09E1

E. Herbaceous communities and communities of lichens and mosses

Danubian sand steppes

Relationships with habitat classifications. EUNIS: E1.2F Pannonic sand steppes; PAL. CLASS.: 34.A1 Pannonic sand steppes; HD 92/43: 6260 *Pannonic sand steppes.

Conservation status. BDA, BC, HD.

Category. Critically endangered [CR – A1, 2 B1 C3 D3 E3 F1 G2 H3].

General characteristics. This habitat comprises steppe coenoses that occupy  the hills of the sandy loess and fixed sands distributed on the flooding terraces of the Danube at Archar village, Vidin district. The hills are about 80–90 m high and are covered with xerothermic, herbaceous, open to semi-open communities and dominated by medium-high to high perennial caespitose grasses or semi-shrubs, together with the related terrophytic communities and the communities of mosses and lichens. At Archar village these coenoses occupy the tops of the hills as well as their slopes, mostly those with southern or western exposure. The main herbaceous species are Achillea ochroleuca, Anchusa hybrida, Anthemis ruthenica, Apera spica-venti, Festuca vaginata, Galium verum, Jasione heldreichii, Koeleria splendens, Logfia minima, Polygonum arenastrum, Potentilla neglecta, Psilurus incurvus, Rumex tenuifolius. A recolonization by the psamophytic steppe species - Achillea ochroeluca, Centaurea arenaria – has started in the abandoned vineyards in the upper parts of the slopes, on the sandy ground. The most open sandy areas are recolonized by mosses (Bryum argenteum, Syntrichia ruralis) and lichens (Cladonia foliacea). The coenoses of Apera spica-venti are typical for these palces. Many ruderal species occur in them such as Conyza canadensis, Digitaria sanguinalis, Trifolium arvense. The coenoses on the western slopes with 20º tilt are better preserved. They have lower projective cover and lower participation of caespitose perennial grasses and terrophytes: Chrysopogon gryllus, Festuca vaginata, Koeleria splendens, Potentilla neglecta, Psilurus incurvus, Silene conica etc. Fragments of shrub vegetation (Crataegus monogyna) also exist. To the South of Archar village secondary coenoses of Pteridium aquilinum also occur.

Characteristic taxa.

Distribution in Bulgaria. Danubian plain: only in one very limited territory of about 400 ha to the South of Archar village, Vidin district.

Conservation importance. Strongly endangered and unique habitat for Bulgaria, covering a very small area and subjected to various negative impacts. This is the only locality for the Pannonic endemic Achillea ochroleuca. Some rare and protected psammophytes also participate in the floristic composition of this habitat like Festuca vaginata and Centaurea arenaria. They have single localities in the interior of the country.

Threats. Urbanization, agricultural practices and illegal extraction of sand for construction activities. The sand extraction has destroyed a significant part of the steppe habitat along the road. Part of the habitat was turned into vineyards that have been abandoned in the recent years and natural recolonisation by the psammophytic coenoses has started in the vineyards. The northern slopes of the hills were planted with Robinia pseudacacia, that spreads by itself.

Conservation measures taken. The habitat is included in Annex № 1 of the national Biodiversity Act. The only locality is within the “Archar” site of the European Ecological Network NATURA 2000 in Bulgaria.

Conservation measures needed. Monitoring of the habitat state and proclamation of Archar Protected Site.

References. Ganchev & Kochev 1963; Nedelcheva & Tzonev 2006.

Authors: Rossen Tzonev, Chavdar Gussev


Danubian sand steppes (distribution map)