, Moringeceae Horseradish Tree

16 Melia azedarach

17 Moringa oleifera

Meliaciae

Local name FamilySubfamily Aam, Anacardiaceae Mango

No. Scientific name 15 Mangifera indica

SubHimalayan tract in Pakistan

Plains eastward from Rawalpindi

Intolerant, variety of soils does best in well drained soil, easily coppiced, endures drought periods and can grow on eroded sites.

Moderately shade tolerant, variety of well drained soils but does best on deep loa my soil, adaptable, humid hot/subtropical to tropical/monsoon climate with precipitation: 7501500 mm/yr, -3.5 to 40 °C, elevation upto 600m Lower Plains of Well drained soils of Himalayas Punjab a nd valleys and ravines, mature (Pakistan and KPK tree is frost and drought Nepal) hardy, easily coppiced, tropical to subtropical temperate climate, precipitation 600-1000 mm/yr, -5-40 °C, elevation range of 900-1700 m.

Distribution Habitat & Ecology

Pakistan, River India, Nepal, valleys of Bhutan Chenab and Ravi, and in irrigated lands in Sindh.

Origin

5100 kcal/kg

Specific Calorific Gravity Value 0.55 4600 kcal/kg

Veneer and 0.56 plywood, construction, boxes and crates, furniture, timber, agricultural implements, sports equipment, fodder, ornamental and medicinal. Ornamental, food, fodder, seed oil, gum and medicinal.

Fruit, chipboard, lumber and construction, ornamental, food and medicinal.

Uses

17.5 m 3/ha/yr

average height for 7 years is 4 meter

Productivity

216 Agroforestry: Prospects and Challenges

Sufed Salicaceae Poplar, Northern Cottonwood

Bahan, Euphrates Poplar

19 Populus deltoides

20 Populus euphratica

Salicaceae

Local name FamilySubfamily Tut, Moraceae Mulberry

No. Scientific name 18 Morus alba

Middle East, Southern Russia, Subcontinent, East to China

North America

Pakistan, China, Central Asia, Afghanistan

Origin

Hot arid areas with river sources/sub surface water

Plains and hills.

Variety of sites including waterlogged/saline soils, arid/ semi arid/ sub tropical climate, -10-45 °C, precipitation: 750-1250 mm/yr, elevation: upto 4000 m, frost hardy, drought resistant and withstands inundation, also considered a riverain species

Moderately intolerant, va riety of well drained rich soils, semi-arid cool/cold subalpine/ subtropical winter/monsson climate, 10-40 °C, precipitation: 750-1250 mm/yr, elevation upto 3300 m, frost hardy and drought tolerant if irrigated Sandy loams/alluvial soils, semi humid to semi arid/cool subtropical temperate climate, precipitation: 750-1250 mm/yr, -20-35 °C

Distribution Ha bitat & Ecology

Specific Calorific Gravity Value Silkworm 0.69 5100 food, fodder, kcal/kg fruit, shelterbelts, carriages, sports goods, veneer, plywood, furniture and medicinal. 5900 Fuel, crates, 0.46 packing kcal/kg cases, matches, pulp, reforestation, plywood, erosion control, fodder and roadside tree. Timber, 0.46 5000 packing kcal/kg cases, crates, matches, erosion control, reforestation, plywood, pulp, fodder, roadside tree and medicines

Uses

8-15 m3/ha/yr

20-40 m3/ha/yr

8.5 m3/ha/yr

Productivity

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23 Prosopis cineraria

Jand, Kandi LeguminosaeMimosoideae

22 Populus nigra Siah Poplar, Salicaceae Lombardy Poplar

No. Scientific Local name Familyname Subfamily 21 Populus Doghla Salicaceae euramericana Poplar, Hybrid Poplar Intolerant, deep soils with abundant water, withstands freezing temperatures but does not tolerate temperature exceeding 4045 °C

Distribution Habitat & Ecology

Uses

10-15 m 3/ha/yr

3-5 m 3/ha/yr

5000 kcal/kg

40 m 3/ha/yr

Productivity

5000 kcal/kg

Specific Calorific Gravity Value 0.280.52

Timber, packing cases, crates, matches, plywood, pulp, fodder, fuel, housing, furniture, chip board and shuttering poles. Western and Northern Well drained soils along Fuel, packing 0.46 cases, crates, Central areas, Azad water courses, arid/coolEurope, Kashmir, cold/subtropical climate, - matches, Subcontinent, Plains 20-45 °C, precipitation: erosion Middle East throughout 650-900 mm/yr, elevation control, the country range 900-3750 m, frost reforestation, hardy plywood, pulp, fodder, roadside plantation, general construction. Pakistan, Dry Variety of dry sites mostly Fodder, fuel, 0.61 India, plains/hills clays/sands, does well in poles and Afghanistan, of Sindh, high alkaline soil, hot construction, Middle East Punjab, arid/semi arid to agriculture KPK and subtropical climate, -6-45 implements, Balochistan °C, precipitation: 75-650 apiculture, mm/yr, elevation upto 450 furniture, soil m stabilization.

Hybrid cultivar

Origin

218 Agroforestry: Prospects and Challenges

Jamun, Myrtaceae Jaman, Black Plum

Imli, Tamarind

25 Syzigium cumini

26 Tamarindus indica

Sindh, Punjab

Subcontinent Plains and lower hills of Punjab, KPK and Azad Kashmir.

Dry plains/hills of Sindh, Punjab, KPK and Balochistan

West Indies, Central and South America, Southwestern United States.

Variety of soils but does best in deep alluvium soils and dry sandy sites as well, hot humid/dry tropical to subtropical climate, 0-40 °C, precipitation: 250-1250 mm/yr, elevation upto 600 m

Variety of dry sites mostly clays to sands, does well on high alkaline sites, drought and frost hardy, -2-45 °C, precipitation: 150-750 mm/yr, elevation upto 1200 m. Large tap root and extensive root system. Well drained soils from sands to loams, semi humid warm hot/subtropical winter/monsoon climate, 5-40 °C, precipitation: 1250 mm/yr, and elevations upto 1500 m, frost hardy and if irrigated then tolerates drought

Distribution Habitat & Ecology

Origin

Leguminosae- Tropical Caesalpinoideae Africa

Local name FamilySubfamily Mesquite LeguminosaeMimosoideae

No. Scientific name 24 Prosopis juliflora

Specific Calorific Gravity Value Fodder, fuel, 0.7 4500 poles and kcal/kg construction, agriculture implements, apiculture, furniture, soil stabilization. Construction, 0.7 4800 fruit, fuel, kcal/kg paper pulp, apiculture, medicinal, tannin, shelterbelts, roadside planting and shade. Implement 0.914969 handles, fuel, 1.28 kcal/kg charcoal, furniture, wheels, axles, food, fodder, apiculture, ornamental and medicinal.

Uses

height increased @ 0.8m/yr

12 m 3/ha/yr

3-5 m 3/ha/yr

Productivity

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Arjun

Ber, Chinese Date

28 Terminalia arjuna

29 Ziz yphus mauritiana

Rhamnac eae

Combretaceae

Local name FamilySubfamily Frash, Tamaricaceae Ghaz, Khaggal, Tamarisk

No. Scientific name 27 Tamarix aphylla Middle East, Pakistan, Central Asia , North Africa

Plains of Punjab, KPK, Sindh, Balochistan and Thal area.

Well drained sandy soils including saline/sodic sites, arid o hot subtropical winter monsoon c limate, 1-50 °C, precipitation: 100500 mm/yr, does not grow on elevation of more than 600 m, frost hardy

Distribution Habitat & Ecology

Uses

5900 kcal/kg

5000 kcal/kg

Specific Calorific Gravity Value 0.68 4835 kcal/kg

Carpentry, agriculture implements, fuelwood, shelterbelts, charcoal, tannin, erosion control, sand dune stabilization. Subcontinent Plains, Shade tolerant, variety of Fuel, 0.9 gardens, moist well drained sites, implements, roadside also grows on erosion plantation saline/sodic/waterlogged control, soils, humid hot wheels, tropical/subtropical fodder, monsoon climate, 0-45 °C, ornamental, precipitation: 750-3800 timber and mm/yr, elevation: 600m. medicines. South Asia Throughout No particular soil Fuel, 0.93 the country requirement, warm charcoal, temperate to subtropical to agricultural tropical climate, -5-50 °C, implements, precipitation 600-1500 fruit. mm/yr, elevation upto 600m.

Origin

average height for 7 years is 5 meter

10-12 m 3/ha/yr

5-10 m 3/ha/yr

Productivity

220 Agroforestry: Prospects and Challenges

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9.10. Conclusion Agroforestry is the purposeful growing or deliberate retention of trees with crops and/or animals in interacting combinations for multiple products or benefits from the same management unit. Furthermore, it is classified in three main classes or agroforestry systems i.e. agrisilviculture, silvipastoral and agrisilvopastoral systems. Poor soils adversely affect the biomass production and yield of agricultural crops. Large area of the world has been classified as degraded soils and bringing such area under cultivation is a big challenge for farmers. However, promotion of agroforestry practices on these areas can provide manifold benefits to farmers like soil reclamation, improving soil fertility through nitrogen fixation and increasing tree cover. Moreover, planting multipurpose trees can also fulfill food and fuelwood requirements of local inhabitants/ farmers.

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Soemarwoto, O. and G.R. Conway (1991). The Javanese Homegardens. J. Farm. Sys. Res. Ext. 2: 95-118. Sreemannarayana, B., L.G.G. Rao and B. Joseph (1994). Evaluation of multipurpose tree species and their influence on soil fertility improvement. International conference: special issue. Range Manage. Agrofor. 15: 199-202. Szott. L.T., C.A. Palm and P.A. Sanchez (1991). Agroforestry in acid soils in the humid tropics. Adv. Agron. 45: 275-301. Tejwani, J.G (1994). Agroforestry in India. Oxford & IBH Publishing Co Pvt. Ltd., New Delhi, India. pp. 233. Thorlakson, T. and H. Neufeldt (2012). Reducing subsistence farmers’ vulnerability to climate change: evaluating the potential contributions of agroforestry in western Kenya. Agric.Food Secur.1:15. UN. (1995). United Nations (U.N.) Population Division, World urbanization Prospects: The 1994 Revision. New York, USA. pp. 87. Wani, B.A. (2003). National Report to the Third Session of the United Nations Forum on Forests (UNFF): 1-7, [Online] `Accessed on January 06, 2014. Williams, P.A., A.M. Gordon, H.E. Garrett and L. Buck (1997). Agroforestry in North America and its role in farming systems. In: Gordon, A.M. and S.M. Newman (ed). Temperate Agroforestry Systems. CABI, Wallingford, UK. pp. 9–84. World Bank. (2011). Wood-based biomass energy development for sub-Saharan Africa: issues and approaches. Washington, DC. Wu, Y and Z. Zhu (1997). Temperate agroforestry in China. In: Gordon, A.M. and S.M. Newman (ed). Temperate Agroforestry Systems. CABI, Wallingford, UK. pp. 149–179. Young, A. (1997). Agroforestry for soil management. CAB Int.Wallingford, UK. pp. 320. Young, A. (1986). The potential of agroforestry for soil conservation and sustainable land use. In: Kozub, J. (ed). Land and Water Resources Management. Washington, DC: Economic Development Institute of the World Bank. pp. 301-317. Zaigham, N.A. and A.N. Zeeshan (2004). Prospects of Renewable Energy Sources in Pakistan. In: Khan, H.A., M.M. Qureshi, T. Hussain and I. Hayee (ed). Proceedings of COMSATS Conference 2004 on Renewable Energy Technologies & Sustainable Development. Commission on Science and Technology for Sustainable Development in South G-5/2, Islamabad (Pakistan); 154 p Zaman, S.B. and S. Ahmad (2012). Wood supply and demand analysis in Pakistan – key issues, Managing Natural Resources for sustaining Future Agriculture, Research Briefings: 4(22):1-12. Pakistsn Research Council Islamabad, Pakistan. Zhu, J.K., P.M. Hasegawa and R.A. Bressan (1997). Molecular aspects of osmotic stress. Crit. Rev. Plant Sci. 16: 253-277.

Chapter 10

Porcupine - A Major Vertebrate Pest of Forest Plantations A.A. Khan and S.H. Khan*

Abstract In Pakistan, there are many vertebrate pests of forestry plantations, however, Indian crested porcupine, Hystrix indica, is abundant and distributed all over the country. It has been identified as a serious pest of traditional as well as non-traditional crops, fruit orchards, vegetables, flowering plants and grasses of forage importance in the rangelands. The most important porcupine damage, however, occurs in forests and reforestation areas. Because of its silvicultural importance it has been included in all the “Forest Management Plans” of the country. In this chapter, its distribution, natural history and habits have been described. Damage and economic impacts of Indian crested porcupine on forest trees, transplants and nursery stocks have been documented. For its management, various tools and technologies have been suggested for adoption. Keywords: Porcupine; Pest; Tree technologies.

damage; Economic

impacts;

Control

* A.A. Khan Plant Protection, Pakistan Agricultural Research Council, Islamabad, Pakistan. * For correspondance: [email protected]

S.H. Khan Department of Forestry and Range Management, University of Agriculture, Faisalabad, Pakistan. Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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10.1. Introduction Vertebrate deteriorations are of great economic concern in the forestry systems of Pakistan. Wild boar, porcupine, flying squirrel, jackal and some species of rats inhabit are widely distributed in forest plantations of Pakistan. Among these wild boars, (Sus scrofa) have well adapted to irrigated forest plantations where thick cover is available for shelter. Though omnivorous in feeding habits, they are, to a greater extant, vegetarian in diet. They feed upon a wide variety of seeds, fruits, leaves, tubers, rhizomes, succulent stems, bird’s eggs, reptiles, insect larvae and earthworms. They damage water courses through digging, and up-root and trample nursery stock of trees in the nursery plots. They are, also, a potential source of diseases to mammalian wildlife species in the forest plantations. In Pakistan, the jackal (Canis aureus) is found in all the irrigated forest plantations, rangelands and plains. Jackals are considered as scavengers and carrion eaters. However, their main diet contents comprise of rodents, reptiles, frogs and supplement this with fruits and beetles. They destroy the nests of ground-nesting birds. They are of no economic importance in forest plantations. However, they have become pests on sugarcane crop, vegetables and sweet melons in the cultivated areas. Among rodents, Indian giant flying squirrel (Petaurista petaurista) and small Kashmir flying squirrel (Hylopetes fimbriatus) are arboreal species and mainly confined to Himalayan moist temperate forests. The limited distribution is reported from Murree Hills, Neelum Valley of Azad Kashmir, eastern Swat, lower Chitral, and south of Kaghan Valley from about 1,350 m elevation to the upper limit of the tree line at about 3,050 m (Roberts 1997). They consume and damage acorn of the hill oak (Quercus dilatata), Horse Chesnuts (Aesculus indica), Walnuts (Juglans regia) and immature cones of Blue pine (Pineus wallichiana). There are few species of field rats, jirds and voles which are commonly found in forests. They have been observed to damage seedlings, roots of young trees and seeds. In the irrigated forests of Punjab, the short-tailed mole rat (Nesokia indica), through burrowing habits, destroy nursery stock of Rose wood or Shisham (Dalbergia sissoo) by covering seeds and seedlings with excavated dirt and forming mounds. Mole rats, also, damage water channels and cause loss of water and spreads in areas where it is not required. Keeping in view of the significant silvicultural importance of Indian crested porcupine, this chapter will mainly focus on the detailed information as forest pest, some aspects of its natural history, economic impacts of damage to trees and nurseries, and damage prevention tools and technologies. Porcupines belong to the order Rodentia and are represented by two families, i.e. Erethizontidae (New World Porcupines) and Hystricidae (Old World Porcupines). Erethizontidae has four genera (Erethizon, Coendou, Echinoprocta and Chaetomys) and 23 species, while Hystricidae, also, has four genera (Thecurus, Hystrix, Atherurus and Trichys) and consists of 20 species (Walker 1999). The genus Hystrix has eight species, i.e. Hystrix cristata Linnaeus 1758 (crested porcupine); H. africaeaustralis Peters 1852 (Cape porcupine); H. brachyura brachyura Linnaeus 1758 (Malayan porcupine); H. javanica Cuvier 1823 (Sunda porcupine);

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H. crassipinis Gunther 1877 (Bornean porcupine); H. sumatrae Lyon 1907 (Sumatran porcupine); H. pumila, Gunther 1879 (Indonesia porcupine) (van Weer 1983). H. indica Kerr 1792 and H. hodgsoni Gray occur within the limits of India and Pakistan, (Agrawal and Chakraborty 1992; Roberts 1997). Indian crested porcupine (H. indica) is the largest rodent species found in Asia and Middle East. It is one of the heaviest rodent with adults weighing within the range of 11-18 kg (Gurung and Singh 1996). It is characterized by a massive body size. Generally, at adult stage, head and body is 640-740 mm in length and short tail which is about 20% of the head and body length, and is covered with short hallow white quills (Prater 1980). The body is covered with quills, banded alternately with dark brown and white. The quills vary in size, measuring 15-35 mm in length. Ventral body surface is scarcely covered with short, black hairs. Among all the quills, there are longer, hallow, rattling quills, which are used by porcupine to alarm the predators (Ellerman 1961). The broad fore-foot has four well-developed digits, each armed with a thick claw. The hind-foot has five digits. The eyes and external ears are very small, characteristics of burrowing and nocturnal habits. The head terminates in a broad blunt muzzle. Mammae are in 3 pairs situated along the lower flanks. There are five teeth in each jaw-one incisor, one premolar and three molars (Michael et al. 2003). The space between premolar and molars is the diastema. The colour of the incisors is yellowish orange.

10.2. Distribution The Indian crested porcupine is widely distributed in different eco-zones of Pakistan (Figure 10.1), and its distribution range extends throughout the southeast, central Asia and parts of the Middle East, including countries, like, India, Nepal, Bhutan, Bangladesh, Sri-Lanka, Israel, Yamen and Saudi Arabia (Corbet 1978; Kingdon 1991; Roberts 1997). The species is well adapted to a variety of environmental conditions and habitats. In Pakistan, it is commonly found in manmade and natural forest plantations, agriculture landscape, sandy deserts of Punjab and Sindh, in the mountainous areas of Khyber PakhtunKhwa (KPK) province, and abundant in steppe mountain regions of Balochistan upto 2,750 m elevation (Greaves and Khan 1978; Geddes and Iles 1991; Roberts 1997; Khan et al. 2000). The species is, also, found in Las belas, Kirthar Range, Kalat, Panjgur and Sibi (Mian et al. 1988; Roberts 1997). Also, it is found in the upland valleys of Jehlum and Neelum of Azad Jammu and Kashmir (AJ & K) and has been recorded in moist temperate deciduous forests of Machiara National Park at 3,200 m elevation, the highest point so far recorded of its distribution (Awan et al. 2004). The presence of porcupine has been reported from Murree Hills, Kohistan, Shogran, lower Chitral, Swat valley, Bannu, and Kurram valley (Roberts 1997; 2005).

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Fig. 10.1 Distribution of Indian Crested Porcupine in Pakistan. Source: Roberts (1997)

10.3. Natural History 10.3.1. Habitat The irrigated forest plantations of Punjab and Sindh are major habitats of Indian crested porcupine. Scrub forests and rangelands are also suitable habitats. In addition to these habitats, the high raised, soil dirt built embankments of link and barrage canals of Indus river system have provided most suitable denning sites for porcupines which have helped in their expanded distribution in the crop lands of Punjab, Sindh and KPK provinces. The embankments of drainage canals, old river channels, dried up Kareezes (under-ground water channels) and grave yards have been found infested with porcupines (Khan et al. 1992). Porcupines often make tunnels under walls and hedges to make an entry into a garden or cultivation.

10.3.2. Food and Feeding Habits The Indian crested porcupine is a generalist forager that exploits a wide variety of cultivated and wild plants, and consumes above ground as well as sub-surface plant material (Gutterman 1982; Alkon and Salts 1985; Ahmad et al. 1987; Brooks et al. 1988; Khan et al. 2000; Pervez 2006; Pervez et al. 2009), including fruits, grains, roots, tubers, and rhizomes (Prater 1980). During one night’s foraging, Indian crested porcupine is known to cover considerable distance. Nowak (1991) reported that the porcupines may cover 15 km in one night, but Kingdon (1991) reported

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that they may cover 30 km before returning to their burrows the next morning. They are also known to chew bones, to meet the requirements of minerals, like calcium, which support the growth of quills (Gurung and Singh 1996), consume insects, small vertebrates and the carrion (Nowak 1991; Michael et al. 2003). The faeces of porcupine contain a large amount of plant fiber, which can be differentiated into identifiable parts of roots, bark, shoots and twigs (Alkon and Saltz 1988), which are characterized elongated and are deposited in clusters on the ground surface .

10.3.3. Reproduction Indian porcupine breeds in spring (February to April) in the Punjab, Pakistan (Taber et al. 1967; Roberts 1997; Mian et al. 2007). In captivity, they breed all the year around (Prakash 1971). Gestation in the species, on an average, lasts 240 days and the brood size varies, ranging between 2 and 4 offsprings per year (Prater 1980), though 5 foetus were recovered from a porcupine captured from Abbotabad by a hunter (Roberts 1997). Young are born with their eyes open and the body is covered with short soft quills. The female has two pairs of nipples and these are situated along the lower flanks, instead of under the belly, as mostly is the case with other rodents. This allows baby porcupines or porcupids to suckle while the mother is standing or lying on her belly. The Indian crested porcupine is usually monogamous, the parents are found in the den with their offsprings throughout the year. Life expectancy in captivity is around 20 years. In the wild, they do not survive for more than 8-20 years (Roberts 1997).

10.3.4. Behaviour Indian crested porcupines are shy, nocturnal creatures and avoid even the moonlight nights for foraging (Nowak 1991; Bruno and Riccardi 1995) and tend to live in relatively remote or inaccessible places such as caves, rock crevices and dens, and emerge from such places only well after the dark (Prater 1980; Michael et al. 2003; Agrawal and Chakraborty 1992). The Indian porcupine may travel from the den to the feeding areas, along well-marked and frequently followed tracks (Walker et al. 1999). The species is basically solitary and nocturnal in its foraging activities, though it may be accompanied with young (Kingdon 1974; van Aarde 1987; Roberts 1997). It has a well developed sense of hearing and smell. Food is recognized by the porcupine not only with the help of its strong sense of smell but also with its long vibrissae on the snout (Roberts 1997). The burrows are usually self constructed and extensive with a long entrance tunnel, single or multiple exists and a large underground chamber (Gurung and Singh 1996), and are used by the same animal for many years (Nowak 1991). One such burrow recorded was 18 m in length, terminating in a chamber 1.5 m below ground level and had three escape holes (Prater 1980). Burrows examined by Greaves and Khan (1978) in the Punjab were found to be up to 20 m in length, often with 2 to 4 side tunnels each ending in an enlarged chamber. It has been reported that pythons and many small mammals occupy porcupine dens, with no living conflicts being together. Mian et al. (2007) recorded small Indian Civet (Viverricula indica) and

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bats escaping from the porcupine den near Chakwal. The first author (KAA) of this chapter observed desert fox (Vulpes vulpes) occupying the upper portion of the main tunnel near Bhakkar, Punjab. Different study reports suggest different number of individuals sharing a porcupine burrow. Roberts (1997) reported that the presence of 10 porcupines in a single burrow system, while Arshad (1987) suggested an average of 4 porcupine/burrow. Indian crested porcupine, when alarmed or irritated, erects quills and rattles the hallow spines present on its tail. If the disturbance continues, it launches backward and sideway attack and strikes near part of its body against the offending animal. This action results in thrusting of the quills deep into the body of the offender, often resulting in serious injuries, which are sometimes fatal (Ellerman 1961). The major part of the injury is caused by the short quills, which are normally present under the longer and thinner quills on the tail. Quite often quills are dislodged from the body of the porcupine and remain in the victim’s body. The old belief that a porcupine can shoot out its quills at aggressor is without any scientific evidence. There have been records of lethal attacks by the porcupine on tigers and leopards, while defending itself (Prater 1980; Gurung and Singh 1996). Dogs become excited in the presence of a porcupine, when encounter takes place the dogs receive serious injuries on the throat and chest (Khan et al. 1989).

