14E1

E. Herbaceous communities and communities of lichens and mosses

Standing stones inland dunes

Relationships with habitat classifications. EUNIS: E1.9B Standing stone inland dunes; PAL. CLASS.: 64.A Standing stone inland dunes; Bondev (1991): 147 Psammophytous grass communities with a prevalence mostly of Leymeta racemosi, Ammophylleta arenariae, Galileeta mucronatae, Centaureeta arenariae, Trachomitum venetum (L.) Woods and shrub communities with a prevalence of Cionureta erectae and others mostly on the coastal sands.

Conservation status. BC.

Category. Endangered [EN – A1 B2 C3 D3 E2 F2 G1 H2 I L2].

General characteristics. The habitat is open Tertiary sands in the western part of the Varna tectonic lowland, on both sides of Beloslav Lake. In some places the openings have erect stone colonies – “standing stones”, that give the name to the area. There are different theories and hypotheses, both biogenic and non-biogenic, for the origin of these stones. The colonies are of silicisized sandstones with fossils of numulitides and bivalves, and have central holes. They were formed, like the neighbouring rock crowns, in several stages during Lower Eocene. The rock outcrops are mainly of quartz sandstones. Well developed dunes with quartz sand occur in Slantchevo Southeast, central, Beloslav west groups and in the Dobreva Tchuka height. In Slantchevo West, Banovska, Central, Teterlika groups significant parts are covered by stones of different sizes which are scattered in the sand. In some places the sand is mixed with fine clay and has a more dense structure (Banovska group, Kariera West). The vegetation of the standing stones dunes is a complex of psammophytic, hasmophytic, forest and shrub coenoses. The largest areas are covered by communities dominated by psammophytes. In some places, in the periphery of the sandy outcrops, there are communities of Chrysopogon gryllus and Dichanthium ischaemum. Hasmophytic communities develop on the rock crowns and on the typical for the Central group “rock mounds”. Relatively small patches of xerophilic forest vegetation dominated by Carpinus orientalis, Quercus pubescens and Crataegus monogina occur in Banovska and Central groups and Pchelina locality. The floristic composition is considerable. More than 300 species have been registered among which the Pontic-Siberian steppe elements prevail. The number of endemics is also high.

The existing studies on the local vegetation are based on the dominant method. Psammophytic communities, dominated by Festuca arenicola and Silene thymifolia,with the participation of Alyssum borzaeanum, Astragalus varius, Lepidotrichum uechtritzianum (= Aurinia uechtritziana), Centaurea arenaria, Euphorbia seguerana, Helichrysum arenarium, Peucedanum arenarium, Silene euxina, Verbascum purpureumcover considerable areas mainly on the dune slopes. They are best developed in Slanchevo Southeast, Slanchevo West, Central and Beloslav West localities. In depressions with clay content in the substrate the participation of more hygrophytic plants is considerable like Carex ligerica, in some places Holoschoenus vulgaris, Artemisia campestris, Anthemis regis-borisii, Dianthus nardiformis, Matthiola fruticulosa,Pulsatilla montana, Scabiosa argentea, and Veronica multifida also participate in stony places. Artemisia austriaca, Campanula sibirica, Ephedra distachya,Gypsophila glomerata, Linum tauricum subsp. tauricum, Potentilla bornmuelleri, Rhodax canus, and Sempervivum zeleborii occur on the rocky outcrops. Communities of annual plants dominated by Secale sylvestre and Corispermum nitidum occur in Banovska and Teterlika groups

Characteristic taxa.

Distribution in Bulgaria. Near Beloslav and Devnya towns and Slanchevo and Banovo villages, Varna district, 100–250 m alt.

Conservation importance. The geological phenomenon and the habitat inland dunes in the area of Pobiti Kamani locality are unique for Bulgaria and for the world. A number of species with limited distribution occur there, such as the Bulgarian endemics Anthemis regis-borisii and Cleistogenes bulgarica, the endemics for the west coast of the Black Sea coast (Alyssum borzaeanum, Anchusa velenovskyi,Lepidotrichum uechtritzianum, Verbascum purpureum, Silene euxina), the Balkan endemics Dianthus nardiformis, Silene frivaldszkyana, Silene thymifolia etc. Arenaria rigida, Syrenia cana (= Erysimum quadrangulum) occur only in Bulgaria. The number of the plant species from the Red List of Bulgaria is 17. The vulnerable moss species Grimmia crinita also occurs there.

Threats. In the past, the inland dunes covered much larger territories and the area resembled to a desert. Intensive planting, mainly with alien tree species started in the 1950s. The nitrogen-fixing Robinia pseudacacia, Gleditsia triacanthos and Elaeagnus angustifolia were planted on the sands while the Black pine was planted in places with a better developed soil layer. As a result of these activities the psammophytic vegetation became strongly fragmented. In the past years the alien trees that have been planted already produce fruits, the seeds germinate and new plants occur. In the group Beloslav West that is close to Beloslav town the cactus Opuntia vulgaris which has been there for years has become an invasive species and reproduces both generatively and vegetatively. Other threats are the illegal exploitation of sand and (in the past) of the standing stones. In the groups near Beloslav town (especially Beloslav West group)  grazing is a thread, since parts of the plants are being spread and thus Opuntia have already reached the group on the Avrenska meadow and Tertelika locality. Tourism pressure is typical for the Central group. It causes trampling and in some places damaging of the small, national populations of Arenaria rigida. The deposition of household waste is also considerable.

Conservation measures taken. A considerable part of the habitat is included in Pobiti Kamani Protected Site (253,5 ha), that encompasses 15 groups (Banovska, Slanchevo West, Slanchevo Southeast, Central North, Central South, West Stone Pit, Kanarata and Drenaka Stone Pit, Perchan Tepe, Strashimirovska Group, Beloslav West, Avrenska Meadow, Teterlika, Goliya Vrah peak, Pchelina locality. This area is included in the European Ecological Network NATURA 2000 in Bulgaria – Pobiti Kamani site. A project for the area management has been elaborated (since 2000).

Conservation measures needed. Termination of the illegal exploitation of sand and stones, illegal grazing and damaging of the standing stones. In the Beloslav West group, it is necessary to remove the black pine plantations that are within the borders of the protected area. The plantations of the black locust have to be destroyed in Central and Slanchevo West groups since this species is alien to the area and has a negative impact on the autochthonous vegetation. In the Central group where the number of tourists is high the visitors should walk only along special routes in order to preserve the habitat and the rare species. The access to the places where Arenaria rigida occurs should be forbidden.

References. Bondev 1997; Davidov 1905; Kochev 1977; Filipova 1971; Filipova-Marinova & Petrova 2003; Cheshitev et al. 1994, Petrova 1997.

Author: Antoaneta Petrova


Standing stone inland dunes (distribution map)