Upland tundra and taiga soil formation in loamy homogeneous and lithologically discontinuous sediments in the European Northeast
The features of upland taiga and tundra soil formation in loamy homogeneous and lithologically discontinuous sediments have been revealed for the European Northeast. Geography of automorphic soils in the region is determined not only by the difference of climatic conditions, but primarily mineral-size distribution and stratigraphy of the soil-forming sediments. The main factors causing the formation of soil profiles are gleyic process, Al-Fe humus and textural differentiation, as well as cryogenesis. Micromorphological study of thins in automorphic loamy soils in the tundra-northern taiga ecotone shows a similarity of cryogenic processes, despite their different manifestation. Structuration of cryometamorphic horizon occurs as a result of alternation of the processes of dispersion and compaction of clay particles under thaw and freeze, with the participation of Fe-humus compounds.