Based on data sets of soil organic carbon (SOC) extracted from the literature about grassland area and different managements, the SOC changes of grassland in the Xilinguole, Inner Mongolia from 2000 to 2007 were estimated to understand the contribution of grassland management on SOC by two approaches, in which one was the IPCC Tier 2, and the other was transfer matrix of SOC under various managements. The results of this study showed that SOC of grassland in the Xilinguole increased by 20.85- 29.80 Tg with an average rate of 2.61-3.72 Tg/a from 2000 to 2007. The increment of SOC in the Dongwuzhumuqin, Xiwuzhumuqin, Sunitezuo, Suniteyou and Abaga, and Xilinhaote city was more than 80% of total increment of SOC. Correlation analysis indicated the SOC estimated by the IPCC Tier 2 showed a similar trend with those estimated by transfer matrix approach, while the total SOC estimated by the IPCC Tier 2 was approximately one third of those estimated by transfer matrix approach. The estimated annual SOC was not consistent between two approaches. The annual increment of SOC before the third year was greater than that after the third year when the IPCC Tier 2 was employed, while the increment of SOC after the fifth year was higher than that before the third year when the transfer matrix approach was employed.%以内蒙古锡林郭勒盟历年草地管理面积和不同草地管理下土壤有机碳变化的文献数据为基础,分别采用《2006年IPCC国家温室气体清单指南》Tier2和基于文献数据的转移矩阵方法,估算2000—2007年该盟草地土壤有机碳变化。结果表明,研究期内该盟草地土壤有机碳增加量为20.85~29.80Tg,年均增加量2.61~3.72Tg。其中,东乌珠穆沁旗、西乌珠穆沁旗、苏尼特左旗、苏尼特右旗、阿巴嘎旗和锡林浩特市有机碳增加占全盟总增加量的80%以上。采用IPCC方法2与转移矩阵法估算的土壤有机碳变化量在空间上具有很好的一致性,但前者的估计值比后者约低1/3。用两种方法估算的逐年有机碳变化量在时间序列上不具可比性,IPCC方法2估算的土壤碳贮量前3年增加迅速,转移矩阵法估算的土壤碳贮量后5年增加迅速。
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