10.3.5. Digs and Digging Behaviour Digging by Indian crested porcupine is a unique ecological process in an environment where surface disturbance is made for purpose of exploring subterranean plant organs as its food material (Alkon and Saltz 1985; Alkon 1999; Gutterman 1982;1987; Gutterman et al. 1990; Khan et al. 2000). Khan et al. (2016) studied the digging behavior of H. indica in an undulating topography of Islamabad, Pakistan. They recorded that the porcupine excavated and consumed subterranean organs of Sorghum halpense and Cyperus rotundus. The vegetation, thus, affected, include shrubs, geophytes, hemi-cryptophytes and annuals. As a result of this activity some plant species are totally consumed but later on germinate in the digs, and plant species partially consumed get renewed vegetatively. In areas where drinking water is seasonally scare or not available, exploitation of sub-surface plant biomass by crested porcupine is a key to its welfare and survival. Boekan et al. (1995) observed that H. indica foraging and digging generates a network of direct and indirect impacts on ecological systems. Diggings become micro-habitats in which water and organic matter accumulates, resulting into nutrient rich sites, and improving conditions for the germination of trapped seeds, seedling establishment and plant growth (Gutterman and Herr 1981). Garkaklis et al. (2000) and Wilby et al. (2001) suggested that vertebrate diggings in which surface litter and organic debris become trapped can provide a site for the development of sub-surface water repellency and sinks of critical environmental resources at many ecological levels (Alkon 1999). Digs can enhance flow of water, which result in erosion of soil and soil nutrients from hilly and watershed areas. Also, some data suggest that pedturbation by mammals (e.g. Indian porcupine) can be an important force in pedogenesis, in structuring landscape, and in maintaining heterogeneity in ecosystems (Whitford and Kay 1999). Thomson (1974) suggested

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that the porcupine, H. africaeaustralis, is an accelerator factor in the long term successful vegetation change along the Nuanetsi River in south-east Rhodesia.

10.4. Status as a Pest Indian crested porcupine has been identified as a serious pest of traditional as well as non-traditional crops, fruit orchards, vegetables, flowering plants and grasses of forage importance in rangelands. The most important porcupine damage, however, occurs in forestry and reforestation areas (McDonald 1927; Taber et al. 1967; Pillai 1968; Nawaz and Ahmad 1974; Ahmad and Chaudhry 1977; Greaves and Khan 1978; Sharma and Prasad 1992; Khan et al. 2000; Mian et al. 2007; Khan et al. 2014).

10.4.1. Damage to Trees Various studies conducted in Pakistan have indicated that the most important porcupine damage is inflicted to the irrigated forest plantations of the Punjab and the Sindh provinces, and the coniferous forests in the northern areas of Pakistan (Nawaz and Ahmad 1974; Ahmed and Chaudhry 1977; Greaves and Khan 1978; Khan et al. 2000; Hussain 2004). In the established stands, the mature and young trees are commonly debarked or completely girdled up to a height of about 20 cm or more, and down to the ground level or even lower, where the spreading roots are damaged and sometimes cut through the bole of young trees. The degree of damage varies from slight to complete girdling, preference for tree species differs in different habitats. The injury may ultimately effect radial growth of the tree (Storm and Halvorson 1967), and sometimes may even result into stunted growth. It has been observed in irrigated plantations that partially or completely debarked Dalbergia sissoo and Morus alba trees are highly susceptible to parasitic fungi, which is followed by more frequent termite or borer attack, leading to the death of the tree. The results of available studies on estimates of porcupine damage to irrigated established plantations of the Punjab have been summarized in Table 10.1. Damage to tree stocking of Pinus roxburghii and Robinia pseudoacacia in Tarbela watershed areas of Abottabad is summarized in Table 10.2. As early as 1967, a common occurrence of girdling of M. alba was reported in the croplands of Punjab (Taber et al. 1967), while Ahmad and Chaudhry (1977) reported damage to same species and serious damage to Melia azedarach in irrigated forest plantation of Punjab. Nawaz and Ahmad (1974) estimated tree damage to Changa Manga irrigated plantations through a total census of 10 randomly selected compartments from 5 blocks. The data revealed that about 15% of the trees in the plantations were damaged by porcupine, M. azedarach (52.5%) was the most vulnerable tree species, followed by M. alba (12.49%) and D. sissoo (1.02%). Greaves and Khan (1978) investigated porcupine damage in Chichawatni plantations and quantified damage to different mature tree species. Accordingly, M. azedarach and M. alba received 72 and 50% porcupine damage, respectively.

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Khan et al. (2000) assessed porcupine damage to D. sissoo in 1995 at Karluwala irrigated plantation (200 ha) where the density of trees was 477 per ha. Total damage recorded was 3.1% of which 1.4% (170 trees) were completely girdled and 1.0% (121 trees) were severed at the ground level. Bark was removed in patches from 98 trees (0.8%). They also observed damage (complete girdling) to young trees of Albizia procera (white variety) but did not quantify the damage as the density of trees was very low and highly scattered in the plantation. Results of some later studies, conducted in previously un-catered areas, have provided further information on the impact of porcupine on forestry resources of Pakistan. Khan et al. (2000) surveyed Daur, Unhar and Kunhar Divisions of Tarbela Watershed for porcupine damage to chirpine (Pinus roxburghii) and robinia (R. pseudoacacia) saplings/ transplants. The chir pine and robinia plants were 1-2 years of age and planted at a density of 1,075 trees/ha. The chirpine damage (complete cutting) ranged from 30 to 95% (x = 60%), while damage to robinia ranged between10 to 90% (x = 42%). This substantial mortality of tree stocking was not astonishing, Table 10.1 Estimates of Indian crested porcupine, Hystrix indica, damage to trees in different man-made irrigated forest plantations, Punjab, Pakistan Tree Species

Location of Plantation

No. of Total No. of No. of % Damage Compartments/ Trees Damaged Sampled Area (ha) Examined Trees Morus alba Changa Manga 2 (20.24) 634 90 14.19 " Gujrat (Daphar) 1 (20.00) 816 37 4.53 869 154 17.72 Dalbergia Mianwali 4 (43.72) sissoo (Kundian) " Bhakhar 4 (25.70) 721 107 14.84 " Layyah 1 (06.00) 139 17 12.23 " Muzaffargarh 1 (06.11) 166 25 15.06 " Chichawanti 1 (16.19) 375 0 0.00 " Changa Manga 4 (32.18) 1335 31 2.32 " Lal-Sohanra 3 (30.00) 990 27 2.73 Eucalyptus Mianwali 3 (30.36) 851 120 14.01 camaldulensis. (Kundian) " Bhakhar 2 (18.22) 821 133 16.20 " Layyah 1 (12.15) 79 1 1.26 " Chichawatni 1 (20.24) 274 0 0.00 " Changa Manga 3 (42.92) 983 5 0.51 Source: Khan et al. (2014)

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Table 10.2 Porcupine, Hystrix indica, damage to tree stockings in Tarbela Watershed Management Project Areas, KPK, Pakistan Watershed division Daur

Trees/ha (No.) 1075

Unhar

1075

Kunhar

1075

Name of Range Sherwan Havelian Batagram Allai Gari Habib- Ullah, Balakot Balakot/Kunhar

Stocking damage (%) P. roxburghii R. pseudoacacia 80-85 60-90 90-95 60-70 35-40 10-15 35-40 10-15 70-80 70-80 30-40

10-15

Source: Khan et al. (2000)

a similar study in Himachal Pradesh (India) indicated 54.4% mortality of P. roxburghii (Sheikher 1998). Hussain (2004) suggested that the chir pine plantation of less than 6 years of age in Sherwan area of Tarbela Watershed was very vulnerable to porcupine attack, resulting in an average estimated damage of 38.1% to ≤ 1 year old trees, and 24% to 1-6 year old plantation. The damage to mature trees, however, was negligible and only partial debarkation of roots and stems was observed. Khan et al. (2014) surveyed eight irrigated forest plantation of the central and southern Punjab to assess the H. indica damage to trees. The data collected revealed average damage to D. sissoo, M. alba and Eucalyptus spp. as 10.45, 9.36 and 7.5%, respectively, and the overall damages were estimated at 9.1%. Tree species having recorded damage by H. indica in Pakistan are listed in Table 10.3. Scattered reports of porcupine damage to trees are also available from India and Iran. Up-rooting of young coconut has been reported from different regions of India (Sharma and Prasad 1992; Idris and Rana 2001; Girish et al. 2005). In Iran, H. indica is one of the important vertebrate pests on reforestation in western oak forests (Fattahi 1997).

10.4.2. Tree Damage Ranking Khan et al. (2000) ranked tree damage by porcupine in seven agro-ecological zones of Pakistan. The damage in all these zones was ranked on the basis of distribution and economic value of different plant species, injury levels and whether the damage was localized or widespread. A species of high economic value, with limited or localized distribution in a zone, was ranked at higher level than a species of lower economic value and widespread distribution. Thus, the damage to tree species and its importance was ranked (Table 10.4). The damage profile noted whether a tree was alive or dead and whether it was completely girdled, or merely had patches of bark removed. Cutting, uprooting and pulling out the young plants were also noted. M. alba and M. azedarach have been ranked in the higher order because these are highly susceptible to porcupine attack and complete girdling is very common. The nursery stocks of M. alba, M. azedarch, B. ceiba, A. indica and J. regia have been ranked in the higher order.

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Table 10.3 Ranking of trees damaged by porcupine, Hystrix indica in various agroecological zones of Pakistan Species Melia azedaracha

Rank 1

Morus alba

2

Dalbergia sissooa Pinus roxburghii Robinia pseudoacacia Acacia modesta Terminalia arjuna Albizia procera Eucalyptus camaldulensis Broussonetia papyrifera Bombex ceibab Aesculus indicab Juglans regiab

3 1 1 4 4 4 4

Agro-ecological zone Southern and northern irrigated plains, Barani lands, dry mountains Southern and Northern Irrigated plains, Dry Mountains Southern and Northern Irrigated plains Wet mountains Wet mountains Barani lands Northern irrigated plains Barani lands Barani lands, N. irrigated plains

4 1 1 3

Barani lands Northern irrigated plains Wet mountains Wet mountains

a Nursery stocks also receive severe damage, bOnly nursery stock receive damage Source: Khan et al. (2000)

10.4.3. Damage to Transplanting Up-rooting and pulling out of transplants is characteristics behaviour of Indian crested porcupine. Porcupine damages have been reported to young transplants of D. sissoo, Bombax ceiba, P. roxburghii, R. pseudoacacia and Eucalyptus spp., and in many cases transplants had to be replaced, sometimes twice (Ahmad and Chaudhry 1977; Greaves and Khan 1978; Hussain 2004). Ahmad and Chaudhry (1977) recorded that in scrub forests, Agave spp. was completely wiped out several times soon after transplanting but Acacia modesta was quite immune to this kind of damage. Nawaz and Ahmad (1974) reported up-rooting of 4700 B. ceiba plants from two compartments (31 ha) at Changa Manga plantations. Greaves and Khan (1978) described one record at Chichawatni plantation which indicated that in a 30 ha plot 16% of B. ceiba (7420/45,000) transplants had to be replaced at least once owing to porcupine attack. Damage to suckers of date palm (Phoenix dactylifera) by up-rooting is also very serious in Punjab and Balochistan. One of the farmers (Dr. Jasra, per comm.) reported the loss of 500 suckers (100% damage) within a month on a farm near Bhakhar. B. ceiba transplants are, however, not vulnerable to porcupine attack, when these are 2-3 years old and with the development of thorns on the trunk. In majority of the cases the collar region of transplants attracts porcupines. The first author (KAA) of this article observed complete up-rooting of about 1,000 saplings of Eucalyptus spp. within three days of their transplantation at Karluwala forest plantation (District Bhakhar). In Sherwan area of Terbela Watershed as many as 60 pine transplants were damaged by the porcupine on the first night after their transplantation (Hussain 2004).

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Table 10.4 Tree species damaged by Hystrix indica in Pakistan Scientific Name Acacia modesta Aesculus indica Ailanthus altissima Albizzia procera Azadirachta indica Bombax ceiba Broussonetia papyrifera Citrus sinensis Cocus nucifera Dalbergia sissoo Eucalyptus camaldulensis Eugenia jambolana Ficus carica Juglans regia Leucaena leucocephala Mangifera indica Melia azedarach Morus alba Nannorhops ritchiana Opuntia ficus indica Phoenix dactylifera Pinus roxburghii Pinus wallichiana Pistacia khinjuk Prosopis juliflora Prunus arminiaca Prunus ovium Prunus amygdalus Pyrus malus Robinia pseudoacacia Terminalia arjuna Zizyphus mauritiana

Common/ Local Name Phulai Horse Chestnut Asmani Sufed Sirin Neem Simal Chinese Shahtut Malta Cocunut Shisham Sufeda Jaman Anjir Walnut Ipil Ipil Aam Bakain Shahtut Mazri Thor Date palm Chir pine Kail Khanjuk Mesquite Apricot Cherry Almonds Apple Robinia Arjun Ber

Source: Khan et al. (2007)

10.4.4. Damage to Nursery Stocks Severe damage can occur in nurseries of the irrigated forests in the Punjab, and elsewhere in Sindh. Chaudhry and Ahmad (1975 b) observed devastation of D. sissoo seedlings cut off at the collar. Similar kind of damage was seen by Greaves and Khan (1978) to M. azedarach in a nursery at Chichawatni with more than 90% of the seedlings destroyed. Khan et al. (2014) examined nurseries of D. sissoo, B. ceiba and M. alba in five plantations of the Punjab (Table 10.5). Accordingly, a nursery of B. ceiba was seriously damaged in Kundian (38.04%), followed by nursery in Changa Manga (16.06%). The highest damage (20.36%) to a nursery of D. sissoo was recorded at Kundian whereas the lowest damage (1.01%) was

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recorded at Muzaffargarh. The percent damage of four nurseries of D. sissoo was 9.85 ± 6.66%. Earlier to this, Ahmad and Chaudhry (1977) reported that in a 4 ha plot, six month old D. sissoo nursery at Kundian, only 25% of the plants escaped porcupine damage, while the rest were found either clipped or thrown on the ground. They also suggested that porcupine damage has become a limiting factor in raising D. sissoo and B. ceiba nurseries at Jhang plantation where only 11% living plants were found in a mixed nursery of the two damaged species. Reports from India indicated that 30% of the seedlings of Neem (Azedarach indica) and 12% of Eucalyptus spp. were damaged by cutting the plants at 5-7 cm above the ground level in Aravelli hills near Jodhpur (Idris and Rana 2001). Table 10.5 Estimates of Indian crested porcupine, Hystrix indica, damage to nursery plants in different man- made irrigated forest plantations, Punjab, Pakistan Tree species

Location of plantation

Dalbergia sissoo " " " Bombax ceiba " Morus alba

Mianwali (Kundian) Bhakhar Layyah Muzaffargarh Mianwali (Kundian) Changa Manga Changa Manga

No. of quadrates/ sampled area (ha) 5 (4.05) 9 (3.64) 4 (0.60) 8 (6.81) 7 (2.61) 11 (6.10) 7 (2.41)

Total no. of damaged % seedlings seedlings damage examined 388 555 137 889 368 2092 882

79 61 5 9 140 336 132

20.36 10.99 3.65 1.01 38.04 16.06 14.97

Source: Khan et al. (2014)

10.4.5. Damage to Rangeland Vegetation Impacts of porcupine digs and digging on microhabitat vegetative conditions and landscape have not been studied in Pakistan. The role of H. indica as a habitat and ecosystem modifier has not been investigated in the subcontinent, except in Israel (Alkon 1999). Studies on Cape porcupine (H. africaeaustralis) in southern Africa have indicated significant effects of porcupine foraging on structure of savanna plant communities (de Villers and van Aarde 1994). Geophytes and hemicryptophytes are consumed by porcupines through its digging and burrowing activities. Gutterman (1982; 1988) and Guttarman and Herr (1981) studied the impact of H. indica on 18 species of geophytes and hemicryptophytes and the influence of digging activity in large areas of the Negev desert highlands of southern Israel. They estimated that for geophytes, 20-30% of the plant population in certain areas was consumed on single occasion. Alkon (1999) studied both microhabitat and landscape impacts of porcupine digs and digging in Negev desert highlands of Israel. The impacts were the trapping of water, organic matter and seeds into the digs which promoted the germination and growth of annual plants including some porcupine forage species. Nine species of grasses (Pennisetum spp., Cenchrus ciliaris, Elionurus hirsutus, Cymbopogan jawarancusa, Sorghum helpense, Cynodon dactylon, Cyperus rotundus, Desmostachya bipinnata and Lasiurus sindicus) were found severely damaged by porcupine diggings at the Karluwala desert range, Bhakhar (Khan et al.

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2000; Khan et al. 2007). It has also been observed that porcupine severely damage Nannorhops ritchiana and Lilium spp through digging. Awan et al. (2004) observed porcupine consuming the tubers of Arisaema jacquemontii and roots of Convolvulus arrinsis. Further studies may add some more species of rangeland vegetation to this list.

10.5. Economic impact of porcupine damage Porcupine damage to a tree result into its deformation, development of internal physiological flaws and radial growth retardation. At Changa Managa, based upon the level of (15%) damage and total annual production of 972, 400 cft, the annual losses to plantation run to the tune of 136, 136 cft of wood (Nawaz and Ahmad 1974) with an economic impact of Rs. 894,413 (US$ 25/ha). Economic losses were probably double in the heavily porcupine infested forest at Chichawatni (Greaves and Khan 1978), as compared with that calculated for Changa Manga forest. Hussain (2004) calculated bio-economic impacts of porcupine damage in Tarbela Watershed areas of KPK. He estimated the losses based upon the material cost from nursery raised transplantation of P. roxburghii at Rs. 8 per plant, excluding cost of loss of time/season, establishment, transportation and other related resources. Assuming an average of 40% mortality of transplants, based upon two studies (Khan et al. 2000 and Hussain 2004), and plant density of 1,075/ha, the economic losses were Rs. 3,440/ha. If this estimate is amplified to five divisions of Terbala Watershed, the total economic loss may run into millions of rupees. Khan et al. (2000) estimated economic losses suffered by irrigated forest plantations in the central Punjab and natural forests distributed in KPK and suggested an estimated annual economic loss of about US$ 60-70 per hectare. The accuracy of these economic losses could be much improved by more exact studies of the damage and its relation to the actual and potential value of timber extracted at different stages in the forest management cycle.

10.6. Control Tools and Technologies Before taking up any operational control measures against porcupines, particularly in irrigated forest plantations, it is highly desirable that surveys be carried out to map out exact location of active/live porcupine dens. This will help in planning and selecting correct type of materials and methods and in the monitoring and evaluation of any control programme.

10.6.1. Non-Chemical Methods 10.6.1.1. Trapping and Snaring The use of live cage traps against Hystrix spp., apparently without any notable success, has been reported by Chuan (1969) in oil palm plantations in Malaysia and by Thomson (1974) in riverine forest in Rhodesia, using fresh baits of sweet potato and pineapple. At Changa Manga, trapping by forest officials was carried out by

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means of “Duplex trap” but caught only one porcupine in four traps baited with sweet potato and meat set in heavily infested areas for a period of several days. At Chichawatni, Greaves and Khan (1978) caught only two porcupines by using five cage traps baited with potato, carrot and cucumber. It would seem from these experiences that cage trapping is of limited value as a control measure, except perhaps carried out intensively. The capital cost of the traps and their transportation, added to their management, are also some other limiting factors in using them on a large scale. Keeping these factors in view, this method cannot be recommended. Vertebrate Pest Control Institute at Karachi evaluated the effectiveness of “Leg-hold” steel traps, near Nooriabad, Karachi. Five such traps were set along the porcupine trails. Not a single animal was caught during three nights of trapping. Farmers in Attock, Abbotabad, Mansera and some areas of Balochistan commonly use snares, made up of clutch wires of motor cycles. The snare is set in front of the main and active opening of the porcupine den. According to farmers this method is highly successful in preventing porcupine damage to crops. 10.6.1.2. Hunting and Shooting In majority of cases, hunting using dogs and shooting is conducted as an individual effort to control porcupines. Expert hunters (shikaris) are attracted when reasonable bounty rates are offered. In 1970’s at Changa Manga reasonable bounty system greatly reduced the population of porcupine in the plantation. Dogs become wildly excited on seeing a porcupine or its presence in the hunting area. On encounter hunting dogs (bullterriers) in most cases, receive lethal injuries and also fatal ones (Khan et al. 1989). These practices need to be ignored as being ineffective in controlling porcupines.

10.6.2. Chemical Control 10.6.2.1. Acute Poison Baiting Indian crested porcupine and other species of the Hystrix genus are omnivores in captivity, readily eating grain, meat and vegetables (Crandall 1964) and there are general evidences and statements in the literature to the effect that porcupines can be controlled with poison baits, including figs treated with thallium sulphate, strychnine or phosphorus (Kumerloeve 1967) and vegetable bait containing zinc phosphide (Lesnyak and Kasymov 1969; Pillai 1968). In the Punjab, irrigated forests, however, Chaudhry and Ahmad (1975a and 1975b) reported that porcupines ignore potato and cucumber, though they readily take guava and, more especially apples. A bait prepared by applying 1.0 to 1.5 g of potassium cyanide to cut pieces of apples was apparently highly successful in small scale trial, but apples similarly treated with zinc phosphide or carbaryl were not taken by porcupine. Mushtaq et al. (2009) conducted a very comprehensive study in Balakot – Abbottabad forests tract to evaluate preference of grain bait bases. Accordingly, groundnut was the most preferred food item, followed by maize, wheat, millet, rice, gram and oats. The results of this study indicated that significantly higher quantities of all the grains were consumed in cracked form than in the whole form. They also suggested that groundnut and maize if offered in 1:1 ratio combination can be a

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useful and cost effective bait base. Faulkner and Dodge (1962) suggested the use of granulated sugar as additive to increase the consumption of acute poison baits. To enhance palatability and consumption of grain bait bases, Mushtaq et al. (2013) evaluated 10 additives (saccharin, common salt, bone meal, fish meal, peanut butter, egg yolk, egg shell powder, mineral and coconut oils) at 2 and 5% using groundnut – maize (1:1) as basic bait. Saccharin at 5% concentration significantly enhanced the consumption of bait over the basic bait. The results of this study suggested that groundnut – maize (1:1) supplemented with 5% saccharin was the preferred bait combination, and can be used with different rodenticides for the management of Indian crested porcupine. With the establishment of FAO/UNDP Vertebrate Pest Control Center at Karachi and availability of funds under Agricultural Linkages Programme, research on porcupine accelerated more on scientific lines in all the agro-ecological zones of the country. Khan et al. (1992) conducted field trials to determine the efficacy of two acute poisons against H. indica in Changa Manga forest plantations and vegetable farms near Quetta. The results of baiting treatments with sodium fluoroacetate (1080) and strychnine indicated a significant efficacy difference between 1080 and strychnine baiting. Baiting with 1080 was highly effective and caused an average 88% reduction in animal activity (range 70-100%). Strychnine was less effective and reduced animal activity by 40% (range 20-40%). Also, there was no difference between potato and squash as bait base when used with 1080. Arshad et al. (1988) tested the efficacy of Temik (10 G), 1080 and Endrin (19.5%) with ripened bitter gourd, chopped mango stones and boiled maize. The results of this study indicated 100% mortality with 1080, 85.7% with Temik and 36.4% with Endrin. However, the baiting technique, ground surface exposure, is highly hazardous that can cause primary poisoning to livestock and non-target wildlife. Ahmad et al. (2003) obtained 86.7% reduction in porcupine activity with 1080. Khan et al. (2006) evaluated 2% zinc phosphide, made up of whole maize grain, 2% cooking oil and 2% molasses, and packed as 100 g plastic sachet. The field trials were conducted in hilly/stoney areas of Fateh Jhang. One plastic sachet, slit open in the middle, was placed deep in the den. Altogether, 36 dens were treated and evaluated 7 days after treatment, which indicated only 27.78% reduction in the activity of porcupine. This small scale reduction in the porcupine activity may be attributed to a garlic like smell, bitter taste and development of bait- shyness to zinc phosphide (Rozoska, 1953). Khan et al. (2010) evaluated the effectiveness of arsenic trioxide, using cut pieces of apple, and obtained 89% reduction in the porcupine activity in a forest plantation near Faisalabad. 10.6.2.2. Chronic or Anticoagulant Baiting Results of some studies conducted in Pakistan indicate that anticoagulants have potential promise against porcupine in various eco-habitats. These toxicants are highly effective, eco-friendly and contain very low level of hazards to livestock and non-target wildlife species, unlike acute poisons (Townsend et al. 1983; Hegdal and Blaskiewicz 1984). Some preliminary studies have been conducted in Punjab and Sindh, using compounds like coumatetralyl and brodifacoum. Ahmad et al. (2003) tested brodifacoum (0.005%) and achieved 72% reduction in animal activity.

