中文摘要：

基于遥感反演的1988年与2000年土地利用数据、土地动态模拟系统（DLS）模拟的2012年与2020年全国栅格尺度的耕地分布数据及我国农业综合区划结果，应用CENTURY模型估算了中国1988～2020年农田土壤有机碳贮量时空变化规律，分析了1988～2000年、2000～2012年与2012～2020年三个时段中国农田土壤有机碳贮量变化情况。研究结果表明，1988～2000年全国大部分地区的农田土壤有机碳贮量呈增长态势；而2000～2012年全国农田土壤有机碳贮量将出现一定幅度的下降；2012～2020年间，虽然全国范围内的农田土壤有机碳贮量仍表现为下降趋势，但下降幅度较2000～2012年间显著减少。研究结果还表明，我国九大农业生态区的农田土壤有机碳贮量变化具有显著的时空分异特征。

英文摘要：

In this paper, we estimate the nationwide soil organic carbon stock in China during the three time periods of 1988-2000, 2000-2012 and 2012-2020 with CENTURY model and analyze soil organic carbon stock changes of cropland in the nine agro-ecological zones, with the support of DLS which provides future land use pattern data. In order to estimate the dynamics of soil organic carbon stock, the CENTURY model, in which a soil organic matter decomposition sub-model, a water budget sub-model, a grassland/crop submodel, a forest production sub-model, and a couple of management and events scheduling functions are encapsulated, was customized and used in this study. In the customized CENTURY model, the flow of carbon was simulated. In addition, the pixel specific area changes of cropland for the period between 2010 and 2012 and the period between 2010 and 2020 were predicted by using the DLS model. DLS model consists of three sub-modules, the sub-module for simulating the dynamics of land systems at a regional extent, the sub-module to explore and represent the driving mechanism of land use change and the sub-module to generate the equilibrium of demands and supply of land area by sectors and by grid pixel and finally to export the maps to identify the temporal and spatial changes of cropland patterns which are the input variables for simulating the soil organic carbon stock in the prediction period. The research results show that soil organic carbon of cropland during 1988-2000 in China experienced a rising trend in most parts of the Chinese Mainland. The aggregated estimation results of CENTURY model show that China had an increase of 3.3 × 10^8 t for the soil organic carbon stock of cropland. By contrast, during the period of 2000-2012, the soil organic carbon stock of cropland declines as much as 1.5 × 10^9 t. In some regions such as Northeast China, the carbon stock decrease accounts for more than one third of the total carbon missed in China. And during the period of 2012- 2020, although the soil organic carbon sto