阔叶红松林不同演替阶段土壤微生物多样性对土壤碳截获的影响

The representing vegetation in temperate region is mixed broadleaved-Korean pine,and the relationship between the soil carbon sequestration and microbial diversity is still unclear at different succession stages. The broadleaved-Korean pine forests ecosystem at different succession stages (Poplar-birch forest, young-middle-aged mixed broadleaved-Korean pine forest and old-aged mixed broadleaved-Korean pine forest) in Xiaoxing’an Mountains are as test objects. The difference of soil microbial diversity at different succession stages is studied by molecular biological technique. The changing characteristics of microbial community structure and functional diversity are analyzed. The key ecological factors affecting microbial diversity are selected. Characteristics of soil organic carbon pool at different succession stages are analyzed, and the relationship between soil organic carbon and environmental factors is studied. Through the relationships of distribution characteristics of soil microbial diversity and soil organic carbon pool, the roles of microbial diversity in soil organic carbon accumulation and carbon sequestration process are studied. The biology process and maintained mechanism of soil sequestration is explained in different succession stages, to provide the scientific basis for understanding the microbial vegetation and soil system response to human management and interference and contribution to global climate change.

阔叶红松林是我国温带典型地带性顶极群落，其不同演替阶段土壤微生物多样性对土壤碳截获的影响尚属不清楚。本研究以小兴安岭阔叶红松林不同演替阶段的森林生态系统（杨桦林、阔叶红松林中幼龄林、阔叶红松林成过熟林）为研究对象，利用分子生物学技术研究不同演替阶段土壤中微生物多样性的差异，阐明微生物群落结构与功能变化的规律，筛选出影响区域微生物多样性的关键生态因子；分析不同演替阶段森林土壤有机碳库的特征以及其与环境因子之间关系；通过土壤微生物多样性特征与土壤碳库特征进行统计相关性分析，分析不同演替阶段土壤微生物多样性对土壤有机质分解与碳截获过程的调控作用，揭示阔叶红松林不同演替阶段土壤碳积累生物学过程与维持机制，为了解微生物-植被-土壤系统对人类经营与干扰的响应以及对全球气候变化的贡献提供科学依据。

阔叶红松林是我国温带典型地带性顶极群落，其不同演替阶段土壤微生物多样性对土壤碳截获的影响尚属不清楚。本研究以小兴安岭阔叶红松林不同演替阶段的森林生态系统（杨桦林、阔叶红松林幼龄林、阔叶红松林成熟林）为研究对象，利用分子生物学技术研究不同演替阶段土壤中微生物多样性的差异，重点研究了不同演替阶段森林生态系统微环境、微生物生物量、群落结构和代谢功能的变化特征以及真菌群落结构与其在调控土壤碳转化功能之间的关联；揭示阔叶红松林不同演替阶段土壤碳积累生物学过程与维持机制。主要成果包括：（1）在自然状态下，随演替正向进行，土壤有机碳含量、微生物生物量碳含量、土壤水溶性有机碳含量均呈逐渐增大的趋势;（2）随演替正向进行，土壤微生物群落对碳源利用的能力逐渐增大，土壤微生物群落利用率较高的碳源类型为糖类、多聚物和氨基酸类；（3）碳氮比、细根生物量、土壤含水量和土壤容重是驱动本研究区域土壤微生物群落结构变化的关键控制因子；（4）子囊菌门酵母菌纲、粪壳菌纲、座囊菌纲及担子菌门伞菌纲真菌群落是影响该区域参与土壤C转化的土壤酶活性的最主要真菌类群。（5）路径分析结果表明真菌通过增强微生物碳的氧化活性而加速土壤碳周转。（6）在项目支持下，已发表学术论文2篇，获得发明专利2项，实用新型专利3项。项目研究成果为了解微生物-植被-土壤系统对人类经营与干扰的响应以及对全球气候变化的贡献提供科学依据。