Warming Induces High Environmental Pressure in the Lakeshore Wetland, Promoting Interactions Among Carbon-Fixing Microorganisms

Global warming has intensified the changes in wetland carbon cycling processes, and the cbbL gene, which plays a key role in carbon fixation, is significantly affected by warming. Therefore, we set up open-top chamber warming and natural controls and used amplicon sequencing to investigate the response of the cbbL carbon-fixing microbial community in the alpine lakeshore wetland to warming. We found that after the warming treatment, the relative abundances of Actinobacteria and Chlorophyta increased, while the relative abundance of Cyanobacteria decreased (p < 0.05). Soil temperature and moisture were the most significant factors influencing the cbbL carbon-fixing microbial community in the lakeshore wetland. Deterministic processes dominated the community assembly of carbon-fixing microbes under warming conditions. Additionally, warming enhanced both cooperative and competitive interactions among carbon-sequestering microorganisms while reducing soil moisture availability and increasing environmental stress, leading to a decrease in the modularity of microbial communities. In summary, warming reduced the carbon sequestration potential of lakeside wetlands but favored the interactions among carbon-sequestering microorganisms.