[Spatial Heterogeneity of Ecosystem Services in Dongting Lake District Based on LUCC and Its Driving Factors]

The Dongting Lake district, as an important ecological barrier and water source conservation district in the middle reaches of the Yangtze River, plays an irreplaceable role in maintaining regional ecological security and flood control and regulation. However, in recent years, human activities such as the reclamation of lakes for farmland and urban expansion have intensified the contradiction between ecological protection and socio-economic development in this district. Taking the Dongting Lake district, a key ecological barrier in the middle reaches of the Yangtze River, as the research district, based on land use change data from 2000 to 2020, combined with the InVEST model and spatial statistical methods, this study systematically evaluated the spatio-temporal evolution characteristics of four ecosystem services: water yield, carbon storage, soil retention, and habitat quality. Local spatial autocorrelation analysis was conducted using GeoDa to reveal the multi-scale trade-off and synergy relationships and their driving mechanisms. The results show that: ① The study district generally presented a land use pattern dominated by "forest land-cultivated land," with significant expansion of construction land and continuous reduction of cultivated land and forest land. ② The total amount of ecosystem services varied significantly, with water yield and soil retention continuously increasing, while carbon storage and habitat quality gradually decreased year by year, showing a gradient feature of "high in the southwest-low in the northeast" in space. ③ The synergy relationship dominated among ecosystem services, but there was a significant trade-off between water yield and habitat quality, and both trade-off hotspots (such as the lakeside zone) and synergy cores (such as the forest land in the southwest) coexisted at the local scale. ④ Logistic regression analysis showed that natural and social factors jointly influenced the spatial heterogeneity of trade-offs and synergies among ecosystem services. Slope and precipitation promoted the synergy among ecosystem services, while elevation and NDVI inhibited the synergy related to water yield. Socio-economic development strengthened the trade-off relationship among ecosystem services, and population density promoted the synergy between habitat quality and soil retention and carbon storage, reducing the possibility of synergy between water yield and soil retention and carbon storage. The study proposes a spatial governance framework of "priority conservation in the southwest and corridor restoration in the northeast," providing a scientific basis for the optimization of the ecological protection red line in the Yangtze River Basin and the sustainable management of global subtropical lakes and marsh wetlands.