天山北坡山地-绿洲-荒漠系统碳储量梯度效应时空演变及机理OA

To support the"Dual Carbon"goals under global change,elucidating the spatiotemporal dynamics and driving mechanisms of carbon storage in arid mountain-oasis-desert systems is crucial for achieving regional carbon balance and sustainable development.This study applied the InVEST model to estimate carbon storage from 1990 to 2020 in the north slope of the Tianshan Mountain.By integrating mountain-descent gradient analysis and bivariate spatial autocorrelation,we systematically revealed its spatiotemporal patterns and the linkage with the gradient.The optimal parameter-based geographical detector was then used to investigate the driving factors.The results indicate that:1)Temporally,carbon storage decreased initially and then increased,with a net gain of 4.06×107 t since 2000,primarily attributed to the conversion of unused land to cropland and grassland.Spatially,it showed a belt-shaped decreasing pattern along the gradient.2)Carbon storage was positively correlated with the gradient.Areal carbon density followed a"stable-then-sharp increase"pattern with increasing elevation,reflecting a dynamic equilibrium between human activities and natural constraints along the topographic gradient.3)The driving mechanisms exhibited spatial heterogeneity:dominated by anthropogenic factors at low gradients,by human-land interaction at medium gradients,and by natural controls at high gradients.Temporally,the dominant drivers shifted from socioeconomic factors to land-use intensity,and finally to a dual synergy between socioeconomic activity and nighttime light intensity,indicating a regional transition toward more refined spatial governance.This study enhances the theoretical understanding of human-land coupling in mountain-oasis-desert systems and provides a scientific basis for territorial spatial optimization and carbon sequestration enhancement in arid regions.