【摘要】 利用内蒙古锡林浩特国家气候观象台1994～2009年牧草生长季逐月实测资料,对CENTURY模型进行检验,模拟内蒙古典型草原1953～2010年间地上净初级生产力(ANPP)动态,并与26个气象因子进行相关性分析。模型检验结果显示,模拟值与观测值之间的相关系数为R2=0.66,斜率b=0.95,误差平方根值为50.51g.m-2,平均绝对百分比误差为44.19%。结果表明:(1)CENTURY模型能比较准确地模拟这类草原的季节动态和年际变化;在过去的58年中,内蒙古典型草原温度增加,降水减少,ANPP下降;ANPP变化趋势与降水量相似。(2)用实际气象观测资料模拟获得的ANPP随气温和降水的变化呈现出明显的变化规律,生长季内地上生物量对降水和温度的季节性分布也非常敏感;相关分析进一步表明,ANPP对生长季内降水量和极端高温非常敏感,而与年极端最低气温、平均地面温度、日照时数、平均风速和最大积雪深度无显著相关关系;过去58年研究区ANPP下降是降水减少、温度升高以及干旱事件频发共同作用的结果。(3)根据预测,在SRES B2情景下,未来50～100年内蒙古典型草原生长季平均最高气温和最低气温都将呈升高趋势,2080s分别升高4.01℃、4.35℃,每10年增加速率分别为0.35℃和0.38℃;降水量略呈增加,2020s、2050s和2080s研究区生长季将分别增加3.17%、5.13%和7.03%,每10年增加速率为0.09mm;ANPP呈下降趋势年际间波动较大,2020s、2050s和2080s研究区将分别下降5.76%、7.52%和11.42%,每10年下降速率为0.76g.m-2。更多还原

【Abstract】 Long-term ecological research collected a large amount of data on aboveground biomass and productivity,together with climatic and soil regimes for typical grassland ecosystem in Inner Mongolia Xilinhaote National Climate Observatory.Using monthly data by observation in growing season during 1994~2009,we tested CENTURY model successfully.Dynamic changes of simulated the aboveground net primary production(ANPP) were studied by CENTURY model in Inner Mongolia typical steppe during the 1953~2010,and correlations of ANPP and 26 meteorological factors are analyzed.Model test results showed that the R2 for the comparison of observed and simulated aboveground biomass was 0.66,slope b was 0.95 and root mean square error was 50.51 g·m-2 and the ratio of the absolute mean error was 44.19%.The means and variation limits of the model are close to that of field data.The results suggested that:(1)CENTURY model can successfully simulate the seasonal and inter-annual dynamics of ANPP in Inner Mongolia typical steppe.In the past 58 years,temperature increased,precipitation decreased and ANPP were on the downward trend,and the change of ANPP was very similar with precipitation.(2)Simulated ANPP using meteorological data showed significant variation with changes of temperature and precipitation.Aboveground biomass of growing season was very sensitive to temperature and precipitation distribution.Correlation analysis showed that most direct meteorological factors impacted on ANPP were precipitation and high temperature during the growing season.ANPP and annual extreme min temperature,mean surface temperature,sunshine duration,average wind speed and max snow cover depth correlation were not related.Precipitation decreasing,temperature rising,and frequency of drought events together led to ANPP on declining curve in the study area.(3)In the SRES B2 scenarios,mean max temperature and mean min temperature in growing season all showed increasing trends in Inner Mongolia typical steppe,in 2080s,respectively,increased by 4.01℃ and 4.35℃,increased rates were 0.35℃ and 0.38℃ per decade.Precipitation in growing season was a slight increase,which respectively increased by 3.17%,5.13% and 7.03% in 2020s,2050s and 2080s,increased rate was 0.09 mm per decade;ANPP was on a declining curve and existed more fluctuations between the annual,which decreased by 5.76%,7.52% and 11.42%,respectively in 2020s,2050s and 2080s,decreased rate was 0.76 g·m-2 per decade.更多还原