Climate Change Drives Shifts in Suitable Habitats of Three Stipa purpurea Alpine Steppes on the Western Tibetan Plateau

The alpine steppe has an important place in alpine ecosystems, and its distribution pattern is strongly influenced by climate change. In this study, we used “biomod2” and “FragStats 4.2” to calculate the migration trends and the habitat fragmentation of three S. purpurea alpine steppes on the western Tibetan Plateau. The results of this study show that the Stipa purpurea-Ceratoides compacta alpine steppe, the Stipa purpurea-Carex moorcroftii alpine steppe, and the Stipa purpurea-Carex montis-everestii alpine steppe are strongly influenced by climate, while other variables have less impact. Their main influence factors are annual precipitation (Bio12), precipitation of the warmest quarter (Bio18), and precipitation of the coldest quarter (Bio19), respectively. The effects of carbon emissions on the suitable habitats of all three S. purpurea alpine steppes are significant in future scenarios. Continued increases in carbon emissions will lead to a continuous reduction in their suitable habitat areas. These communities are bounded by 33° N. South of the boundary, steppe communities are influenced by mountain ranges and show a tendency to migrate to higher elevations in a southward direction. North of the boundary, steppe communities show a tendency to migrate to higher elevations in a northward direction. Climate change reduces community aggregation, leading to gradual habitat fragmentation. The findings of this study provide a scientific basis for the migration and conservation of three S. purpurea alpine steppes on the western Tibetan Plateau, thereby contributing to the improvement of ecosystem stability and species diversity.