Terrestrial ecosystem carbon storage responses to land cover evolution under future multi-scenario in ecological function zone for soil and water conservation of the Three Gorges Reservoir, China

The Ecological Function Zone for Soil and Water Conservation of the Three Gorges Reservoir (EFZSWCTGR) is a key ecological barrier but has undergone land use and cover change that may alter terrestrial carbon storage (CS). Here, we propose a framework to quantify CS responses to land cover evolution and simulate three scenarios for 2040: MES-maintaining ecosystem stability by protecting forest and promoting Grain for Green; SRC-accommodating urbanization and cultivated land protection; and HCS-high CS by expanding carbon sinks and reducing carbon sources. From 2000 to 2020, CS declined, with sinks concentrated in the Daba and Wuling Mountain ranges and sources clustered in the hydro-fluctuation belt and low-altitude arable land. Scenario simulations show that HCS yields a net CS increase, MES slows CS loss, and SRC causes additional decline. The findings provide spatially explicit guidance for reconciling ecological protection, cultivated land conservation and low carbon development in EFZSWCTGR and similar zones.