STUDIES ON MICROBIAL MECHANISMS OF PERMAFROST CARBON CONVERSION TO CLIMATE WARMING: RETROSPECT AND PROSPECT

Recently, very active studies have been undertaken on the response and stability of permafrost carbon pool and key biogeochemical processes in permafrost regions to climate warming. By observing the significant differences in microbial community structure in regions of seasonal frost and permafrost, it is evident that microbes play key roles in the conversion of permafrost carbon. This paper reviews research progress at the cutting edges on the conversion and decomposition of permafrost carbon to climate warming and subsequent changes in microbial activities over the past decade. Findings indicated that: (1) Freezethaw cycles of soils in the active layer in permafrost regions showed an increasing annual trend and the existing survival patterns of permafrost microbes may be altered by the increasing freeze-thaw frequency; and (2) Soil microbes are an essential part of the cold-regions ecosystem and they play vital roles in soil carbon and nitrogen cycling, the mineralization and decomposition of soil organic matter. Thus, climate warming and subsequent permafrost degradation affect the conversion and decomposition of permafrost carbon, resulting in changes in CO2 and CH4 emissions, soil environmental factors, and soil microbial community structures. The laws for governing permafrost carbon conversion and the self-regulation mechanisms of soil microbes are important for natural ecosystems and environments in cold regions, and affect the strengths of greenhouse gas sources and sinks in permafrost regions.

Automated summary

This paper reviews the research progress on the conversion and decomposition of permafrost carbon and subsequent changes in microbial activities in response to climate warming. The findings indicate that climate warming and permafrost degradation affect the conversion and decomposition of permafrost carbon, resulting in changes in greenhouse gas emissions, soil environmental factors, and soil microbial community structures.