气候变暖背景下森林土壤碳循环研究进展

Advance in Research of Forest Carbon Cycling Under Climate Warming

由人类活动引起的温室效应以及由此造成的气候变暖对森林生态系统的影响已引起人们的普遍关注.森林土壤碳循环作为全球碳循环的重要组成部分,是决定未来陆地生物圈表现为碳源/碳汇的关键环节,揭示这一作用对于准确理解全球变化背景下陆地生态系统碳循环过程具有重要的指导意义.本文主要通过论述影响土壤碳循环过程的5个方面(土壤呼吸、土壤微生物、土壤酶活性、凋落物输入与分解、土壤碳库),综述了近10a来全球气候变暖对土壤碳循环过程的影响.近年来,尽管已开展了大量有关土壤碳循环对气候变暖的响应及反馈机制的研究,并取得了一定的成果,但研究结果仍然存在很大的不确定性.整合各种密切关联的全球变化现象,完善研究方法和实验手段,加强根际微生态系统碳循环过程与机理研究将是下一步研究的方向和重点.

Greater attention has been paid to human-induced climate warming,resulting from the enhanced greenhouse gases,and its impacts on forest ecosystems. As an important component of the global carbon cycling,gaining a better understanding of the responses of soil carbon cycling processes to climate warming is critical for predicting the changes in terrestrial ecosystem carbon cycling in the future. This paper reviews the recent progress of the research on climate warming and the factors influencing soil carbon cycling, including soil respiration, microbes, litterfall input and decomposition, enzyme activity and carbon pool. Recently, the effects of climate warming on soil carbon cycling have aroused great concern, but there remains a fundamental uncertainty regarding the research results. To advance our understanding of how climate change influences the soil carbon cycling of forest ecosystem, further studies are needed to address multifactor experiments in the field and enhance the interaction between field studies and modeling approaches. Also, there is an urgent need to analyze the distribution and fate of carbon fluxes in rhizosphere microecological system under climate change. Ref 70