中文摘要：

评估气候变化对草地生产力的影响对于草地生态系统的可持续发展和草地荒漠化的防治有重要意义。通过分析A2（中-高气体排放情景）和B2（区域经济和社会环境可持续发展情景）气候变化情景下内蒙古地区的气候变化特征，并基于草地生态系统模型CENTURY模拟了未来气候变化对内蒙古草地生产力的影响。结果表明：未来气候变化情景下，内蒙古自治区各区域的年平均最高和最低温度都呈明显的上升趋势（P〈0．01），且A2情景增幅大于B2情景；全区降水量呈极显著增加趋势（P〈0．01）。A2及B2情景下，内蒙古西部大部分地区及东部小部分地区各时段草地生产力呈降低趋势，东北部大部分地区则呈上升趋势；草甸及典型草原草地生产力呈增加趋势，但其变率随时段的推移呈增加趋势，且B2情景下较A2情景下变率更大。荒漠草原和草原化荒漠生产力呈减少趋势，其中荒漠草原生产力的变率随时段推移呈降低趋势；草原化荒漠生产力的变率在A2情景下随时段推移呈增加趋势，而B2情景下则呈降低趋势，荒漠草原和草原化荒漠生产力在A2情景下的变率均高于B2情景。

英文摘要：

Evaluating the impact of climate change on grassland ecosystem is important to the sustainable development of grassland and the prevention of grassland desertification. In this paper, the future climate change scenarios （A2 and B2 scenarios） were chosen to analyze the climate change characteristics in Inner Mongolia. And the CENTURY model was used to simulate the impact of climate change on grassland pro- ductivity. Results showed that annual average maximum and minimum temperature had an increasing trend in each region of Inner Mongolia （P〈0.01）, and the increasing trend under the A2 scenario was higher than the B2 scenario. Annual average precipitation had significant increase across the whole area in Inner Mongolia （P〈0.01）. Annual average aboveground biomass decreased in the most area of western Inner Mongolia and the small parts of eastern Inner Mongolia at different periods, while increased in the most ar- ea of northeast Inner Mongolia under both A2 and B2 scenarios compared to baseline climate. Grassland productivity of meadow steppe and typical steppe grassland showed an increasing trend under future cli- mate change scenarios. The variability of grassland biomass increased with time going. And the change rate of grassland biomass variability was higher under B2 scenario than under A2 scenario. The decrease trend of grass productivity occurred at desert steppe and steppification desert. The variability of grassland biomass decreased at desert steppe. However, at steppification desert, the variability of grassland biomass increased under A2 scenario, while decreased under B2 scenario with time going. The variability of grass- land biomass at both steppes was higher under A2 scenario than under B2 scenario.