中文摘要：

本研究用综合顺序分类法（CSCS）分析了1950-2000年和2001-2050年期间的草原类型演替及碳汇动态。证明中国草地的碳汇主体依次是冻原和高山草地、温带湿润草地、斯泰普草地和半荒漠草地大类,占中国潜在草地总面积的85.52%,年碳汇潜力占中国潜在草地年碳汇潜力的93.29%。全球草地的碳汇主体是萨王纳、冻原和高山草地大类,两者的面积和占全球潜在草地总面积的48.50%,年碳汇潜力占全球潜在草地年碳汇潜力的72.22%。在全球气候暖干化的强（A2a）、弱（B2a）情景下,与当前（1950-2000年）情景相比,中国将呈现草地面积减少,林地面积增加的态势;与中国的趋势相反,全球将呈现草地面积增加,林地面积减少的态势。在全球暖干化的A2a和B2a模式下,草地年碳汇潜力,中国将分别提升14.6%和18.5%,全球将分别提升17.3%和16.8%。但两者的增长方式不同,全球是以温带湿润草地大类年碳汇潜力大幅增加为特征,而中国是以负增长为特征。我国的暖干化趋势在草地年碳汇潜力上的反映较之全球更强烈。尽管造成全球气候暖干化的自然因素远非人力所能控制,但系统问题只能靠系统综合的办法治理。这是草地工作者当前的使命。

英文摘要：

The comprehensive and sequential classification system of rangeland（CSCS） was applied in analysis of the succession of grassland types and the dynamics of carbon sequestration tendency between the periods of the 1950-2000 and 2001-2050 year,which indicates that the main contributors to the carbon sequestration capacity of the Chinese grassland area,in sequence,the tundra and alpine grassland,temperate humid grassland,steppe and semi-desert.They in total occupy 85.52% of the all total potential grassland areas of China and 93.29% of the country＇s entire carbon sequestration capacity of potential grassland per year.In a global view,the main parts of the grassland are the savanna,tundra and alpine types and these two types occupy 48.50% of the total global potential grassland and 72.22% of the global potential grassland carbon sequestration capacity per year.In current situation of strong（A2a） and weak（B2a） in global climate warming and drying,China will reduce its grassland while increase its forest area in comparing to its status during 1950-2000.In contrast to the trend in China,from the global perspective,grassland will increase while forest area will decrease.Under the model of strong（A2a） and weak（B2a） in global climate warming and drying process,China will increase 14.6% and 18.5%,while the world will increase 17.3% and 16.8% in terms of carbon sequestration capacity per year.However,the two are different in their mode of increase.The global increase is characterized by huge increase of potential carbon sequestration capacity in the temperate humid grassland,while the China＇s increase is characterized by its decrease in the same area.Comparing with the global trend the warming and drying tendency in China is more intense in terms of carbon sequestration capacity of potential grassland per year.Although the factors caused the global climate warming and drying cannot be controlled by human beings but the system problems can only be dealt with by the means of system synthesis,which is the