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Seven lakes circus


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SEVEN LAKES CIRCUS

Two vegetation belts characterize the Seven Lakes region (Sedemte Ezera). The sub-alpine shrub belt (the dwarf-pine belt) occupies the lowest cirque gradines. The phytocenoses of the dwarf pine (Pinus mugo), the mat grass (Nardus stricta), the meadow grass (Poa media), and the bent grass (Agrostris rupestris) form the vegetation cover. One very substantial component of the sub-alpine belt in the region of the Seven Lakes is the mat grass (Nardus stricta) phytocenoses. They cover not only the lower elevation parts around the lakes, but also the crests. The Rila primrose (Primula deorum), which is endemic to the mountain, also takes part in different floral associations.

The main phytocenoses in the alpine treeless belt are that of the hooked turban (Sesleria comosa), the curved sedge (Carex curvula). The phytocenoses of the bog whortleberry (Vaccinium uliginosum) and more rarely of the crowberry (Empetrum nigrum), with co-dominant Iceland moss (Cetraria islandica) are also spread. The hianophillic vegetation of least willow (Salix herbacea), buttercup (Ranunculus crenatus), cowslip (Primula minima), etc., occurring near snow in the Seven Lakes region is also interesting. Along the chalk veins in the cirque the most interesting are the alpine communities of mountain avens (Dryas octopetata). A lot of screes of different sized rock fragments, as well as rock disclosures occur in the high parts, on which are found phytocenoses formed by lichens and mosses.

The floral diversity is exceptionally rich. The altitudinal range of change of the elevation predetermines the occurrence of conditions for the development of diverse vegetation cover. A total of 178 higher plant species, divided into 44 families have been established. The Bulgaria’s Red Data Book has included 17 species, of which 15 have been qualified as “rare” and 2 species fall into the category “endangered”. The endemic species are 17, of which 5 are the Bulgarian and 12 are the Balkan endemics. Of a special interest is the distribution of the species Rila primrose (Primula deorum Vel.), which is a local endemic species for Rila, and has category Rare according to IUCN. Along the slopes of the cirque may be observed the golden columbine (Aquilegia aurea Janca), dotted-flowered gentian (Gentiana punctata L.), crowberry (Empetrum nigrum), common thrift (Armeria alpine Willd.), the Bulgarian avens (Geum bulgaricum Panc.), bird’s-eye primrose (Primula farinose L.), Rila fescue (Festuca riloensis Markgr.-Dannb.) and a number of other rare and threatened species.

The faunal diversity of the region is also rich. A total of 1135 species of the invertebrates fauna (excluding the insects) have been established, of which 15 are local, 99 the Bulgarian and 25 the Balkan endemic species. The rare (stenotypic) taxa are 477, the glacial relict species 133q and the pre-glacial relict species 136. The populations of 26 species are of significance for conservation. The studies groups include Protozoa (unicellular), Rotatoria, Branchiopoda (crustaceans), Copepoda (lower crustaceans), Araneae (spiders), Myriapoda (centipedes). The diversity of insects is represented by 747 species, of which 66 are the Bulgarian and 25 are the Balkan endemic species. The rare taxa are 171; the glacial relict species are 217, while the preglacial ones are 8. Protected under IUCN are 20 species, and the CORINE indicator species are 24.

The amphibians and reptiles occurring in the region comprise the glacial relict species the common frog (Rana temporaria) and the viviparous lizard (Lacerta vivipara); the CORINE indicator species the (Coronella austriaca) and the adder (Vipera berus). The slow worm (Anguis fragilis) and the spotted salamander (Salamandra salamandra) could also be observed. The species of Balkan trout (Salmo trutta fario) and the common minnow (Phoxinus phoxinus) represent the ichtiofauna.

Among the bird kingdom, mostly the petrophillic (rock preferring) species occur most often, such as the alpine chough (Pyrrhocorax graculus /L./) and the wall creeper (Tichodroma muraria). The raven (Corvus corax) and the kestrel (Falco tinnunculus) also occur in the region. Species like the Balkan shore lark (Eremophila alpestris balcanica L.) and the alpine accentor (Prunella collaris subalpina Scop.) are also Balkan endemic subspecies. Of the sparrow-like bird order (Passeriformes) also occur the robin (Arithacus rubecula), the common redpoll (Carduelis cannabina) and the whinchat (Saxicola ruberta).

Three species of bats could also be observed in the region: the lesser horseshoe bat (Rhinolophus hipposideros), the lesser mouse-eared bat (Myotis blythi), and the Savi’s pipistrelle (Hypsugo savii).



The small mammals of conservation importance, which inhabit the region, include the hedgehog (Erinaceus concolor) a species protected in Bulgaria and the mole rat (Nannospalax leucodon) listed in the European Red List, a glacial relict species being the snow vole (Microtus nivalis Mart.) a species included in the Bern Convention and in the lists of IUCN. The large mammals that could be observed in the region include the roe deer (Capreolus capreolus L.), the wild boar (Sus scrofa L.), the wolf (Canis lupus L.) and the red fox (Vulpes vulpes L.). Individual specimens of the Rila Mountain population of the chamois (Rupicapra rupicapra L.) sometimes reach the western slopes of the Haiduta peak.

NOTES:

Endemic. An organism being "endemic" means exclusively native to a place or biota.

Relict. The term relict is used to refer to surviving remnants of natural phenomena. In biology a relict is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas. The distribution of a relict is characterized as endemic.

IUCN. The World Conservation Union or International Union for the Conservation of Nature and Natural Resources (IUCN) is an international organization dedicated to natural resource concervation. Founded in 1948, the IUCN brings together 83 states, 108 government agencies, 766 NGO’s and 81 international organizations and about 10,000 experts and scientists from countries around the world.

CORINE (Coordination of information on the environment) is a European programme initiated in 1985 by the European Commission, aimed at gathering information relating to the environment on certain priority topics for the European Union (air, water, soil, land cover, coastal erosion, biotopes, etc.). Since 1994, the European Environment Agency (EEA) integrated CORINE in its work programme.

Bern Convention. The Bern Convention on the Conservation of European Wildlife and Natural Habitats 1979 came into force on June 1, 1982. It has now been signed by the 39 member states of the Council of Europe.


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