以红松为建群种的阔叶红松林是我国东北地区地带性顶级植被，也是我国温带针阔混交林带内最典型、最多样、最重要的森林生态系统。原始红松林退化演替为亚顶级群落后，缺少了建群种红松，土壤生境必然会发生较大的变迁。本研究选择在隶属于东北林业大学的黑龙江省伊春市带岭区凉水国家级自然保护区内的原始红松林和退化演替后的亚顶级群落硬阔叶林大样地内进行。拟以原始红松林作为对照，对其退化演替为硬阔叶林后土壤有机碳周转的重要驱动因子展开研究，比较两者在植被凋落物的分解、细根的周转归还、土壤呼吸及土壤微生物组成结构和分解、合成代谢特征等方面的变化，以期对两者的土壤有机碳周转水平进行科学评价；建立微生物群落结构、功能代谢变化等与各重要驱动因子之间的耦合关系，揭示土壤微生物在碳输入和碳输出过程中的原位生态功能。研究结果对未来我国东北森林的碳汇管理提供科学依据，也是全球气候变化大背景下极具现实意义的科学结论。

Broad-leaved korean pine forest which taken korean pine as edificator is climax vegetation in northeast, and temperate conifer-broadleaf forests most typical, diverse and important forest ecosystem in temperate zonal of China. Great changes will occur in the soil environment after original korean pine forest degenerated into sub climax community, due to lack of korean pine as edificator. The research will be carried out in the original Pinus koraiensis plots and sub-climax community of hard broad-leaved forest plots that are adjacent to Liangshui National Nature Reserve in Dailing Distric, Yichun of Heilongjiang province, which is affiliated to Northeast Forestry University. Soil organic carbon turnovers important driving factors will be research objects after original Korean pine forest degenerated into hardwood forests. Their changes in vegetation litter decomposition, return and turnover of fine root, soil respiration, soil microbial composition and catabolism and anabolisms characteristics will be compared, in order to scientifically evaluate the turnover of their soil organic carbon. Coupling relationship among the microbial community structure, functional metabolic changes and the important driving factors will be established, and the in-situ ecological function of soil microbes in carbon input and output will be revealed.The results will provide scientific basis for the future forest carbon sink management in the northeast of China. They will be also a scientific conclusion with realistic significance in the context of global climate change.