采伐对森林土壤碳库影响的不确定性

森林土壤有机碳(SOC)是全球碳循环的重要组成部分,然而,多样的森林类型和不同森林经营措施的干扰,使得森林土壤碳库维持机制以及碳固存过程的研究和森林土壤碳库的估算存在较大的变异。作为主要的森林经营措施之一,采伐对森林土壤碳储量以及碳过程均产生直接或间接地影响。为深刻理解森林土壤碳库对于采伐干扰的响应,本文综述了近十几年来不同采伐方式下森林土壤碳储量及其主要碳排放过程——土壤呼吸的研究现状,综合分析了采伐方式、森林类型、采伐剩余物管理以及微生物因子等对土壤碳库的影响及其不确定性,并在此基础上阐述了研究中尚未解决的主要问题:1)生物因子作为CO₂产生的主体,在应对干扰时结构、功能的变化直接影响着土壤碳排放以及碳固定,但它们具体作用机制以及过程并不清楚,需展开进一步的调查;2)不同森林采伐方式对不同地区和不同类型森林土壤的影响的复杂性,亟须在进一步加强实验研究的基础上,发展森林土壤碳循环的过程或机理模型,为森林生态系统完整的碳循环过程表达及碳计量提供技术支撑,以期为我国森林经营以及碳汇等方面研究提供参考。

Uncertainty Effect of Forest Harvest on Soil Carbon Pool:A Review

Forest soil carbon(SOC) is the key part of the global carbon cycle. However, the existence of multiple forest types with various forest managements makes huge variabilities on maintenance mechanism of forest soil carbon pool and soil sequestration process, so as the evaluation of forest soil pool. Being the main method of forest management, harvest has effect on forest carbon pool and carbon process directly and indirectly. Therefore it is critical to have deeper understanding of response of the forest SOC to forest harvest. By literature review, this paper summarized research progress on forest soil carbon pool and soil respiration with different harvest types at home and abroad, and the uncertainties that influenced results had been analyzed. Harvest types, forest types, harvest residue management and microbial factors were main factors regulated SOC. Based on the review, unsolved problems of the recent research, emphasis of related work in the future had also been proposed:1)biotic factors was the main producer of CO₂, and its sturcture and function changed responsed to disturbance, which influenced the soil carbon realese and sequestration straightly, however the machanism of this process was unclear, needed to be investugated further; 2) the effects of various harvest types to different area and forest soil types was so complex that process models and machnism models needed to be developed based on the intensive experiment researches, to provide technical support for carbon cycle and carbon accounting of forest ecosystem, and reference for the studies about forest management and carbon sink in China.