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However, the authors did not mention the quantity of bait applied per den of porcupine. Khan et al. (2006) evaluated coumatetralyl (0.0375%) bait made up of whole maize grain, 2% cooking oil and 2% molasses, and one kg of the bait was packed in plastic bags. Seventy four porcupine dens were treated by placing one bag, slit open in the middle, deep in each den. After the first baiting, the porcupine activity was reduced by 66.67 and 71.43% at two sites, respectively. The second supplement baiting gave 100% reduction at the two sites. Khan and Mian (2008) studied the field efficacy of coumatetralyl (0.0375%) maize grain bait against H. indica in a floriculture farm, where Dutch Iris and gladiolus were being severely damaged. The bait was placed underneath a bait station, in an earthen container. The bait stations were established either near an active den or at entry points along the fence line of the farm. Bait consumption increased up to 7th day, thereafter, it steadily decreased by the 14th day, reaching zero level on the 15th day. As a result of baiting, dead porcupine showed symptoms of anticoagulant poisoning. Analysis of post-treatment porcupine activity showed no signs of activity on the farm, indicating 100% reduction of porcupine population. 10.6.2.3. Fumigation Fumigation is a technique that must be considered for the control of any burrowing rodent, and was suggested long ago by Fletcher (1914) using the materials available at that time such as carbon bisulphide or pyrotechnic mixtures containing sulphur. McDonald (1927) found that a cyanide gassing powder (Cyanogas) pumped into porcupine den at an average dosage of 80 g per den was effective in the Kanpur district in India. In Pakistan, Chaudhry and Ahmad (1975a and 1975b) reported the same fumigant as giving a 50% kill when applied at a dosage of 225 g per burrow in stony soil or 450 g in the longer burrows in loamy soils, the powder was packed in plastic bag attached to a long stick and deposited deep in the burrow, the borrow entrance was then firmly blocked with soil dirt. A large scale porcupine eradication programme in 1973-1975 was carried out in Changa Manga forest plantation in which cyanide gassing powder was used. The dosage applied per burrow was 225 to 900 g by means of a hand pump. Altogether, 887 active porcupine burrows were treated. As a result of this 83% success was obtained in the prevention of porcupine damage to trees. They calculated that as a result of this eradication programme, the damage of 14.5% in the entire plantations was reduced to 0.026%. Khan et al. (1992) described a new method of gassing porcupine burrows in which cyanide powder was pumped into the active burrow using a “Dust-R” pump (B&G Equipment Company, Plumstead ville, PA, USA). The procedure adopted was to block the emergency exists to the burrow and plugged the mouth of one or two of the major active openings with brushwood and soil dirt. Before doing this, plastic hose pipe measuring 1.5 m length and 1.5 cm in diameter was inserted deep into the burrow and then covered up firmly with soil dirt, leaving about 25 cm of hose pipe outside the burrow. After fumigation, the hose pipe is withdrawn from the burrow and blocked. Khan et al. (1992) treated 65 burrows by adopting this procedure in Changa Manga plantation. They pumped the cyanide gas into the burrow at the rate of 15 strokes (9.45 g), 25 strokes (15.75 g) and 35 strokes (22.05 g), and obtained 70, 80 and 100% control of porcupines. This method is much superior, effective and economical compared to practices already described. By this method cyanide

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powder is evenly distributed inside the burrow and reacts quickly with the moist air inside the burrow to produce sufficient quantity of hydrogen cyanide gas to the porcupine and pose no threat to the operator. Aluminium phosphide is another potential fumigant which has not been studied in detail except in few cases. Chaudhry and Ahmad (1975a and 1975b) reported that aluminium phosphide tablets, each containing 1.0 g of phosphine gas, gave 100% mortality when applied at the rate of two or more tablets per burrow in stony soil or more tablets per burrow in loamy soil. Khan et al. (1992) tested the efficacy of aluminium phosphide (Phostoxin) in the arid areas near Quetta and irrigated plantations of Changa Manga. They obtained 43-83% reduction in animal activity near Quetta and 50-87% in Changa Manga, apparently showed no significant difference between the two locations. Ahmad et al. (2003) attempted further studies in the dry lands of Malir district of Karachi Division. They applied 4, 6 and 10 tablets per burrow and obtained 100, 95.6 and 96% reduction in activity, respectively. Mushtaq et al. (2008) evaluated aluminium phosphide fumigation in a more scientifically designed field experiment near Haripur-Havelian, KPK. In randomly selected burrows, they obtained 100% reduction in burrow activity with the application of eight tablets per burrow, 85% with six tablets/burrow and 75% with four tablets/burrow. In categorized burrows, 100% reduction in burrow activity was recorded when four tablets/burrow were used in small (circumference, 100.2± 2.75 cm), six tablets in medium (127.7 ±0.93 cm) and eight tablets in large (157.4 ±2.44 cm) sized burrows. Khan et al. (2010) observed that four tablets/burrow were ineffective, five and six tablets/burrow provided partial control, while seven, tablets provided complete control of porcupine in an irrigated forest plantation in the district of Faisalabad. Presently, carbon monoxide gas has been advocated as fumigation gas for control of burrowing mammals. The gas is generated with the ignition of various types of pyrotechnic devices containing mixture of various materials. Charcoal and sodium nitrate, commonly used in such devices, are relatively innocuous agents and have a low toxicity profile. However, the ignition product, carbon monoxide, is highly toxic to mammals. Savarie et al. (1980) developed a two ingredient pyrotechnic fumigant containing (w/w) 65% sodium nitrate and 35% charcoal powder. They obtained a mortality rate of 96% in coyote pups with the usage of 240 g cartridge. Ramey (1995) and Ross et al. (1998) tested successfully two-ingredient cartridge against badgers and rabbits. Khan et al. (1992) evaluated a prototype cartridge of various weights in Changa Manga and in dried up riverine channels near Quetta. The cartridge, after ignition, is placed 25 cm deep into the porcupine burrow and, after making certain that smoke is being generated smoothly, the burrow is plugged with brush wood and soil dirt. Post-treatment observations are taken 48 h after treatment. They obtained 72 and 87% success on using 100 and 150 g cartridges, respectively, and 100 % reduction in porcupine activity by using 250 g cartridge. Again, Khan et al. (2006) using 250 g cartridge obtained 95.9% reduction at Changa Manga, while 100% reduction was achieved at Dogar Kotli and Piranwala. At Karluwala and Hassan Abdal, the reduction achieved was 89.29 and 94%, respectively. Overall, average reduction in the porcupine activity at five locations was 95.89%.

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During the studies with two- ingredient cartridge a small indigenously prepared safety fuse (1.5 cm in length) was used, and the cartridge after ignition was placed deep into the porcupine burrow with the help of a shovel. There were some problems with this technique; some cartridges did not burn, leakage of gas during plugging of the burrow, and health hazards to operators. To overcome these problems a new delivery system was designed by Khan et al. (2011) for carbon monoxide fumigation of Indian crested porcupine burrow using two-ingredient cartridge. The delivery system consists of a 140 cm long steel pipe with a 3 cm inside diameter. A 0.5 cm hole is drilled 25 cm from one end of the pipe. A plastic cape is fixed at the other end to stop any exhaust of smoke containing carbon monoxide. Commercial safety fuse is used for ignition of the cartridge (Nobel Industries (Pvt) Wah Cantt, Pakistan. The fuse consists of a central core of specially formulated black gunpowder with jute and cotton countering, waterproofed by a mixture of bitumen, wax and polyvinyl chloride. It is specified to burn at a rate of 100-120 sec/m in damp and dry conditions. A length of 125 cm of the fuse is inserted into exterior hole of the pipe and pulled at the distal end. At this end the cartridge is fixed along the pipe with masking tape and coupled with the fuse. The cartridge fixed pipe is lowered down into the porcupine burrow at least 100-110 cm deep and the burrow is then plugged firmly with vegetation and soil dirt, keeping the fuse end of the pipe exposed. At this stage the system is ready to operate and the fuse is then ignited (Figure 10.2). It takes about 8.5 minutes for the complete burning of the fuse and the cartridge. After 10 minutes the pipe is withdrawn from the burrow. Khan et al. (2011) tested this new delivery method by treating 190 burrows in Bhakkar, Gujrat and Islamabad, using cartridges of 250, 350 and 375 g. In all cases 100% reduction in porcupine activity was obtained. The Detailed results of these trials are summarized in Table. 10.6.

Fig. 10.2 Schematic diagram of fumigation system using a two-ingredient carbon monoxide cartridge for the control of Indian crested porcupine. Source: Khan et al. (2011)

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Table 10.6. Carbon monoxide fumigation against Hystrix indica using a twoingredient cartridge in different soil and vegetation conditions. Geographic location Bhakhar Gujrat Pothwar

Site

Soil type

Cartridge weight (g) Dagar Kotli Porous 375 Karluwala sandy 350 Goharwala 250 Daphar Clay loam 375 Daphar 350 Daphar 250 Islamabad Silt loam 375 Islamabad 350 Islamabad 250

No. dens treated 25 18 23 23 20 25 18 17 21

No. dens reopened 0 0 0 0 0 0 0 0 0

Reduction (%) 100 100 100 100 100 100 100 100 100

10.6.2.4. Repellents A number of toxicants has been suggested for application to trees as porcupine repellents (Witmer and Pipas 1988) including a mixture of whitewash and lead arsenate (Fletcher 1914) and zinc phosphide in starch paste, acid free coal tar or other sticker (Chuan 1969). Endrin is said to have been tried in this way in Pakistan, but was considered to be too costly and hazardous, and of limited effectiveness. It may be assumed that rodent repellents could find a use against Hystrix where a limited number of trees require protection for a short period of time. It is reported that the use of zinc phosphide/coal tar mixture is standard practice in large-scale oil palm plantations in Malaysia (Chuan 1969). According to the same author of the paper application of sodium arsenite and sulphur gave complete protection of young oil palms.

References Agrawal, V.C. and S. Chakraborty (1992). The Indian crested porcupine, Hystrix indica, (Kerr). In: Prakash, I. and P.K. Ghosh (ed). Rodents in Indian Agriculture, Vol. 1, Scientific Publishers, Jodhpur, India, pp.2-30. Ahmad, A. and M.I. Chaudhry (1977). Studies on habits, habitat and damage of porcupine, Hystrix indica, Rodentia: Mammalia. Pak. J. For. 27: 147-150. Ahmad, S.M., A. Pervez and A.A. Khan (2003). Deterioration impact and evaluation of control methods of Indian crested porcupines (Hystrix indica) on rangelands in Sindh, Pakistan. J. Nat. Hist. Wildl. 2:19-23. Ahmed, E., I. Hussain, M.H. Khan and J.E. Brooks (1987). Vertebrate pest damage to maize in Faisalabad district, Pakistan. Tech. Rep., 10, Government of Pakistan /USAID Project on Vertebrate Pest Control, NARC, Islamabad, Pakistan. Alkon, P.U. and D. Saltz (1988). Influence of season and moonlight on temporal activity patterns of Indian crested porcupine, Hystrix indica. J. Mammal. 69(1): 71-80. Alkon, P.U. and D. Saltz (1985). Potatoes and the nutritional ecology of crested porcupine in a desert biome. J. Appl. Ecol. 22:727-737.

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Alkon, P.U. (1999). Microhabitat to landscape impacts: crested porcupine digs in the Negev desert highlands. J. Arid Environ. 41:183-202. Arshad, M.I. (1987). Studies on habitat pattern, feeding preferences, reproductive biology and strategy for control of Indian crested porcupine (Hystrix indica Linn.) around Faisalabad agriculture biome. M.Sc. Thesis, University of Agriculture, Faisalabad, 77 pp. Arshad, M.I., R.A. Khan and A. Khaliq (1988). Strategies for the control of Indian crested porcupine, Hystrix indica. Pak. J. Sci. Indus. Res. 31(1): 784-785. Awan, M.S., R.A. Minhas, K.B. Ahmed and N.I. Dar (2004). Distribution, food and habitat preferences of small mammals in Machiara National Park, District Mazaffarabad, Kashmir, Pakistan. Punjab Univ. J. Zool. 19:17-31. Boeken B., M. Shachak, Y. Gutterman, S. Brand (1995). Patchiness and disturbance: plant community responses to porcupine diggings in the central Negev. Ecolography, 18: 410-422. Brooks, J.E., E. Ahmad and I. Hussain (1988). Characteristics of damage by vertebrate pests to groundnut in Pakistan. In: Crabb, A. and R.E. Marsh (ed). Proceedings of Vertebrate Pest Confernce, Univ. Calif. Davis, C.A. USA. pp. 129-133. Bruno, E. and C. Riccardi (1995). The diet of the crested porcupine, Hystrix cristata L. 1758 in a Mediterranean rural area. Zeitschrift fr Sugetierkunde. 60: 226-236. Chaudhry, M.I. and A. Ahmad (1975a). Porcupines-how to control them? Leaflet, 8 pp, Pakistan Forest Institute, Peshawar, Pakistan. Chaudhry, M.I. and A. Ahmad (1975b). Trials of poisonous gases and baits against porcupines. Pak. J. For. 25: 46-50. Chuan, C.R (1969). Porcupines and grasshoppers as pests of the oil palm. Progress in oil palm, 155-161. Incorporated Society of Planters, Kuala Lumpur. Crandall, L.S. (1964). Management of Wild mammals in Captivity. University Chicago Press, USA. Corbet, G.B. (1978). The Mammals of the Palearctic Region: a taxonomy review. London and Ithaca, British Museum and Cornel University Press, NY. 314p. Ellerman, J.R. (1961). The fauna of India including Pakistan, Burma and Ceylon, Mammalia, Vol.3 (Rodentia) Part I. Delhi, Govt. of India, 482 pp. Fattahi, M. (1997). Effect of Hystrix indica on reforestation of western oak forests of Iran. In: XI World Forestry Congress, Antalya, Turkey, 13-22 October, 1997. Vol. 1. Fletcher, T.B. (1914). Some South Indian insects and other animals of importance, Govt. Press, Madras, India. Faulkner, C.E. and W.E. Dodge (1962). Control of the porcupine in New England. J. For. 60:36-37. Garkaklis, M.J., J.S. Bradley, R.D. Woollwer (2000). Digging by vertebrates as an activity promoting the development of water repellent patches in sub- surface soil. J. Arid Environ. 45:35-42. Geddes, A.M.W. and M. Iles (1991). The relative importance of crop pest in south Asia. Natural Resources Institute, London, Bull. No. 39, 102 pp.

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Girish, C., B.B. Hosetti and A.K. Chakravarthy (2005). Porcupine menace in coconut palm ecosystem of Dakshina Kannada region of Karanataka. Tigerpaper. 32: 28-32. Greaves, J. H. and A.A. Khan (1978). The status and control of porcupines, genus Hystrix, as forest pests. Common For. Rev. 57: 25-31. Gurung, K.K. and R. Singh (1996). Field guide to the mammals of Indian subcontinent, Academic Press, San Diego, USA. Gutterman, Y. and N. Herr (1981). Influence of porcupine (Hystrix indica) activity on the slopes of the northern Negev mountains: germination and vegetation renewal in different geo-morphological types and slopes directions. Oecologia. 51: 332-334. Gutterman, Y. (1982). Observation on the feeding habits of the Indian crested porcupine (Hystrix indica) and the distribution of hemicryptophytes and geophytes in the Negev desert highlands. J. Arid Environ. 5: 261-268. Gutterman, Y. (1987). Dynamics of porcupine (Hystrix indica Kerr) diggings: their role in the survival and renewal of geophytes and hemicryptophytes in the Negev desert highlands. Israel J. Bot.35:133-143. Gutterman, Y. (1988). An ecological assessment of porcupine activity in a desert biome. In: Ghosh, P.K. and I. Prakash (ed). Ecophysiology of Desert Vertebrates. Scientific Publishers, Jodhpur, India, pp. 289-372. Gutterman, Y., T. Golan, M. Garsani (1990). Porcupine diggings as a unique ecological system in a desert environment. Oecologia 85:122-127. Hegdal, R.I. and R.W Blaskiewicz (1984). Evaluation of the potential hazard to barn owls of TALON (brodifacoum bait) used to control rats and house mice. Environ. Toxicol. Chem. 3: 167-179. Hussain, I. (2004). Investigation on Indian crested porcupine Hystrix indica, damage to forest flora and development of prevention practices in TerbelaMangla Watershed areas. 1st Annual Progress Report (2003-2004), ALP Project, IPEP, NARC, Islamabad, 21 pp. Idris, M. and B.D. Rana (2001). Some observations on infestation of porcupine, Hystrix indica Kerr in the forest nursery of arid region. Rodent Newsl. 25(1-2): 5. Khan, M.A., N.I. Chaudry, W. Akhtar (1989). Porcupine quill: A cause of cutaneous sinus tracts in dogs. Pakistan Vet. J. 9(3):148-149. Khan A.A., M. Ahmed, S. Ahmed and S.W.A. Rizvi (1992). Evaluation of the comparative efficacy of fumigants and acute poison baits against Hystrix indica. For Ecol. Managt. 48: 295-303. Khan A.A., A. Mian, R. Hussain (2007). Pictorial guide of porcupine (Hystrix indica) damage to trees and crops in Pakistan. Pakistan Agricultural Research Council, Islamabad/ University of Arid Agriculture, Rawalpindi, Pakistan. Khan, A.A. and A. Mian (2008). Field evaluation of coumatetralyl bait (0.0375%) against Indian crested porcupine Hystrix indica Kerr. Pak. J. Zool. 40:63-64. Khan, A.A., A. Mian and R. Hussain (2006). Investigations on the use of poison baits and fumigants against Indian crested porcupine (Hystrix indica) Pak. J. Sci. Ind. Res. 49: 418-422.

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Khan, A.A., A. Mian and R. Hussain (2011). A delivery system for carbon monoxide fumigation of Indian crested porcupine, Hystrix indica, den using two-ingredient cartridge. Pak. J. Zool. 43: 727-732. Khan, A.A., S. Ahmad, I. Hussain and S. Munir. (2000). Deterioration impact of Indian crested porcupine, Hystrix indica, on forestry and agricultural systems in Pakistan, Intl. Biodet. Biodeg. 45:143-149. Khan, A.A., S. Hafeez, M. Abbas and W. Mehmood (2010). Assessing the efficiency of aluminium phosphide and arsenic trioxide in controlling the Indian crested porcupine (Hystrix indica) in an irrigated forest plantation of Punjab, Pakistan. Pak. J. Agric. Sci. 47: 99-103. Khan, A.A., A. Mian and R. Hussain, (2014). Deterioration impact of Indian crested porcupine, Hystrix indica Kerr in irrigated forest plantations in Punjab, Pakistan. Pakistan J. Zool. 46:1691-1696. Khan, A.A., M. Mushtaq and A.M. Ghumman. (2016). Digging and clipping behavior of Indian crested porcupine, Hystrix indica Kerr, in a green belt of Islamabad. Pak. J. Zool. 48:817-820. Kingdon, J. (1974). East African Mammals in Evaluationary Atlas. Academic Press, London. Pp. 204. Kingdon, J. (1991). Arabian Mammals – A Natural Histry. Academic Press, London, 279 pp. Kumerloeve, H. (1967). Zur Verbreitung des Stachelschweines Hystrix leucura (Sykes, 1831) in Kleinasien. Saugertierliche Mitteilungen. 15: 242-249. Lesnyak, L.P. and T.A. Kasymov (1968). The diet of the porcupine in the Chatal’skie mountains. Referativnyi Zhurnal Biologiya. No. 51555. McDonald, M.J. (1927). Destruction of rats and porcupines. Indian For. 53: 444445. Mian, A., A.A. Khan and R. Hussain (2007). Biology and management of porcupine, Hystrix indica, in central Punjab, Pakistan. ALP Project, Final Progress Report (2003-2007). Department of Zoology, PMAS Arid Agriculture Universirt, Rawalpindi, Pakistan. Mian, A., M. Ali, R. Ali and S.B. Tousif (1988). Distribution of some mammalian pests of orchards in Balochistan. Pak. J. Agric. Res. 9:125-128. Michael.H., G. Devra, G. Kleiman, C.M Volerius, Mellisa (eds.) (2003). Grzimek’s Animal life Encyclopedia, 2nd edition, V-12-16, Mammals I-IV.Farmington Hills,ME: Gale Group. Mushtaq, M., A. Mian, I. Hussain, S. Munir, I. Ahmed and A.A. Khan. (2009). Field evaluation of different grain baits bases against Indian crested porcupine, Hystrix indica, Pak. J. Zool. 41(1): 7-15. Mushtaq, M., A. Mian, I. Hussain, S. Munir, I. Ahmed and A.A. Khan (2013). Field evaluation of some bait additives against Indian crested porcupine (Hystrix indica) (Rodentia: Hystricidae). Integrative Zool. 8: 285-292. Mushtaq, M., A.A. Khan and A. Mian (2008). Evaluation of aluminium phosphide fumigation for the control of Indian crested porcupine (H. indica) in scrubland. Pak. J. Zool. 40:179-183. Nawaz, A. and F. Ahmad (1974). Control of porcupines in Changa Manga irrigated plantation. Tech. Rep., Forest Deptt. Punjab, Pakistan, 14 pp.

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Nowak, R.M. (1991). Walker’s Mammals of the World. 5th Edition, Vol. 1. Johns Hopkins Univ. Press, Baltimore, U.S.A. Pervez, A. (2006). Developmental biology, feeding patterns and management strategy against Indian crested porcupine (Hystrix indica) in Sindh and Balochistan. 3rd Annual Report (2005-2007) ALP/SARC/PARC Karachi,56 pp. Pervez, A., S.M Ahmad, S.B. Lathiya, E. Khadijah (2009). Food habits of the Indian crested porcupine, Hystrix indica, in Sindh, Pakistan. Pak. J. Zool. 41(4):319-322. Pillai, P.N.R . (1968). Pests of rubber in India. Pesticides Annual, Bombay, India, 97: 89-91. Prakash, I. (1971). Breeding season and litter size of the Indian desert rodents. Z. Angew Zool. 58(4): 441-454. Prater, S.H. (1980). The book of Indian Animals. 3rd Edition, Bomboy Nat. Hist. Soc., Bombay, India. 324 pp. Ramey, C.A. (1995). Evaluation the gas cartridge for coyotes in controlling badgers. 6th Eastern Wildl., Damage Control Conf., pp. 79-84. Roberts, T.J. (1997). The Mammals of Pakistan. Oxford Univ. Press, Karachi, Pakistan. pp. 525. Roberts, T.J. (2005). Field Guide to the Sall Mammals of Pakistan. Oxford University Press, Karachi. pp 280. Ross, J., R.J.C. Page, A.K. Nadian and S.D. Langton (1998). The development of a carbon monoxide producing cartridge for rabbit control. Wild. Res. 25:305314. Rozoska, J. (1953). Bait shyness – a study in rat behavior. Brit. J. Anim. Behav. 1: 128-135. Savarie, P.J., J.R. Tigner, D.J. Elias and D.J. Hayes (1980). Development of simple two-ingredient pyrotechnic fumigant. In: Clark, J.P. (ed). 9th Vertebrate Pest Conference, Univ. Calif. Davis C.A., USA. pp. 215-221. Sharma, D. and S.N. Prasad (1992). Tree debarking and habitat use by porcupine (Hystrix inidica Kerr) in Sariska National Park in Western India. Mammalia. 56(3): 351-361. Sheikher, C. (1998). Porcupine damage in agroforestry system in Himachal Pradesh. Rodent Newsl. 22: 12-13. Storm, G.L. and C.H. Halvorson (1967). Effect of injury by porcupines on radial growth of Ponderosa pine. J. For. 740-743. Taber, R.D., A.N. Sheri and M.S. Ahmad (1967). Mammals of the Lyallpur region, West Pakistan. J. Mammal. 48: 392-407. Thomson, W.R. (1974). Tree damage by porcupine in southeast Rhodesia. J. South Agr. Wildl. Managt. Assoc. 4: 123-127. Townsend, M.G., E.M. Odam, P.I. Stanley and H.P. Wardail (1983). Assessment of the secondary poisoning hazard of warfarin to weasels. J. Wildl. Managt. 48: 628-632. van Aarde, R.J. (1987). Demography of Cape porcupine (Hystrix africaeaustralis) population. J. Zool. London. 213: 205-213. van Weer, D.J. (1983). Specific distinction in Old world porcupines. Zool. Garten NF., Jena. 53(1983), 3/5.S:226-232.

