Spatiotemporal Evolution Characteristics and Future Sustainable Scenario Simulation of Habitat Quality in the Chishui River Basin

Habitat degradation has become a critical bottleneck that restricts watershed ecological security and sustainable development. This study aims to reveal the spatiotemporal evolution of habitats in the Chishui River Basin, in order to provide scientific guidance for regional ecological conservation and restoration. Based on land use datasets from 1990 to 2023 in the basin, the InVEST-PLUS model is adopted to quantify habitat quality and conduct exploratory multiscenario simulations of future habitat conditions across the study area. The main results are as follows: (1) The average habitat quality index of the Chishui River Basin tends to decrease, with the area of high-grade habitat decreasing by 50.30%. The basin has undergone four distinct phases: high-intensity degradation, continuous but low-intensity structural change, large-scale ecological restoration, and active bidirectional adjustment. (2) Spatial pattern of habitat quality is strongly heterogeneous. Specifically, high-quality habitats are primarily distributed in the northern region of Chishui River Basin, while degraded habitats are concentrated in the central and southeastern parts of the basin, with an expanding trend. Habitat changes are characterized by leapfrog transfer and path dependence. Notably, low-grade habitats show an extremely high persistence rate of 97.16%. (3) Simulation outputs under diverse scenarios show that ecological protection serves as an effective strategy for improving habitat quality within the basin. Habitat quality of the Chishui River Basin has displayed a phased evolutionary pattern of initial degradation followed by recovery. Strengthening ecological protection will be the core approach to ameliorate watershed habitat quality and safeguard ecological security in the future. The study provides a scientific reference for watershed ecological conservation and restoration, territorial spatial optimization, and the construction of ecological barriers in the upper reaches of the Yangtze River.