Variation in abundance across a species' range predicts climate change responses in the range interior will exceed those at the edge: a case study with North American beaver

Abstract

The absence of information about how abundance varies across species' ranges restricts most modeling and monitoring of climate change responses to the range edge. We examine spatial variation in abundance across the northeastern range of North American beaver (Castor canadensis), evaluate the extent to which climate and nonclimate variables explain this variation, and use a species-climate envelope model that includes spatial variation in abundance to predict beaver abundance responses to projected climate change. The density of beaver colonies across Québec follows a roughly logistic pattern, with high but variable density across the southern portion of the province, a sharp decline in density at about 491N, and a long tail of low density extending as far as 581N. Several climate and nonclimate variables were strong predictors of variation in beaver density, but 97% of the variation explained by nonclimate variables could be accounted for by climate variables. Because of the peak and tail density pattern, beaver climate sensitivity (change in density per unit change in climate) was greatest in the interior and lowest at the edge of the range. Combining our best density-climate models with projections from general circulation models (GCM) predicts a relatively modest expansion of the species' northern range limit by 2055, but density increases in the range interior that far exceed those at the range edge. Thus, some of the most dramatic responses to climate change may be occurring in the core of species' ranges, far away from the edge-of-the-range focus of most current modeling and monitoring efforts.

Global warming will affect the maximum potential abundance of boreal plant species

“…Second, forecasting the maximum potential abundance is an implicit recognition of uncertainties on future realized distributions related to species’ dispersal capacities and to reliability of land‐use change scenarios. Although the technique is gaining popularity with time (Eastwood et al , Schröder et al , Vaz et al , Chessman , Cozzoli et al ), quantile regression is not yet widely used by ecologists, and has virtually never be used for forecasting the effects of global warming (but see Jarema et al ).…”

Can Recent Global Changes Explain the Dramatic Range Contraction of an Endangered Semi-Aquatic Mammal Species in the French Pyrenees?

“…Yet, broadening our understanding of the effects of global change to other freshwater taxa is required to assess more comprehensively the vulnerability of freshwater ecosystems. For instance, few studies have been conducted on semi-aquatic mammals (but see in [ 19 – 24 ]), in spite of the numerous endangered species [ 25 ]. Among them, the Pyrenean desman ( Galemys pyrenaicus ) is a semi-aquatic mammal endemic to the Pyrenees (France, Spain and Andorra) and to the northern mountains of the Iberian Peninsula.…”

Bird population trends are linearly affected by climate change along species thermal ranges

“…In other words, an average trend for a given species at a European level can mask high heterogeneity in the populations responses of that species within Europe (see Both et al 2006). To investigate this issue one should test whether population responses to climate warming within the core-range of species thermal distribution differ from those occurring near species thermal range edges ( Jamera et al 2009;Jones & Cresswell 2010).…”