ИСТИНА

The treeless alpine belt along the Greater Caucasus is situated above the absolute heights of 2500-2800 m. The alpine plant communities’ physiognomic diversity is limited by four main types: alpine meadows or heaths on the steep, convex slopes; carpet-like alpine meadows or carpets on the gentle, concave slopes; plant communities on the screes and rocks. The diversity of alpine vegetation phytosociologic units is higher. According to the completed syntaxonomic classification there are 8 associations of the alpine meadows or heaths (Cl. Juncetea trifidi), 6 associations of the alpine carpets-like meadows (Cl. Salicetea herbaceae), 6 associations of the plant groupings on screes (Cl. Veronico telephiifoliae-Lamietea tomentosi) and 3 ones of the plant groupings on rock crevices. These plant communities are characterized by exclusive species abundance and specifity. Among 807 vascular plant species of the Caucasian alpine flora belt there are 423 endemics and lot of rare and endangered species from regional Red books and Red book of Russian Federation. For determining the sozologic status of the alpine communities the following criteria were used: locality, habitat’s naturalness and diversity’s parameters. According to these criteria the endangered plant communities were determined: heaths – ass. Nardo-Geranietum, AlopecuroAsteretum, Hedysaro-Campanuletum, Alchemillo-Caricetum; carpets – ass. TaraxacoGeranietum, Minuartio-Agrostietum, Gageo-Dichodontetum and all of screes and rocks syntaxa. All these communities are protected in the 6 reserves, 3 national parks and several sanctuaries which could be considered as the potential territories of the Emerald network.