Zhang Ni, Yang Ziwei, Qi Desheng, Li Lin, Chen Kelong, Fu Li, Sun Jianqing
Qinghai Province Key Laboratory of Physical Geography and Environmental Process, College of Geographical Science, Qinghai Normal University, Xining, China.
Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining, China.
Front Microbiol. 2025 Jun 6;16:1592315. doi: 10.3389/fmicb.2025.1592315. eCollection 2025.
Global warming intensifies the hydrological processes in wetlands, thereby affecting the carbon dynamics of these ecosystems. The cbbL gene, a key gene involved in carbon fixation, is significantly influenced by changes in precipitation. In this study, precipitation manipulation treatments with 25 and 50% increases and decreases, along with a natural control, were established to assess the response of cbbL-carrying carbon-fixing microbial communities to altered precipitation in the source wetland of Qinghai Lake. Amplicon sequencing was conducted to characterize microbial community composition and dynamics. The results showed that with increased precipitation, the relative abundance of Actinobacteria exhibited a decreasing trend, while Cyanobacteria showed an increasing trend. Chlorophyta exhibited an "n"-shaped variation pattern ( < 0.05). Soil carbon and nitrogen were the most important factors influencing the cbbL carbon-fixing microbial community in the source wetland, with their concentrations decreasing as precipitation increased. The 25% increased precipitation treatment enhanced the environmental selection of cbbL carbon-fixing microbes, shifting the community assembly process from randomness to determinism. In addition, with the increase in precipitation, the network complexity and connectivity among cbbL carbon-fixing microbial species increased. In summary, reduced precipitation helps to enhance the carbon sequestration potential of the source wetland.
全球变暖加剧了湿地的水文过程，从而影响这些生态系统的碳动态。cbbL基因是参与碳固定的关键基因，受降水变化的显著影响。在本研究中，设置了降水增加25%和50%、降水减少25%和50%的处理组以及一个自然对照组，以评估携带cbbL基因的碳固定微生物群落对青海湖源湿地降水变化的响应。通过扩增子测序来表征微生物群落组成和动态。结果表明，随着降水量增加，放线菌的相对丰度呈下降趋势，而蓝细菌呈上升趋势。绿藻呈现出“n”形变化模式（<0.05）。土壤碳和氮是影响源湿地cbbL碳固定微生物群落的最重要因素，其浓度随降水量增加而降低。降水增加25%的处理增强了对cbbL碳固定微生物的环境选择，使群落组装过程从随机性转变为确定性。此外，随着降水量增加，cbbL碳固定微生物物种之间的网络复杂性和连通性增加。总之，降水减少有助于增强源湿地的碳固存潜力。
