Study on the Spatiotemporal Changes and Driving Factors of Habitat Quality in the Yarlung Zangbo River From 2000 to 2020.

The Yarlung Zangbo River (YLZB), the world's highest plateau river, possesses a particularly fragile ecosystem, making it highly vulnerable to global climate change. Understanding changes in YLZB habitat quality and their driving mechanisms is crucial for ecological protection and sustainable development in the region. Based on land use data from 2000 to 2020, we conducted a quantitative study on the spatiotemporal changes and driving mechanisms of habitat quality in the YLZB. This study employed habitat quality model, Land Use Transition Matrix, optimal parameter geographical detector, and partial least squares structural equation model (PLS-SEM). The results show that: (1) Forests, grasslands, and unused land account for 94.14% of the basin area. The areas of unused land, forest land, and water bodies have continuously increased, while the areas of grasslands, permanent glaciers, and snowfields have continuously decreased. The decline was most pronounced from 2005 to 2010. (2) The habitat quality in the study area is higher in the southeast and lower in the west. The area of degraded habitats is significantly larger than that of improved habitats. (3) NDVI, elevation, and annual average temperature are key factors affecting changes in habitat quality. Elevation indirectly affects NDVI by influencing climate conditions, leading to a decline in habitat quality. This study provides a scientific basis for understanding ecological trends in YLZB habitat quality, it provides new insights into the intrinsic driving mechanisms in high-altitude regions, and it offers theoretical support for relevant departments to implement sustainable management and conservation efforts.