Circuit-theory applications to connectivity science and conservation : Circuit Theory

Abstract

Conservation practitioners have long recognized ecological connectivity as a global priority for preserving biodiversity and ecosystem function. In the early years of conservation biology, ecologists extended principles of island biogeography to assess connectivity using measures of source patch proximity and other metrics derivable from binary maps of habitat. From 2006–2008, the late Brad McRae introduced circuit theory to many ecologists and conservation biologists as an alternative approach to model gene flow and the dispersal or movement routes of organisms. He posited concepts and metrics from electrical circuit theory as a robust way to quantify movement across multiple possible paths in a landscape, not just a single least-cost path or corridor. Here we discuss applications of circuit theory and related tools to the science and practice of connectivity conservation. We begin with a brief introduction to the foundations of circuit theory and a synthesis of recent publications from multiple geographies. We then sample and explore the diverse array of applications of circuit theory and the open-source software Circuitscape , focusing on how these tools have been used to understand genetic structuring, the movement and dispersal paths of organisms, habitat corridors and barriers, and the impacts of humans and climate change on connectivity. Finally, we consider the impact that circuit theory is likely to have on conservation science and practitioners, as well as the maintenance and restoration of connectivity for species and fundamental ecological processes around the globe.