The map of steppe vegetation of Eastern Transcaucasus region

Abstract

Mountain steppes play important role in vegetation cover of East Transcaucasus. They have some similar floristic and phytocoenotic features with North Caucasus and Black Sea plain steppes, but by origin they related to the South-West Asian steppes. The characteristic feature of these steppe communities (especially the middle-height mountain ones) is the participation of xerophytic cushion-like thorn-dwarf semishrubs and shrubs (species of gg. Acantholimon, Astragalus). The main subdivisions of the legend show altitudinal subtypes of steppe vegetation: piedmont and lowmountain sagebrush-bunchgrass desert steppes; piedmont and low-mountain herb-bunchgrass and bunchgrass true steppes; low– and middle–height mountain xerophytic dwarf semishrub and shrub and shrub-bunchgrass (tragacanth, thyme) steppes; middle-height and high-mountain herb-grass and grass-herb meadow steppes. The main mapping units are associations or groups of ecologically similar associations. The most wide-spread dominants of Transcaucasus steppes are Bothriochloa ischaemum, Stipa tirsa, S. pennata, S. pontica, S. capillata, Festuca valesiaca, etc. This map is of considerable significance as the areas of natural steppe vegetation are the models for ecological monitoring and the objects of study and protection.