中文摘要：

本研究利用1953-2014年气象数据和1998-2013年实测数据驱动CENTURY模型模拟内蒙古典型草原生态系统地上净初级生产力（ANPP）的动态变化,并分析影响其动态变化的气象因素。结果表明,1）研究地点1998-2013年的ANPP观测值与模拟值变化趋势吻合度较高,Pearson相关性系数为0.79,均方根误差为25.92g/m^2,CENTURY模型适用于模拟气候变化对内蒙古典型草原影响的研究。2）模型参数敏感性分析得出模型中的主要参数分别是研究地点土壤理化性质、草地植物生长的潜在生长力系数、植物生长最适和最高温度,这些参数的确定决定着模型模拟结果的准确度。3）1953-2014年,内蒙古锡林浩特的气温呈现极显著增加的趋势（P〈0.01）,主要是年平均最低气温明显上升;降水呈明显的年际波动,变异系数为30.2%。4）1953-2014年模拟的ANPP呈减少的趋势,但是变化趋势不显著（P〉0.05）。通过相关性分析得到,降水是影响ANPP变化的主要因素,年降水量与ANPP的相关系数r值达到0.959（P〈0.01）,温度与ANPP呈弱相关性。

英文摘要：

The CENTURY model was used to simulate the dynamic changes in aboveground net primary productivity（ANPP）in the typical steppe of Inner Mongolia,based on meteorological data from 1953 to 2014and measured data from 1998 to 2013.The overall aim was to analyze the correlation between dynamic changes in ANPP and meteorological factors.The main findings were as follows：1）the trends in the measured values were highly consistent with those in the simulated values of ANPP at the research site from 1998 to 2013（Pearson＇s correlation coefficient,0.79;root-mean-square error,25.92g/m^2）.These results indicated that the CENTURY model has good applicability in the typical steppe in Xilinhaote,Inner Mongolia.2）The sensitivity analysis indicated that the main parameters of the model are soil physicochemical properties,the potential growth coefficient of grassland plants,and the most suitable and the highest temperature for plant growth at the research site.The determination of these parameters affected the accuracy of the model simulation results.3）From 1953 to 2014,the temperature in Xilinhaote,Inner Mongolia,significantly increased（P〈0.01）because of the significant rise in the annual average minimum temperature.The precipitation showed significant interannual fluctuations（variable coefficient,30.2%）.4）The simulated ANPP at the research site showed a declining trend from 1953 to 2014,but the trend was not significant（P〉0.05）.Correlation analyses showed that precipitation was the most important factor affecting the changes in ANPP（correlation coefficient between annual precipitation and ANPP=0.959;P〈0.01）.Temperature was weakly correlated with ANPP.