Rare and endangered vegetation and vascular plants in canyon "Gorodskaya shchel' (Town Crack)" in southern part of Khibiny Mountains (Murmansk Region, Russia)

Rare and endangered habitat types and vascular plant species were studied in the canyon associated with slope cirque "Gorodskaya shchel' (Town Crack)" in the southern part of Khibiny Mountains (Murmansk Region). Habitat types are interpreted based on a phytosociological approach (Braun-Blanquet classification). Habitat type "D4.2. Basic mountain flushes and streamsides, with a rich arctic-montane flora" of the Emerald Network (partly coincides with type 3220 "Alpine rivers and the herbaceous vegetation along their banks" of Council Directive 92/43/EEC) includes two associations: Mniobryo–Epilobietum hornemannii Nordhagen 1943 of alliance Mniobryo–Epilobion hornemannii Nordhagen 1943, сlass Montio–Cardaminetea Br.-Bl. et Tx. ex Klika et Hadač 1944, and Oxyrietum digynae Gjaerevoll 1956 of alliance Saxifrago stellaris–Oxyrion digynae Gjaerevoll 1956, class Salicetea herbaceae Br.-Bl. 1948. Habitat type "H2.6 Ultra-basic screes of warm exposures" of the Emerald Network is represented by community type Racomitrium spp.–Ranunculus glacialis (class Thlaspietea rotundifolii). These habitats harbor a number of Red Data Book species: 16 rare vascular plants including two species of the Red Data Book of Russia, four species of Red Data Book of Murmansk Region and ten species which need special attention to their state in the natural environment if the Murmansk Region occurred in the studied canyon, cirque and nearest surroundings. As the area is out of the borders of National Park "Khibiny" and has high conservation value, it is necessary to establish here the botanical nature monument.