Simulation of Potential Distribution of the Xizang Brown Bear and Analysis of Its Driving Factors Based on Biomod2: A Case Study of the Three-River-Source National Park

The Xizang brown bear (Ursus arctos pruinosus) is a Class II national protected wildlife species by the Chinese government and one of the flagship species in the Three-River-Source National Park. Identifying its potential habitat distribution is of great significance for maintaining regional ecosystem balance, preserving biodiversity, and reducing human-wildlife conflicts. Based on the existing distribution data and environmental factors (e.g., climate, human activity, soil, and vegetation), the research applied the species distribution models form Biomod2 to simulate the potential habitat distribution of the Xizang brown bear. The results suggest: (1) the RF model out of the 8 models exhibits the highest accuracy and simulation performance; (2) the total area of medium- and high-suitability areas for the Xizang brown bear in the Three-River-Source National Park is 24,700 km², most of which are concentrated in the Yangtze-River-Source Park and the Yellow-River-Source Park; (3) isothermality, annual precipitation, mean diurnal temperature range, and distance to villages are key factors influencing the potential distribution of the Xizang brown bear.