中国典型冻土区土壤有机碳组分、周转率和温度敏感性研究

Frozen soil area is one of the largest carbon reservoirs, and air temperature has significantly increased during the past decades. Therefore, permasrost plays an important role in regulating glboal carbon cycle and future climate. However, there are large uncertainties on the turnover rate and temperature sensitivity of soil organic carbon, which resulted into low model performance for global carbon budget. This proposed study aims at improving estimated parameters on trunover rates and temperature sensivity of soil organic carbon by combing incubation experiments and parameter inversion method. This project is to collect the soil samples of soil depths at mutiple dynamic ecosystems over the permafrost areas, and then conducted incubation expeiments at several control temperature conditions. Then, parameters inversion method was used to estimate the turnover rates and temperature sensivity of the three-carbon pool model, which will directly be used into the terrestrial ecosystem carbon models to improve the estimations of regioanl carbon budget.

冻土区生态系统中存储着大量的土壤有机碳，在全球碳循环中扮演着重要的角色，并对气候系统有着不容忽视的反馈作用。然而，目前对于冻土区土壤有机碳分解的关键功能属性仍然存在着极大的不确定性，大大降低了区域碳源汇估算的准确性，限制了预测其对未来气候变暖响应的能力。本项目瞄准冻土区生态系统碳循环的核心要素（土壤有机碳），以准确量化有机碳分解属性为出发点，借助于室内控制实验和参数反演相结合的新方法，估算中国典型冻土区生态系统土壤有机碳组分、周转率和温度敏感性，改进现有碳循环模型的模拟能力，实现准确评估冻土区土壤有机碳变化趋势及其对区域气候系统的反馈作用。该项目不仅为量化碳循环过程的关键参数探索一条新路，同时也为准确估算国家尺度碳源汇格局奠定科技基础。

本项目针对冻土区生态系统碳循环研究中存在的问题和不足，瞄准冻土区生态系统碳循环的核心要素(土壤有机碳)，以准确量化有机碳分解属性为出发点,借助于室内控制实验、集合分析和参数反演相结合的方法，估算中国典型冻土区生态系统土壤有机碳分解和周转特性，并利用室内培养实验结果改进和校正土壤有机碳微生物模型，对比不同模型的结构差异，校正关键模型参数，提高其对于土壤有机碳分解的模拟能力，实现准确评估冻土区土壤有机碳变化趋势及其对区域碳源汇的影响。项目发表SCI文章5篇，另外两篇英文文章尚在审稿中，完成了既定的工作任务。