Soils of the Lake Baikal Drainage Basin: Results of Research for 1980–2017

Abstract

Long–term soil research efforts (1980–2017) in the Baikal drainage basin revealed a widespread occurrence of thin layers of skeletal soils in the tundra zone: peat–lithozems, coarse humus and humous and dark–humus lithozems, and petrozems. A variety of complete–profile soils is represented by podburs, peat podburs, gleyic podburs, podzols and gleysols. It is determined that the soil cover of the mountain–taiga zone is nonuniform because of the manifestation of the vertical zonality, the aspects of slopes and permafrost of different types. The main background of the Khangai soils consists of cryosols and podburs; Khentii – sod podburs and dark–humus soils; in the Lake Khovsgol region – cryosols, podburs and sod podburs; the Baikal region – podburs, podzols, peat podburs and sod podzols, and on the windward slopes of the mountain ridges facing Baikal – podburs and coarse humus burozems. The occurrence and development of burozem soils in the Baikal region is confirmed. In the forest–steppe zone of Hangai and Khentii, the soil diversity is presented by cryosols, sod podburs, dark– and grey–humus soils, and in the forest–steppe contact zone by chernozems and castanozems. It is established that in the Selenga middle mountains, the basis for soil cover is provided by sod podburs, and the accompanying soils are grey metamorphic, light–humic and cryoarid soils. We identified a new type of soils, cespitose–grey soils. Psammozems and light–humus soils occur on sands. Chernozems prevail in the steppe zone, and castanozems, cryoarid and, light–humus soils are dominant in the arid steppe zone. It is determined that the floodplain develops soils of different types: immature, alluvial and halophytic. A study is made of the specific character of floodplain soil formation determined by the mountains on the territory, the regional features of floodplain–alluvial processes, the extremely continental climate, and by the functioning of soils in conditions of the combined manifestation of cryodization and aridization. It is emphasized that the 1:5 000 000 soil map of the Lake Baikal drainage basin was created using a unified methodological framework and a unified classification by soil scientists of Russia and Mongolia. It is established that the soils of the Baikal region differ from the soils located at the same latitude of the European territory of Russia. It is found that the mountain zonality has a determining influence on the formation and spatial distribution of soils.