Географический и фитоценотический ареалы эндемика Южного Урала Delphinium uralense Nevski

Abstract

The geographical and phytocoenotic areas of the endemic of the Southern Urals Delphinium uralense that is a relic species of the ancient Pleistocene steppe were studied. Species is listed in the Red book of the Russian Federation (2008) and the Red Book of the Republic of Bashkortostan (2011). The main part of the geographical area of the investigated species is limited by the Zilair plateau located in the south-western tip of the Ural Mountains, within the Urals fold-block surface. The phytocoenotic area of this species includes the xerophytic communities referring to 2 classes, 3 orders, 4 alliances, 1 suballiance, 2 associations, 1 subassociation, 1 variantand 4 non-ranking communities The formation of the unique complex of xerophytic oak-larch sparse forests and rocky steppes in the southern Urals is linked with the occurrence of the mountainous steppe with larch groves, which were the remnants of the xerophytic mountain landscape —“Pleistocene floristic complex” (Igoshina, 1961, 1963). The enrichment the floristic composition of the complex took place in the late Pleistocene due to following facts: the appearance of rock and mountain-steppe Asian relict species (Ryabinina, 1993), the migration of Eastern Siberian elements to the West, the movement of European species to the East, the formation of the Urals endemic floristic races (Krasheninnikov, 1939). Later, in the Holocene, the Pleistocene floristic complex was enriched by some species of broad-leaved forests (including oak Quercus robur), the penetration ofthe south richsteppe flora, and replenishment of the floristic complex by the Pontic and Sarmatic species (Igoshina, 1961). As a result of mentioned above processes a unique complex of xerophytic rocky mountain steppes and of sparse oak and larch elfin woodswas formed in the Zilair plateau.