Climate migrants' survival threatened by "C" shaped anthropic barriers.

Abstract

Despite studies on range shifts being abundant, the problem of dispersal barriers limiting climate migrants' movement is yet to be fully included into any modeling framework. For this reason, we introduce a novel concept whereby the interplay of range shifts and dispersal barriers of a particular spatial configuration can threaten the persistence of populations under a climate change scenario. We named this concept "C-trap," based on the topographic shape of such barriers. After elaborating on the theoretical features of C-traps, we provide a simple method that combines environmental data and future climate projections to locate them spatially. We use this method to determine where high C-trap densities have the potential to further threaten the conservation of endangered, endemic animals across the world's terrestrial realm, in a climate change scenario. Our methodology detected potential C-traps for the study system, with areas of high density mostly located in east Europe, south Asia and North America. However, finer-scale analyses are required to assess the magnitude of the threat locally. Dispersal barriers add an additional dimension to range shift studies and can ultimately prevent otherwise successful climate migrants from tracking their climatic niche. The methodology presented here is simple and flexible enough to be adapted to a wide range of taxa and locations as well as the fast development of range shift modeling. Therefore, we encourage researchers to include the effects of anthropogenic dispersal barriers in range shifts models and in the planning of effective conservation strategies with reference to climate change.