Domains of scale in cumulative effects of energy sector development on boreal birds

Abstract

Abstract Context: Industrial development in Canada’s boreal forest creates cumulative environmental effects on biodiversity. Some effects may be scale-dependent, creating uncertainty in understanding and hindering effective management. Objectives: We estimated cumulative effects of energy sector development on distributions of sixteen migratory songbird species at multiple spatial scales within the boreal region of Alberta, Canada, and evaluated evidence for scale domains in species responses. Methods: We used a hierarchical, multi-scale sampling and modelling framework to compare effects of human footprint on sixteen boreal songbird species at five spatial scales. We used Bayesian Lasso to facilitate direct comparison of parameter estimates across scales, and tested for differences in grouped parameter estimates among species. Results: We found consistent scale-dependent patterns, showing variable responses to development occurring at the smallest scale, little effect at intermediate scales, and stronger, mainly positive effects at the largest scales. Differences in grouped parameter estimates across scales showed strong evidence for scale domains in the response of songbirds to energy sector development. Conclusions: Our evidence for domains of scale reflected differences between local scale habitat selection and landscape scale distributional effects. Our analysis provides a sampling and modelling framework for understanding effects of land-use change on biodiversity across multiple spatial scales. We show that limiting cumulative area of disturbance within a given management unit is the most likely path towards conserving avian biodiversity in this region.