黄河源区植被总生产力对气候干旱的响应OA

Drought,as a key climatic factor influencing the terrestrial ecosystem carbon cycle,plays a significant regulatory role in vegetation gross primary productivity(GPP).The response mechanism of vegetation productivity to drought in the Yellow River Source Region,a crucial water conservation area in the Yellow River Basin,remains unclear.Therefore,based on Bayesian theory,Copula joint distribution,and SHAP interpretability methods,this study systematically evaluated the spatiotemporal impacts of drought on vegetation GPP and its driving mechanisms.The results indicated that:1)from 2002 to 2022,vegetation GPP in the Yellow River Source Region generally exhibited an increasing trend,with a spatial gradient decreasing from the southeast to the northwest;2)the standardized precipitation evapotranspiration index(SPEI)showed a positive correlation with GPP at the pixel scale,with a maximum correlation coefficient of 0.23;3)the lag time of vegetation response to climatic drought displayed spatial heterogeneity,with shorter lags in the southern and southeastern regions and longer lags in the northern and northwestern regions;4)the risk of vegetation loss in the western part of the source region was higher than in the eastern part,and the probability of vegetation loss increased with drought severity,though the rate of increase was relatively limited;5)temperature was the primary driver of GPP variation,coordinating with other environmental factors to influence vegetation productivity.This study reveals the spatiotemporal differences in vegetation productivity response to climatic drought in the Yellow River Source Region,providing a scientific basis for adaptive management of alpine ecosystems.