内蒙古草地NPP变化特征及其对气候变化敏感性的CENTURY模拟研究

气候变化及其对植被净初级生产力的影响是全球变化研究的核心内容之一。基于空间化的CENTURY生物过程模型,分析1981-2010年内蒙古草地净初级生产力（NPP）的时空演变规律及其对关键气候因子的敏感性特征。结果表明：近30年内蒙古草地大部分区域NPP呈下降态势但趋势并不显著,全区平均降速约为1.17 g C/m²·a;NPP年代际变化时空差异较大,1980s至1990s约69.65%的区域NPP下降,1990s至2000s NPP下降加剧,下降面积较前者扩大了17.50%;NPP对降水与温度的敏感性特征空间异质性较强,但总体上区域降水减少可能是近30年内蒙古草地NPP下降的主要因素,温度升高同样会导致草地NPP下降,但作用程度较小。

Analysis of changes in net primary productivity and its susceptibility to climate change of Inner Mongolian grasslands using the CENTURY model

Climate change significantly influences regional terrestrial carbon balances. The grasslands of Inner Mongolia, located within the mid-Eurasian continental steppe zone, play an important role in the study of global change processes in the context of their particular geographical location, characterized by climatic variability and a complex natural environment. In this study, a CENTURY-based modeling system (converting the CENTURY model from a site-based model to a spatial model) was used to investigate climate change -- driven spatiotemporal variations in the vegetation net primary production (NPP) within Inner Mongolian grasslands from 1981 to 2010. Our simulation indicated that the NPP has decreased over the majority (88.62%) of the Inner Mongolian grasslands since 1981, at an average rate of 1.17 g C/m²·a over the entire area. However, there is significant decadal variability. From the 1980s to 1990s, some 69.65% of the domain experienced a reduction in the decadal average NPP, while the NPP decreased over 81.84% of the total area from the 1990s to 2000s, suggesting the worsening status of vegetation in recent decades. At the regional scale, changes in precipitation and temperature respectively accounted for 78% and 22% of the NPP decrease; however, their relative contributions were not constant across the study area or across different grassland types.