Construction of ecological security pattern based on ecological carrying capacity assessment 1990-2040: A case study of the Southwest Guangxi Karst- Beibu Gulf

The construction of ecological security pattern and ecological security network and reasonable ecological se-curity planning are of great significance for ecosystem protection and restoration and optimal regulation. This study takes the Southwest Guangxi Karst -Beibu Gulf as the study area. Based on the improved ecological footprint model and the Patch-generating Land Use Simulation (PLUS) model, the ecological carrying capacity changes and driving mechanisms from 1990 to 2040 were analysed. The study proposed the idea of "history -present-future" to construct an ecological security pattern, We have constructed an integrated "points, lines and surfaces" ecological security network and carried out ecological security optimization planning. The results show that (1) The overall 1990-2040 belongs to the medium-high carrying capacity grade, showing a trend of rising and then falling, and the spatial changes are dominated by the type of unchanging ecological carrying capacity. Nanning is the most severely damaged. Slope and temperature are the main driving factors. (2) A total of 17 ecological source patches were identified in this study. The ecological source patches account for the overall area in general, and their distribution is relatively concentrated, so the ecological security of the central city needs to be focused on. (3) This study extracts 17 ecological corridors and 11 karst ecological corridors, generating an integrated ecological security network structure of "points, lines and surfaces". The ecological optimization planning proposal of "two belts, three screens, four zones and multiple centers" is proposed.