Abstract: Construction and optimization of ecological security network is an efficient way to ensure regional ecological security and achieve sustainable development. Based on the morphological spatial pattern analysis method, circuit theory and other methods, we constructed the ecological security network of the Shule River Basin. The PLUS model was used to predict the land use change in 2030, with the aim to explore the current ecological protection direction and propose reasonable optimization strategies. The results showed that there were 20 ecological sources in the Shule River Basin, with a total area of 15774.08 km², accounting for 12.3% of the total area of study area. The ecological sources were mainly distributed in the south part of the study area. A total of 37 potential ecological corridors were extracted, including 22 important ecological corridors, which showed the overall spatial characteristics of vertical distribution. Meanwhile, 19 ecological pinch points and 17 ecological obstacle points were identified. We predicted that the expansion of construction land would continue to squeeze the ecological space by 2030, and identified 6 warning areas of ecological protection space to effectively avoid conflicts between ecological protection and economic development. After optimization, 14 new ecological sources and 17 stepping stones were added, and the circuitry, ratio of line to node and connectivity index of the ecological security network increased by 18.3%, 15.5%, and 8.2% respectively compared with those before optimization, forming a structurally stable ecological security network. The results could provide scientific basis for ecological security network optimization and ecological restoration.

Key words: ecological security, network optimization, morphological spatial pattern analysis, ecological security pattern, Shule River Basin