中高纬冻土区是陆地生态系统重要的碳汇，也是气候变化的敏感区。气候变暖将对区内有机碳库产生重要影响，继而反馈于区域及全球变化。根输入是土壤有机碳的重要来源，气候变暖会影响植物根系向土壤输入碳的过程，作用于土壤碳平衡。活性碳组分是土壤有机碳变化的早期指标，受温度和根输入等因素影响，然而，增温背景下冻土区土壤活性碳组分的变化及其受根输入的影响尚不清楚，这些问题是评估碳固持能力的关键。本研究以冻土区泥炭地主要植被白毛羊胡子草为研究对象，通过野外原位增温控制实验模拟气候变暖，揭示增温对细根分解、根系分泌物、土壤有机碳及其活性碳组分的影响，分析细根分解和根系分泌物与土壤有机碳和活性碳组分之间的耦合关系，阐明增温背景下植物根输入对冻土区泥炭地土壤碳库稳定性的影响，为科学评估冻土区碳汇能力和应对气候变暖提供科学依据。

The mid-high latitude permafrost regions act as important carbon sinks in terrestrial ecosystem and are sensitive to climate change. Soil organic carbon (SOC) pool in these regions would be significantly affected by climate warming, which will feed back to regional and global climate change. Root input is an important source of SOC. Warming climate influences the process of plant root carbon input to the soil, which acts on soil carbon balance. Labile organic carbon fractions are early indicators of changes in SOC, and are affected by temperature and root input. However, changes in labile organic carbon fractions of permafrost regions under warming and how they are affected by root input prove to be not clear now, which are essential to estimate the ability of carbon sequestration. Based on the field warming experiment simulating warming climate, this project investigates the main vegetation Eriophorum vaginatum in the peat land of permafrost region, aiming to disclose the effects of warming on fine root decomposition, root exudates, SOC and its labile fractions, analyzing the coupling relation between root decomposition, root exudates and SOC and its labile fractions, clarifying the influences of plant root input on the stability of SOC pool in peat land in permafrost regions. Based on aforementioned work, the present study hopes to provide scientific basis for scientific assessment of carbon sink capacity and response to climate change in permafrost regions.