岩溶峰丛洼地土壤CO2固定细菌的群落结构及固碳活性

土壤微生物固碳研究是当前全球气候变化下的前沿课题。CO2固定细菌能够利用土壤中的CO2 并最终转化为有机碳，在一定程度上能够减缓气候变化。然而，调控CO2固定细菌群落结构和固碳活性的主导因子依然未知。本项目以桂林毛村岩溶试验场的长期定位研究为基础，通过比较岩溶区与非岩溶区表层土壤CO2固定细菌群落与土壤有机碳、pH和CO2浓度等多种因子的关系，明确岩溶区土壤CO2固定细菌群落结构和固碳活性以及调控它们的关键因子；通过实验室培养和结合稳定同位素探针技术验证岩溶区土壤的关键因子对CO2固定细菌群落结构和固碳活性的影响，探讨固碳机理，以促进我们对岩溶区CO2固定细菌固碳过程的深入认识。

Progress and mechanism of carbon sequestration by soil microbe now are focused under the background of climate change. CO2-fixing bacteria in soil can assimilate CO2 and manufacture soil organic carbon (SOC), which mitigates climate change to some extent. However, the dominant factors in soils regulating the community structure of CO2-fixing bacteria and their capacity to sequester carbon are not clear. In this project, the two subjects will be discussed based on the long-term trial results in Maocun Karst experimental site, Guilin. Firstly, the relationship between the community structure of CO2-fixing bacteria, their activity of sequester carbon and the soil factors, such as SOC, pH and CO2 will be analyzed and compared in epikarst and non-epikarst ecosystem. The precise soil factors in soil can be known which can affect CO2-fixing bacteria community significantly. Secondly, effects of the important factors in epikarst soil on community struture of CO2-fixing bacteria and their sequester carbon activities will be verified by using laboratory culture and stable isotope probing to explore the mechanism of action, which enriches the theory of carbon-sequestration.