金沙江流域植被建设的碳效应评估与适宜阈值分析OA

Vegetation restoration serves as a crucial measure for enhancing terrestrial carbon sequestration and mitigating climate change;however,it may indirectly affect the power generation capacity and carbon reduction benefits of hydropower stations by influencing evapotranspiration and runoff in the basin.Deter-mining the appropriate scale of vegetation restoration at the basin level plays an important role in the en-hancement of its direct carbon sink effect and indirect contribution to hydropower carbon reduction bene-fits.This study employs the WaSSI-CN water-carbon coupled model to simulate the spatiotemporal re-sponses of runoff and net primary productivity(NPP)in the Jinsha River Basin under future climate change and various land-use scenarios.The aim is to evaluate the impact of vegetation expansion on both carbon sink effect and hydropower-driven carbon reduction benefits,and to propose suitable thresholds for vegetation restoration that maximize integrated carbon reduction benefits.The results indicate a warming and wetting trend across the basin under SSP1-2.6,SSP3-7.0,and SSP5-8.5 scenarios,with forest area expanding progressively from downstream to midstream regions,primarily through conversion from grass-land.As the forest proportion increases,runoff decreases while NPP rises,and then both eventually sta-bilize at a certain level.The integrated carbon reduction benefit of the basin reaches its peak when the forest area increases by 11%,achieving values of 501×106,482×106 and 500×106 t CO2/a under SSP1-2.6,SSP3-7.0,and SSP5-8.5 scenarios,respectively.These findings quantitatively reveal the trade-off between the ecosystem carbon sink and hydropower-related carbon reduction induced by vegeta-tion restoration.The identified optimal threshold provides a scientific basis for ecological planning and low-carbon development strategies in the Jinsha River Basin.