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de Villers M.S. and R.J. van Aarde (1994). Aspects of habitat disturbance by Cape porcupines in a savanna ecosystem. South Agr. J. Sci. 29: 217-220. Walker, E.P. (1999). Mammals of the World Vol. III. Johns Hopkins University Press, Baltimore, USA. Witmer, G.W. and M.J. Pipas (1988). Porcupine damage and repellent research in the interior Pacific northwest. In: Baker, R.O. and A.C. Crabb (ed). Proc. 18th Vertebr. Pest Conf. univ. Calif. Davis. pp. 203-207. Whitford W.G., F.R Kay (1999). Biopedturbation by mammals in deserts: a review. J. Arid Environ. 41:203-230. Wilby A., M. Shachak, B. Boeken (2001). Integration of ecosystem engineering and tropic effects of herbivores. Oikos 92: 436-444.

Chapter 11

Urban Forestry M.A.A. Quraishi, H.M. Ahmad and I. Qadir*

Abstract Pakistan is a forest deficient country and under prevailing set of climatic conditions, it is very difficult to rapidly increase the forest area in Pakistan. Therefore, it is urgent need of time to grow the trees on every available piece of available land to fulfill our urging demands for forest resources. Urban forestry is one of the best option to grow and manage trees in urban settlements including public and private organizations and institutions. Generally, trees in the urban areas are grown to increase the aesthetic value and for their environmental services. Though wood production is not the priority in urban forestry but harvested of course as one of the major tree product. In this chapter, importance of urban forestry, suitable places to grow urban forests and key points to manage the urban forests have been discussed. At the end, some common and suitable trees are mentioned, which could be grown in urban forests. Keywords: Trees: Urban: Parks: Landscape: Environment, Wood.

11.1. Introduction Urban forestry is the practice of forestry in an urbanized environment. It can be described as the science and art of growing trees in urban and peri-urban areas for obtaining various forest products as well as environmental benefits. Urban forestry deals with the role of trees as an integral part of urban infrastructure. It is practiced

* M.A.A. Quraishi, H.M. Ahmad˧ and I. Qadir Department of Forestry and Range Management, University of Agriculture, Faisalabad, Pakistan. ˧ Corresponding author’s e-mail: [email protected]

Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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by municipal and commercial arborists, municipal utility foresters, environmental policy makers, city planners, consultants, educators, researchers and such other members of the civil society. Urban foresters plant and maintain trees, support appropriate tree’s growth, preserve forest, conduct research and explore/promote as many benefits as trees provide (Dixon 1995; Fall 2003). So urban forestry, more precisely, can be defined as; the establishment, management planning and design of individual trees and forest stand with some amenity values, suited in or around urban areas. Trees in the urban environment are often referred to as the urban forest, comprising trees in civic wood lands, parks and the streets. Earlier, urban trees were mainly regarded as aesthetic elements, whereas today these are recognized as having a positive impact on the environment as well as providing economic and social benefits. The value of urban forest is being increasingly recognized as a vital component in the maintenance of sustainable urban environment around the world as well as its high potential role in forest production. To develop a sustainable urban forestry model, trees are planted and managed along the motor ways, high ways, in streets, municipal parks, gardens and reserves, gulf courses, cantonments, schools, colleges, universities, hospitals and all other public places where there is some space available for tree planting (Grey and Deneke 1978). Due to ever increasing human population with meagre resources we are no more able to convert any other land use into conventional forestry. It is very difficult to increase forest cover in Pakistan by conventional methods. According to an official estimate of Punjab Forest Department, to increase 1% forest area in Punjab Province we need 0.5 million acres of land, 6000 cusec water and the funds of three thousand million rupees. We cannot bear so much huge expenses. The alternate option is to apply non-conventional approach to increase tree cover in Pakistan. Among them, urban forestry is extremely suitable approach by which we can enhance number of fast growing trees and hence forest production. It is worth mentioning that two hundred mature trees in scattered form have the combined effect and production equivalent to one acre of compact forest plantation.

11.2. Quantification of Urban Forestry Services Trees are precious gift of God which have so many benefits for human beings and ecosystem (Price 2003). It is necessary to grow trees in urban areas. There are several economical, ecological, environmental, social and cultural benefits which are provided by urban forests as well as trees planted in an urbanized environment.

11.2.1. Economic Benefits Urban forests provide a number of benefits which are very important for the continued economic growth and welfare of the society. Trees provide timber and fuel wood for domestic as well as industrial use, forage for livestock, food, fruit and medicine for human beings. Planting of fruit trees in urban areas is a giant step to ensure food security which is the burning issue of the globe at present. There are several other economic aspects of urban trees. It is a common observation that the

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values of properties in tree lined areas will be much greater than in similar areas without trees. People like to do business in those urban areas where sufficient numbers of trees with good landscape are present. Similarly, tree cover has a positive effect on saleability of the properties. Properties on tree lined streets are said to be in more demand and easy to sell out.

11.2.2. Social and Cultural Calues Trees have a significant role in bringing peace harmony and brotherhood. Man always had a strong affinity for the trees. These are the source of spiritual replenishment. It has been proved by research that appropriate vegetation cover can lead to reduced crime rates. Areas with higher vegetation cover were found to have lower crime rates, as measured by police reports. Vegetation cover has a mitigating effect on mental fatigue and illness. Trees can help improve road safety in a number of ways. Trees lining of roads give the impression of narrowing the street and encourage slower driving. The stress reduction effect of trees has the effect of reducing road rage and improves the attention of drivers. It is universal truth that, sufficient number of trees is a guarantee of healthy and peaceful society.

11.2.3. Ecological and Environmental Importance Trees are the most important feature of the environment in which we live, work, play and enjoy the blessings of nature. Trees play an important role in the provision of neat and clean air (Selmi et al. 2016). It is well known that trees absorb carbon dioxide and release oxygen during the process of photosynthesis. The carbon absorbed by trees in this process is stored in the wood. On the other hand, trees can remove a number of pollutants from the atmosphere, including ozone, nitrogen dioxide and other toxic particulates (Lackner 2003). They have highest carbon sequestration rate among all type of vegetation. They have a significant role in energy savings. Careful tree planting can reduce the amount of fuel used on both heating and cooling buildings (Lackner et al. 1995). Trees provide shelter and reduce wind speed, thus reducing heat loss from buildings during winter. These also provide shade in the summer while the evapo-transpiration of water from the leaf surface area has a general cooling effect on the atmosphere. This can significantly reduce the need for air conditioning during hot weather. Trees in the urban environment can reduce storm runoff and improve water quality. They play an important role in the mitigation of sound pollution by reflecting and absorbing the sound energy. One estimate suggests that up to 8 db noise reduction can be achieved from every 30 meterS wide shelterbelt. To cut the long story short, the important beneficial aspects of urban forestry can be summarised by highlighting the following points. •

Production of timber, fire wood and forage

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Environmental amelioration

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Reduction of pollution and energy use

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Beautification and aesthetic sense

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Shade, recreation, amenity and pleasure

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Conservation of biological diversity

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Sustainability in urban ecosystem

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Savings in public health care and increase in economic investment

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Provision of basic needs like food, fruit, fibre and shelter

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Employment opportunities in urban areas

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Reduction of air, land, water and noise pollution

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Reduction in wind/water storm and erosion

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Reduction of pressure on state forest

11.3. Distinctive Features of Urban Forestry 11.3.1. Objectives of Management Establishment of forest vegetation for environmental amelioration and beautification are the major objectives of urban forestry. Urban forestry among other things seeks to manage the trees in a city as a renewable resource that can produce a range of benefits which may include small timber and five Fs. viz., fuel wood, food, forage, fibre and fertilizer.

11.3.2. Due Regard to Ornamentation Urban forestry is somewhat overlapping with landscape horticulture. In urban forestry, special consideration is given to landscape principles. The greatest contribution that urban forester can bring to a city is its skills to plan, establish and manage the urban forest in the best interest of human beings and their ecosystem. Plants having ornamental and amenity values are selected to develop an urban forest. Single stem forestry is applied here. Clear felling in urban areas is not recommended as felling on large areas can cause some social and environmental issues.

11.3.3. Efficient Utilization of Available Resources All necessary resources in the form of suitable site, planting material, sewage and rain water, trained and untrained labour, funds and capitals are available in urban areas. In remote areas, sometimes labour is not available or so much costly to perform different silvicultural operations. We have no problem to face the shortage of labour in cities. Planting material is at our disposal at every time. Normally sufficient funds are allocated for the development and beautification of urbanized environment. So, the need of the time is to utilize these precious resources efficiently by adopting proper planning and applying suitable management techniques.

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11.3.4. Less Competition for Space and Nutrients Trees in urban forest generally face less competition for space, nutrients and water. Sufficient spaces remain available for plants because these are planted by maintaining proper distance and spacing. All types of water i.e. rainwater, canal water, underground water, domestic waste water and industrial waste water is ready to irrigate. Normally, there is no shortage of water for urban forestry trees and hence, no competition for water. Similarly, most of the nutrients which are essential for plant growth are present in urban areas which can be used to promote forest vegetation without the danger of extermination.

11.3.5. Protective Role of Trees is Dominant Over Productive Role Although urban vegetation plays productive as well as protective role in the environment and ecosystem but their protective role is dominant over productive role. Urban trees are more important for their intangible benefits rather than tangible benefits. The productive potential of trees can also be enhanced by exploiting and utilizing the special favourable conditions for tree growth in urban areas.

11.3.6. Attractive Market There is no difficulty in the marketing of urban forestry products. Transportation of all these products is very easy. There are minimum transportation and carriage expenditures. Availability of labour for harvesting and handling is another favourable point for urban forestry. So, all these factors make the urban forestry as most suitable practice in the urban areas of Pakistan.

11.4. Various Types of Urban Forests Different kinds of urban forests are found in Pakistan. Some of them are briefly described here.

11.4.1. Road Side Plantations Road side are distributed throughout the Pakistan along the motor ways, high ways, G.T. roads and all other inter-city and intra-city roads and avenues as mentioned below in Figure 11.1. These are owned by Govt. and generally have limited space to grow. These should face a greater extent of pollution and hardships. These plantations need regular pruning to remove the branches causing hurdle in traffic flow. The first impression about the greenery of a country can be picked by the extent and magnitude of road side plantations. So, these plantations must be managed as these have a significant role to develop the soft image of a country.

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11.4.2. Canal Side or Drain Side Plantations Canal side and drain side plantations perhaps grow in best conditions in an urban environment as mention below in Figure 11.2. These have to face relatively less extreme conditions due to availability of a permanent source of water. These also need continuous management. Especially our canal sides have a significant potential to support forest vegetation. Due to which, these sites are called as “Timber Mines” of Pakistan. Fig. 11.1 Road side Plantation

11.4.3. Plantations along Railway Tracks Rail side plantations have sufficient spaces to grow on both sides of railway track all over the Pakistan as mention below in Figure 11.3. But unfortunately, these plantations are not looked after and maintained properly due to negligence of the government.

11.5. Institutional Plantations The trees grown in schools, colleges, universities and hospitals are said to be institutional plantations as mentioned below in Figure 11.4. These plantations relatively have larger spaces to grow. Their establishment, protection and management is easier than roadside plantations. Due to increased awareness among public and better availability of resources in the form of labour, water and funds, these plantations are more precisely managed for landscape purpose.

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Fig. 11.2 Canal side or Drain side Plantation

Fig. 11.3 Plantation along Railway Tracks

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Fig. 11.4 Institutional Plantations

11.5.1. Airport Plantations The plantations in and around the boundaries of airports are called airport plantations as mention below in Figure 11.5. Normally, airports have thick tree populations for security reasons. These lands can be rightly said as best sites for tree production in urban areas. Generally trees growing in these areas are not allowed to fell and human interference in these areas is kept limited. Fig. 11.5 Airport Plantations

11.5.2. Parks and Garden Plantations The trees in parks are a source of pleasure and relaxation for people as mention below in Figure 11.6. These ameliorate the climate, provide shade in summer and add to the beauty of area. These plantations need permanent care and management, otherwise their beauty and growth is affected badly.

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Fig. 11.6 Parks and Garden Plantation

11.5.3. Home Garden Plantations Due to ever increasing human population, the magnitude of home gardens is decreasing day by day. At present limited number of homes in urban areas have gardens or parks and very limited numbers of trees have been planted in these areas. Generally home gardens are intensively cared and managed by the custodians of homes as mention below in Figure 11.7. Home gardening is a healthy and useful hobby which should be promoted to keep the people physically and mentally sound.

Fig. 11.7 Home Garden Plantations

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11.6. Management of Urban Forests •

In urban forestry, more concentration is given on environmental and social benefits rather than economic benefits.

•

In urban forests, trees are not cut or harvested until and unless they grow old, get diseased and expired

•

Thorny species are generally avoided in roadside planting

•

Flowering and foliage ornamental trees are specially selected for road side planting but one should not plant trees along the roadside having large watery flowers which shed on ground in large numbers and cause accidents.

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Plant trees, which have relatively broader leaves so that they can capture more dust

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Water loving plants should be planted along the canals and drains. For example, willow and poplar

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Remove the branches/limbs which create hurdles in smooth running of traffic.

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Fell those trees which are old or grow slowly or which have been attacked by insect pest or pathogens.

• Save the plants from lopping and pollarding by un authorized people Table 11.1 Major urban forestry trees of Pakistan Woody Trees S. No 1 2 3 4 5 6 7 8

Common Name Sheesham Sufaida Siris Poplar Neem Bakain Mullberry Simal

Scientific Name Dalbergia sissoo Eucalyptus camaldulensis Albezzia lebbek Poplus deltoides Azadirachta indica Melia azedarach Morus alba Bombax ceiba

Common Name Gul Mohr Amaltass Neelam Gul e Nishtar Dhak Kachnar Paulownia

Scientific Name Delonix regia Cassia fistula Jacaranda mimosifolia Erythra suberosa Butea frondosa Bauhinia purpurea Paulownia tomentosa

Flowering Trees: S.No 1 2 3 4 5 6 7

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Foliage Ornamental Trees: S. No 1 2 3 4 5 6 7 8 9 10

Common Name Devil Tree Toon Pilkhan Silver oak Kangar Kanak-champa Jiaputra Baid-e-Majnoo Baid-e-Laila Arjum

Scientific Name Alastonia scholaris Cedrela toona Ficus infectoria Grevillea robusta Pistacia integerrima Pterospermum acerifolium Putranjia roxburghii Salix babylonica Salix tetrasperma Terminalia arjuna

Reference Dixon, R.K. (1995). Sources or sinks of greenhouse gases. Agrofor. Syst. 31:99– 116 Fall, L.M.W. (2003). Urban Greening and Social benefits. J. Arbori. 29: 137-140. Grey, G.W. and F.J. Deneke (1978). Urban Forestry. John Wiley and Sons, New York, USA. Pp. 156. Lackner, K.S. (2003). A guide to CO2 sequestration. Science 300:1677–1678. Lackner, K.S., C.H. Wendt, D.P. Butt, E.L. Joyce, and D.H. Sharp (1995). Carbon dioxide disposal in carbonate minerals. Energy 20:1153-1170. Price, C. (2003). Quantifying the aesthetic benefits of urban forestry. Urb. For. Urb. Green. 1 :123-133. Selmi, W., C. Weber, E. Riviere, N.G. Blond, L. Mehdi and D. Nowak (2016). This study is a first-time estimate in France that assesses the role of urban trees to reduce air pollution. Comparison of removal rates with emissions rates in Strasbourg city shows that trees modestly remove air pollution. Urb. For. Urb. Green. 17:192-201.

Chapter 12

Managing Carbon in Forests S.M. Nizami, G. Yasin and M.T.B. Yousaf*

Abstract This chapter is not only helpful for forestry students, forest managers, people working on REDD+ and forest carbon budgeting as well as for policymakers. Forests are of utmost importance for mitigating the change in global climate as they are the huge reservoirs of carbon and have the potential to sequester more from the atmosphere. Investigations on forest biogeoochemistry, climate, disturbances, as well as the spatial and temporal heterogeneity of carbon sequestration across regions has gain importance in the last two decades. This chapter provides a comprehensive synthesis and review of the science of carbon in forests at the start and then reviews the different ways of measuring and estimating carbon in forests and summarizes the best-known estimates of storage and loss. Later, it reviews methodologies for estimating carbon in above ground pools, a key topic for many nations in international policy discussions because of the need to develop standardized methods of carbon accounting with an emphasis on verifiable results. This chapter closes with analyzing the relationship between forests, socioeconomic and policy considerations round the world and particularly in Pakistan. Key Words: Climate change; Above and below ground biomass; Carbon; Measurements; Simulation and Policy.

* S.M. Nizami Integrated Mountain Area Research Center, Karakoram International University, Gilgit, Pakistan. For correspondance: [email protected]

G. Yasin and M.T.B. Yousaf Department of Forestry and Range Management, University of Agriculture, Faisalabad, Pakistan. Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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12.1. Forest and Carbon Sequestration 12.1.1. Links between Climate Change, Carbon Dioxide and above Ground Tree Biomass Climate change is a change in the statistical distribution of weather patterns, especially, when that change lasts for an extended period of time (i.e., decades to millions of years). Changes in climate are happening which are unparalleled. Global warming is among the greatest terrible horrors of the modern times. It is believed that carbon is among the most significant causal factors which cause global warming. The mean concentration of CO2 in the atmosphere was 280 μ mol mol−1 before the development of industries. And in the year of 1994 after industrial development it has reached up to 364 μ mol mol−1. Now-a-days, the rate at which concentration is increasing is about 1.5 μ mol mol−1 year−1 (Kerr, 2007). It has strengthened the importance to understand the terrestrial global carbon cycle. Trees store up to 90% of the global plant biomass and are therefore a very important variable in the global carbon cycle. This above mentioned fact tells us about the significance of forest ecosystem and the importance of determining the accurate amount of carbon which is being stored in these forest ecosystems. 12.1.1.1. Climate Change The climate on Earth is driven by interactions between incoming solar radiation and the Earth’s atmosphere and surface. Incoming solar radiation is partially filtered by the upper atmosphere with the majority continuing on to be absorbed or reflected by the Earth’s surface. Reflected radiation predominantly returns to space, with the absorbed solar radiation being re-emitted back into the atmosphere as lower energy radiation. This low energy radiation is partially trapped within the troposphere (lower atmosphere) by greenhouse gases before finally making its way back into space (Figure 12.1). The amount of low energy radiations trapped by the troposphere determines the climatic conditions of earth (Gribbin 1982; IPCC 2001a; Kininmonth 2004). After water vapour, carbon dioxide (CO2) is the most important greenhouse gas (IPCC 1996). Average atmospheric CO2 concentrations have increased from 280 ppm (in CA 1750) to 401 ppm (as of 2005; CO2 Now, 2014). These increases have been attributed to human activities predominantly relating to burning of fossil fuels and land clearing (IPCC 1996; Schlesinger 1997). Climate models indicate that increasing concentrations of greenhouse gases have trapped additional radiation, leading to increases in global temperatures and causing climate change (Gribbin 1982; IPCC 2001b; Schlesinger 1997). Global climate change threatens water supplies, food production and ecosystem health and viability (Lowe 2005; Oldfield 2005; Schneider et al. 2007). 12.1.1.2. Carbon (C) Cycle Carbon cycle comprises of those natural processes which are involved in the storage and transfer of Carbon between different spheres of earth. These spheres

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include biosphere, geosphere, hydrosphere and hydrosphere (IPCC 2001b; Schlesinger 1997; SCOPE 1984). The rates and amounts at which carbon is being transferred between these stores is different at different intervals of time. Different types of biological processes, geological phenomenons and climatic conditions are responsible for controlling the rates and amounts of Carbon (Figure 12.2; IPCC 2001b; Schlesinger 1997). Terrestrial ecosystems are one store that has the ability to sequester C in a short time-frame that is relevant in addressing climate change. It is also a store that can and has been altered by human activity (IPCC 2001b; Schlesinger 1997).

12.1.2. Forest C and Forest Components Of all terrestrial ecosystems, forests contain the largest store of C (Table 12.1; IPCC 2001b; Schlesinger 1997; SCOPE 1984). The term forest has been defined as vegetation with a minimum height of 2 m and minimum crown cover of 10% in the Marrakesh Accords, which specify the rules that are to be used in the Kyoto Protocol (UNFCCC 2001). Worldwide, forests covers 4x109 ha (30% of land area) and, relative to non-woody vegetation, have a large biomass per unit area of land (FAO 2005). Carbon is mainly stored in the plant biomass whether it is above ground or below ground, woody debris which is abrasive in nature, litter and soil (containing organic and inorganic C; Figure 12.2; IPCC 2003; Richards & Evans 2004). These are the major carbon sinks in the forest ecosystem. The amount of carbon stored in these carbon pools continues to rise as the life cycle of forests increases until it reaches up to the state of equilibrium. When equilibrium state is gained then the amount of CO2 which is released by plants and soil in the process of respirational and degradation of biomass equals the growth rate (e.g. Acker et al. 2002; Smithwick et al. 2002).

Fig.12.1 Interactions between incoming solar radiation (W m-2) and the surface and atmosphere of the Earth. Source: Kiehl and Trenberth (1997)

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Where the forest growth is disturbed or the forest is destroyed, CO2 and other greenhouse gases (i.e. Methane ‘CH4’, nitrous oxide ‘N2O’) are released back into the atmosphere via respiration, combustion or decomposition (IPCC 2003; Richards & Evans 2004; Schlesinger 1997). Forests have the capability of both sequestering and releasing greenhouse gases. Moreover, the rate at which forests are being removed are the main factors to include the forests and land use change in the United Nations Framework Convention on Climate Change (UNFCCC) and in the Kyoto Protocol (KYOTO 1997; UNFCCC 1992). Table 12.1 Area, carbon stock and density, and net primary productivity (NPP) of world terrestrial ecosystems Ecosystem (biome)

Area Global carbon stock (Pg C) (109 ha)1 Plants1 Soil2 Total 1.75 340 213 553 1.04 139 153 292 1.37 57 338 395 2.76 79 247 326

Carbon density (Mg C ha-1) NPP (Pg C yr-1) 1 Plants1 Soil2 194 122 21.9 134 147 8.1 42 247 2.6 29 90 14.9

Tropical forests Temperate forests Boreal forests Tropical savannas & grasslands Temperate 1.78 23 176 199 13 99 7.0 grasslands& shrublands Deserts and semi 2.77 10 159 169 4 57 3.5 deserts Tundra 0.56 2 115 117 4 206 0.5 Croplands 1.35 4 165 169 3 122 4.1 Total 14.93 654 1567 2221 62.6 1. From Mooney, Roy and Saugier (2001); wetlands are not recognised in this classification; temperate grassland and Mediterranean shrubland categories combined; 1.55x109 ha ice cover not listed 2. From IGBP-DIS (International Geosphere-Biosphere Programme – Data Information Service) soil carbon spatial database (Carter & Scholes 2000 Source: IPCC (2001b)

The amount of C stored in plant biomass is more than that of atmospheric CO2. It is also estimated that almost 90 % of plant biomass carbon is being captured by tree biomass (Table 12.1). This tells us that how much forest ecosystems are important in the global carbon cycle, the requirement of precise evaluation of the amount of C accumulated in forest ecosystems, and the implications a change in land-use will have for C-storage in forests. For example, a replacement of old, slow-growing, high-C-stock forests by a young, fast-growing, low-C-stock forests always represent a dramatic net loss of C per unit land area over a 100 year time period (Körner 2006). Hence, reforestation has the potential to mitigate increased atmospheric CO2 concentrations, but a much greater effect in terms of C pools comes from the preservation of old forests, a point often overlooked (Körner 2000).

