12H3
Ultrabasic rocks with pioneer herbaceous vegetation
Relationships with habitat classifications. EUNIS: H3.2I Temperate serpentine and basaltic cliff communities.
Conservation status. None.
Category. Vulnerable [VU – B2 C1 D2 E2 F2 G1 H1 L1].
General characteristics. These habitats occupy the bare serpentine rocks at 400–700 m alt., mainly on southern, southeastern and southwestern slopes that are 40–60° steep. The vegetation is poor, consisting mainly of herbaceous communities with considerable participation of annuals like Alyssum alyssoides,A. parviflorum (= Alyssum minus), A. umbellatum, Arenaria serpyllifolia, Briza media, Clypeola jonthlaspi, Danthonia alpina, Hypochoeris glabra, Linaria pelliseriana, Lotus angustissimus, Medicago minima, Minuartia hybrida, M. viscosa, Ornithopus compressus, Parentucellia latifolia, Psilurus incurvus, Scleranthus annuus, Sherardia arvensis, Silene conica, Torilis japonica, Vicia lathyroides,etc. The total projective cover varies and on the steep places it is 5–10%. Specific floristic complexes develop according to the local climatic conditions. Parts of the bare rocks are covered by shallow serpentine soil. Xerophytic vegetation develops, dominated by grasses from the genera Festuca, Koeleria, Agropyron, Aira, Bromus, flowering species from the genera Thlaspi, Minuartia, Silene, Dianthus, Onosma, and some hasmophytes like Alyssum murale, Paronychia kapela, Verbascum humile,etc. The participation of the following endemics is also specific: Aethionema rhodopaeum, Galium velenovskyi, Hypericum rumeliacum, Micromeria dalmatica, Saponaria stranjensis, etc. In the cracks of the rocks there are different fern species but mainly the serpentinophytes Notholaena maranthae and Asplenium cuneifolium occur. Some very rare species adapted to the ultrabasic rocks also occur, such as Thymus bracteosus, Aethionema rhodopaeum,etc. In places with shallow serpentine soil the groupings of Convolvulus boissieri subsp. parnassicus, Plantago subulata, and the endemics Verbascum adrianopolitanum, Jurinea mollis subsp. anatolica, etc. occur. Mediterranean and sub-Mediterranean species prevail in the species composition. Some Asia Minor – Mediterranean species like Cistus incanus, Galium scabrifolium, Genista anatolica, Hypericum cerastoides, Stachys obliqua are typical for this habitat type.
Characteristic taxa.
- Vascular plants: Aethionema rhodopaeum, Alyssum murale, Asplenium cuneifolium, Asyneuma limonifolium, Convolvulus boissieri subsp. parnassicus, Cistus incanus, Dorycnium herbaceum, Genista anatolica, Linum tauricum, Micromeria dalmatica subsp. bulgarica, M. juliana, Minuartia hybrida, M. viscosa,Notholaena maranthae (= Cheilanthes maranthae), Onosma pavlovae, Plantago subulata, Silene fabarioides, S. flavescens, Thlaspi kovatsii, T. praecox, Thymus bracteosus, Trinia glauca, etc.
Distribution in Bulgaria. This habitat type occurs in East Rhodopi Mts. (Haskovo, Krumovgrad and Katdzhali regions). The most impressive ultrabasic rocks occur near Dobromirtsi village. The habitat is 5–6 km long and 3 km wide. The habitat area near Fotinovo village is 5–6 km long and 1 km wide. Very steep, almost vertical slopes with southern or southwestern exposure, occur near Varbitsa village. Considerably smaller areas of this habitat type are the ultrabasic rocks near Golyamo Kamenyane village (400 m alt.) and Avren village (600–700 m alt.), Krumovgrad region.
Conservation importance. This is an important habitat for the preservation of many endemics and species of conservation value, most of which are in the Red Data Book of Bulgaria and BDA. Such are Anthemis rumelica, Armeria rumelica, Cerastium decalvans, Dianthus corymbosus, D. cruentus, D. gracilis, D. moesiacus subsp. moesiacus, Festuca thracica, Galium mirum, G. velenovskyi, Hypericum rumeliacum, H. umbellatum, Inula aschersoniana, Koeleria macrantha, K. nitidula (= K. penzesii), K. simonkaii, Limodorum abortivum, Linum tauricum subsp. bulgaricum, Micromeria dalmatica subsp. bulgarica, Moenchia graeca, Potentilla regis-borisii, Saponaria stranjensis, Serapias vomeracea, Silene gigantea, Stachys cretica subsp. bulgarica, Verbascum adrianopolitanum, V. humile, Viola aetolica,etc.
Threats. Mines for chromic ore used to exist in these areas in the recent past. The traces of flotation processes are preserved that are related with the extraction of chromium and asbestos. Therefore the erosion processes are very strong. Threats are grazing and trampling by domestic animals, forestation of the deforested areas, fires and deposition of household wastes.
Conservation measures taken. Conservation activities for the assessment of the state, composition and structure of this habitat, monitoring. A large part of this habitat type is within sites from the European Ecological Network NATURA 2000.
Conservation measures needed. To establish a protected are to preserve the locality near Dobromirtsi and Fotinovo villages.
References. Pavlova 2001, 2007; Pavlova et al. 2003.
Authors: Dimitar Dimitrov, Dolya Pavlova
