Pinus wangii

Pinaceae

This species is only known for certain from karst limestone areas of three counties in Yunnan where it has been heavily exploited for its timber, despite the ruggedness of the terrain. Lower altitude sites are also indirectly impacted by the clearance of the valleys and lower slopes for agriculture.

Description

Taxonomic Notes

Similar five needle pines occur in northern Việt Nam in the karst areas of the north east and to the southwest of Hanoi. These are sometimes identified as Pinus kwangtungensis which itself is treated as a synonym of Pinus fenzeliana Hand.-Mazz. on the IUCN Redlist. Subpopulations in Son La and Hoa Binh have been described as a separate species, Pinus eremitana Businsky. In other taxonomic works Pinus kwangtungensis is treated as a variety of P. wangii so that at the species level, it has a wider distribution in Việt Nam, possibly Lao PDR and southeastern China.

Habit

Small trees 8-20m tall, dbh to 80cm, older trees with broad flattened crown

Foliage

Needles in fascicles of 3-5, usually five, conspicuously curved into a crescent shape, usually 30-60mm long, 0.8-1.5mm wide, usually with very distinct stomatal bands on the ventral side.

Cones

Female cones pendulous at maturity, 4-10cm long and 3.5-6.5cm wide when fully open with 6-20mm long peduncle. May be weakly persistent in whorls. Seeds with short and broad wing.

For a detailed description see Businsky (2004)

Distribution

In China this species is recorded fron southeastern Yunnan in the counties of Malipo, Xichou and Maquan. Historic and recent herbarium records indicate that there were 4-5 localities. Recent surveys in all counties have only located about 50-350 individuals in three counties with the majority in Malipo (Sun Wei Bang, KUN, pers.comm. 2013). The number of mature trees is estimated to be less than 250.

Habitat and Ecology

Pinus wangii is restricted to the karst areas of a small part of Yunnan and possibly in adjoining areas of northern Việt Nam. It occurs on steep slopes and limestone ridges and is associated with Quercus variabilis and other, mostly small-leaved, evergreen trees and shrubs. Its historic altitudinal range is from 1500 to 1800 metres above sea-level. Tsuga chinensis, Taxus chinensis and Amentotaxus yunnanensis have also been recorded growing with this pine (Businsky, 2004).

Human Uses

Locally used for house building.

Conservation Status

Proposed Global and National Status and Rationale

Critically Endangered C1

Pinus wangii is very localized and has undergone a recent decline due to logging and forest conversion. Its area of occupancy and extent of occurrence are within the thresholds for Endangered. However, recent surveys indicate that the total population in China is less than 250 and that some trees have been recently logged. A continuing decline of at least 25% is likely.

Conservation Actions

In Yunnan this species has been recently targetted as part of the Implementation Plan of Rescuing and Conserving China’s "Plant species with extremely small populations" - PSESP- (2010–2015). The total population is estimated to be about 350 individuals with less than 250 mature tress. These are not located in any protected area. Seed collecting for ex-situ conservation is being planned. Further taxonomic work is required to establish the relationship between the Yunnan trees and similar pines in Việt Nam as well as with other taxa such as Pinus kwangtungensis.

References and further reading

Businsky, R.( 2004). A revision of the Asian Pinus subsection Strobus (Pinaceae). Willdenowia 34: 209-257.
Farjon, A. (2010). A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Farjon, A. 2013. Pinus wangii. In: IUCN (2013). IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org>. Downloaded on 13 July 2013.
Nguyen, T.H., Phan, K.L., Nguyen, D.T.L.,Thomas, P.I., Farjon, A., Averyanov, L. & Regalado Jr., J. (2004). Vietnam Conifers: Conservation Status Review 2004. Fauna & Flora International, Vietnam, Hanoi.
Tiancai Huang, Chunlin Long (2011). Priorities for genetic resource collection and preservation of wild gymnosperms in Yunnan: an analysis based on the “3E” principle. Biodiversity Science 19(03): 319-326
Yongpeng Ma, Gao Chen, R. Edward Grumbine, Zhiling Dao & Weibang Sun (2013). Conserving plant species with extremely small populations (PSESP) in China. Biodiversity and Conservation. 22(3): 803-809