Роль демутационных процессов в трансформации почвенно-растительного покрова залежных земель бассейна Байкала

Abstract

In the article the features of demutational processes in fallow lands are considered on the example of key plots with soils of light granulometric composition in Transbaikalia. There is a «failure » of the classical scheme for the restoration of fallow land on alkaline sands. There is a development of biological crusts, which prepare the substrate for the settlement of higher vegetation. A record decrease in the humus and fine earth content (particles less than 0,05 mm in diameter) is noted in the surface horizons of the fallow land, which is 0,45 % in the Barguzin basin and 0,38 % in Ust-Kiran. During the process of restoration, in Ust-Kiran key plot, the stage of weedy and annual species of polynyas and motley grass has already been passed, and at present the vegetative composition is represented by a small mosaic of mono-dominant parcels. In the «Upper Kuitun» key plot, overgrowing of deposits by higher vegetation is prevented by the moss-lichen cover formed on the soil surface. The process of so-called «soil sequestration», which discovered in the ecosystems of this site, not only leads to a special type of degradation of pasture vegetation, but contributes to the depletion of its water potential.