林火干扰对森林生态系统土壤有机碳的影响研究进展

Effects of forest fire disturbance on soil organic carbon in forest ecosystems:A review

林火干扰是森林生态系统特殊而重要的生态因子,可改变生态系统的养分循环与能量传递。研究林火干扰对森林生态系统土壤有机碳的影响,有助于理解森林生态系统中土壤碳固持和碳循环过程,为制定科学合理的旨在减缓全球变化的林火管理策略具有重要意义。从4个方面阐述了林火干扰对森林生态系统土壤有机碳的影响及内在机制:分别从大尺度和小尺度两个方面阐述了林火干扰对土壤有机碳的影响及对森林生态系统碳循环与碳平衡的作用机制;探讨了不同林火干扰类型和林火干扰强度下,土壤活性有机碳对林火干扰的响应机制;阐明了林火干扰对土壤惰性有机碳的影响及作用机制;论述了林火干扰主要通过改变土壤有机碳的输入和输出过程进而影响土壤有机碳的稳定性及内在机制。最后提出了提高林火干扰对森林生态系统土壤有机碳影响定量化研究的4种路径选择:(1)全面比较研究不同林火干扰类型对土壤有机碳循环及其碳素再分配过程的功能特征;(2)进一步阐明林火干扰通过改变植被结构进而影响土壤生物群落结构,剖析土壤碳库循环的内在机制;(3)完善不同时空尺度下林火干扰对森林生态系统土壤碳库周转过程的定量化研究;(4)加强不同林火干扰类型土壤碳库稳定性差异的研究。

Forest fire disturbance is a special and important ecological factor in forest ecosystems,and it changes nutrient circulation and energy transfer of the ecosystem.Studying the impacts of forest fire disturbance on soil organic carbon(C)in forest ecosystems improves the knowledge of soil C sequestration and C cycle processes in forest ecosystems,which facilitates strategies formulation for scientific and reasonable forest management aiming at slowing down global climate changes.The influencing mechanisms of forest fire disturbance on soil organic C in forest ecosystems has been reviewed in this paper.The mechanisms of forest fire disturbance affecting soil organic C along with C cycle and balance in the forest ecosystems at small or large scale has been analyzed.Response mechanisms of soil labile and inert organic C to different forest fire characteristics such as types and interference intensity were elucidated.In addition,it was elucidated that forest fire affected stability of soil organic C by changing its input and output processes.Based upon above,four ways to improve quantitative study of the impact of forest fire disturbance on soil organic C have been put forth.1)It is needed to comprehensively compare functional characteristics of different forest fire disturbance types on soil organic C circulation and redistribution process;2)The potential mechanism of forest fire disturbance changing vegetation structure and hence affecting soil biological community structure along with C circulation in soil should be clarified;3)By means of quantitative study,the effect of forest fire disturbance on turnover process of soil C pool in forest ecosystem under different spatial and temporal scales could be improved;and 4)impacts of different forest fire disturbance types on stability of soil organic C pool should be intensively studied.