Soils of the Taiga Forest – Steppe Landscape Ekotone of Western Transbaikalia

Abstract

A new view on the genesis and structure of the soil profile in the landscape ecotone of the taigasteppe of the Western Transbaikal is proposed, which are represented by the North Asian taiga and Central Asian steppe ecosystems. The peculiarities of the ecological conditions of the soil formation: the climate continentality, the mountain-depression relief, the nature of the soil-forming rocks, the peculiarities of hypergenesis cause the formation of soils of the organic-accumulative division. It is revealed, that organicaccumulative soils are characterized by transition from a humus-accumulative part directly to soil-forming rock about what specify physical and chemical properties. The elemental composition of these soils is dominated by fine sand fraction and coarse dust, the second fraction of humic and fulvic acids is dominated. The soil-absorbing complex is saturated with bases. pH value is represented by a weakly acidic and alkaline range. Soil texture varies from sandy loamy to light loamy. The middle horizons affected by soil-forming processes are not expressed or poorly expressed and can be represented at the level of soil signs. The listed properties make it possible to classify these soils as gray-humus, dark-humus and light-humus. Thus, the soddy-steppe and soddy-forest types of soil formation predominate at the contact of taiga-steppe.