Faculty of Mathematics and Natural Sciences - Biogeography

Faculty of Mathematics and Natural Sciences | Geography Department | Biogeography | News | Importance of rear-edge populations under climate change

Importance of rear-edge populations under climate change

 

N. Habibzadeh, A. Ghoddousi, B. Bleyhl & T. Kuemmerle

 

Summary:

Climate change threatens wildlife populations globally. Particularly rear-edge populations that typically occupy warmer areas than core populations are at stake when temperatures rise. In our new paper, we show for Caucasian grouse that rear-edge populations harbor important adaptive capacity for species to adapt to warmer climates. Our study also demonstrates that ignoring rear-edge populations in range shift predictions leads to a substantial underestimation of the future potential range. Preventing the loss of rear-edge populations should therefore be a priority to support climate change adaptation for species.
 

Abstract:

Climate change disproportionately threatens alpine species, by reducing available habitat and by isolating their populations. These pressures are particularly relevant for rear-edge populations, which typically occupy more marginal habitat compared to populations at the core of species’ ranges. We studied Caucasian grouse Lyrurus mlokosiewiczi in the Caucasus ecoregion, a global biodiversity hotspot where this species is endemic, to understand potential climate change impacts on the species. Specifically, we assessed how climate change impacts rear-edge populations and how important these populations are for understanding range shifts and adaptive capacity under climate change. We used maximum entropy modelling to assess changes in the distribution of climatically-suitable habitat under present and 2070 climate conditions for the representative concentration pathways 8.5 (RCP8.5). Our results revealed that ignoring rear-edge populations leads to a significant underestimation of the future range (by about 14,700 km²). Rear-edge populations were better adapted to warmer climates compared to core populations, and ignoring them therefore also underestimates adaptive capacity. Preventing the loss of rear-edge populations should therefore be a priority for conservation planning in the face of climate change. Because the Caucasian grouse is associated with alpine mountain tops, conservation should focus on establishing connectivity between rear-edge and core populations (e.g., via transboundary corridors or assisted colonizations). Our study reveals how species distribution modelling can highlight the importance of rear-edge populations for mitigating climate change impacts on species of conservation concern.

Link to the manuscript: https://doi.org/10.1111/csp2.375

Citation:  Habibzadeh, N., Ghoddousi, A., Bleyhl, B., Kuemmerle, T. Rear‐edge populations are important for understanding climate change risk and adaptation potential of threatened species. Conservation Science and Practice. 2021;e375. https://doi.org/10.1111/csp2.375