Structural organization and composition peculiarities of soil neoformations in some types of automorphic soils in the southeast of the Bolshezemelskaya tundra

Abstract

Automorphic tundra soils of different gleying degree and various permafrost table depth were studied. The chemical composition and distribution of different structural components, including skeletans (sandy-silty cutans), clay cutans, and Fe-Mn concretions in Dystric Cambisol and Turbic Cryosol profiles (permafrost table occurs 2–5 m and 0.9 m depth) were investigated. It is shown that the upper part of the profile of Dystric Cambisol forms under the current active processes of pedogenesis (gleying, Al-Fe-humus illuviation, specific cryogenic organization), signs of previous stages of soil genesis are preserved (the presence of humus pedorelicts, fragments of clay deposits) in the lower part. The chemical composition of the intraped mass reflects the eluvial-illuvial differentiation of Dystric Cambisol profile. The maximum amount of Fe-Mn concretions is observed in the middle profile part. This is due to redox processes in this type of soil. Turbic Cryosols is characterized by insignificant profile differentiation of structural components by chemical composition, weak intensity of pedogenic processes, cryoturbations, inherited signs of earlier stages of pedogenesis (fragments of clay cutans, humus pedorelicts) in the lower horizons. Gleying is one of the leading soil-forming processes. Cryogenic transformation of the soil layer affects the distribution of small amount of skeletans and concretions.