29F7

F. Shrub communities

Communities of Milk vetch (Astragalus angustifolius)

Relationships with habitat classifications. EUNIS: F7.482 Moesian [Astragalus angustifolius] hedgehog-heaths; PAL. CLASS.: 31.782 Moesian [Astragalus angustifolius] hedgehog-heaths; HD 92/43: 4090 Endemic oro-Mediterranean heaths with gorse; Bondev (1991): 125 Shrub communities of Astragaleta thracici.

Conservation status. BDA, BC, HD.

Category. Endangered [EN – A1, 2 C2 D2 E2 F1 G2H2 I L1].

General characteristics. The habitat encompasses coenoses of Astragalus angustifolius, which are mainly of secondary origin and occur in the belt of xerothermic oak forests up to the subalpine belt (from 180 up to 2090 m alt.). They occupy dry, calcareous, rocky places with strongly eroded humus-carbonate soils, with high quantity of skeletal material and rock outcrops. They cover sunnymountain ridges and peaks with southern, eastern or western exposure. The humidity is low and mainly from atmospheric origin. The coenoses are open or semi-open. The shrubs of Astragalus angustifolius consist of numerous stems spreading on the ground and making dense, cushion-like tufts that are 25 cm high and 80 cm in diameter. The leaves are with very spiny central veins that protect the inflorescences situated below from grazing. The projective cover varies between 40 and 85%. An uneven horizontal structure is typical for the plant communities: the dominant species occur in groups or patches. The vertical structure is unclear. Apart from Astragalus angustifolius, Satureja montana subsp. kitaibelii, Artemisia alba, Bothriochloa ischaemum (= Dichantium ischaemum), Festuca dalmatica, F. thracica, F. valesiaca, Thymus jankae, and T. Striatus also can behave as dominants or co-dominants. The species composition is rich, including more than 130 species of vascular plants, mainly xerophytes/semi-cryptophytes, hamephytes and terrophytes. Together with the dominants and co-dominants the following herbs also frequently occur: Agropyron cristatum, Asperula cynanchica,Bothriochloa ischaemum, Centaurea chrysolepis, Euphorbia myrsinites, Festuca dalmatica, F. stojanovii, F. thracica, Fumana procumbens, Hyacinthella leucophaea, Hypericum rumeliacum, Festucopsis sancta, Rhodax canus, Teucrium montanum etc. The communities of Astragalus angustifolius have several different aspects throughout the vegetative season. In spring and early summer, during flowering of the dominant species, the communities have a white aspect. When Thymus spp. and Satureja montana subsp. kitaibelii become co-dominants during July and August the aspect is violet, and when Artemisia alba is a co-dominant in the autumn the aspect is yellow. Syntaxonomically the communities of Astragalus angustifolius belong to the alliance Astragalo angustifolii-Seslerion coerulantis. This habitat type can also participate in complexes with xerothermic herbaceous communities, mainly petrophytic steppes, communities of Amygdalus nana and open (rare) woods of Quercus pubescens.

The wood remnants in the coenoses of A. angustifolius prove the secondary development of this habitat type in places of destroyed forests. Its primary distribution is related to open and rocky places and peaks.

Characteristic taxa.

Distribution in Bulgaria. The habitat occurs in the following regions: Golo Bardo Mts., Zemenska Mts., Paramunska Mts. and Konyavska Mts.; Petrich village, Sofia district; Pirin Mts. (Vihren and Orelek peaks), Slavyanka Mts. (Shaban and Gotsev peaks), Central Rhodopi Mts. (Trigrad and Zabardo villages), East Balkan Range (Sedlalovo and Glushnik villages, Sliven region; Lozenets village, Yambol region; and Kamchiya village, Burgas region).

Conservation importance. In the communities of Astragalus angustifolius some rare and endemic plants occur such as Achillea clypeolata,Bromus moesiscus, Centaurea chrysolepis, Festuca stojanovii, Hypericum rumeliacum, Satureja montana subsp. kitaibelii, Verbascum urumovii etc.

Threats. Grazing, afforestation with coniferous species, burning, ruderalization, household waste deposits in the localities that are close to urban areas.

Conservation measures taken. The habitat is in Annex № 1 of BDA. Its localities are within protected areas: Pirin National Park and Alibotush Strict Nature Reserve, Trigradsko Zdrelo Protected Site as well as in sites of the European Ecological Network NATURA 2000.

Conservation measures needed. Mapping and assessment of the state of the habitat localities and monitoring.

References. Velchev & Vassilev 1984.

Author: Chavdar Gussev


Communities of Milk vetch (Astragalus angustifolius) (distribution map)