摘要
The Yellow River Basin spans three geographical steps across eastern,central,and western China and exhibits pronounced regional heterogeneity and sensitivity to extreme heat conditions.This study employed the Carnegie-Ames-Stanford Approach(CASA)model to quantify the spatiotemporal patterns of vegetation net primary productivity(NPP)in the basin(2000-2022).A dynamic climate econometric model was employed to evaluate the impact of extreme heat stress on vegetation carbon sequestration and quantify the anthropogenic contributions to heat-induced NPP changes.The results indicated that extreme heat significantly suppressed vegetation carbon sequestration in the Yellow River Basin from 2000 to 2022.Each additional day of extreme heat reduced the NPP by approximately 0.21%,with this inhibitory effect persisting into the following year.The marginal effects of extreme heat exhibited significant heterogeneity,modulated by both the mean annual temperature and temperature variability.Specifically,more pronounced NPP suppression was observed in regions characterized by elevated mean annual temperatures and enhanced temperature variability.Furthermore,the anthropogenic contributions to extreme heat days progressively increased,with a continuously expanding spatial influence.Consequently,anthropogenic extreme heatinduced carbon sequestration losses accelerated after 2008,reaching 1.49×10^(13)g C in 2020(~7.05%of annual sequestration).These findings provide critical evidence for optimizing ecological strategies in the Yellow River Basin and inform global climate change policies.
基金
supported by the National Natural Science Foundation of China(Grant Nos.42471467&42293270)。
