中文摘要：

利用农业生态系统过程模型（Agricultural Production Systems s IMulator,APSIM）,研究了1980-2010年间中国华北平原农田土壤有机碳（Soil Organic Carbon,SOC）的时空变化。模型验证结果表明,校正后的APSIM模型总体能够较好地模拟徐州、郑州和昌平3个长期定位试验站点中各处理下小麦和玉米的产量变化以及SOC的变化。区域模拟结果显示,1980-2010年间华北平原大部分农田SOC呈增加趋势,仅河北省的北部、山东省中部和东部部分地区农田SOC减少。华北平原总的农田面积约为24.52 Mha（1 ha=0.01 km^2）,其SOC密度的平均变化速率为0.35 Mg（C）ha^-1 a^-1,总的SOC贮量增加了约257.43 Tg。在京津冀地区、山东省以及河南省的农田中,SOC分别平均增加了102.05、59.82、95.56 Tg。SOC的增加,主要归功于过去几十年里外源碳投入量的增加。

英文摘要：

A process-based model （Agricultural Production systems SIMulator, APSIM）, which was developed in Australia, was used to study the spatiotemporal changes in agricultural soil organic carbon （SOC） across the North China Plain （NCP） from 1980 to 2010. The modeling results suggested that the calibrated APSIM model generally performed well in terms of simulating changes in yields of wheat and maize and SOC under different treatments at three selected long-term experimental sites： Xuzhou, Zhengzhou, and Changping. The regional simulations showed that most croplands of NCP experienced an increase in SOC, except several areas of the northern part of Hebei Province, and central and eastern parts of Shandong Province. The average rate of change of SOC was 0.35 Mg（C） ha^-1 a^-1, and the total increase in the SOC pool was 257.43 Tg （with a total cropland area of -24.52 Mha in NCP）. Spatially, the cropland SOC pool increased by 102.05, 59.82, and 95.56 Tg in the Beijing-Tianjin-Hebei area, Shandong Province, and Henan Province, respectively. The increase in cropland SOC was mainly attributed to the increasing amount of carbon input during the past several decades.