Landscape Ecological Security of the Lijiang River Basin in China: Spatiotemporal Evolution and Pattern Optimization

The ecological security of karst basins is receiving increased attention as a result of intense human activity and climate change. However, how ecological security evolves in spacetime and the optimization of ecological security patterns still remain unclear. This study developed a methodological framework for evaluating ecological security and optimizing ecological security patterns of the Lijiang River Basin (LRB). The 3S technology was used to analyze the current status and evolution characteristics of landscape ecological security in the LRB from 1990 to 2020. This study identified and optimized ecological security patterns by adhering to the basic paradigm of "source identification-resistance surface construction-corridor extraction-node determination". The results showed that the overall ecological security of the LRB was at a medium to high level, with an index showing an initial increase followed by a decrease. The LRB exhibited 24 ecological pinch points, 74 ecological corridors, 30 ecological sources, and 6 ecological barrier points. The predominant landscape types found within these pinch points and barrier points encompass forests, cultivated land, and urban areas. A scheme of "three cores, two belts, and six zones" was proposed to optimize the ecological security pattern of the LRB. This study provides a theoretical basis and technical references for the integrated management of the rivers, grasslands, farmlands, mountains, lakes, forests, and sands in the LRB, as well as for the ecological restoration of other regions.