Identifying the ecological security patterns of the Three Gorges Reservoir Region, China.

Identifying and improving the existing ecological security patterns (ESPs) are of great importance to promoting ecological security and achieving sustainable development goals. The Three Gorges Reservoir Region (TGRR) is an area with a sensitive, fragile, and complex ecological environment in the Upper Reaches of the Yangtze River. The construction of ESPs for the TGRR is significant for maintaining regional ecosystem stability and promoting peaceful coexistence between humans and nature. The main objective of the study is to identify the ecological nodes, ecological corridors, and ecological sources that play essential roles in the ecosystem. Based on land use data and human interference factors, we have evaluated the current habitat quality using the InVEST model and identified vital ecological sources for the TGRR. The negative exponential transformation function was used to convert habitat suitability into a landscape resistance layer. Circuit theory modeling was utilized to identify ecological corridors, and the final ESPs of the TGRR were then constructed. Results showed that (a) the spatial distribution of habitat varied significantly in the TGRR. The optimal habitats were concentrated in the northeast, east, and southwest, accounting for 45.98% of the total suitable habitats; (b) habitat quality varied through space, with habitat quality being higher in the northeast and lower in the western regions. (c) Ecological sources were distributed primarily in the forests with high vegetation coverage in the east. The total area of ecological sources was about 15,412 km2, approximately accounting for 34% of the study area; (d) the ESPs were dominated by ecological sources composed of forests, which were radially connected by ecological corridors. In total, these included 14 significant ecological sources, 25 clusters of ecological corridors, and 23 ecological nodes. The results are of great significance to promote the ecological security of the TGRR and could provide theoretical support for biodiversity conservation and territorial space planning for the Three Gorges Region.