土壤呼吸是土壤碳库向大气碳库输入的主要途径，而气候变暖会影响土壤呼吸从而改变全球碳平衡。由于土壤呼吸各组分发生的部位与所利用的碳源不同，其对增温的响应也存在显著差异。因此，准确区分和量化土壤呼吸组分及其对土壤CO2排放的贡献是深入了解气候变暖背景下森林生态系统碳循环过程的基础。本项目基于在鼎湖山森林生态系统定位研究站建立的野外大型模拟增温实验平台，首先应用静态箱-气相色谱法，研究增温对南亚热带不同森林类型土壤总呼吸的影响；进一步通过稳定同位素技术区分和量化土壤有机质呼吸和根源呼吸组分对土壤总呼吸的贡献，并探讨增温对两种组分贡献率的影响；最后从植物根系形态结构特征、微生物群落结构及酶活性、土壤有机碳组分等角度，阐明南亚热带森林生态系统土壤呼吸及其组分对增温的响应机理。研究结果将为气候变化条件下全球碳平衡的估算，以及生态模型参数的验证提供基础数据和科学依据。

Soil respiration is the main efflux of carbon pool from soil to atmosphere. Subtle change of soil respiration caused by warming can result in significant change in global carbon balance. Responses of soil respiration components to climate warming may be different, since the components differ in occurrence sites and sources of carbon. Thus, it is essential to partition and quantify soil respiration components and their contributions to soil CO2 emission for deeply understanding the carbon cycles in forest ecosystem under global warming. Basing on the translocation experiment at Dinghushan Forest Ecosystem Research Station, in situ CO2 flux from soil of three different subtropical forests was measured by using static chamber-gas chromatograph technique firstly. Then we aim to partition and quantify the soil respiration components (SOM-derived respiration and root-derived respiration) and their contribution to the total soil respiration by using the carbon isotope measurements, and their different of response pattern to warming was further compared. Finally, we will also try to clarify how the responses of these two components to warming in subtropical forest from the perspective on the morphological structure of plant roots, microbial community composition, extracellular enzyme activities and soil organic carbon components. The results will provide basis data support to carbon balance estimation, and give scientific basis for the ecosystem models verification under the effect of climate change.