Climate Velocity and Species Migration Corridors

Abstract

Climate velocity -- the rate and direction at which climatic conditions are shifting across the landscape, expressed as
km/year in the direction of greatest temperature change -- determines whether species can track their climatic niche
through space as climate changes, and where migration corridors are needed to facilitate range shifts that fragmented
landscapes would otherwise prevent. This study mapped climate velocity at 1 km resolution across Europe under three
CMIP6 scenarios (SSP1-2.6, SSP2-4.5, SSP5-8.5) for 2050 and 2070, and integrated climate velocity maps with species
distribution models (SDMs; MaxEnt; n = 284 vertebrate species) and landscape connectivity models (Circuitscape) to
identify priority migration corridors where current protected area networks are insufficient to facilitate species range shifts
at the pace required by projected climate velocity. Mean European climate velocity under SSP5-8.5 by 2070 was 4.84 +-
1.84 km/year (northward and upslope), ranging from 1.84 km/year in topographically complex Alpine terrain to 8.84
km/year in flat lowland agricultural landscapes. Species-specific velocity debt -- the difference between projected climate
velocity and observed or modelled dispersal capacity -- was positive (velocity exceeding dispersal) for 184 of 284 species
(64.8%) under SSP5-8.5, identifying these as unable to track climate without corridor-assisted dispersal.
Circuitscape-based corridor mapping identified 48 priority migration corridors across Europe with combined area of
28,484 km2, concentrated in four major latitudinal transition zones. Corridor implementation cost-effectiveness analysis
showed that targeted restoration of 284 km2 of habitat in identified pinch-points would reduce velocity debt for a mean of
18.4 additional species per pinch-point. These results provide a spatially explicit framework for integrating climate
velocity into European protected area planning under the EU Nature Restoration Law (2023) and Kunming-Montreal
Global Biodiversity Framework Target 3.