Spatial-temporal evolution and driving force of carbon sequestration function in typical counties of the Three Gorges Reservoir area: Wanzhou case

Under global climate change, ecologically fragile regions face prominent ecological and climate challenges. Examining the spatiotemporal evolution of carbon sequestration in such regions is crucial for reinforcing ecological protection and mitigating climate change impacts.This study aims to analyze the dynamic response of carbon sequestration to land use types, reveal the driving mechanisms of natural and socioeconomic factors, and assess carbon stock variations in sloping farmland under erosion–deposition conditions in Wanzhou, Three Gorges Reservoir Area (TGRA).This study adopts multi-source remote sensing data and a geographical detector model to investigate Wanzhou in the Three Gorges Reservoir Area (TGRA) from 1990 to 2020.Wanzhou’s land use showed distinct spatiotemporal heterogeneity, presenting a "four decreases and three increases" pattern. Cultivated land reduced most (112.88 km²), while construction land increased most (87.16 km²). Carbon sequestration ranged 0–12.02 t·ha⁻¹·a⁻¹, with a net gain of 839.3 thousand tons; forest land was the main carbon sink, and converting sloping farmland to forest enhanced sequestration. Carbon sequestration was co-driven by natural and socioeconomic factors, with precipitation having the highest explanatory power (0.35), followed by NDVI (0.084), and all factor interactions strengthened explanatory capacity. Erosion–deposition dynamics strongly affected sloping farmland carbon stocks (CV: 2.07, 2.4, 2.55, 2.2), with obvious spatial clustering changes.The findings offer a scientific basis for enhancing terrestrial carbon sequestration and guiding spatial management of sloping farmland in the TGRA.