Cryogenic Soils in the Chara River Valley (Transbaikalia)

Abstract

The object of the study are the cryogenic soils located within the Chara valley. We attributed soils in a post-pyrogenic sparse larch forest on the terrace of the Chara River, to the type of gleyzems (Gleysols), subtypes - permafrost cryogenically ferruginized cryoturbated and permafrost cryogenically ferruginized post-pyrogenic. The field diagnostics of these two soils is ambiguous, since the soil profiles contain some morphological features that make it possible to identify them as podburs (Entic Podzols): a bright red color of the BF horizon, a sandy loam texture, containing less than 19% of clay particles (" 10 µm). Field diagnostics, together with laboratory studies, indicate that the soils in the section on the stone run at the top of the Udokan Ridge belongs to peat-lithozem (Histic Leptosols). Chemical analyses have shown that the described soils are acidic with pH ranges from 4.9 to 5.4 and relatively slightly saline, TDS ranges from 8.1 to 18.9 mg/L. The carbonate alkalinity is also relatively low: 2.4–4.8 mmol(-)/100 g of soil. The sections are strongly differentiated by the content of organic carbon. Permafrost peat-lithozem contains from 9.3 to 37.8%, permafrost cryogenically ferruginized post-pyrogenic gleyzem is much less enriched in it, the content here does not exceed 6.8%, usually being around 0.9%.