Soils of Southern Cisbaikalia: Diversity and Spatial Distribution Patterns

Abstract

Abstract Soil studies were conducted in Southern Cisbaikalia. It has been established that climate and topography significantly affect the soil cover diversity and spatial distribution at the macro- and mesolevel. The complex geological structure, uneven age, and variety of bedrocks, as well as the composition and weathering degree of soil parent rocks, determine the distinct features of soils in the study area. As an example, the development of residual-calcareous brown forest soils is confined to outcrops of highly carbonaceous Cambrian rocks. At the microlevel, the soil cover structure is determined by the paleocryogenic Late Pleistocene microrelief. Its hummocky–pitted forms contribute to the differentiation of soil formation processes, thus, increasing the soil cover sophistication. Contrasting soil microcombinations are represented by complexes of automorphic autonomous soils on hummocky polygons and semihydromorphic heteronomous soils in cryogenic wedge-shaped structures (depressions). On hummocky polygons, the soil profile is formed in undisturbed ground masses, which is consistent with the postlithogenic soil formation type; while removals of the soil materials that occur on a regular basis indicate the denudation pedogenesis model. In depressions, the soil profile is formed in redeposited soil materials, while the presence of one or several buried humus horizons is consistent with the synlithogenic soil formation type and the accumulative–sedimentary (sedimentation) pedogenesis model. Based on the data collected in the course of this study, landscape and soil maps of Southern Cisbaikalia have been produced by interpolating the soil sampling points in the Quantum-GIS program with the application of landscape indication methods.