12.1.3. Political Responses to Climate Change The UNFCCC was developed at the 1992 Rio ‘Earth Summit’ (Kininmonth 2004). It was the first international political response to the threat of climate change (ICSU 2006; SCOPE 2004), and was based on scientific conferences preceding the summit (Kininmonth 2004; SCOPE 2004). Scientific evidence arose from research that

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stretched back to the 1960s when the Global Atmosphere Research Programme (GARP) – a joint initiative of the International Council of Scientific Union (ICSU) and the World Meteorological Organization (WMO) – was initiated to understand global weather (Bierly 1988; ICSU 2006). GARP was a result of technical advancements and political requirements relating to long-term weather forecasts that were needed to improve food security (Bierly 1988; ICSU 2006). The Kyoto Protocol is the highest international agreement ever developed for greenhouse gases (GHGs), and builds on the UNFCCC by setting binding targets for GHG emissions from industrialised countries. Development of the Kyoto Protocol involved extensive negotiations from its initial adoption in 1997 to its enforcement in 2005 (SCOPE2004). These negotiations were needed to clarify protocol coverage, and to address the political concerns of a sufficient number of countries to ensure the protocol was ratified (SCOPE 2004). Nonetheless, a number of countries did not sign the protocol, notably the United States of America (largest GHG emitter) and Australia (largest GHG emitter per capita). Similar political concerns prevented inclusion of binding targets in the UNFCC thirteen years earlier (Kininmonth 2004). This meant that there were more UNFCCC signatories than the Kyoto Protocol, but that the UNFCCC had minimal impact on GHG emissions (Kondratyev et al. 2003; SCOPE 2004).

12.2. Protocols of Measuring Carbon in Forests 12.2.1. Measuring Carbon in Forests Broadly speaking, there are two primary approaches to measuring carbon stocks and fluxes in each forest carbon pool: Generally, biomass, which is readily measured, are widely used to estimate certain stocks using proven formulas for the ratio of carbon to biomass instead of measuring carbon directly, particularly for aboveground carbon (Brown 1997). Generally speaking, carbon stocks and fluxes can be measured by two key approaches in any forest carbon pool: (i) measuring changes in carbon stock, and then inferring a carbon flux under a certain degree of confidence; and (ii) measuring carbon flux directly. Normally, biomass is calculated by the help of established formulas. Biomass is easy to measure. After measuring biomass carbon is estimated with the help of formulas which are generally based on biomass. The ratio of carbon to biomass is the main tool to calculate. Above ground carbon is estimated by using this method (Brown 1997). It is easy to classify the carbon stocks which are present in forests into different measurement pools. These stocks can be classified into five different measurement pools: •

Aboveground biomass– As it is obvious from the name that it includes all the living biomass which is present above the soil. Stem, bark, seeds, stump, branches, and foliage all are included in aboveground biomass. We can also that live understory is included in this category.

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•

Belowground biomass– As it is obvious from its name, all living biomass of roots which is greater than a particular defined diameter is included in it.

•

Dead wood– All non living biomass is included in it whether it is standing, lying on the ground (litter is not included in it) or present in the soil.

•

Litter – This includes all the non living biomass which is lying on the ground and has attained a certain diameter. Litter and humus layes of the surface of soils are included in it.

•

Soil organic carbon (SOC) – All the organic material which is present upto the soil depth of 1 m is included in this except the layer of litter and coarse roots of the belowground biomass.

In this chapter, four categories of methods which are currently used to measure forest biomass and estimate carbon have been reviewed: i) forest inventory (biomass); ii) remote sensing (relationship between biomass and land cover); iii) eddy covariance (direct measurement of CO2 release and uptake); and iv) the inverse method (relationship between biomass, CO2 flux and CO2 atmospheric transport). Level of accuracy is different for every method and the resolution which is feasible to obtain data is also variable. There are advantages and disadvantages of every technique and each is suitable for circumstances to measure CO2 flux and carbon storage for variable temporal and spatial scales of assessment and calculation.

12.2.2. Forest Inventories and Aboveground C Stock Assessments Forest inventories can be used to determine the carbon stock. The reason behind using this method is this method is that national forest inventories are easily accessible to numerous countries. There are different techniques which have been developed to calculate the above ground biomass (AGB) from inventories These can be divided into different types according to the source from which data is collected. Data can be collected from field measurement, remote sensing or ancillary data which is used in GIS based modeling (Lu 2006; Wulder et al. 2008). Table 12.2 shows different approaches to estimate the stocks of carbon from each of these different sources of data. 12.2.2.1. Field Based Methods The field based study is commonly mentioned as inventory assessment. It can be classified into two additional categories. The two main approaches are volume to biomass and diameter to biomass. The approach is selected on the basis of the availability of the data and the anticipated results. Timber volume is generally available. So, the approach is used to convert timber volume into biomass. Although, it has more uncertainty but less details are required in this approach. The allometric equations are more useful because this approach is capable of giving more accurate results but it requires the detailed information about diameter and field measurements. If these two parameters are available than allometric equations are preferred.

S.M. Nizami, G. Yasin and M.T.B. Yousaf Cement

Fossil Fuel

Biomass Energy

Landuse Change

Fire

267 Natural Fire

Heterotrophic Respiration

Land sink

Netprimary Production

weathering

River outgassing

soil erosion

weathering

1.1 Exportedtoocean

Fig. 12.2 The current global carbon cycle in Pg (1Pg = 1015g = 109 t). Black arrows and numbers indicate background or pre-anthropogenic carbon stocks (in square brackets) and carbon fluxes. Red arrows and numbers indicate human induced changes in stocks and fluxes. Source: SCOPE (2004) In an ideal situations the parameters which should be recorded in every inventory dataset are included prevailing species, diameter of trees at breast height which is commonly known as DBH, height of trees, age of the stand, increment of any kind (age, diameter etc.) and defects (LeBlanc 2009). The above mentioned scenario is of ideal conditions but in reality different countries have different datasets of information due to different standards to calculate inventory information. Moreover, capacity and resources also play an important role in detailing the inventory information. As, in Pakistan, the basic purpose of practicing forest inventories is to develop forest working plan for different types of forests. These inventories are conducted by forest department of each province. Not only the growing stock of existing forest is estiamated but also the stock for coming years is projected by these inventories. Nevertheless, carbon stocks estimation has been undertaken in these forests by the provincial forestry departments. The, FAO has prepared a report known as The Global Forest Resources Assessment (GFRA) in 2005. Ten workshops at regional and sub-regional levels were organized by FAO to prepare this report. Experts were invited in these workshops and discussions were conducted to gather data about Pakistan’s growing stock. The data regarding Pakistan in GFRA 2005 presents the total carbon stocks (Mt) for the entire country. This report gives us information about the total carbon stocks (Mt) in the whole country. But there is lack of any scientific work to estimate the actual measurements of carbon stock and biomass for any specific forest type of Pakistan. The estimates in GFRA (2005) were made on the basis of remote sensing. Remote sensing is not a very reliable technique and there can be errors in this report GFRA (2005).

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i. Estimating biomass from Timber volume The ratio between all the above ground standing biomass (AGB) to that of volume of the growing stock (Mg/m3) is known as biomass expansion factor (BEF) (Fang et al. 2001). If the data regarding timber volume among the classes of diameter is available then BEF can be used for the estimation of AGB (Brown 2002). BEF is of great significance to estimate the AGB in those countries which are still in the phase of development. These countries don’t have detailed information regarding forest biomass. Simply, the regression relationships are used to estimate carbon stock with the help of BEF. The three parameters which are related to above ground biomass are: merchantable tree volumes, non-merchantable tree volumes and their annual increment. Afterwards this above ground biomass which was calculated by trees volumes could be further expanded to large areas. Uniformity of size, stocking ageclass distribution should be given due consideration while manipulating the results (see Fig.12.3) (Wulder et al. 2008). BEF is not a constant value and it varies from one forest stand to another forest stand. It depends on numerous factors like age of forest, class in which site falls, stand density, and various biotic and abiotic factors (Brown et al. 1999; Fang et al. 2001). ii. Estimating biomass from tree diameter or diameter plus height Reliability of the forest carbon and the understanding of the dynamics of carbon in forest ecosystem can be increased by applying the current knowledge concerning tree allometry in the form of volume and biomass allometric models (Jenkins et al., 2003; Zianis and Mencuccini, 2003; lethonen et al., 2004). The biomass allometric models can be used to directly estimate the stand tree biomass, from tree measurement data (diameter or combination of diameter and height) in forest stand inventory, or by adding specific gravity or wood density and the biomass expansion factor (IPCC, 2003) or the biomass conversion and expansion factor (IPCC, 2007) in using tree volume allometric models. By using the allometric models that are already formulated, the biomass of one tree can be estimated just by entering the parameters of the results of the measured dimensions of the tree like diameter at breast height (dbh) and height. The stand biomass can be estimated by having information on stem density and then by extrapolating methods. If we want to take the precise allometric equation for any type of forest, the sample of tree sizes and species should be taken in an adequate amount. If there is sufficient data regarding size and species of trees, we can find very precise result by the help of allometric approach. This approach is being used on limited scale. The reason behind its limited use is that there is not sufficient allometric information for each forest type and every region (especially in Pakistan). 12.2.2.2. Remote Sensing Methods This method is based on the monitoring of forests at various temporal, spectral, altitude, latitude and spectral resolution (Patenaude et al. 2005). There are a great number of applications which are available for mapping the land cover with the

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help of remote sensing. These applications can be classified into two main branches passive (optical) or active (radar). Optical or passive remote sensing consists of mainly following types: i) aerial photographs of dffferent kinds i.e. infrared, color, black and white, ii) NDVI images that are captured by using radiometer of high resolution (AVHHR) sensor, iii) images at a low resolution obtained from using Landsat Thematic Mapper.

Fig. 12.3 An overview of the process used to estimate biomass from the forest inventory data. Source: Wulder et al. (2008). Active remote sensing is a technique in which images are being derived from radar and LiDar. 12.2.2.3. Eddy Covariance Technique In this method, different sensors are installed on a tower at different heights and continuous data of fluxes are recorded with the help of data loggers. After downloading the data from all the sensors via data loggers different software is used to do analysis of data. Now a days, a great number of software programs have been developed which are able to derive the above mentioned quantities like momentum, heat and fluxes of gas (including CO2) after processing the data of eddy covariance. The programs are available at a wide range which are specifically designed to work according to the conditions of data available. The complexity, litheness, availability of instruments,

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variables, help system and user support. There are two types of programs used in this eddy covariance. They can be open source software or closed source software. EddyPro is the free fully supported open source software, ECO2S, ECpack is unsupported open-source software, EdiRe, TK3, Alteddy are closed programs softwares, Matlab is a commercial software which uses eddy covariance. 12.2.2.4. Inverse Method Atmospheric CO2 concentration can be estimated from sink and source measurements of carbon (forest inventories, flux measurements) combined with transportation models (that model gas movement) using meteorological information. Atmospheric CO2 concentration can be calculated from sink and source measurements of carbon along with transportation models by means of meteorological data. We can also measure it directly. Inverse method is used to estimate the sinks and sources of CO2 with the help of a Bayesian inversion technique from (Gurney et al. 2002; Rodenbeck et al. 2003). This is known as an inverse method because with the help of three-dimensional transport models sinks and ources of carbon are backed out in this method (Gurney et al. 2002) The precision of this method is mainly dependent on the transportation models which are being used and the data of atmospheric CO2 concentration (Patra et al. 2006). The summary of above mentioned four categories is presented in Table No: 12. 3. Each method has some advantages and there are also some limitations of every method.

12.3. Forest Stand Dynamics and Simulation of C Stocks The community of flora and fauna dominated by woody vegetation is known as forest. The major proportion of forests is made of plants. Plants could be of different sizes and different species. Diversity is one of the main characteristics of forests. Structure and composition of forests is not static. The structure and composition of forest change over the period of time. The study of forest dynamics chiefly deals with this change. The behavior of forest population is also in response to any external stimuli whether it is natural or anthropogenic is also studied in forest dynamics. The amount of biomass which is being produced by a plant or stand in a certain time period is known as growth. This time period could be 1 day, 1 week, 1 month, 1 year or 5 years etc. on the other hand yield can be defined as the amount of biomass which is being accumulated since the time of the establishment of the stand. The forest dynamics are greatly influenced by thr growth of trees and disturbances. These two factors are heavily associated with resources available (e.g. Radiation, water, nutrient supply) and environmental conditions (e.g. Temperature, soil acidity, or air pollution).

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While considering the assessments of C stocks in the forest, as the forest keeps on increasing biomass ultimately the C stocks are changing. The parameters of the forest biomass, which are the determent of C stock dynamics over the time are: dbh, height, volume, CAI, mortality, turnover rates, relative growth rates etc. In addition to these soils, products and Bioenergy parameters are also important. There are different models which are used not only for estimation of C stocks, but also simulate these stocks for a certain period of time. One such example is CO2 Fix which describes in detail as follows: Table 12.3 Summary of different methods for estimating carbon budgets Methods Forest inventory

Remote Sensing

Temporal Spatial Scales Scales Annual Regional or decades

Daily to annual

Eddy Hours to Covariance years

Inverse method (Carbon Tracker)

Weekly

Regional and Global

Over the course of year or more Global, at 1º × 1º resolution

Data availability Historical data worldwide

Uncertainty

1% for the growing stock volume 2-3%of net volume growth and removal, and almost 40% of changing in growing stock volume. Stat from the The RMSE for an end of 70`s aggregation area of 510 ha of the unit land area 8.7% for ACIS and 4.6% for world volum Starts fom ±50 gCm −2year −1 1960`s (ideal size)

2000–2006

Targat Carbon stocks in the forests.

Carbon stocks in the forests.

Net CO2 exchange across the canopyatmosphere interface −1.65 PgCyr (for Net CO 2 North exchange American terrestrial between the biosphere) terrestrial biosphere and the atmosphere

Sources: Brown (2002); Patenaude et al. (2005); Lu (2006); Baldocchi (2008); Giglio et al. (2006) and Peters et al. (2007).

12.3.1. The CO2 FIX V3.2 Model The full carbon accounting approach is the basics of this CO2 FIX model. The C stocks and fluxes are quantified by using this approach in CO2 FIX Model. The differences in the carbon stocks over the period of time for all carbon pools are calculated in this approach (Noble et al., 2000).

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The total carbon physically stored in the system at any time (CTt) can be calculated by using this equation CTt= Cbt + Cst……………………………… (Mg ha-1) Where Cbt is the total carbon stored in living (above plus belowground) biomass at any time ‘t’ (Mg ha-1) and Cst is the carbon stored in soil organic matter (Mg ha-1).

12.3.2. Carbon Stored in Living Biomass Cohort Model Approach is basically used to measure the carbon stock and flows in the living biomass of forests (Reed, 1980). This approach is based on cohorts. Cohort is based on the growth response. A group of individual trees or group of species which have an almost similar growth rate are combined to form a cohort. And this cohort will be considered as a single factor in the model (Vanclay, 1989, Alder and Silva, 2000). The total biomass at any time is estimated as the sum of stem (including bark), foliage, branches and root biomass of all cohorts (Masera et al., 2003). If we want to calculate the total biomass then the biomass of stem (including bark), foliage, branches and root is calculated of every cohort. Then this biomass of each cohort is added (Masera et al., 2003). Then, the biomass of each cohort is added to calculate the carbon stored in the living biomass of the whole stand. It can be expressed as: Cbt = ∑Cbit………………………………..…… (Mg ha-1) Where Cbit is the carbon stored in the living biomass of cohort ‘i’ at time ‘t’ (Mg ha-1). For each new time step, Cbit is calculated as the balance between the original biomass, plus biomass growth (Gbit), minus the turnover of branches, foliage and roots (Tit), minus tree mortality due to senescence (Msit), minus harvest (Hit) minus mortality due to logging (Mlit), i.e. Cbit+1= Cbit+ Kc [Gbit– Msit– Tit- Hit- Mlit]…… (Mg ha-1) Where Kc is a constant to convert biomass to carbon content (Mg Mg-1 biomass dry weight).

12.3.3. Biomass Growth The growth rates of stem volumes are being used as an input to simulate Gbit in this model. The stem volumes can be easily calculated by the help of yield table or forest inventories. Time- dependent allocation coefficients are used to calculate the growth rates for foliage, branches, and roots from stem volume. It is obvious that the stem volume growth rate in m3ha-1yr-1 acts as the main input in this model. Allometric approach is being applied to estimate the growth from stem volume of major biomass components. After estimating the growth rate for each cohort, these growth rates are altered by the interactions among themselves and with other cohorts. The site quality is not same. Good, medium and poor sites conditions could be prevailed in the forest stand. To correct these and other differences which are

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present due to the differences in growth parameters, modifications could be made accordingly (Nabuurs and Mohren, 1995). Mathematically, Gbit = {KvYist [1+Ʃ (Fijt)] ×Mgit}…………………. (Mg ha−1 yr-1). Where Kv is a constant to convert volume yields into dry biomass (basic density, in kg DM m-3of fresh stemwood volume); Yist, the volume yield of stem wood for each cohort “i” in m3ha−1yr-1, Fijt, the biomass allocation coefficient of each living biomass component “j” (foliage, branches, and roots) relative to stems, for each cohort “i” at time t (kg kg-1) and Mgit is the dimensionless growth modifier due to interactions among and within cohorts.

12.3.4. Tree Mortality due to Senescence Mortality due to senescence is estimated as a function of tree age or as a function of the relative biomass (standing biomass divided by the maximum stand biomass): Msit = ƒ (age) or Msit = ƒ (Bit/Bimax) Where, Msit is the cohort mortality due to senescence at time t in years. If data on mortality related to age is not available—a typical situation for tropical natural forests, the mortality can be modelled as a function of relative cohort biomass.

12.3.5. Turnover In addition to tree mortality, an accurate estimation of carbon dynamics in living biomass needs to account for the turnover of foliage, branches, and roots. This turnover is also very important to adequately model the carbon dynamics of soil organic matter. We model the turnover for each cohort (Tit) as the sum of the turnovers of each component “j”, which in turn is simply the existing biomass of the particular component “j” multiplied by a decay or turnover constant (KijT). Mathematically, Tit = Ʃ Bij Kij T ……………………………… (Mg ha−1 yr-1) Where KijT ranges between 1 per year (i.e. All the component biomass are lost during the year) to 0 per year (no turnover at all). If the forest ecosystem which is under analysis is sustained properly, part or the greater part of the tree biomass may be evacuated through thinning, particular logging or clear-cutting. This collected biomass is subtracted from the current biomass, and is designated to the soil module.

12.3.6. Mortality due to Logging (Harvesting) Damage Forest logging operations brings about improvement of the mortality of the rest of the trees. This destruction especially depends upon the nature of forest, the type of expertise and procedures used as a part of logging. Logging results in high mortality rate, up to 20% of the enduring basal area in tropical forests (Alder and

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Silva, 2000). The mortality because of logging is straightforwardly identified with the intensity of logging and can be stated as the basal area, volume, total number of trees or biomass logged. Additionally, it may bring about mortality several years after the operation. In several cases, initially the mortality rate is high through the early years after the logging, and this rate will reduces slowly, achieving 0 in 10–20 years, depending upon the nature of forest and the methods used (Pinard and Putz, 1997). In the CO2FIX V3.2 model, logging harm mortality coefficient (Klit) years after logging, as a linear function of time with three parameters is determined as: Initial mortality (Moi), (b) duration of the damage (π), and (c) intensity of the initial logging (Ioi). Mathematically, Mlit =Bit ×Klit………………. (Mg ha−1 yr-1) Where Klit =Moi − π× Ioi

12.3.7. Carbon Stored in Soil Organic Matter The dynamic soil module of YASSO in the model can be used to evaluate the soil carbon stocks. The input factor of soil carbon could be specifically introduced from biomass module having three lingering portions and five disintegrating parts. Soil module for soil carbon requires several Parameters such as litter input (Mg ha-1 yr1 ), fine roots, twigs; coarse roots and stems, evaluated from turnover rates, natural death rate, and mortality during management and logging slice gave by the stimulator in different modules of the model. For calculating prospective evapotranspiration of a certain area the mean temperature and precipitation for the region is required, significant in explaining the rates of decay. The mass of nonwoody litter, fine and coarse litter pools pools is dictated by contributions from number of litter sources, minus the fractionation rate per pool. The extent distributed to solvent mixes, holocellulose, and lignin-like mixtures is thus controlled by fractionation rates and litter quality classes (Nabuurs et al., 2001). The production of the carbon stocks can be any number of years. The yield of the model can be expressed in both forms i.e. tubular and graphic. Graphically the simulation is showed in Figure 12.3. Managing carbon Stocks both in Forest and Forest products means using methods which can decrease carbon loss and enhance carbon storage in the forests. For example around 15% of total global greenhouse gas is emitted annually from Tropical forests as a result of deforestation and degradation. Policy makers are working to create explanations that speak climate change, there has been significant spotlight on joining forests into the overall climate solution. Several silvicultural practices should be a necessary of diminishing carbon loss and enhancing carbon capture and storage if we are to resolve this worldwide task while addressing resource needs.

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12.4. The Management of Carbon in Forest and Products A little work on silviculture has been carried out in the tropical forests (ever-wet and semi-evergreen), however just in particular places; while in montane or deciduous forests almost no work has been has carried out so far. Forests can be considered economically feasible as compared to other land uses. Through the incorporation and cultivation of different species forests provide both timber and non-timber products that are arranged and are perfect with service values i.e. water quality and capturing and storage of carbon. For increasing forest carbon stock it is important to involve the societies to develop forest stands which ultimately results in increase in carbon storage. Numerous logged over and succeeding forests are perfect possibility for recovery through improvement planting of supplemental long-lived trees for capturing carbon.

12.4.1. Important Considerations and Trends Managing forests on sustainable basis is a key factor to attain carbon emission reductions, to negotiate the global climate change, providing chances in forest management. Managing forests for carbon the most imperative aim is to protect already standing forests, particularly primary growth forests which have high carbon contents. Carbon uptake and storage by forests differs considerably and based on several factors like environment, soils, hydrology, and kind of trees. While managing a forest for carbon sequestration it is necessary to give prime importance to above mentioned factors. Although Reduced impact logging (RIL) is known as an imperative application to decrease carbon loss, but to increase the storage of carbon it is essential to focus beyond RIL by establishing new refined, thoughtful forest management systems with better silvicultural practices that give high regeneration establishment, post establishment relief, and prolonged rotations of the new woodlands.

12.5. Socio-Economic and Policy Consideration of Carbon Management in Forests Different traditional standards along with economic and policy are used to formulate authentic practices to manage forest stands. The financial policy drivers that can disturb the probabilities for managing forest stands with carbon view point are essential to be explored. Generally, the economic pressures and incentives coming on the way are: high deforestation rates as forestland is transformed to new agricultural land. The remaining huge regions of comparatively complete forests are a outcome of physical or market remoteness; furthermore, in Pakistan, where the financial matters of creating area for buildings far out-measures the incentives for conserving land as farmhouses and forests, discovering approaches to utilize arrangement to conquer these incentives for land managers to change forestlands to

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more lucrative practices of the area are of most extreme significance. The elements to be considered when choosing utilization of the carbon markets (through offset schemes) or protecting the forests through direct public funding can be defined at both the worldwide level as part of the REDD+ consultations.

