What drives at‐risk species richness? Environmental factors are more influential than anthropogenic factors or biological traits

Philip A Stephens,Christine Howard,Curtis H Flather

doi:10.1111/conl.12624

Philip A Stephens, Christine Howard + Show 1 more

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https://doi.org/10.1111/conl.12624

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Abstract

AbstractSpecies at risk of extinction are not uniformly distributed in space. Concentrations of threatened species may occur where threatening processes are intense, in refuges from those processes, or in areas of high species diversity. However, there have been few attempts to identify the processes that explain the distribution of at‐risk species. Here, we identified the relative importance of biological traits, environmental factors, and anthropogenic stressors in driving the spatial patterns of both total and at‐risk species richness of North American mammals and birds. Environmental factors are the predominant drivers of both total and at‐risk species richness. Strikingly, the directions of variable relationships differ substantially between models of total and at‐risk species richness. Understanding how environmental gradients differentially drive variation in total and at‐risk species richness can inform conservation action. Moreover, our approach can predict shifts in at‐risk species concentrations in response to projected environmental change and anthropogenic stressors.

Highlights

Models fitted to total and at-risk bird species richness explained a moderate amount of variation in observed richness patterns
At a near-continental scale, that abiotic environmental parameters are generally the most important drivers of variation in both total and at-risk species richness of both birds and mammals
We discuss our findings in light of the processes driving spatial patterns of extinction risk and the utility of our analyses for conservation practitioners

Summary

Introduction

Responses to threatening processes by different taxa in different regions are variable (Batista, Gouveia, Silvano, & Rangel, 2013), whilst the implementation and success of conservation actions are often substantially influenced by social and economic factors (Knight, Cowling, Difford, & Campbell, 2010). There is widespread recognition that conservation planning and policy cannot account for the idiosyncratic nature of every vulnerable population's plight (Franklin, 1993). Conservation practitioners require a comprehensive understanding of the location of, and threats to, biodiversity, in order to make informed choices about the relative costs, benefits, and likely success of different conservation actions (Brooks et al, 2006). Identifying where concentrations of threatened species occur, and which processes drive their occurrence, will enable conservation practitioners to ascertain the conservation actions that will deliver the best returns for biodiversity (Wilson et al, 2005)

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