Habitat fragmentation of three ungulate species in the Altay region of Xinjiang, China

Under global climate change and intensified human activities, habitats in northwestern China’s Altay region—comprising forests, grasslands, deserts, and alpine areas—are increasingly fragmented. This study assessed the suitable habitat distribution and fragmentation characteristics of three ungulate species: red deer, goitered gazelle, and Siberian ibex. An ensemble species distribution model based on BIOMOD2 was used, and fragmentation metrics were calculated with the landscapemetrics R package. Red deer had the largest suitable area (20,688.54 km²), followed by goitered gazelle (16,342.25 km²) and Siberian ibex (11,477.62 km²). Fragmentation analysis revealed that red deer habitat patches in forest areas had the highest patch density (PD = 0.042); grasslands showed the largest dominant patches (LPI = 63.31) and highest aggregation (AI = 74.45). Gazelle habitats in deserts were the least fragmented (PD = 0.017, AI = 92.06), while ibex habitats in grasslands had higher fragmentation (PD = 0.046) but moderate aggregation (AI = 75.31). The results reveal clear interspecific differences in habitat suitability and landscape patterns, highlighting species-specific responses to environmental gradients. This study provides a scientific basis for habitat management, conservation planning, and connectivity enhancement for large herbivores in cold-arid ecotones.