12.5.1. Why to Protect Large Intact Forests? Large and intact forests (e.g steep forest on Moist and Dry temperate forests in Pakistan) are extremely crucial for the large number of the environment services they give. Although they are globally very important, yet, only 18% of the area had been assigned as protected as of 2008 (Potapov et al. 2008). Unluckily, even with this label, protection is negligible. Though these forests persisted mostly intact, they are repeatedly in the regions which are under continuous pressure from conversion of forest land into agricultural land, construction of buildings along roadside and timber removal. In recent years in Borneo deforestation rate because of illegal felling and land conversion for agriculture and buildings is very fast (Curran et al. 2004). High deforestation rates have a great influence on greenhouse gas emissions globally. Therefore illegal felling of trees and land conversion issues should be discussed immediately, either through business sector incentives for example carbon credits, supervisory organizations to progress authority, or a mixture of both (Zhang et al. 2006; Betts et al. 2008; Buchanan et al. 2008; Nepstad et al. 2008) . 12.5.1.1. Carbon Sequestration and Storage High amount of carbon is stored in large and intact forests so carbon markets may offer actual economic incentives to prevent conversion of land and illegal felling in these woodland areas. Three of the four countries i.e. Brazil, Russia, and the Democratic Republic of Congo are with the biggest area of enduring intact forestland. The forested area of these countries holds an expected 384 billion tons of carbon dioxide equivalents in terms of carbon storage including above and below ground biomass along with living and dead biomass (FAO 2005). In association, globally energy utilization is responsible for 29 billion tons of carbon dioxide emissions in 2006 (EIA 2006). These three countries have higher amount of carbon stored in their primary and intact forests is due the reason that those forests contain higher concentrations of carbon both in soils and aboveground biomass than despoiled or secondary forests due to consistently larger numbers of sluggish growing trees with heavier wood. 12.5.1.2. Co-Benefits of Protecting Large and Intact Forests These large intact forests not only play a significant role in global carbon cycle but they protect the land as well, showing their role in controlling local climate (Hoffman et al. 2003; Spracklen et al. 2008). These intact forests provide a substantial cooling effect on both regional and global climate in the boreal region of the world by the gathering of clouds from the evapo-transpiration of boreal forests (Spracklen et al. 2008). In tropics, especially in the Amazonian region this cooling outcome is produced via evapo-transpiration of large forests. An extensive part of the precipitation in inside and mainland areas of the Amazon Basin is gotten

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from evapo-transpiration that is discharged through the span of a day (Makarieva and Gorshkov 2007). It is not possible for inner areas of wet tropical forests to maintain their present forest type, because of the change of rainfall patterns along with deforestation at the forest boundaries, (Makarieva and Gorshkov 2007). At the point when huge swaths of earlier intact tropical forests are cleared, rate of evapotranspiration increases which results in disturbance of rainfall patterns (Roy et al. 2005). In one study, a model of rainfall in the Congo Basin proposed that rainfall could be diminished by 10% in specific regions as a consequence of deforestation (Roy et al. 2005). Second, in tropical forests when rainfall patterns changes, they can prompt to reformed fire regions which results in when changes to precipitation patterns occur in tropical forests, they can lead to altered fire regimes, which can affect the resilience of residual forests. Many nations in the tropics with noteworthy rates of deforestation and land conversion now facing more regular and severe fires (Siegert et al. 2001; Hoffman et al. 2003). These subsequent fires can intensify deforestation and land degradation rates in residual forests, ultimately have a great influence on worldwide carbon emissions (Hoffman et al. 2003). This impact was found in the 1997 fires on the island of Borneo, discharged an expected range of 8–25 billion tons of CO2 equivalent into the air, equivalent to 13–40% of the mean annually global emissions from the burning of fossil fuels. Third, there is adequate proof that forest destruction and degradation substantially affect both floral and faunal species composition within a given area (Curran and Leighton 2000; Hoffman et al. 2003; Roy et al. 2005). Several variations in tree species structure can negotiate the strength of a whole environment and lessen its ability to withstand disruption. Many plant species rely on large areas of forest for their regeneration and cannot successfully breed in mosaic or destructed areas (Curran and Leighton 2000). These forests not only ensure the plant biodiversity, but in addition they give a portion of the main appropriate habitat for wildlife in their particular regions (Joppa et al. 2008).

12.5.2. Drivers of Deforestation Despite the fact that there is general acknowledgment that conversion of land for farming purpose is responsible for a major portion of deforestation throughout the world but the elements that drive the conversion of forest into agricultural lands are less clear. Academic argument has extended from basic, single driver theories, such as over population or poverty is considered as the main reason of land use change to more difficult models that list mixtures of market-based clarifications and other socio-economic issues. Econometric models and observational studies are frequently used to clarify the blend of components that drive deforestation with an end goal to plan better strategies that will slow forest loss while lightening to the basic reasons of encroachment into forest regions. A review of the literature (i.e. Allen and Barnes 1985; Angelsen and Kaimowitz 2001; Barbier and Burgess 2001; Lambin et al. 2001; Geist and Lambin 2001, 2002; Achard et al. 2002; Fearnside 2005) shows that there are three noteworthy classes of deforestation drivers in the tropics e.g. financial, institutional, and socio economic factors.

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12.5.2.1. Socio Economic Factor i. Population Growth: In developing regions increasing population is considered as a major factor of deforestation for agriculture (Lambin et al. 2001; Allen and Barnes 1985). Though, the point that over population effectively describes clearing of forests is not as vigorous as earlier believed. For instance, scientists normally point that deforestation in tropics to growing populations of fluctuating farmers, despite the point that latest FAO data describes that moving growers responsible for only 5% of land conversion in tropics (Chomitz et al. 2007). According to some scientists there is a direct relationship between increasing population and deforestation at the state level, nevertheless studies disclose that increasing populations that move into forested regions and successively clear the forested land are determined to do so because of a host of several other issues that comprises construction of buildings, fertile soils, occupation chances and remoteness to markets (Angelsen and Kaimowitz 1999). Over population is known as an autonomous feature to describe clearing of forests in many areas around the world fails to explain for the composite social and economic situation driving population development in these areas. The reasons of clearing forests for farming cannot be assumed without precise understanding of the interactions among local peoples and the climate of that area (Fairhead and Leach 2008). Additionally latest effort emphases less on the effects of increasing population and in spite tries to describe land conversion trends as they narrate to diverse population types. Jorgenson and Burns (2007) studied the patterns of population growth, migration ways and financial improvement in both urban and rural areas to attract differences between the location of population growth and the effects on forest cover. Their outcomes show that increasing rural population does accelerate the deforestation whereas increase in urban population really have a little impact on clearing of forests for farming as subsistence villagers move to urban areas for work. Other work on increasing population and forest degradation recommends that the area of population development is huge; the earlier individuals arriving in a frontier area have great influence on clearing of forests in a region than population development movement in previously populated zone (Pfaff 1996). These discoveries might be huge for forest policy, as they show the significance of spatial heterogeneity of population thickness, describing various rates of deforestation. ii. Urbanization: For investigating the link among increasing rates of population and deforestation, urbanization and the association of human populations are very chief aspects. While urban regions have a tendency to be more minimal and require less land, fluctuating urban regimes and utilization designs at last prompt a more prominent strain on pastoral expected assets. Furthermore, land conversions from urban zones

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often enlarges into adjacent farming land, in this way pushing farming loads into forest lands (Lambin et al. 2003). Overall, the effects of urbanization ashore utilize change in forests should be concentrated more carefully in the native area. Urbanization patterns lead to complex and non-straight input mechanisms that incorporate provincial infringement, the relocation of landless workers from urban

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regions back to rural zones, or desertion of farming lands that results in secondary growth (Jorgenson and Burns 2007). iii. Poverty: According to some scholars similar to population, the poverty premise is also a key factor that is responsible for conversion of forested areas into agricultural areas around the world. The reason is that farmers of developing countries have a greater amount of a motivating force to deforest in the short period rather than waiting for longer time period to get more incomes from other land practices (Lambin et al. 2001; Angelsen and Kaimowitz 1999). Though, this perspective features a significant part of the deforestation that is happening for farming purposes in tropical areas to poor smallholders rather than to instead of to bigger industrial plantations, government-supported concessions or strategies to use the land on large sclae (Dove 1987, 1993; Angelsen 1995; Fearnside 2005). A substitute perspective of the poverty theory resists that smallholders do clear a portion of the timberland for subsistence purposes, however they do not have the capital, work, and access to credit that is required to put resources into vast scale woodland clearing (Angelsen and Kaimowitz 1999). These results are in the line of finding of Chomitz et al. (2007) that forest clearing and conversion to expansive farming represents around 45% of area clearing in Asia and 30% in Latin America, while moving agriculture by smallholders represents roughly 5% of forests clearing. iv. Economic Inequalities: Because of financial differences on a local and provincial scale, access to financial chances, equipment knowledge, and land contrasts across households and areas, which effects the trends of forest clearing. In the 1970s, for instance, subsidized credit for technology and organic inputs was mainly given to the farmers of Brazil at a large scale for soybean production (Kaimowitz and Smith 2001). Not astonishingly, the high product cost of soy and funded credit results in increase in land prices. It is not possible for small landholders to compete with large farmers for expensive machinery and chemical inputs for producing mechanized soy, resulted in land merging by big operators (Kaimowitz and Smith 2001). Results show that the production of soybean through the increase mechanization lead to the dis-placement of 11 farmers for each laborer utilized (Altieri and Bravo 2006). v. Transportation: Roads are often appeared to be exceptionally related with an expansion in deforestation in most of the world forests, containing roads built for farming purposes (Angelsen and Kaimowitz 1999; Laurance et al. 2001) . Expanded infrastructure takes into consideration more prominent access to inner forests and to end markets for goods. In the literature, there is a general agreement that more access will result in less forest, roads are considered as nonstop facilitators of clearing of woods and additionally by-results of other monetary exercises causing deforestation previously (Lambin et al. 2003; Angelsen and Kaimowitz 1999). While roads are thought to be an essential driver of deforestation in most tropical regions, there are some significant special cases. For instance, areas like West Kalimantan, Indonesia, with low population pressure from growth, don't demonstrate a solid relationship between the existence of cemented roads and

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pressure of forest clearing (Curran et al. 2004). Though, it is not identified whether this pattern is for short period of time or for long period of time. Roads have very important role in the landscape varies by geography and other components. In West Kalimantan, the high estimation of dipterocarp timber trees and the influence of the timber trade in the area have a much-grounded effect on clearing of forests as compared to existence of either roads or communities. Moreover, roads can advance connectivity between villages and nearby cities, in this way giving people employments that may diminish their need to clear forestland for money (Chomitz et al. 2007). Along these lines, even though roads are considered as an essential cause of deforestation in many parts of the world especially tropics result in change in their local effect. vi. Technology: Increase in agricultural productivity because of local economy and skills have largely been related with both clearing of forests and evaded deforestation. While a few theories have been produced to investigate the causal connections amongst innovation and deforestation, two are very important. To begin with, the Borlaug theory attests that new higher-yielding innovations can increment agricultural production and benefit results in decrease in deforestation rate. (Angelsen and Kaimowitz 2001). In spite of the fact that this theory might be valid for worldwide food production, it has been demonstrated that commodity prices greaterly affect agricultural increase than innovative change at the local and regional levels, especially on forest frontiers. Second, the economic development theory suggests that expanded farming efficiency because of innovation will upgrade general financial advancement, ultimately lessen poverty decrease pressures on forests (Angelsen and Kaimowitz 2001). With the passage of time advancements in agricultural technology reduce the deforestation rates, as demonstrated by the two theories. No doubt agricultural technology impacts on forest degradation depend upon several factors, comprising farmer features, the scale of selection, how the labor deal with new technology and the financial benefits of farming on the forest frontier (Lambin et al. 2003; Angelsen and Kaimowitz 2001). Those technologies which are very effective in reducing deforestation, results in high productivity and enable farmers to save capital and create employment opportunities. Although, the automation of agricultural growth has serious effects on land as it can be degraded because of soil erosion, compaction, and loss of fertility, ultimately increase the rate of land conversions. 12.5.2.2. Institutional Factors i. Land Tenure: Property and land tenure rights are also known as essential factors responsible for conversion of forested land into agricultural land. There is a substantial literature on this issue (Dove 1987; Godoy et al. 1998; Angelsen and Kaimowitz 1999; Geist and Lambin 2001). Various Studies revealed that securing land tenure will lessen the deforestation to some extent, but not on complete basis (Angelsen and Kaimowitz 1999; Geist and Lambin 2001), particularly when governments have set up motivating forces to clear the forest. For a landowner, forest protection and preservation is a viable management choice, the financial advantages of keeping the forest in place must exceed the net present benefit of

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clearing the trees for farming purposes. In this way, several factors, for example, implementation and administration are responsible for the affiliation of deforestation and land tenure system. ii) Institutions and Governance: Institutional components, for example, administration and political insecurity, add to deforestation in several ways. Basic decision making frameworks, ecological laws, and structure of property rights are extremely imperative parts of government that influence which groups are given concessions or are permitted to use natural resources of forests. However, in many countries of the world having substantial forest resources do not monitor and avoid clearing of forests in various regions where it is banned because of corruption and absence of administrative empowerment (Lambin et al. 2003). Several protected regions in some countries are facing illegal felling of trees only because of absence of authorization. In the course of recent decades, developing countries have progressively accepted decentralization rules as a procedure to enhance governance and management of natural resources (Tacconi 2007). A study carried out by the World Bank, for instance, found that more than 80% of developing nations, having populations larger than five million were endeavoring to decentralize their administration structures (Silver 2003). Donor agencies and development organizations, such as the World Bank, The U.S. Agency for International Development (USAID), the International Monetary Fund, uphold decentralization as a method for expanding responsibility, straightforwardness, and vote based system in developing nations (McCarthy 2004). The prominence of decentralization approaches among important donor organizations and educational thinkers has brought about attempts by numerous developing countries with imperative forest assets to hand over control over forest resources from central to local governments. Local control over forest resources prompts enhanced resources resource governance, practically speaking, decentralization has prompted power battles over resources and misperception over designation of authorities (Ribot et al. 2006; Thorburn 2002). 12.5.2.3. Economic Factors i. International Trade and Economic: Global business market, along with financial relaxation and association, also has molded land use patterns associated to farming. Economic liberalization laws and policies, for example, the regulation of commerce institutions and the expulsion of duties and exchange hindrances, have normally energized incremental area transformation for agricultural purposes. These approaches can change capital flows and interests in an area, prompting land use changes that may incorporate deforestation (Lambin et al. 2003). As governments keep on removing hindrances to trade and concentrate on exchange markets, people turn out to be progressively determined by business sector price variances. Therefore, conversion of forested land to farming develops more firmly connected to worldwide product markets. ii. National Economic Policy: Financial growth and national safety are largely dependent on the National economic rules formulated by the authorities. Most of the time these policies are not be planned to consider subsequent influences on the forest Depending on the area, financial policies motivating clearing of forests for

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farming include credit strategies, subsidies for farming inputs and out-puts, tax collection plans, and agricultural price supports. iii. Household and Local Economics: Decisions regarding the land use, at the household level, are specifically connected to nearby market access and variations in on-farm and off-farm incomes. At the point when greater market access and financial prospects develop, people will regularly react by amassed manufacture of valuable profitable and extending farming procedures (Lambin et al. 2003). iv.Culture and Household-Level Decision Making: Land use decisions are made by individuals on daily basis considering social inclinations, accessible data, and cultural and financial desires (Lambin et al. 2003). The accumulation of these individual choices can interpret into wide deforestation and land use change. Deforestation rates can be lowered by providing appropriate incentives, results in conservation of forests. Impacted by the political economy, biophysical attributes of the area, and culture of a region, people will settle on judicious choices regarding what kind of land use they select to implement, differing from swidden farming and agro-silvopastoral systems to se vere monoculture farming and pasture (Lambin et al. 2003; Bebbington 1996). This procedure is imperative to consider when planning carbon capturing and sequestration encouragements, especially since exercises identified with carbon storage and sequestration will be one of frequent land use decisions accessible to landowners.

12.5.3. The Role of Climate Policy in Reducing Deforestation One potential system for explaining deforestation has developed through the worldwide climate negotiations under the United Nations Framework Convention on Climate Change (UNFCCC). Policy incentives to reduce deforestation and forest degradation, or REDD, are being considered as part of a new climate agreement. Real advance was made in Cancun in November, 2010, and will keep on being arranged at the next meetings. “REDD+” goes beyond deforestation and forest degradation and incorporates the part of protection, feasible administration of timberlands and improvement of forest carbon stocks. There are numerous issues that must be considered when outlining arrangements to protect forests either utilizing an asset or carbon markets. Since national, local and local-level would eventually regulate household REDD+ programs, execution challenges in developing world must be considered when assigning funds for REDD+. For governments that have feeble administrative requirement structures, it is hard to screen and implement behavior that preserves carbon stocks of standing forests. Correspondingly, for governments where dishonesty is a big problem, it might be hard to guarantee that REDD+ funding and benefits are impartially circulated to people who are decreasing deforestation on their properties or increasing carbon sequestration through reasonable land use practices. Describing land tenure problems and financial inequities are essential components when instituting official capacity for REDD+. There must be other financial and incentives policies should be developed to manage forests and farming lands for

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carbon capturing and storage on appropriate basis, for farmers who do not have formal title to their land. It is not clear to date, whether farmers without ownership of land will have access to REDD+ funding or not. One solution may be to advance existing cooperatives and agriculturists' relationship to channel REDD+ assets to small farmers who keep their property forested or who build up agroforestry and silvopastoral systems to enhance carbon storage and sequestration. Cooperatives, agriculturists' affiliations and extension offices additionally could serve as a mechanism to give on REDD+ preparing on REDD+ and to help small farmers in acquiring payments to support reduced forest clearing and other economical land use performs. Though, clear land tenure does not generally prompt clear responsibility for carbon credits from trees and forests. The progress of actual laws and organizations that simplify land tenure and get profits from the sale of carbon credits at the local, provincial and national levels are important to advance decreased deforestation and consider for reasonable access to revenue generated by REDD+. Since REDD+ policies and projects eventually will be directed by national governments, evaluations and changes of opposing government-drove strategies and projects that lead to across the board deforestation in nations additionally should happen before REDD+ can be a fruitful technique. National governments cannot stimulate forests preservation and restoration policies and programs at the same time (i.e., REDD+) whereas in the meantime give incentives for farming venture into forested zones (either directly or indirectly) by means of sponsorships and laws that promote and advance these practices.

12.6. Conclusions Carbon cycling is dependent on several variables in forests and is considered as a very difficult process. General examples of stand carbon cycling are all inclusive, yet the temporal elements of these examples are extremely site particular. Subsequent conclusions are imperative to deliberate: 1) Succession results in more accumulation of carbon in forest stands. Most studies demonstrated that the most prominent rate of carbon take-up happens during the stem segregation stage, yet even mature stands sequester and store noteworthy amounts of carbon. Some latest studies ensure that this can be critical even for old forests, especially when such old stands illustrate important rations of large territories. 2) Decomposition of forest vegetation and soil organic matter results in release of carbon which cause disturbances in forest ecosystem. Future climatic conditions will assume a noteworthy part in carbon cycling in forest stands, similarly future forest stand conditions will impact the atmosphere. 3) Rainfall patterns and moisture regimes will shape the stand structure, its composition and production all over the globe. However, those changes will fluctuate extraordinarily with both site and timing.

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4) The joined impacts of environmental change are being examined, however frequently there are too few factors being considered, making the worldwide utilization of results from these studies slightly doubtful. Zones of vulnerability in forests carbon science at the stand level give various chances to future research. A noteworthy region of uncertainty in present investigation is the long-term impact of changing atmospheres on woods ecosystems. The four types of approaches assessed in this part depend on biomass measurement data, remote sensing data, CO2 flux data (from eddy covariance) and CO2 concentration data. They all show their own points of interest and inconveniences in assessing CO2 flux and supplement each other in various ways. Inventory techniques measure biomass inside forests, and are classified by their long history and sufficient information attention (especially in developed countries). However, because of their low time resolution (years) and inconstant norms of estimation, Remote sensing strategies are most solid if remote sensing data is mutually utilized with forest carbon inventories and biological community models. Though, deficient data restricted by remote sensing methods and uncertainties in the models need extra improvement strategy is progressed in its high precision and fine temporal determination (hours), and is a decent technique for direct estimation of CO2 flux at the environment scale. Because of fewer numbers of observation sites and higher systematic biases, it is restricted for calculating carbon from forest stands. Inverse techniques are utilized at central to worldwide scales. They recover the quality of both anthropogenic and non-anthropogenic sources and sinks from atmospheric CO2 amount data and transportation models. Carbon Tracker is considered as one of the best inverse model. In these inverse techniques, the data assimilation models are being enhanced for higher precision and better spatial determination. No single technique can meet the precision and determination necessities of all users. A nation, user or site will settle on a decision of strategy considering the specifics of the situation. To enhance progresses, the user is urged to attempt information correlation, coordinated effort and assimilation among various strategies (Heinsch et al. 2006; Gough et al. 2008). Such advancements ought to expand on a watchful synchrony among techniques. For instance, CO2 spending estimations from forest stock and inventory depend on biomass aggregation, while CO2 flux estimations reflect photosynthesis and respiration – generally a 1-year time lag will be found between these two results. Along with this a better and more complete perception system of CO2 concentration is compulsory. Decreasing emissions, and increasing storage, through enhances forest management and administration is an imperative procedure at present being discussed under REDD+. The carbon capturing and storage limit of a particular forest fluctuate significantly relying upon the specific region, forest type, geophysical qualities, species creation and composition site degradation, land tenure, and human use.

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1) To create and actualize satisfactory forest management methodologies, it is critical to understand that most are not reasonably oversaw, but rather exploited. 2) Applying stand-level land utilize depiction, harvest arrangements and planning lessened impact logging strategies can ensure significant effects on growing forest carbon. 3) More multifaceted silvicultural practices should be done to increase the carbon uptake and storage along with timber production. This approach will secure the recovery of the ancied species and the proceeded with vertical stratification of the stand, will build efficiency, and will advance the presence of the objective types of high monetary and carbon sequestration value. 4) For precise silvicultural methods proper forest management is very important. 5) If suitable silviculture is accomplished, forests will be stronger to the unpredictability of unsettling influence and environmental change, making them appropriate as stable long-term carbon sequestration and storage reservoirs. Future research needs to move beyond reduced impact logging (RIL) and concentrate on how forested lands can be accomplished for carbon capturing and storage, along with water, biodiversity, and other ecological values. Still there is no technique has been developed to clarify financial drivers of forest clearing for cultivation across all regions of the world. The conditions that drive deforestation are privately based and rely on a number of factors that incorporate social, political, authentic, and land contemplations. Policies are needed which must be multidimensional, historically-grounded, and should look at the fundamental reasons for financial variables, alongside bigger macroeconomic strategies and institutional plans that may influence local level land use choices to describe the deforestation in the world. As REDD+ negotiations keep on considering the different ways carbon financing can be utilized to safeguard carbon captured in forests and to advance viable land utilize and supervision stratigies that improve carbon storage and sequestration, it is vital to consider what is by and large acknowledged fanincial drivers of tropical deforestation, as well as what is less well assumed: 1) Substantial factors responsible for deforestation are regularly context definite and are influenced by indigenous, administrative, financial, social, and biophysical factors that are molded by complex historical condition. 2) In different parts of the world the role of overpopulation and poverty has been considered as a major factor in deforestation is overstated. 3) Transportation foundation is unequivocally associated with deforestation. In this way, supporting national policies and laws results in reduction of pressure on forest development or necessitate better land use arrangement could be a compelling technique for diminishing deforestation along streets and roads.

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4) Fluctuating product costs for agricultural crops, timber, and domesticated animals can specifically affect family unit basic leadership to deforest for farming or to keep up the forest. 5) Economic strategies at the national level including endowments and access to credit – can assume a key part in affecting deforestation for agriculture.

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Chapter 13

Tree Soil Interactions M.F. Nawaz, M.A. Tanvir and G. Bourrié*

Abstract Edaphic factors are very important environmental factors that determine the tree growth. However, once trees are established, being perennial in nature, they are more influential on soil, micro-climate and ecosystem as compared to other types of vegetation. Trees have the ability to alter the physical, biological and chemical properties of soils through the interaction of their above ground and below ground biomass referred as stem and root respectively. But the effects of trees on soil are species specific and site specific. Water stress and heavy metal’s presence in the soil can reduce the tree growth but some trees are efficient in tolerating the water stress and accumulating the toxic heavy metals in their functional body parts. In this chapter, authors have briefly described the physico-chemical properties of soils and nutrient cycling of primary nutrients in the tree grown soil. A critical review to examine the influence of trees on physico-chemical properties of soils has been presented. Soil microbial diversity and influence of trees on them has been discussed. At the end, the two major problems (water stress and heavy metal stress) in soils with relation to trees have been addressed. Keywords: Nutrient cycling; Heavy metals; Water stress; forest growth.

* M.F. Nawaz˧ and M. A. Tanvir Department of Forestry and Range Management, University of Agriculture, Faisalabad, Pakistan. ˧ Corresponding author’s e-mail: [email protected]

G. Bourrié INRA, UMR 1114 Emmah, F_84911 Avignon, France. Managing editors: Iqrar Ahmad Khan and Muhammad Farooq Editors: Muhammad Tahir Siddiqui and Muhammad Farrakh Nawaz University of Agriculture, Faisalabad, Pakistan.

