Permafrost degradation may induce soil carbon (C) loss, critical for global C cycling, and be mediated by microbes. Despite larger C stored within the active layer of permafrost regions, which are more affected by warming, and the critical roles of Qinghai-Tibet Plateau in C cycling, most previous studies focused on the permafrost layer and in high-latitude areas. We demonstrate in situ that permafrost degradation alters the diversity and potentially decreases the stability of active layer microbial communities. These changes are associated with soil C loss and potentially a positive C feedback. This study provides insights into microbial-mediated mechanisms responsible for C loss within the active layer in degraded permafrost, aiding in the modeling of C emission under future scenarios.

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Against the background of global climate warming, the relationship between plant communities in high‐cold ecosystems and environmental gradients has attracted much attention. We investigated the relationship between the distribution of plant communities and environmental factors in a semi‐arid region of the Qinghai‐Tibet Plateau. We analyzed the effects of environmental factors on the distribution of plant communities using two‐way indicator species analysis and canonical correspondence analysis. The most important factor explaining the distribution of plant communities was the depth of the active layer of permafrost (denoted as PF), followed by soil water content at 40‐cm soil depth. There was a strong correlation between these two factors. With changes in the PF, the dominant species in plant communities showed an obvious transition. The indices of species richness and species diversity decreased markedly with increasing PF, whereas biomass and vegetation coverage showed weaker responses to changes in the PF. The distribution structure for plant communities in this area mainly results from changes in the PF. Furthermore, the PF has remarkable and important effects on the characteristics of the plant community.

In the current study, psychrophilic, endolithic, and epilithic bacterial strains were isolated and characterized from the nonpolar Laohugou glacier (LHG) no. 12, the largest valley glacier in the western Qilian Mts. located on the northeastern edge of the Tibetan Plateau. Five different types of samples, rocks, soil, glacial water, ice/snow, and cryoconite, were collected. A total of 48 bacterial strains were isolated by using the R2A bacterial cultural medium. The findings revealed that the Gram‐positive bacteria 41 (85.4%) dominated the Gram‐negative bacteria 7 (14.6%) in this extremely harsh environment. Molecular characterization based on 16S ribosomal RNA gene sequencing exhibited that the obtained isolates belong to four phyla, among which the diversity of Firmicutes (58.33%) was higher followed by Actinobacteria (23.0%), Proteobacteria (14.6%), and least diversity was reported in Euryarchaeota (4.2%). The bacterial communities were most dominant in soil samples followed by cryoconite sample and least dominant in the ice and snow samples. Moreover, the obtained bacterial isolates were found resistant to high concentrations of heavy metals (Cr3+, Cd2+, Hg2+, and Ar3+) and sodium chloride, and, therefore, exhibited polyextremophilic characteristics. LHG no. 12 is rich in bacterial and archaeal diversities and provides a potentially curious site for further in‐depth exploration of microbial diversity and their biotechnological applications.

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