Abstract
Climate change and land-use changes are key drivers of global
biodiversity loss. Many species are shifting to higher elevations or
latitudes in response to global warming, often encountering unfavorable
land-use conditions during the shift. This leads to reduced range size
and increased extinction risks, particularly for mountain species, often
confined to narrow, high-altitude habitats. Predicting future
distributions of mountain species requires an accounting for their
bioclimatic responses, detailed topographical distribution, land-use
preferences, and ability to colonise new areas via dispersal mechanisms.
These elements are rarely considered together over large scales. Here,
we projected the future distribution of 32 mountain mammal and 344
non-migratory mountain bird species by 2050 under different emission
scenarios (SSP-RCP 1-2.6 and SSP-RCP 5-8.5). Using Species Distribution
Models (SDMs) that incorporated topography, climate, and land-use data,
we assessed the impacts of global change on species’ ranges across
mountain regions worldwide, accounting for realistic dispersal
scenarios. Under the high-emissions scenario, species were projected to
experience significantly greater range loss compared to the
low-emissions scenario, with a difference of 17% of loss for birds and
16% for mammals. The number of species that shift their range also
increased, passing from 73 to to 84. The most severe range losses were
projected for species located in tropical mountain ranges, while
European and North American mountains showed lower losses, highlighting
substantial regional differences in vulnerability. When land-use changes
were included in the models, projected range losses increased further,
particularly under the low-emissions scenario (+2%). Our findings
emphasize the importance of considering both climate and land-use
changes when assessing biodiversity risks in mountain regions. Our
results highlight the urgency of mitigating climate change and managing
land use to preserve the unique biodiversity of these areas.