2000-2020 年青海湖流域植被净初级生产力时空格局及驱动分析.

[Objective] The primary objective of this study is to investigate the spatiotemporal variations in net primary productivity (NPP) of vegetation within Qinghai Lake Basin from 2000 to 2020. Additionally, it aims to reveal the key factors and their contributive drivers of changes in vegetation NPP. The research is designed to provide a baseline scientific investigation on the dynamics of NPP within Qinghai Lake Basin. [Methods] We used data on vegetation NPP, temperature, precipitation, fractional vegetation cover, and human activity intensity in Qinghai Lake Basin from 2000 to 2020 to analyze the spatiotemporal changes of vegetation NPP across sub-basins, elevations, and micro-terrain in Qinghai Lake Basin. We applied spatial analysis using ArcGIS and the geographic detector model to conduct these analyses. Furthermore, we also investigated the correlations of vegetation NPP with temperature, precipitation, and fractional vegetation cover, as well as the driving factors of vegetation NPP. [Results] (1) In the past 21 years, the annual vegetation NPP in the Qinghai Lake Basin exhibited a fluctuating increase across temporal scales, with a growth rate of 2.22 g C·m²/a, and a spatially increasing trend from northwest to southeast. (2) The study also revealed spatially significant correlations between annual vegetation NPP and mean annual temperature, annual precipitation, and annual fractional vegetation cover, with ratios of 40%, 9%, and 59%, respectively. The primary partial correlation coefficients between mean annual temperature and annual precipitation with annual vegetation NPP encompassed 59.26% and 33.39% of the basin area. (3) The results of our study also revealed that temperature (q=0.58), elevation (q=0.54), and human activity intensity (q=0.38) were principal drivers of basin-scale NPP. Additionally, the interactive impact of these factors was found to better explain these drives than any single factor. [Conclusion] The NPP of vegetation in Qinghai Lake Basin increased over temporal scales from 2000 to 2020. Our study showed spatially significant differences in NPP across elevation, sub-watersheds, and microtopographic patterns. The interactions of temperature, altitude, and human activities were the main driving factors of NPP in the Qinghai Lake Basin. [ABSTRACT FROM AUTHOR]