1019 ISSN 1064-2293, Eurasian Soil Science, 2019, Vol. 52, No. 9, pp. 1019–1027. © Pleiades Publishing, Ltd., 2019. Russian Text © The Author(s), 2019, published in Pochvovedenie, 2019, No. 9, pp. 1029–1038. Soils of Cryogenic Landforms in the South of the Vitim Plateau: Distribution and Role in the Allocation of Soil Carbon Pools G. D. Chimitdorzhieva a, *, E. O. Chimitdorzhieva a , E. Yu. Milkheev a , Yu. B. Tsybenov a , A. V. Dmitriev b , T. N. Chimitdorzhiev b , R. A. Egorova a , Z. A. Soldatova a , D. B. Andreeva a , Ts. D.-Ts. Korsunova a , and T. V. Davydova a a Institute of General and Experimental Biology, Siberian Branch, Russian Academy of Sciences, Ulan-Ude, 670047 Russia b Institute of Physical Materials Science, Siberian Branch, Russian Academy of Sciences, Ulan-Ude, 670047 Russia *e-mail: galdorj@gmail.com Received October 24, 2017; revised April 15, 2019; accepted April 24, 2019 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 sur- veys, 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 consider- able variation in the thickness of horizons and their inversion because of frost heave and cryoturbation pro- cesses. 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 cherno- zems (Gleyic Chernozems). Keywords: thermokarst depressions, heave mounds, quasigley chernozem, gleyic cryoturbated chernozem, gleyic dark-humus soil, satellite radar interferometry DOI: 10.1134/S1064229319090023 INTRODUCTION Carbon accumulated in permafrost regions is the least studied of carbon pools and is probably character- ized by the most significant potential impact on the cli- mate because of its large size [19, 20]. At present, the rise in air temperatures is the most obvious manifesta- tion of climate changes [10]. Under the changing cli- matic conditions, the global carbon dynamics may be significantly inf luenced by the carbon of organic matter preserved in the permafrost, because permafrost degra- dation as a result of climate warming may result in a sig- nificant increase in greenhouse gas emissions [5, 21]. Regional and local parameters of climate changes differ from global ones [10]. Climate changes are significant in temperate latitudes, where warming is characterized by an increase in air temperature by 1.6–2.1°C over the last 30–35 years. Climate warming in the Baikal region is more pronounced in comparison with the entire Rus- sia and the world. This is evidenced by more sharply ris- ing mean annual air temperature: it increased by 2.3°C from the beginning of the 20th century [8]. In a number of points of the Transbaikal region, the mean annual air temperature has risen above 0°C. The response of the permafrost to changes in the radiation and heat balance of the surface is seen in a decrease in its area and an increase in the permafrost temperature and the depth of seasonal thawing. Among cryogenic landforms, seasonal and peren- nial heave mounds and small thermokarst lakes are widespread. Cryogenic landforms are highly dynamic because of the cyclic enhancement of thermokarst processes and frost heave of soils upon freezing of water-saturated taliks under lakes. The heaving intensity is determined by the amount of moisture migrating to the freezing front and by the rate of freezing [3]. Water-saturated silty sands, sandy loams, and loamy sands are highly susceptible to frost heave. In the first years, the growth rate of heave mounds interrelated with thermokarst depressions may be significant. After the highest point is reached, the tops of the mounds become dissected by cracks and fissures, and their inner ice core often outcrops to GENESIS AND GEOGRAPHY OF SOILS