Biogeographic patterns shape the bacterial community beyond permafrost gradients

Abstract

Global warming has led to extensive permafrost degradation, particularly in thermally vulnerable permafrost in the marginal or transitional zones of altitudinal or latitudinal permafrost. However, comprehensive knowledge about microbial communities in response to rapid permafrost degradation at large (or interregional) scales remains elusive. In this meta-analysis, existing published data were utilized to identify the distributive and co-occurrence patterns of the microbiome in two interregional locations: the Qilian Mountains on the northeastern Qinghai–Tibet Plateau (NE-QTP) and the Xing’anling Mountains in Northeast China (NE-China). Both areas are situated in the marginal zone of large permafrost units. The results reveal that the rapidly degrading permafrost did not overshadow the regional biogeographic pattern of the microbial community. Instead, the results show some distinctive biogeographic patterns, as characterized by different groups of characteristic bacterial lineages in each of the two regions. Soil pH has emerged as a crucial controlling factor on the basis of the available environmental data. Network-based analyses suggest a generally high level of natural connectivity for bacterial networks on the NE-QTP; however, it collapses more drastically than that in NE-China if the environmental perturbations exceed the tipping point. These findings indicate that the biogeographic patterns of the bacterial community structure are not significantly altered by permafrost degradation. This research provides valuable insights into the development of more effective management methods for microbiomes in rapidly degrading permafrost.

Keywords

• microbial community
• permafrost
• Da Xing’anling Mountains in Northeast China
• Qilian Mountains on the Qinghai–Tibet Plateau (QTP)
• network
• keystone species