Impacts of Climate-Land Dynamics on Global Population and Sub-Populations of a Desert Equid.

Climate change and escalating land-use transformations pose a significant threat to global biodiversity by disrupting natural habitats. The Asiatic wild ass (Equus hemionus), a near-threatened species, faces various pressures across its Asian range. This study employs a niche modeling approach to assess suitable habitats for the Asiatic wild ass at both the global population and sub-population levels. The analysis integrates the impacts of climate scenarios and land use change across three temporal periods: past, present, and future. To investigate the uncertainty of climate models for the Asiatic wild ass habitat, we used two climate models, CMIP5 and CMIP6, at both global and sub-population levels. Niche overlap models were developed to examine patterns of niche similarity among sub-populations. The results demonstrate a severe decline in both suitable habitat area and the number of viable patches for all sub-populations. Projections reveal that the Mongolian wild ass and Indian wild ass endure the highest levels of isolation and habitat loss, alongside the extinct Syrian wild ass. Sub-population models often predict larger distributions compared to global population models using the same inputs. The outputs of the models indicate a severe decline in suitable habitat, underscoring the necessity of accounting for both ecological and conservation perspectives to understand species distribution dynamics. Our study highlights the need to consider both global population and sub-population levels in climate change assessments. These models provide essential guidance for conservation strategies by identifying suitable habitats and sites for reintroduction. Identifying habitat patches as refuges for large herbivores amidst land-use changes and climate fluctuations is crucial. Incorporating these patches into conservation planning is imperative for preserving biodiversity.