Permafrost soils differ significantly from other soils because they serve as a huge reservoir for organic carbon accumulated during the Quaternary Period, which is at risk of being released as the Arctic warms. This study aimed to characterize existing carbon pools, delineate possible mineralization risks of soil organic matter and assess microbial communities in the tundra and forest–tundra permafrost soils of the southern Yamal region of Russia. The profile distribution of carbon, nitrogen and the C:N ratio showed non-gradual changes with depth due to the manifestation of cryopedogenesis in soil profiles, which lead to cryogenic mass transfer. Mean carbon stocks for the study area were 7.85 ± 2.24 kg m⁻² (0–10 cm layer), 14.97 ± 5.53 kg m⁻² (0–30 cm) and 23.99 ± 8.00 kg m⁻² (0–100 cm). The analysis of the humus type revealed a predominance of fulvic type and low-molecular-weight fragments in the fulvic acid fraction, which indicates high mineralization risk of humic substances under Arctic warming conditions. The taxonomic analysis of soil microbiomes revealed 48 bacterial and archaeal phyla, among which proteobacteria (27%) and actinobacteria (20%) were predominant. The pH range and nitrogen accumulation were the main environmental determinants of microbial community diversity and composition in the studied soils.

多年冻土不同于其他土壤，因为它们是第四纪期间积累的有机碳的巨大储集层，随着北极变暖，有机碳有被释放的风险。这项研究旨在表征现有的碳库，描述土壤有机物可能的矿化风险，并评估俄罗斯南部亚马尔地区的冻原和森林冻原多年冻土中的微生物群落。由于低温剖面在土壤剖面中的表现，碳，氮和碳氮比的剖面分布随深度显示出非逐渐变化，这导致低温传质。研究区域的平均碳储量为7.85±2.24 kg m ^-2  （0-10 cm层），14.97±5.53 kg m ^-2  （0-30 cm）和23.99±8.00 kg m⁻²  （0–100厘米）。腐殖质类型的分析表明，在黄腐酸级分中主要存在黄腐型和低分子量碎片，这表明在北极变暖条件下腐殖质的矿化风险很高。土壤微生物组的分类学分析显示，细菌和古细菌门有48个，其中以蛋白质细菌（27％）和放线菌（20％）为主。pH范围和氮积累是研究土壤中微生物群落多样性和组成的主要环境决定因素。