18C3
Mediterranean tall-grass communities along rivers and in dune depressions
Relationships with habitat classifications. EUNIS: C3.31 Ravenna cane [Saccharum ravennae] communities; PAL. CLASS.: 53.61 Mediterraneo-Pontic Ravenna cane communities; HD 92/43: 6420 Mediterranean tall humid grasslands of Molinio-Holoshoenion; Bondev 1991: 147 Psammophytous grass communities with a prevalence of mostly Leymeta racemosi, Ammophylleta arenariae, Galileeta mucronatae, Centaureeta arenariae, Trachomitum venetum and shrub communities with a prevalence of Cionureta erectae and others, mostly on the coastal sands.
Conservation status. BDA, HD.
Category. Critically endangered [CR – A1, 2 C3 D3 E3 F2 G3 H2 I J L1].
General characteristics. Hydrophytic communities dominated by tall grasses and sedges in dune depressions along the S Black Sea coast and riverside sand terraces in the southern part of the water catchment of Struma river. The dominants – Calamagrostis epigejos, Erianthus ravennae (= Saccharum ravennae), Holoschoenus vulgaris, Juncus littoralis – are species that occur widely in the Mediterranean area. These phytocoenoses develop on sand substrates but their ecological characteristics are relevant for the moderately humid substrates with more stabilized herbaceous cover. They cover very limited areas, flat depressions among the dunes, riverside deposit terraces or bottoms of deep ravines. They are flooded by rainwater or the river high water. The horizontal structure is uneven and the total projective cover is 60–70%, reaching 90% when the humidity is high. Usually Erianthus ravennae is the edificator, with its large mats reaching 70 cm in diameter and 1,5–2 m height. The species contributes to the morphology of the coenoses. Artemisia campestris, Calamagrostis epigejos, Holoschoenus vulgaris, Juncus littoralis etc. also have a dominant role, but in general the communities have poor species composition. This is typical for most of the localities of this habitat type and especially for the Struma river valley. The phytocoenoses on the dune depressions in Sunny Beach Resort, close to Hadzhiiska river are richer in species. They have relatively typical structure and larger areas. Apart from the above-mentioned dominants, Agrostis stolonifera, Equisetum ramosissimum, Inula salicina subsp. aspera,and Schoenus nigricans also occur. Single plants of Blackstonia perfoliata, Carex ligerica, Centaurium turcicum, Chondrilla juncea, Cynanchum acutum, Daucus guttatus, Epipactis palustris, Erysimum diffusum, Gnaphalium luteo-album, Lycopus europaeus, Lythrum virgatum, Odontites verna subsp. serotina, Ononis arvensis, Pulicaria dysenterica, Scabiosa argentea,and Trifolium angustifolium also participate in the herbaceous cover.
The habitat makes transitions and complexes with the Mediterranean halophytic communities of tall rushes and sedges on stabilized grey dunes, with communities of tall hygrophytes ( Phragmites australis, Scirpus lacustris (= Schoenoplectus lacustris),and Typha angustifolia) in the over-wet dune depressions and with communities of Tamarix ramosisisma and T. tetrandra along rivers.
Characteristic taxa.
- Vascular plants: Agrostis stolonifera, Artemisia campestris, Blackstonia perfoliata, Calamagrostis epigejos, Chondrilla juncea, Epipactis palustris, Erianthus ravennae (= Saccharum ravennae), Holoschoenus vulgaris, Juncus littoralis, Lycopus europaeus, Lythrum virgatum, Odontites verna subsp. serotina, Pulicaria dysenterica.
- Fungi: Micromycetes – Ascochyta lamiorum, Erysiphe biocellata (on Prunella vulgaris), Septoria eupatorii (on Eupatorium cannabinum), Uromyces junci (on Juncus maritimus).
Distribution in Bulgaria. South Black Sea coast – the dune complexes near Nessebar town; Sunny Beach resort; southwards from Kiten village; the valley ofStruma river and some of its smaller feeders southwards from Kresna town; up to 400 m alt.
Conservation importance. Very limited distribution, eco-coenotic specificities and participation of rare and endangered plant species such as Blackstonia perfoliata, Erianthus ravennae, Imperata cilindrica, etc.
Threats. Construction of tourism infrastructure, changes in the hydrological regime of the water bodies that provide the underground water for the habitat, deliberate planting of invasive species (Amorpha fruticosa and Elaeagnus angustifolia), burning, extraction of inert materials.
Conservation measures taken. The habitat is in Annex № 1 of BDA. Some of the localities are within protected areas – Pyasachni Dyuni-M. Babata-Slanchev Bryag Natural Monument and in sites of the European Ecological Network NATURA 2000.
Conservation measures needed. Monitoring of the habitat and elaboration of action plan for its protection.
References. Meshinev et al. 1994.
Author: Chavdar Gussev
