Trade-offs and synergies among ecosystem services and their responses to land use change: A Case study from the subtropical hilly region of Guangdong, Jiangxi and Fujian provinces in China

The Guangdong, Jiangxi and Fujian (GJF) provinces, located in the subtropical region of southeastern China, is one of the national key regions for soil erosion control and ecological restoration. This region is characterized by extensive red soil development and high rainfall erosivity, making it a representative landscape for exploring the interactions between land use change (LUC) and ecosystem services (ES). Despite the recognized importance of ES in hilly regions, comprehensive assessing the impacts of LUC on ES remain limited. This study investigates five key ES: water yield, soil conservation, carbon conservation, food supply, and habitat quality in GJF region from 2000 to 2020. By applying the InVEST model and the Geodetector method, we assessed the trade-offs, synergies, and transitions among ES, identified the natural and social drivers of ES dynamics, and quantified the contribution of LUC to ES changes using the ecosystem service contribution index. The results showed that cropland and woodland were the dominant land use types. Ecological restoration efforts positively influenced ES, with synergies intensifying and trade-offs diminishing over time. Land use conversions, particularly among woodland, grassland, and cropland, exerted significant impacts on ES. In particular, the conversion of woodland to other land uses had markedly negative effects on soil conservation, carbon conservation, and habitat quality. Forest cover was identified as a major driver of ES dynamics. These findings highlight the importance of maintaining and expanding forest and grassland cover, strengthening red soil conservation, and optimizing land use structure to achieve coordinated ecological protection and socioeconomic development in the subtropical hilly regions of southern China.