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13.1. Introduction Soil is generally defined as the loose surface of the upper earth crust having the properties of the rocks and minerals of origin from which it is derived through weathering processes and it is composed of solid phase (stones, pebbles, sand, silt, clay, life forms and organic matter), air (different gases in exchange with atmosphere) and water. To better understand the soil of a particular place at a given time it is important to have the knowledge about the soil geology (soil origin), soil chemistry (chemical composition of soil), soil physics (soil physical properties) and soil biology (soil interaction with every form of life) because these four aspects are bringing changes in soil continuously. Soils vary considerably in fertility, texture, colour, depth, water holding capacity etc. depending on the type of original rock, the climate, biotic factors, slope of land, age and other factors. Soil supports the different forms of life as well as the intermediate substances between living and non-living such as virus. Among living things there are prokaryotic (bacteria, cyanobacteria and actinomycetes) and eukaryotic (plants, animals and fungi). Trees are the main perennial living forms that influence the subsoil surface (below 15 cm depth) as well as soil surface (0-15 cm). In fact, soil is the dynamic natural body in which trees grow and interact through their roots and biomass fall below ground and above ground respectively. Soil provides mechanical support to the trees and different macro and micro nutrients required by them. However, any variation in soil properties can change the composition and productivity of forests. It is the fact that most of the researchers in forestry neglect the soil in their studies but in the forest ecosystem soil is very important as : (1) it provides the medium for tree growth: e.g. stability of trees in a forest against wind storms and drought is totally dependent on physico-chemical properties of soils such as soil depth, soil structure, soil moisture and soil nutrients etc. (2) soil acts as recycling system for nutrients: the quality of forests is the litterfall that is intense in deciduous forests and less in tropical forests. All the nutrients kept in the dead portions of trees are released again in the soil and availability of these nutrients to vegetation is dependent on soil properties; (3) soil acts as the modifier of the atmosphere: e.g. (i.) proportion of different gases released from the soil as the result of soil respiration and decomposition of organic matter can modify the atmospheric composition in the forests, (ii.) albedo level and moisture retaining properties of soil as well as soil fertility determine the evapo-transpiration rates and ultimately can alter the atmospheric temperatures at micro-scale; (4) soil is an habitat for organisms including the macro- and micro-organisms: it is estimated that one acre of topsoil can contain 900 pounds of earthworms, 2400 pounds of fungi and 1500 pounds of bacteria, 133 pounds of protozoans and 890 pounds of arthropods and algae (Takeda et al. 2007). Although every one gram of soil contains more than one million bacteria, microbial community in forest soil is dominated by Fungi, which are more efficient to decompose the organic matter than bacteria (Sylvia et al. 2005). All the macro- and micro-organisms living in forest soils are adaptive to soil changes and performance of the decomposers is dependent on physico-chemical properties of soils (Hackl et al. 2004).

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Although more than 90 elements can be absorbed by plants, there are only 20 essential nutrients for the plants. The essential nutrients can be divided into macronutrients and micro-nutrients (Fe, Mn, Cu, Zn, Mo, B, V, Cl, Co) according to the requirements. The former can be further categorised as primary nutrients (C, H, O, N, P, K) and secondary nutrients (Ca, Mg, S, Na, Si). The available form for each nutrient in soil solution is different: the nutrients like C, H, O, N, S are available in the form of CO2, H2O, O2, NO3-, NH4+, N2, SO42-, SO2; nutrients like P, B, Si are available in the form of phosphate, boric acid or borate and silicate; K, Na, Mg, Ca, Mn and Cl are available in the respective ion forms; Fe, Cu, Zn, Mo are either available in the form of ions or in chelates form. Each nutrient has a specific role in the structure and functioning of trees and deficiency of any nutrient can affect plant growth. However, the quantity required of a nutrient and severity of damage in case of its absence varies in different plant species. In a forest ecosystem, the most important and dominant factor is trees. They affect all other factors of forest ecosystem including soil. Soil is a basic component of forest ecosystem, so effect of trees on soil cannot be overlooked. Trees do not only influence soil fertility but they also play a major role in soil formation: tree roots play an important role in biological weathering of rocks. Roots of trees penetrate into the joints and crevices of rocks that can result in cracks and these cracks may be extended by the tremendous pressure exerted by roots during their development and growth. Roots also secrete exudates and acids that can dissolve directly some part of rocks in it. Release of CO2 by respiration contributes also to rocks weathering of rocks by supplying protons necessary to attack ionic bonds, releasing cations and silica in solution, with HCO3- as a by-product of the hydrolytic reaction. Effect of trees on soil is two dimensional. They have direct as well as indirect effects on soil. In direct effects, there is root growth effect, which in turn brings about formation of soil aggregates and soil pores (Angers and Caron 1998). Litter production is also considered as direct effect which is the source of soil organic matter content, and affects soil chemistry and soil structure (Brady and Weil 2010). Regarding indirect effects, effects on soil biota are included. Some tree species encourage the activity of particular types of decomposers that are useful for soil (Wardle 2006). These decomposer communities provide benefit to plants either by production of litter or by mineralization of essential nutrients. Various evidences are found that soil properties are influenced by the type of vegetation and/or tree species. For different species growing on same site, a difference of 20% is observed with respect to forest floor mass, for litter fall and for nitrogen contents. It is necessary to know about the effect of trees on soil as it can help to understand local and global biogeochemical cycles. In addition, it can also tell us about water storage and water cycle as well as soil carbon storage and carbon cycling, which is important to reduce the effects of global climate change. By knowing the relationship between trees and soil, we can understand the effect of various tree species and different characters of different trees and the role of biodiversity for efficient working of forest ecosystem.

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13.2. Nutrient Cycling in Forest Soils The main difference between cultivated soils and forest soils is the characteristic of nutrient recycling that makes the forest soils fertile and rich in organic matter. To understand the concept of nutrient cycling in forests, the cycles of four primary nutrients (C, N, P and K) are presented (Fig. 13.1 to Fig. 13.4) and discussed in this section.

13.2.1. Carbon Cycle The two main reservoirs of carbon include oceanic and terrestrial ecosystems; however, carbon stocks in the lithosphere are much higher than oceans (Falkowski et al. 2000). Forests play a significant role in the carbon cycle as well as in regulating the global climate. They not only accumulate a major portion of atmospheric carbon but they are also able to sequester the carbon on long term basis. It is estimated that about 352 to 536 billion tons of carbon are stocked in the world’s forest ecosystems (Dixon et al. 1994).

Fig. 13.1 Carbon cycle in forest soils During the photosynthesis, trees remove the atmospheric carbon to make the carbohydrates and to store the C in the form of tree structure: leaves, stem and roots. This stored carbon makes its way to soil through litter fall, deadwood and dead roots. These tree constituents are decomposed in the presence of decomposers and carbon is added into the soil, mainly as carbon dioxide in soil atmosphere that is in equilibrium with soil solution. Respiration of soil living things and

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decomposition of tree constituents result in the CO2 release back to atmosphere. However, a small quantity of dissolved carbon dioxide can be leached down as HCO3-, equilibrating electrically cations released by weathering, during groundwater C transport, while some organic carbon can remain stored in soil for long times depending upon several internal factors protecting it from microorganisms, such as interaction with soil clay minerals in aggregates, or external factors such as erosion, climate, anthropogenic activities, etc. Harvesting of trees and erosion of soil result in carbon removal from the system (Figure 13.1). The two major processes of C control in forest ecosystem (photosynthesis and respiration) are strongly affected by climatic conditions especially temperature and precipitation.

13.2.2. Nitrogen Cycle Nitrogen is essentially required by trees to produce proteins and nucleic acids, therefore, productivity of forest ecosystems like many other ecosystems can be regulated by N availability (Galloway et al. 2004). About 78% of the atmosphere consists of diatomic nitrogen (N2) but this form of nitrogen is unavailable to most of the living organisms due to strong triple bond. There are several processes involved in nitrogen cycling such as biological nitrogen fixation (BNF), ammonification, mineralization, nitrification and denitrification. Major N inputs to soil include BNF, organic N, and N deposition in the form of anthropogenic addition as well as acid rains (HNO3). Atmospheric nitrogen is converted into ammonia (NH4+) by nitrogen fixing bacteria and some actinomycetes and this ammonia is either directly absorbed by plants or converted to nitrates (NO3) by the nitrifying bacteria. Decomposers and other bacteria also play a major role in the decomposition and/or transformation of dead tree litter to organic N and then to ammonia through mineralization. Some amount of nitrogen can also be released back to atmosphere in the form of ammonium (NH3) during litter decomposition. Nitrate is the most available form of nitrogen for plants, so, nitrates are quickly absorbed by living fauna and trees. However, denitrifying bacteria convert some of the nitrates to diatomic N2, NO or N2O, which are released back to atmosphere. Similar to carbon cycle, soil erosion and leaching can result in the removal of site specific N and harvesting of trees can result in the removal of assimilated N from the system (Figure 13.2).

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Fig. 13.2 Nitrogen cycle in forest soils

13.2.3. Phosphorus Cycle The Phosphorus is essential part of plant DNA and RNA, component of molecules that store the energy (ATP and ADP), and are present in the fats (phospholipids) of cell membrane (Ruttenberg 2003). Under normal conditions of temperature and pressure, almost all of the phosphorus compounds are present in the solid form and in the atmosphere, it can only be found as small dust particles. Naturally, phosphorus is present in the rock sediments as the salts of phosphate that enters in the soil water due to weathering and erosion processes. Available forms of phosphorus (PO43- and HPO42-) are absorbed by plants rapidly. Very small quantities of plant available phosphorus are present in soil waters, so, often it is the limiting growth factor for plants. Cycling of phosphorus is very slow in sediments and rocks as compared to cycling in living organisms such as trees and animals. Input sources for phosphorus include precipitation, dissolution from minerals/sediments, fertilizer, litter from trees and dead organisms (Figure 13.3). Decomposers play a major role in the mineralization of organic-P and to make it available to plant. However, large concentrations of phosphate in water precipitate in a large diversity of forms, such as iron phosphate, calcium phosphate etc. that are insoluble and not available to plants. These phosphate minerals again become the part of sediments. If the phosphate is in shallow sediments, it may be readily recycled back into the water for further reuse. Leaching and run off also play a major role in washing out of phosphorus from the forest soils.

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Fig. 13.3 Phosphorus cycle in forest soils.

13.2.4. Potassium Cycle The main cations required by plants are calcium (Ca2+), magnesium (Mg2+) and potassium (K+). Ca and Mg are constituents of organic structures in plants: Ca is active in cell walls and plasma membrane while Mg is key element in chlorophyll and some enzymes (Campo et al. 2000). K+ is present in solution in the plant cell rather being a part of essential organic molecules and its main functions are as osmo-regulation and regulation of enzyme activities. Deficiency of potassium may result in disturbance of plant metabolic processes and low tolerance against disease and drought (Barre et al. 2007). Four sources of potassium are present in soils: 1) primary minerals (e.g. mica and feldspars) where K+ is very slowly available; 2) secondary minerals (e.g. vermiculite or colloidal size mica) where K+ is nonexchangeable form termed as “fixed K” and is slowly available; 3) readily available potassium that is on the cation exchange sites of soil colloids; and 4) potassium present in soil water in dissolved form that is immediately taken up by plants (Figure 13.4). Mineral weathering of primary and secondary potassium minerals is the ultimate source of potassium in the soil waters. Major proportion of K+ (90 to 98%) is present as structural K+ or in primary minerals while only less than 0.5% is present in soil solutions that is in equilibrium with exchangeable K+. Trees take up the potassium in K+ form and return it to soil in very small quantities in the form of litterfall. Mineralization of organic matter contributes very little in solution K+ as most of K+ is leached down or fixed on exchangeable sites of soil colloids. Leaching and run off result in the major loss of soil K+ as potassium is not lost from soils in gaseous form.

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Fig. 13.4 Potassium cycle in forest soils.

13.3. Effect of Trees on Physico-Chemical Properties of Soils Soil types are identified on the basis of their morphological, physical and chemical properties. Major morphological and physical properties of soils include soil porosity, soil colour, horizonation, soil texture, soil structure, soil consistency, soil bulk density, soil moisture, soil colloids and soil temperature. While, major chemical properties of soil include cation exchange capacity (CEC), organic matter, pH, electrical conductivity (EC), alkalinity, soil reaction and buffering, concentrations of primary, macro and micro nutrients, and other constituents of chemical origin in soil including heavy metals and plant derived beneficial/toxic compounds. There can be great variation in soil physico-chemical properties among distant soil profiles as well as within a profile depending upon several external abiotic/biotic factors and parent material. There are several factors that contribute in the soil formation and development of particular soil physico-chemical properties but trees due to perennial nature and deep root system affect the soil significantly as compared to other types of vegetation or by crops on agricultural soils, which are more under human influence. Furthermore, there could be great variation in soil physico-chemical properties of two ecologically different forest types: soil carbon pools (Gt) of Boreal forests are much higher (471) than Tropical forests (216) (Malhi et al. 1999). In this section, we will examine how forest soils

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are different from agricultural soils in a general way. The question “What will happen if we clear a forest and cultivate the land? will be addressed and a particular influence of trees on soil is discussed.

13.3.1. Difference between Forest and Agricultural Soils There is no particular soil classification for agricultural and forest soils. However, agricultural soils were generally classified as cultivated soils (Committee 1995) and forest soils were classified once by USDA in 1938 in Zonal soil Order as Pedalfers with the following suborders (Buol et al. 2003): c) Soils of forest grassland transition d) Light coloured podzolized soils of timberland regions e) Lateritic soils of forested warm temperature and tropical regions. Forest soils have been defined as the soils developed under forest cover or a forest canopy (Lal 2006). The major difference between forest soils and agricultural or cultivated soils is the level of human control. Forests render many services to human and to maximize these services, man interferes and even disturbs the forest ecosystems but generally forest soils are neither fertilized nor ploughed in contrast to agricultural soils. However, forest soils can be indirectly influenced by human activity in terms of acid rains and deposition of chemicals or pollutants. Some natural factors that can disturb the forest soils include forest fires, insect or disease attacks, and windstorms. The influence of human activity can be significant if forests are managed. During forest management; the use of heavy machinery for several planting and logging operations, use of fertilizer to enhance productivity, use of pesticides to protect against insect and disease attack, and controlled burning to avoid wild fires can change the soil physico-chemical properties (Nawaz et al. 2013). In contrast to forest soils, agricultural soils are ploughed several times, fertilized and irrigated according to crop requirements that result in subsoil compaction and leaching of dissolved nutrients (Gregorich et al. 2011). Furthermore, even in the case of managed forest sites, frequency of human interference is much larger on agricultural soils as compared to forest soils because in forests the rotation age of trees is much larger as compared to rotation time of crops. History of agricultural practices also makes difference between forest and cultivated soils. In the past, most of fertile lands have been cultivated while the less fertile, less productive and less accessible were left for natural vegetation. In addition to fertility criteria, less rock contents were also important criteria to cultivate the soil due to hindrance in agricultural activities on rocky soils. Therefore, most of forest soils are shallower, sloppier and younger as compared to cultivated soils (Binkley and Fisher 2013). Forest soils can also be differentiated from agricultural soils in term of horizonation. In the forest soils, the top layer is of organic matter commonly called “Forest floor” and named as “O horizon”. Furthermore, in well established old forests, O horizon can be differentiated into Oi horizon (undecomposed plant

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debris), Oe horizon (Semi-decomposed, fragmented organic matter and humus), and Oa horizon (amorphous organic matter without mineral material). Generally, under the organic surface horizons, there are A horizon (mineral surface horizon), E horizon (leached subsurface mineral horizon), B horizon (accumulation subsurface mineral zone), C horizon (roots penetrable mineral horizon), and R horizon (bed rock). Any of the E, B, C and R horizons may be absent or modified due to soil forming processes, among which depth of the groundwater table (hydromorphy, waterlogging) and presence of large concentrations of salt in water (salt-affected soils). Cultivated soils lack O horizon and other horizons such as E and B could be mixed with A horizon due to continuous ploughing and this practice can result in the formation of artificial horizon “Ap horizon” (plough layer). Deep cultivation could result in breaking of B and C horizon. Deep root system of trees creates other differences between cultivated and forest soils. Root system of a tree depends on kind of tree, its age, type and condition of soil and competing vegetation. Tree roots extend down into the soil very deeply – often 12 ft and sometimes 30 ft or more. Lateral roots may extend from the trunk for long distances – often 35 feet in each direction. Whereas, in cultivated soils the crops roots are generally restricted in only upper 20-30 cm soil layer.

Fig. 13.5 A spruce stand under temperate climate in Tharandt, Germany

13.3.2. Land use Change Effects on Soil Land use change (LUC) is a process by which human activities transform the landscape i.e. conversion of forests site to agriculture, conversion of pastures to

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cultivated sites, conversion of cultivated sites to residential areas etc. Concerns about LUC were raised few decades ago when it was realized that land surface processes can affect the global processes like climate (Lambin et al. 2003). After 1970, it was realized that LUC can modify the surface albedo (proportion of incident radiation reflected by a surface: darker forests reflect less light as compared to light-colored cultivated fields) thus influencing climate at regional level; afterwards, it was found that LUC results in the alteration of carbon sources and sinks at ecosystem level resulting in changes in carbon cycle and global climate as CO2 is a green house gas (Houghton et al. 1985). It was estimated that LUC at global level has resulted in an increase of 25% green house gases in the atmosphere and among them the major gas was CO2 (Houghton 1990). LUC affects the climate not only by the change in the emissions of green house gases but also by other processes like via water cycle due to change in evapotranspiration rates and change in biotic diversity of a site (Eltahir and Bras 1996). Historically, rate of land use change is often parallel to rate of population growth. Initial studies were focused to analyze the conversion of pristine forests to agriculture uses (deforestation) but recent studies have provided in depth knowledge of LUC and replaced the simple notion linked with deforestation to complex processes by developing the projection models. Hence, in this section, the effects of LUC on soil linked with deforestation are discussed. Clearing the forests for agriculture use remained very common practice in the past. According to a recent study, more than half of the ice free land surface of planet Earth has been modified by human activities in the previous 10,000 years (Lambin et al. 2003). The forest cover has reduced from 50% about 8000 years ago to 30% today and these forests are largely converted to agriculture land to meet the demand for food and fiber (Ball 2001). According to another study, cropland has increased from 300-400 million ha in 1700 to 1500-1800 million ha in 1990 and forest area has decreased from 5000-6200 million ha to 4300-5300 million ha during said time period (Goldewijk and Ramankutty 2004). The global net decrease in forest area was 9.4 million ha per year between 1990-2000 and this decrease was the largest in tropical regions (Mather 2005). About two third of Africa’s original forests have been lost and are largely converted to agriculture land use. Recent studies have shown that clearing of forests and their conversion result in numerous detrimental effects at various biological levels: Soil: Conversion of forest to cultivated site results in alteration of soil physical, chemical and biological properties. i.

Soil structure is disturbed by soil compaction and loss of organic matter.

ii.

Decreased water holding capacity and increased erosion are some of the consequences that can alter water cycle, resulting in flooding and/or siltation of dams.

iii. In some cases modified irrigation practices on converted lands can even lead to salinization and waterlogging. iv. Forest canopy acts as insulator and when removed, moderation of soil temperatures and soil moisture is decreased.

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v.

Most of the soil chemical processes linked with nutrient cycling, availability/depletion of nutrients and decomposition of organic matter are modified.

vi. As agriculture is generally associated with cultivation of monoculture crops contrary to forests where diversity of plants and animals are present, the conversion results in quick decrease in diversity and quantity of soil microbes and soil fauna. Atmosphere: Land use change from forests to cultivated lands deteriorates the atmospheric quality in following ways: i.

Conversion of forests to agriculture land is carried out generally by burning of trees and understory plants that result in the emission of undesirable/greenhouse gases such as carbon monoxide, methane, nitrous oxide and carbon dioxide.

ii.

Depending upon the land use, the emissions of these gases may be further increased such as emission of methane from paddy fields and cattle raring and emission of nitrous oxide due to excessive application of nitrogen fertilizer.

iii. LUC alters the emissions of biogenic volatile organic compounds (BVOCs) that control the atmospheric loading of pollutants such as tropospheric ozone, methane and aerosols. Moreover, it is said that emissions of BVOCs are larger from forests as compared to cultivated lands (Unger 2014). iv. Albedo increases, with temperature increase and precipitations decrease. v.

Change in the evapo-transpiration rates result in the modification of atmospheric temperatures and water cycle.

Ecosystem: Removal of forest and cultivation of crops destroy the whole ecosystem. i.

Forests provide the food, shelter and breeding place for wildlife. Clearing of forests result in decline of diversity of plants and animals.

ii.

There can be invasion of new pathogens and pests evolved from agriculture that could destroy the nearby forests also.

iii. Introduction of exotic species on cultivated lands can result in the displacement/elimination of native species in nearby forests. iv. Forests sustain natural cycling of minerals (C, N, P, K), whereas, output and input, after certain time come in equilibrium and not much connected with external environment. Cultivation of land completely changes the cycles due to crops harvest and nutrients depletion that is compensated by fertilizer application. Changes in land use bring in many changes from local to regional level. In above mentioned scenario, the conversion of forests to cultivated lands has been discussed, however, positive effects on soil physico-chemical properties have also been reported in terms of increased organic carbon and nitrogen when cultivated

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lands are afforested (Hernandez-Ramirez et al. 2011). From policy making perspectives, it should be remembered that afforestation of deforested sites may restore the tree biomass per unit area and plant cover but effects of previous agricultural land use on forest biodiversity would be irreversible (Dupouey et al. 2002).

13.3.3. Species Specific Changes in Soil Properties On the one hand, soils can favor the growth of a particular tree species and affect the composition and productivity of forests; while on the other hand, trees also modify soil properties. It is always difficult to conclude whether prior differences in soil properties influenced the species composition or species influenced soil properties. Overall, in a forest, the influence of trees on soil is at larger scale in terms of soil depth (upto 10 m) as compared to its understory comprising of shrubs (upto 5 m) and grasses (0.1-0.5 m), however, contribution of understory towards soil properties are often not ignorable. As morphology, physiology, litter quality and nutrient requirements of a tree species are characteristic, so, effects of trees on physico-chemical properties are specific in term of input, output and cycling. There are strong evidences that effects of a tree species on soils are very slow and very limited except by nitrogen fixing trees. Major processes through which trees can alter soils include atmospheric deposition, nitrogen fixation, mineral weathering (exudates), C addition, soil organisms, moderation to soil physical properties and soil formation. All these processes can alter the soil physico-chemical properties; however, major influential interactions can be classified as root-soil interactions and litterfall-soil interactions. It has been found that among species, forest floor mass can differ by about 20%, N contents can differ by 20-30%, N mineralization rate can vary upto 50%, pH difference can be from 0.2 to 0.9 unit and C pools can show a variation of 30% (Binkley and Giardina 1998). There are several generalizations and field observations that showed the effects of a tree species on soil properties keeping other factors such as climate, soil and water constant. Among conifers, it is reported that “norway spruce” acidifies the soils due to accumulation of strongly acidic organic matter and “white pine” increases the soil N availability (Binkley and Valentine 1991). The same study has reported that hardwoods promote more N availability than conifers (Binkley et al. 1992b). Among broad leaves, Eucalyptus camaldulensis is referred to as the cause of vertical water drainage from soils due to its high water use (Akilan et al. 1997); Acacia nilotica and Dalbergia sissoo are referred to increase soil N due to N fixation through symbiotic relation (Pandey et al. 2000). However, there are very few well replicated experiments, which showed any significant effects of trees on physico-chemical properties of soils (Binkley 1995). Different trees are capable of absorbing from soil and atmosphere different concentrations of various elements and nutrients. The major influence on soil starts by providing variable quantities of litter mass of varying chemical composition. The decomposition of above ground litter and below ground litter is dependent on soil macro- and micro-diversity and micro-environmental factors. The by-products released from litter may precipitate (Phosphorus), result in sorption (cations), or

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humification. Decomposition, mineralization (oxidation or hydrolysis), exchange reactions and dissolution make the nutrients available to plants while leaching may eliminate the nutrients from soil. So, prior physico-chemical properties are important in determining the nutrient dynamics of forest soils. There are several trees species belonging to Fabaceae family which have been reported to develop symbiotic relationships with certain prokaryotes such as Rhizobium and actinomycetes. These bacteria live in root nodules and fix atmospheric nitrogen in soil by converting N2 to amino N, i.e. reduction from N(0) to N(-III). In reward, they receive protection and carbohydrates supply. These trees (such as Acacia, Albizzia, Leucaena etc.) are capable of fixing nitrogen at the rate of 100 kg ha-1 annually (Binkley 1995; Sprent and Raven 1985). Nitrogen fixation rates by trees without symbiotic relation are generally very low ( 5 g cm3-1. Herbivore: Organism that survive by eating live plants. Heterotroph: Organism that uses organic matter formed by other organisms rather than making organic matter itself. Holard: The total soil water that can be divided into Echard and Hygroscopic water. Home gardens: Closed, multistory combination of multipurpose trees preferably fruit trees, vegetable crops around homesteads. Humification: It is the process of humus formation. Humus: Humusis the final product after the decomposition of organic matter. Hydrological cycle: Water cycle which collects, purifies, and distributes the earth water from the environment to living organisms and then back to the environment. Hydathodes:Hydathodes are specialized pores along the margins and apex of the leaf through which the secretion of water (guttation) takes place. Hydrosphere: The hydrosphere refers to discontinuous shell of water on the earth. It contains oceans with connecting rivers, streams, and snow. Hygroscopic water: Nonavailable water that remains sticked to the soil. Hypertrophied Lenticels: A conspicuous pore located on the tree stem for exchange of gases which helps to enhance oxygen in plant roots in saturated (waterlogged/flooded) soils. Hypogeal germination: The germination of a plant takes place below the ground is called hypogeal germination. ICSU: International Council of Scientific Union. Imbibition Theory: It is a special type of diffusion when water is absorbed by solids-colloids-causing them to enormously increase in volume. The

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classical examples of imbibition are absorption of water by seeds and dry wood. Improved fallow: In this practice, fast growing, leguminous trees are grown during a fallow period. Incisors: A pair of teeth adapted for cutting. Indicator species: Thosespecies which gives early indication that an ecosystem or community is being degraded. Infiltration: Lateral, generally slow movement of free water through soil surface and through litter layer under the force of gravity. Inorganic pollutants: These are the substances of mineral nature. Important examples are heavy metals, ceramics, common metals, synthetic plastics, as well as water Investors: The prospective investors, who want to invest their money in a business, want to know the progress and prosperity of the business, before investing their amount. They can know the profitability and the financial position of the organization given in the financial statement of the organization. Khareez: Underground water channel found in Balochistan. Lake: Precipitation, land runoff, or groundwater flow fills a natural depression in the earth to form a large body of standing fresh water. Late wood: The part of thewoodin a growth ring of a tree that is produced later in the growing season. The cells oflate woodare smaller and have thicker cell walls than those produced earlier in the season. It is also termed as summer wood. Lesion: Any unusual change in the tissue of an organism which has suffered from disease or stress. Loam: Type of soil with considerable shares of at least two size classes of soil particles. Lopping: Removal of branches to use these without any regard to the health and vigour of standing tree stem. Mammae: Modified sebaceous glands, terminating in a nipple, to secrete milk. Management: The art of getting things done through other is termed as management. Accounting information provides the eyes and ears to management and hence it helps the manager in appraising the performance of the subordinates Mangroves Forest:A group of trees and shrubs that live in the coastal intertidal zone. Meristematic cells: Ameristemis the tissue in most plants containing undifferentiatedcells (meristematic cells), found in zones of the plant where growth can take place. Meristematic cellsgive rise to various organs of the plant and keep the plant growing. Mg C: Mega grams of Carbon. Migration: It meansmovement of organisms into and out of a particular geographic area. Mineralization: It is the process by which an organic substance is converted into inorganic substance. Mitigation: Mitigation is the effort to reduce loss of life and property by lessening the impact of disasters.

