Quantitative analysis of the impact of climate change and human activities on vegetation NPP in the Qilian Mountain

Abstract Qilian Mountain as an important ecological security barrier and water connotation area in China, Research on its vegetation NPP driving mechanism can provide reference for ecological security protection in northwest China. Based on Qilian Mountain MOD17A3 remote sensing data from 2000-2019, using one-dimensional linear regression, partial correlation analysis, multiple linear regression, residual analysis and land transfer matrix. The spatial and temporal dynamics of vegetation NPP in the Qilian Mountain and its correlation with precipitation, temperature and human activities were analyzed, and quantified the effects of climate change and human activities on vegetation NPP. The results show that: 1) from 2000 to 2019 vegetation NPP in Qilian Mountains had an overall fluctuating upward trend and decreased from east to west, with a multi-year average of 138.54 g C·m−2·a−1 and an average annual increase of 1.67 g C·m−2·a−1; 2) vegetation NPP was positively correlated with precipitation and temperature, with precipitation having a more significant effect on it; 3) the area of grassland in LUCC increased the most and contributed 183.12% to vegetation NPP, while the area of unused land decreased the most and its contribution to vegetation NPP was −119.6%; 4) In the vegetation recovery area, climate change and human activities explained 89% and 11% of the vegetation recovery, respectively. While in the vegetation degradation area, they explained 22% and 78% of the vegetation degradation, respectively.