30F7
Communities of Astracantha aitosensis
Relationships with habitat classifications. EUNIS: F7.4I1 Northern Thracian tragacanth hedgehog-heath; PAL. CLASS.: 31.7J1 Northern Thracian tragacanth hedgehog-heath; HD 92/43: 4090 Endemic oro-Mediterranean heaths with gorse; Bondev (1991): 125 Shrub communities of Astragaleta aitosensis.
Conservation status. BDA, BC, HD.
Category. Critically endangered [CR – A1, 2 B2 C3 D3 E2 F2 G2 H3 I L1].
General characteristics. This habitat includes the endemic, relic and unique for Bulgaria coenoses of Astracantha aitosensis (=Astragalus aitosensis), a small (30–35 cm), spiny, mat-forming shrub. In the conditions of transitional-continental climate the coenoses are adapted to volcanic rocks (andesites, volcanic tuffs, etc.) and partly to limestone (marls, marly limestones, conglomerates). The phytocoenoses of A. aitosensis cover slanting slopes and rounded hill tops. The slopes are from 5º to 45º. The exposure is mainly southern or with a southern component, but it can also be western, eastern and northern. The soils are Chromic Cambisols, strongly eroded and underdeveloped, poor and dry. The coenoses can occupy also the fissures of rock outcrops. The horizontal structure of the coenoses is mosaic. Astracantha aitosensis makes specific umbrella-like tufts that are almost regularly distributed. Among them are the subdominants and the remaining species from the communities. The projective cover varies between 35–80%, and depends on the eco-biological characteristics of the participating species. The composition of these coenoses is very diverse. As co-dominants sometimes the following species participate: Agropyron cristatum, Alyssum tortuosum, Bothriochloa ischaemum (= Dichanthium ischaemum), Festuca dalmatica, Melica ciliata and Poa bulbosa. Achillea depressa, Asperula cynanchica, Chrysopogon gryllus, Cleistogenes bulgarica, Euphorbia myrsinites, Koeleria splendens, Minuartia setacea, Stipa capillata, Trifolium leucanthum, Trigonella monspeliaca, Velezia rigida, Medicago minima etc. occur frequently. In places where the soil is less eroded Astracantha aitosensis forms complexes with the shrubs Carpinus orientalis, Colutea arborescens, Fraxinus ornus, Jasminum fruticans, Paliurus spina-christi, Prunus spinosa, Quercus pubescens etc. The coenoses of Astracantha aitosensis are autochthonous. In the beginning the coenoses of the species used to cover limited areas in rocky places. Consequently, its distribution expanded as a result of anthropogenic activities and degradation of the forest communities. The total area of the habitat is about 1220 ha.
Characteristic taxa.
- Vascular plants: Achillea depressa, Agropyron cristatum, Alyssum tortuosum, Asperula cynanchica, Astracantha aitosensis (=Astragalus aitosensis), Centaurea diffusa, Chrysopogon gryllus, Cleistogenes bulgarica, Crupina vulgaris, Bothriochloa ischaemum, Euphorbia myrsinites, Festuca dalmatica, Koeleria splendens, Medicago minima, Melica ciliata, Poa bulbosa, Scleranthus perennis, Stipa capillata, Teucrium polium, Thymus striatus, Tragopogon balcanicus, Trifolium leucanthum, Trigonella monspeliaca, Velezia rigida, Xeranthemum annuum.
- Fungi: Macromycetes – Brevicellicium olivascens, Disciseda calva, Geastrum minimum, Hyphoderma radula, Inocybe brunneoatra, I. fastigiata, Polyporus rhizophillus; Micromycetes – Puccinia graminis (on Chrysopogon gryllus), Uromyces anthyllidis (on Medicago minima).
- Animals: Calandrella brachydactyla, Burhinus oedicnemus.
Distribution in Bulgaria. East Balkan Range, the southernmost parts of Aitoska mountain, the hills near Aitos town, and Sadievo, Lyaskovo, Zetjovo, Zaichar and Karageorgievo villages, between 90 and 550 m alt.
Conservation importance. Cleistogenes bulgarica, Pyrus elaeagrifolia, Poa aitosensis and fungal species of conservation importance occur in the coenoses and complexes of Astracantha aitosensis.
Threats. Grazing, burning of the coenoses in order to “renew” the herbaceous composition, use of the species as dry forage during cold winters, planting of coniferous species, ruderalization and deposition of household waste in the places close to the urban areas.
Conservation measures taken. The habitat is in Annex № 1, and the species is in Annex № 3 of BDA. Part of the habitat is within Hisarya Protected Site and Bodlivo Sgrabiche Nature Monument. The whole locality of the habitat is within “Aistoska planina site from the European Ecological Network NATURA 2000.
Conservation measures needed. Monitoring of the habitat and elaboration of an action plan for its protection.
References. Velchev & Bondev 1975; Apostolova & Dimitrova 2002.
Author: Chavdar Gussev
