The most massive and fast-eroding thaw slump of the Northern Hemisphere located in the Yana Uplands of Northern Yakutia was investigated to assess in detail the cryogenic inventory and carbon pools of two distinctive Ice Complex stratigraphic units and the uppermost cover deposits. Differentiating into modern and Holocene near-surface layers (active layer and shielding layer), highest total carbon contents were found in the active layer (18.72 kg m(-2)), while the shielding layer yielded a much lower carbon content of 1.81 kg m(-2). The late Pleistocene upper Ice Complex contained 10.34 kg m(-2)total carbon, and the mid-Pleistocene lower Ice Complex 17.66 kg m(-2). The proportion of organic carbon from total carbon content is well above 70% in all studied units with 94% in the active layer, 73% in the shielding layer, 83% in the upper Ice Complex and 79% in the lower Ice Complex. Inorganic carbon is low in the overall structure of the deposits.

The variability of soil carbon and nitrogen and the lack of information regarding the properties of deep soils in alpine permafrost regions hinder our understanding of ecosystem responses to climate change. The objective of this study was to examine the effects of pedogenesis and soil physicochemical parameters on the distributions of soil carbon and nitrogen and their characteristics of alpine meadows in permafrost regions. The results showed that pedogenesis was an important factor in the distribution of soil organic carbon (SOC) and total nitrogen (TN) in both the active layers and deep soils. The average water-soluble organic carbon (WSOC) content in the permafrost layer was higher than that of the active layer, which implied that the carbon pool in the permafrost layer was easily decomposable. Soil pH was an important factor that influenced soil inorganic carbon (SIC), which was closely associated with SOC in deep soils. The significant negative relationships between the SIC, pH and C/N ratios in permafrost regions implied that SIC can play an important role in the turnover of SOM and TN. (C) 2016 Elsevier B.V. All rights reserved.