Temporal and spatial analysis of the ecosystem service values in the Three Gorges Reservoir area of China based on land use change.

The Three Gorges Reservoir area (TGRA) has complex geological conditions and a fragile ecological environment. The construction of the Three Gorges Project triggered ecological and environmental issues and social disputes, which have attracted considerable attention in recent years. However, how the temporal and spatial characteristics of ecosystem service value (ESV) in the TGRA changed in each stage of the Three Gorges Project with the implementation of ecological restoration plans remains ambiguous. Based on four periods of land use data from 2000 to 2018, the changes in land use were investigated, and the ESVs were estimated. Then, the spatial distribution and dynamic changes in ecosystem services were analysed. The results showed that grassland and construction land were the land use types that had the greatest reductions and increases in area over time, respectively. The conversion of cropland to forestland, grassland and construction land represented the most important land type changes. In the past 18 years, because of an increase in forestland and water area, the ESVs increased by 2.7 billion yuan, with a growth rate of 3.46%. The conversion of cropland to forestland had the largest contribution rate to the increase in ESV. The ESV was higher in the northeast and lower in the southwest, and its changes had a significant positive autocorrelation in terms of the spatial distribution. The hot spots of ESV change were mainly distributed in the main stream of the Yangtze River and the reservoir area. This research provides a reference for land resource allocation and experience for the ecological environment protection and sustainable development of the Yangtze River Basin.