西藏草地净初级生产力的时空格局演变及其驱动机制分析

本研究基于遥感和气象数据,采用净初级生产力(Net primary productivity,NPP)作为草地指标,辅以模型模拟和野外观测等方法探究西藏草地N PP的格局演化特征,并探究其潜在驱动因素.结果表明:研究期内西藏草地NPP年均值为136.46 gC·m-2·a-1,并以1.57 gC·m-2·a-1的变化率...

Analysis of the Spatial-Temporal Evolution Patterns of Grassland Net Primary Productivity and Its Driving Mechanisms in the Tibet

In this study,based on remote sensing and meteorological data,the evolution pattern and its potential driving factors of Tibetan grassland NPP (Spatiotemporal dynamics,Stability and continuity) were analyzed by using the Net primary productivity (NPP) combined with model simulation and field observations in this study.The results showed that the annual mean NPP of grassland in Tibet was 136.46 gC·m^-2·a^-1,and it showed a significant increasing trend with the change rate of 1.57 gC·m^-2·a^-1 during the study period.Grassland NPP showed a decreasing trend from southeast to northwest.In terms of future changes,the grassland NPP in Nyingchi,Nagqu and other places will consistently increase or decrease,while the junction of Xigaze,Ali,and Nagqu show an inconsistent tendency.The NPP distribution of different grassland types was also quite different,the alpine and subalpine meadows have the highest NPP value,while plain grasslands were the lowest.Grassland NPP was positively correlated with temperature,but not significantly correlated with precipitation,indicating that temperature was the limiting climate factor for grassland NPP in the region.The implementation of policies for human activities,such as rotation grazing in areas,fences,and enclosures has played an important role in promoting the increase of grassland NPP in Tibet.