内蒙古草原NPP时空变化及驱动力

植被净初级生产力（NPP）及驱动力分析是全球变化研究的核心内容。以1982—2015年内蒙古草原为研究对象，基于GIMMS NDVI3g、ERA5气象和草原类型数据，采用CASA模型生成年草原NPP。综合运用趋势分析、偏相关、复相关及残差分析法探讨1982—2015年草原NPP变化趋势，并定量确定气候因子和人类活动对草原动态变化的影响程度。结果表明：（1）内蒙古1982—2015年NPP极显著和显著增加的草原面积占草原总面积的11.76%、18.92%。NPP极显著和显著减少的草原面积占草原总面积的4.26%、8.08%。草原NPP增加的面积大于减少的面积，草原处于恢复状态。（2）内蒙古草原92.87%的区域NPP与气候因子之间表现出很好的相关性，气温驱动、降水驱动和降水、气温复合驱动分别占总面积的2.06%、70.71%和20.11%，气候变化对3种草原影响程度荒漠草原>典型草原>草甸草原。（3）人类活动对草原NPP也产生很大影响。其中起到正向作用通过显著性检验（P<0.1）的区域占草原总面积的41.12%，起到负作用（P<0.1）的占5.34%。综上所述，1982—2015年内蒙古草原总体处于恢复状态，在气候和人类活动共同作用下生态环境得到了极大改善。

Spatial and temporal variation of grassland NPP and its driving forces in Inner Mongolia

Net primary production（NPP）and its driving force analysis is one of the key issues in global change research. Based on GIMMS NDVI3g， ERA5 meteorological and grassland type data， annual grassland NPP was generated by CASA model. Taking grass of Inner Mongolia as the research object， the change trend of grassland NPP （1982-2015） were analyzed by using the trend analysis， partial correlation， multiple correlation and residual analysis， and the impact of climate factors and human activities on the NPP change was quantitatively determined. The results showed that： （1） From 1982 to 2015， the grassland area with extremely significant （P<0.01） and significant （P<0.05） NPP increase accounted for 8.83% and 24.01% of the total area of the study area； while the area with extremely significant （P<0.01） and significant （P<0.05） decrease accounted for 4.26% and 8.08%. The area of NPP increase was greater than the area of decrease， showing the grassland in recovery state. （2） 92.87% of the area in the study area showed a good correlation of NPP with climate factors. The temperature driving， precipitation driving and composite driving of precipitation and temperature accounted for 2.06%， 70.71% and 20.11% of the total area， respectively. The impact of climate change on the three grasslands was desert steppe > typical steppe > meadow steppe. （3） Human activities also had a great impact on grassland NPP. Among them， 41.12% of the total grassland area played a positive role （P<0.1） and 5.34% played a negative role （P<0.1）. In summary， from 1982 to 2015， the grasslands in Inner Mongolia were generally in a state of restoration， and the ecological environment was greatly improved under the combined effects of climate and human activities.