Soils of Cryogenic Landforms in the South of the Vitim Plateau: Distribution and Role in the Allocation of Soil Carbon Pools

Abstract

The results of the study of cryogenic landforms (heave mounds and thermokarst depressions) and soils developed on them under conditions of the ultracontinental climate of Buryatia and relatively shallow permafrost are discussed. According to the analysis of data of a Tandem X radar and terrain geomorphic surveys, the spatial distribution of local heave mounds and depressions in the Eravna Basin in the south of the Vitim Plateau has been mapped. Heave mounds are mainly allocated to watersheds and foothill fans; soils formed on them are represented by gleyic cryoturbated chernozems (Haplic Chernozems (Stagnic, Turbic) and gleyic dark-humus soils (Stagnic Phaeozems). Thermokarst depressions are allocated to the bottom of the basin and to the wide leveled loamy watersheds. The soil cover here is formed by quasigley chernozems (Gleyic Chernozems) and calcareous quasigley humus soils on stratified lacustrine sediments (Calcaric Gleyic Phaeozems). The soils of heave mounds and thermokarst depressions are characterized by considerable variation in the thickness of horizons and their inversion because of frost heave and cryoturbation processes. They pronouncedly differ in morphology and physical and chemical properties. The distribution of carbon pools in the profiles of these soils differs considerably from that in the background quasi-gley chernozems (Gleyic Chernozems).