Glossary

337

Monogamous: The state or custom of being married to one animal at a time. Monsoon: Tropical or subtropical system of air flow described by a seasonal shift between usual onshore and offshore winds. Mortality: Relative incidence of death within a specific population categorized according to different factors. Multipurpose trees: Trees which can benefit in terms of timber, fuelwood, fruit and fodder. Mutualism: Symbiotic interaction between two species that benefits both partners. Muzzle: Mouth of an animal with projecting jaws and nose. Mycorrhizae: Mutual relationship between fungal hyphae and plant roots, by which plant get nutrients from fungus. Net assimilation rate: A useful measure of the photosynthetic efficiency of plants. Nocturnal: Occurring in the night or active at night. Nucleoplasm: The substance of a cell nucleus, especially that not forming part of a nucleolus. Nursery: Nursery is a place where seedlings, cuttings and grafts are raised with care before transplanting. Obligate parasite: This is an aparasitic organism that cannot complete its lifecycle without exploiting a suitable host. Omnivore: Organisms that can eat both plants and other animals as food. Organic chemical pollutants: The contaminants produced from organic sources or generated by biological material of some living organisms. Osmosis: A process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one. Owners: The persons who provide funds or capital for the organization. They need accounting information to know the profitability and the financial position of the concern in which they have invested their funds. Parasite: Organism that lives and feeds on another living organism known as the host. Passive transportis a movement of biochemical and other atomic or molecular substances across cell membranes without need of energy input. Pasture: Land covered with grass and other low plants suitable for grazing animals, especially cattle or sheep. Pathogen: Small living organism that causes infection or disease such as bacterium, virus, fungus etc. Perennial plants: Plants that complete their biological lifecycle in more than two years. Pericycle: Thepericycleis a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants. Phenology: In organisms’ time course of periodic events, linked with climate. Photosynthesis: Photosynthesisis the process by which plants, some bacteria, and some protistans use the energy from sunlight to produce sugar, which cellular respiration converts into ATP, the "fuel" used by all living things. Phytoplankton: In aquatic ecosystems, small floating plants e.g. algae and bacteria.

338

Glossary

Pioneer species: First hardy species such as microbes, lichens and mosses that start to inhabiting a specific area as the first stage of succession. Pith: Pith, or medulla, is a tissue in the stems of vascular plants. Pithis composed of soft, spongy parenchyma cells, which store and transport nutrients throughout the plant. Plant anatomy: Plant anatomy is the general term for the study of the internal structure of plants. Plant physiology: Itis a sub discipline of botany concerned with the functioning or physiology ofplants. Pole: The stage of plant from the fall of lower branches to the time when the rate of increase in height begins to fall off and crown expansion becomes more prominent up to the diameter of 5’’. Population: Similar organisms from the same species, living at one place at any given time. Porcupids: Young ones of porcupine just after birth. ppm: parts per million. Precipitation: Any form of water, such as rain, snow, sleet, or hail, that falls to the earth's surface. Predator: Organism that captures and feeds on another organism. Prey: Organism that is captured and used as feed by another organism. Primary succession: Succession in a bare area that has never been remains under the community of organisms. Pristine Forest: An ancient forestthat is saved from logging or any other damage caused by anthropogenic activities. Producer: Organisms that uses solar energy (green plants) or chemical energy (some bacteria bacteria) to manufacture the organic compounds. Protein banks: Plantation of protein rich and nutritious trees on agriculture land/ pastures/ rangelands for cut-and-carry fodder production. Pruning: Removal of branches from lower 1/3rd portion to improve the timber quality of standing tree. Pycnidium: (Plural pycnidia) A globular or flask shaped fruiting body bearing conidia on conidiophores. Rangelands: Rangelandsare grasslands, shrub lands, woodlands, wetlands, and deserts that are grazed by domestic livestock or wild animals. Receipts: Includes all cash received, whether it is “revenue” for the Association or not. Non-revenue items can include NEA and state dues, security and damage deposits for rental space and expense reimbursement from outside sources. Reforestation: It refers to the establishment of trees on land that has been cleared of forest within the relatively recent past. Regeneration: To renew a forest crop by natural or artificial means; also the new crop so obtained. Relative humidity: The amount of water vapors present in air expressed as a percentage of the amount needed for saturation at the same temperature. Remittance: The sum of money sent to someone at the distance. Revenue: Receipt of cash (or a promise to pay) in exchange for an item or a service delivered to someone within a fiscal year. Typical items included are local

Glossary

339

association dues, NEA and state projects, and related funds and interest earned on investments. Please note that NEA and state dues are “pass through” amounts that are recorded as Revenue at the organizational level where the dues are owed, not at the local. Ribosomes: A minute particle consisting of RNA and associated proteins found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins. Riverine forests: These are tall flood plainforestsalong flowing waters such as tidal rivers and creeks. RNA: Ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses, RNA rather than DNA carries the genetic information. Root Hair: Each of many elongated microscopic outgrowths from the outer layer of cells in a root, absorbing moisture and nutrients from the soil. Root pressure: Itis osmoticpressurewithin the cells of arootsystem that causes sap to rise through a plant stem to the leaves. Root pressureoccurs in the xylem of some vascular plants when the soil moisture level is high either at night or when transpiration is low during the day. Rotation age: Age when trees will be felled after fulfilling the precise objective. RSC: Residual sodium carbonates Runaway water: The left-over amount of water after soil saturation, getting itself drained into rivers, ponds and streams. Runoff: Lateral, generally fast movement of free water on ground surface and through litter layer under the force of gravity. Sapling: Sapling refers to a small tree between one and five inches in diameter. Sapwood: Itis the living, outermost portion of a woody stem or branch. Scavenger: Organisms that feed and survive on other dead organisms e.g. vultures and crows. Sclerenchyma cells: Any of various kinds of hard, woodycellsthat serve the function of support in plants. Maturesclerenchyma cellsare deadcellsthat have heavily thickened walls containing lignin. Secondary growth: Increase in thickness of plant body due to formation of secondary tissue by activity of vascular cambium and cork cambium is known as secondary growth. Secondary succession: Ecological succession which takes place on previously vegetated area after a disturbance in which there are remaining effects of organisms present before the disturbance. Seed: Seed is an embryonic plant enclosed in a protective outer covering. Seedling: Seedling is a tree which is less than one inch in diameter. A typical youngseedlingconsists of three main parts: the radicle (embryonic root), the hypocotyl (embryonic shoot), and the cotyledons (seed leaves). Seepage: The slow escape of a liquid or gas through porous material or small holes out of root zone. Selectively permeable membrane: It is also termed assemipermeable membrane or a differentially or partiallypermeable membrane. It is a type of

340

Glossary

biological or synthetic, polymericmembranethat will allow certain molecules or ions to pass through it by Sericulture: Preferably, Morus alba is grown for silk worm rearing. Shelter wood Silvicultural System: Asilvicultural systemin which the overwoodis removed gradually in two or more successive felling depending on the progress of regeneration. Shrub: A woody plant which is smaller than a tree and has several main stems arising at or near the ground. Sieve cells: a sieve element of a primitive type present in ferns and gymnosperms, with narrow pores and no sieve plate. Silvi-pastoral system: The production of woody plants combined with pasture is referred to as Silvipastoral system. Snowline: It is the altitude in a particular place above which some snow remains on the ground throughout the year. Sorption: This term is collectively used for the processes of absorption and adsorption. Absorption is the incorporation of a substance in one state into another of a different state (e.g., liquids being absorbed by a solid or gases being absorbed by water). Species evenness: Relative abundance of individuals within each species in a community. Species richness: It is defined as number of different species in a community. Species: Species is a very frequently used term in ecology which is defined as group of similar organisms that can mate and produce offspring successfully. Stele: The part of the stem inside of the cortex is known as the stele. The stele consists of 3 regions-the pericycle, the vascular bundles region and the pith. Steppe: Discontinuous grassland having scattered shrubs or stunted trees. Stomata: Stomata are small breathing pores in the leaf that allow gaseous exchange where water vapour leaves the plant and CO2 enters. Guard cells control each pore’s opening or closing. Succession: Succession is the natural replacement, in time, of one plant community with another. Conditions in the existing plant community create conditions favorable for establishing the next stage. Symplastic pathways: The symplast of a plant is the inner side of the plasma membrane in which water and low-molecular-weight solutes can freely diffuse. Synecology: Synecology deals with the study of groups of organisms which are associated together as a unit e.g. study of a forest. Taungya: Growing agricultural crops with young trees either on borders or in between, a common practice in West Africa and Savannas. Thorn forest: Itis a dense, scrub like vegetation characteristic of dry subtropical and warm temperate areas with a seasonal rainfall averaging 250 to 500 mm. It consists of thorny plants. Threatened species: Wild species that is still abundant in its natural area but is expected to become endangered because of decrease in number.

Glossary

341

Timber line: A geographic boundary beyond which trees cannot grow. It is also called tree line. Topography: The detailed mapping or charting of the features of a relatively small area, district, or locality. Tracheid: A type of water-conducting cell in the xylem which lacks perforations in the cell wall. Transition zone: A transition zone is an area where the predominant species changes from one to another form. Transpiration pull: The cohesion of water explains only maintenance of the sap column; the explanation for the upward movement of the water is accounted for by a mechanism, calledtranspiration pull that involves the evaporation of water from leaves. Transpiration: Process, in which water is absorbed by roots of a plant, passes through stomata in leaves or other parts, and evaporates into the atmosphere as water vapor. Tree crown: Thecrownof a woody plant (tree, shrub, liana) is the branches, leaves, and reproductive structures extending from the trunk or main stems. Shapes ofcrownsare highly variable. Tree: Refers to a woody perennial plant having a single usually elongated stem or trunk, generally with few or no branches on its lower part. Tundra: It is a type of ecosystem that is too cold to support the tree growth. Vascular tissue: It is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are thexylemandphloem. Vegetation Cove: Refers to trees, perennial bunchgrasse sandgrasslands, legumes, and shrubs with an expected life span. Vibrissae: Stiff hairs located about the nostrils or on other parts of the face in mammal. Vital force theories: "Vital force theory" is a proposed mechanism for the ascent of sap through the xylem tissue of plants. According to the vital force theory, the conduction of water up the xylem vessel is a result ofvitalaction of the living cells in the xylem tissue. Viviparous germination: Germinatingor producing seeds thatgerminatesbefore becoming detached from the parent plant, as in the mangrove. Water Erosion: The removal thin layer of soil through water is called water erosion. Watershed: A sloppy area that drains surplus water into a river, stream or a water body. Weather: Short-term fluctuations in the temperature, pressure, humidity, precipitation, sunshine, cloud, wind and other conditions in the troposphere at a given time and place. Wetland: Land that is covered all or partially with salt or fresh water except streams, lakes, and ocean. Wilderness: Area where the earth and its ecosystems have not been disturbed by humans. Windbreak: A row of trees or a fence, wall, or screen, that provides shelter or protection from the wind.

342

Glossary

Wood: It refers to the hard-fibrous material made up of cellulose and lignin, forms the main substance of the trunk or branches of a tree or shrub, used for fuel or timber. Xerophytes: Species that can survive in water scarcity. Xylem Tissue: the vascular tissue in plants which conducts water and dissolved nutrients upwards from the root and helps to form the woody element in the stem. Zooplankton: They are small floating herbivores which depend for feed on plant planktons.

Index A horizon, 304 Abiotic, 70 Abundance, 88 Acacia nilotica, 23, 24, 25, 26, 117, 148, 154, 155, 156, 157, 162, 195, 210, 211, 307, 326 Actinomycetales, 309 Adventitious root, 32, 329 Aggregation, 83, 85 Agrisilviculture, 193, 198 Agroforestry, 15, 193, 194, 195, 196, 197, 198, 199, 202, 203, 206, 207, 208, 209, 212, 221, 222, 223, 224, 287, 329 Agroforestry system, 203, 222, 223, 287, 329 Air, 10, 81, 325 Albizia, 148, 149, 204, 232, 234, 308, 323 Albuminous seeds, 329 Algae, 93, 309 Alley cropping, 198, 205, 329 Alluvial plain, 329 Alpine, 19, 20, 21, 92, 100, 121, 124, 128 Alpine tundra, 100 Altitude, 82 Amelioration, 204 Amenity, 329 Amphibiophytes, 82, 311 Angiosperms, 30, 31, 330 Animals, 92, 99, 100 Ap horizon, 304 Apiculture, 199, 330 Aquatic biomes, 91, 101 Arctic, 92, 100 Arctic tundra, 100 Aspects, 248 Atmosphere, 265, 306, 330 Autecology, 66, 79, 330 Autotrophs, 309

B horizon, 304 Bacteria, 309 Biodiversity, 87, 103, 221, 330 Biogeochemical cycle, 77, 330 Biologists, 87 Biomass, 154, 156, 157, 265, 272, 292, 330 Biomes, 90, 91, 92, 101 Biosphere, 264, 288, 291, 330 Biotic, 72, 79, 84, 291, 310, 330 Biotic factors, 79, 84 Blight disease, 178, 180 Boreal Forest, 92 Boundary layer, 53, 330 Broadleaved, 20, 21, 331 C horizon, 204, 304 Cambium, 34, 37, 38, 39, 331 Canopy, 26, 96, 97, 331 Capillary force theory, 49 Carbon cycle, 262, 298 Carboniferous, 1, 5 Carnivores, 72, 75, 331 Cavitation, 331 Cell division, 331 Changa Manga, 2, 24, 129, 231, 232, 234, 235, 236, 237, 238, 239, 240, 241, 246 Chasmophytes, 83 Clear felling system, 331 Climate, 19, 20, 23, 69, 85, 122, 124, 261, 262, 264, 283, 288, 290, 291, 293, 294, 331 Climatic factors, 79, 83 Climax species, 331 Coastal, 23, 94, 95, 124 Cohesion and transpiration pull, 49, 331 Cold, 94, 96 Community, 67, 130, 134, 309, 331 Community ecology, 67 Competition, 85, 86, 253, 331 343

344 Conifer, 22, 53, 331 Conservation, 12, 15, 101, 122, 137, 202, 206, 223, 252 Consumers, 72, 332 Cortex, 32, 34, 332 Crops, 198, 199, 325 Cuticle, 53, 332 Dalbergia sissoo, 24, 25, 26, 27, 118, 149, 162, 163, 166, 175, 180, 181, 182, 183, 186, 187, 188, 190, 191, 195, 226, 231, 232, 234, 235, 236, 258, 307, 326 Deciduous, 20, 92, 332 Decomposers, 72, 74, 299, 300, 332 Defoliator, 115, 116 Deforestation, 9, 10, 147, 277, 283, 289, 332 Desert biome, 91, 94 Desertification, 332 Deserts, 92, 94, 264 Dew, 80 Distribution, 2, 19, 88, 117, 163, 166, 169, 170, 173, 176, 177, 179, 180, 182, 227, 228, 244, 246 E horizon, 304 Early wood, 333 Earth, 1, 2, 5, 6, 7, 13, 30, 65, 66, 72, 77, 94, 96, 103, 159, 162, 262, 263, 264, 290, 291, 305, 330, 334 Ecesis, 85 Ecology, 62, 65, 66, 67, 68, 102, 103, 323, 324, 333 Ecosystem, 66, 67, 68, 73, 77, 78, 87, 101, 103, 264, 306, 333 Ecosystem diversity, 87 Ecosystem ecology, 67, 101 Edaphic factors, 79, 83, 295 Endemic species, 333 Endodermis, 33, 34, 333 Endosperm, 333 Energy, 15, 50, 66, 73, 76, 224, 259, 289, 290, 292 Energy pyramid, 76 Environment, 27, 28, 67, 79, 159, 249, 293, 324, 333 Epidermis, 32, 35, 333 Epigeal germination, 333

Index

Erosion, 341 Eucalyptus camaldulensis, 26, 39, 148, 149, 155, 156, 157, 158, 232, 234, 235, 258, 307, 322 Evaporation, 55, 334 Evergreen rainforest, 97 Evolutionary ecology, 67 Fauna, 97, 98 Fertilization, 222 Flora, 97, 98, 334 Flowers, 202, 221 Food chain, 75, 334 Food web, 74, 75, 334 Forest biome, 91 Forest ecology, 68, 334 Forest ecosystem, 68, 69, 73, 78, 101, 103, 334 Forest floor, 303, 334 Forest resources, 4, 186 Forest soils, 203, 303, 334 Freshwater, 92, 101 Fungi, 84, 163, 169, 170, 173, 185, 186, 187, 191, 296, 309 Fusiform, 31, 37, 334 Gamma diversity, 87 Genetic diversity, 88 Global climate, 262 Grasses, 20, 25, 75, 335 Grasslands, 92, 98 Grazing animals, 84 Growth rings, 61, 335 Gymnosperms, 30, 335 Hail, 79 Halophytes, 83 Hedgerows, 206 Hekiskotherm, 80 Herbivores, 72, 73 Heterotrophs, 309 Home Field, 310 Home gardens, 208, 335 Humidity, 49, 80 Hydathodes, 335 Hydrological cycle, 335 Hydrology, 323 Hydrophytes, 311 Hygroscopic water, 311, 335 Improved fallow, 336

Index

Inorganic substances, 71 Insects, 100 Juniper, 19, 20, 21, 133, 177, 179, 185, 188, 189 Land use change, 304, 306 Landscape ecology, 67 Layout, 111 Leaching, 300, 301 Leaf Spot, 165, 167, 168 Leaves, 30, 35, 95, 169, 179, 180 Leguminous plants, 86 Life, 37, 103, 229 Lithophytes, 83 Logging, 273 Man, 24, 68, 251 Marine regions, 93 Megatherm, 80 Meristematic cells, 336 Mesopytes, 82 Mesotherm, 80 Micro flora, 94 Microbes, 69 Microclimate, 69 Microtherm, 80 Migration, 85, 336 Mineralization, 301, 336 Mountain forest, 326 MPTs, 198, 209, 211 Multipurpose trees, 193, 198, 211, 337 Mutualism, 86, 337 Mycorrhizae, 46, 337 Nitrogen cycle, 300, 324 Norway spruce, 309, 323 Nursery, 105, 106, 107, 108, 109, 110, 111, 112, 114, 116, 117, 120, 234, 235, 337 Nutrient cycling, 202, 203, 222, 295 O horizon, 303, 334 Oa horizon, 304 Obligate, 337 Oceans, 93 Oe horizon, 304 Oi horizon, 303 Omnivores, 72 Organic, 43, 71, 83, 143, 274, 314, 337

345

Organic compounds, 71 Organic matter, 83, 143 Osmosis, 55, 337 Oxylophytes, 83 Passive transport, 337 Perennial plants, 337 Pesticides, 247, 326 Phosphorus, 300, 301, 307 Phosphorus cycle, 301 Photosynthesis, 50, 337 Physical factors, 71 Physiological ecology, 67 Phytoremediation, 314, 315, 316, 318, 319, 320, 326 Pioneer species, 321, 338 Plant physiology, 338 Population, 11, 28, 67, 140, 224, 278, 315, 338 Population ecology, 67 Potassium, 204, 301, 302 Powdery mildew, 162, 163, 164, 185, 186, 187 Precipitation, 79, 83, 91, 96, 97, 99, 324, 336, 338 Primary succession, 88, 338 Producers, 72 Productivity, 77, 144, 154, 202, 291 Protein banks, 199, 338 Psammophytes, 83 Pseudomonadales, 309 Pyramid of biomass, 76 Pyramid of energy, 76 Pyramid of number, 76 Rain, 92 Reaction, 86 Regeneration, 25, 338 Relative humidity, 53, 80, 338 Rivers, 93 Root pressure theory, 48 Rust, 175, 176, 185, 186 Saline soil, 142, 143 Sapling, 339 Savanna biome, 91 Savannas, 98, 340 Schizomycetes, 309 Seasonal rainforest, 97 Seedling, 108, 339

346 Semi evergreen forest, 97 Semiarid, 94, 95 Semiarid desert, 95 Sericulture, 199, 340 Shelter, 21, 22, 340 Shisham Dieback, 186 Shrub, 340 Silvicultural, 22, 24, 340 Silvopastoral, 198 Site, 111, 243 Snow, 80, 128 Soil air, 83 Soil conservation, 203 Soil organic matter, 83 Soil organisms, 83 Soil structure, 83, 142, 305 Soil temperature, 46, 84 Soil texture, 83 Soil water, 54, 83 Sooty mold, 173, 174, 189 Species diversity, 87 Spores, 178, 180 Stabilization, 86 Stomata, 35, 53, 54, 340 Streams, 93 Subtropical, 21, 22, 124 Succession, 78, 88, 284, 338, 340 Sunlight, 71 Survival, 89 Sustainability, 13, 252 Symbiosis, 86 Synecology, 66, 79, 84, 340

Index

Taiga, 92, 98 Taungya, 198, 340 TCI, 211 Temperate forest, 97, 264 Temperate grassland, 98, 99, 264 Terrestrial biodiversity, 87 Terrestrial biomes, 91 Thinning, 115 Topographic factors, 79, 82 Transpiration, 45, 49, 51, 52, 54, 56, 331, 341 Tree crown, 341 Trophic Level, 75 Tropical, 15, 22, 23, 92, 96, 98, 159, 264, 274, 302, 326, 337 Tropical forest, 96, 264, 274, 302 Valleys, 130 Vegetation, 19, 20, 21, 22, 23, 25, 69, 80, 207, 236, 251, 293, 325, 341 Vertebrate, 225, 226, 238, 239, 243, 288 Water cycle, 335 Water factors, 79, 82 Wetlands, 93 Wilt, 187 Wilting point, 311 Wood, 2, 21, 24, 26, 28, 30, 36, 41, 42, 43, 62, 127, 154, 157, 162, 170, 172, 224, 249, 319, 342 Xerophytes, 82, 311, 342 Xylem Tissue, 342