DISTRIBUTION PATTERNS OF PERMAFROST-AFFECTED SOILS ON THE PIEDMONT PLAINS OF THE SUBARCTIC IN THE EUROPEAN NORTH-EAST OF RUSSIA
D.A. Kaverin, A.V. Pastukhov, E.M. Lapteva
Institute of Biology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
Keywords: soil cover, seasonally thawed layer, permafrost zone, quaternary deposits, foothills, classification criteria
Abstract
A geoinformation analysis of the spatial differentiation of the soil cover of the piedmont plains in the northeastern part of European Russia has been carried out. Geographical distribution patterns of soils differentiated by the active layer thickness have been identified, taking into account the bioclimatic and geocryological zoning in the region. The studies were carried out in typical and southern tundra, forest-tundra and northernmost taiga with continuous, discontinuous, massive-island and island distribution of permafrost. In studying the soil cover, classification criteria were used, which distinguished shallow and medium-depth permafrost, deep-permafrost and non-permafrost (seasonally freezing) soils. Latitudinal changes in geocryological and bioclimatic conditions are accompanied by significant spatial changes in soil cover. Shallow and medium-deep permafrost-affected soils are widespread in the northern part of the regional permafrost zone, and deep-permafrost soils are widespread in the southern part. When analyzing the soil cover geographically, it is advisable to divide the soils of the regional permafrost zone into groups of profiles: permafrost-affected soils with a shallow occurrence of the permafrost table, seasonally freezing soils with a deep occurrence of the permafrost table, and seasonally freezing soils on thawed soil-forming deposits. In the northern forest-tundra, under conditions of massive island permafrost distribution, the proportion of permafrost-affected soils with a shallow permafrost table is sharply decreased. A significant decrease in the portion of soils functioning on deep permafrost is observed further south, i.e. in the northernmost taiga with an island permafrost distribution. Soil-forming deposits largely determine the spatial differentiation of permafrost-affected soils, especially in the northern part of the regional permafrost zone. Vegetation cover largely determines the distribution of permafrost-affected soils in the southern permafrost zone.
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