土壤具有巨大的固碳潜力，揭示土壤有机碳变化的微生物作用机制对缓解全球变化有重要意义。松嫩平原是世界三大苏打盐渍土集中分布区之一，该区域苏打盐碱地开垦为水田后土壤有机碳含量显著增加，但这一过程的微生物作用机制并不清楚。本项目以揭示盐碱水田中土壤有机碳变化的微生物机制为主要目标，围绕松嫩平原西部苏打盐碱地开垦为水田后土壤有机碳含量增加这一生态过程逐步深入展开：首先，采用高通量测序和生物信息学分析方法，探明苏打盐碱地开垦后的土壤微生物群落结构和功能变化特征；其次，采用田间试验分析与室内控制试验相结合的方式，解析影响土壤微生物群落结构和功能变化的主控因子；最后，采用稳定性同位素核酸探针技术（DNA-SIP），探明土壤有机碳变化过程中发挥关键作用的核心微生物类群，并结合前述内容解析其生态功能、变化特征与影响因素。本研究将促进相关领域研究进展，为区域碳库管理提供理论依据，具有重要的科学和实践意义。

The potential soil carbon sink capacity is huge, so a deep understanding of microbiological mechanisms underlining the changing soil organic carbon (SOC) has great significance to mitigate global climate changes. Songnen Plain is one of the three largest saline-sodic soil regions in the world. The paddy fields cultivated from saline-sodic soil in this region can lead to significant increase of SOC, but the microbiological mechanisms of this ecological process are still unclear. The main objective of this project is to understand the microbiological mechanisms of increasing SOC in saline-sodic paddy soil. We will conduct deep study focusing on the SOC increase process after the cultivation of original saline-sodic soils to rice fields. First, we will investigate changes in the community structure and function of soil microbes after the cultivation of saline-sodic soil using high-throughout sequencing technology and bioinformatics analysis. Second, we will analyze the main driver of soil microbial changes from microcosm experiments to the field scale. At last, we will identify the core microbial groups affecting SOC change using DNA-based stable isotope probing (DNA-SIP), based on these studies we will further analyze the ecological function, change features and main drivers of these core microbial groups. Our study, with important scientific and practical significance, will promote further research in relative fields and provide theoretical basis for managements of regional carbon pool.