林火干扰下大兴安岭森林生态系统碳库转换过程及其动态变化机制

准确计量森林碳收支是制定我国林业应对气候变化自主行动计划的前提。目前森林碳收支计量存在较大的不确定性，其中林火干扰是重要的影响因素之一，它一方面将森林固定的碳直接排放到大气中；另一方面使森林生态系统中碳库发生转换，从而影响森林的碳库动态。然而，在当前森林碳收支计量中，很少考虑火后森林生态系统碳库转换过程；同时，对林火干扰下森林生态系统各碳库的动态变化过程还缺乏深入的了解，限制了林火管理措施--森林可燃物处理在我国的实施。本项目通过野外调查、遥感和地理信息系统与模型模拟相结合的方法，分析不同强度林火干扰下，大兴安岭森林生态系统碳库的转换过程及其动态变化机制；通过森林可燃物处理来调控林火干扰过程。本项目在准确计量森林生态系统碳收支、科学制定林火管理策略、增加森林的碳减排增汇效应等方面均有重要的研究意义，是制定我国林业应对气候变化自主行动计划的科学需求，也是我国中长期森林防火的国家需求。

Accurate estimate of carbon budget is the premise for making forestry action plan to mitigate and adapt to climatic change. There exists great uncertainty in current forest carbon budget estimating and forest fire is believed to be one of the important influencing factors. Forest fires release sequestrated carbon in forest biomass and soils back to the atmosphere in one hand, and redistribute carbon among major carbon pools of forest ecosystems, which has a strong impact on post-fire forest carbon pool dynamics. However, the processes of carbon relocation among the major carbon pools of forest ecosystems are seldom taken into account when estimating forest carbon budget at present. And there still lacks the fully understanding of the mechanisms how forest fire disturbance affects forest carbon budget, which prevents the forest fire management measure, forest fuel treatment, from being implemented in China. In this proposal, we will analyze the processes of carbon relocation among the major carbon pools of forest ecosystems in the Great Xing’an Mountains, and the dynamic changes of these carbon pools under fire disturbance with various fire severities by integrating field inventory, remote sensing, geographic information system and model simulation; We will also mediate the forest fire disturbance process by implementing forest fuel treatment. Therefore, this research project has critical implications for accurately estimating forest ecosystem carbon budget, scientifically making forest fire management scenarios, and strengthening the effects of increasing carbon sink and reducing carbon emissions of forest ecosystems. We believe the proposal is the scientific needs for making relevant forestry action plan to mitigate and adapt to climatic change in addition to the national needs for mid- to long-term forest fire prevention.