Home – Home – Jornals – Contemporary Problems of Ecology 2020 number 5

The steppes occupy an important place in the vegetation of the mountains of Southern Siberia. However, they significantly differ in the mountains of various climatic facies, these features are especially pronounced in the spatial and phytocenotic structure of extrazonal steppe phenomena - on the ecotones in adjacent altitudinal belts. In the geography of Inner Asia, these steppe manifestations in landscapes entered under the concept of “uburs” meaning warm insulated slopes. The expositional combinations of forest and steppe communities in the vegetation of the mountain forest-steppe belt are the most complex, the structure of this transitional belt is differentiated into two categories of sub-belts: “peristeppe” and “periforest”, with the differentiation into lower and upper variants. The role of the steppes in the structure of vegetation of expositional forest-steppe in the mountains of a semi-humid climatic facies is not limited to the boundaries of the “peristepppe” and “periforest” sub-belts, steppe communities as extrazonal phenomena penetrate deep into the forest belt in the form of mosaics of steppes, stepoids on the insolate slopes. The participation of the steppes during forest domination is very insignificant (from 20 to 5 % or less). They include both the formed steppe communities and steppe groups with the inclusion of forest shrubs, subalpine and mountain-tundra species. The imposition of gradients - high-altitude and expositional displays in the specificity of the species and coenotic diversity of the steppes, in the spatial structure. In these original ecotones of the mountain steppes, processes of speciation are intensely manifested, often combined with populations of relict plant species.