Circuit theory applications to connectivity science and conservation
Citation:
Dickson, B., C. Albano, R. Anantharaman, P. Beier, J. Fargione, T. Graves, M. Gray, K. Hall, J. Lawler, P. Leonard, C. Littlefield, M. McClure, J. Novembre, C. Schloss, N. Schumaker, V. Shah, AND D. Theobald. Circuit theory applications to connectivity science and conservation. CONSERVATION BIOLOGY. Blackwell Publishing, Malden, MA, 33(2):239-249, (2019). https://doi.org/10.1111/cobi.13230
Impact/Purpose:
This manuscript reviews the scientific and technical contributions of the late Dr. Brad McRae. It was written by colleagues as a tribute to his work. Dr. McRae’s biggest contribution to ecology was the development of a theoretical framework (circuit theory) and analytic tools (Circuitscape and Linkage Mapper) necessary to quantify landscape connectivity at large spatial scales and realistic settings. Dr. McRae and colleagues have used his ideas and tools to improve efforts to protect the environment generally, and specifically to advance species conservation efforts, our understanding of gene flow and genetic sustainability, to develop novel insights into rates and patterns of disease spread in complex real-world settings, and even to understand patterns of human migration over past millennia. Dr. McRae’s work has, and continues to have a large impact on ecology and conservation. His work commonly appears in undergraduate and graduate coursework in Landscape Ecology and related disciplines, and has influenced theoretical and applied research domestically and internationally.
Description:
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 as an alternative approach to model gene flow and the dispersal or movement routes of organisms. His major innovation was recognizing that movement can occur 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, such as the software package Circuitscape, to the science and practice of connectivity conservation. We begin with an 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.
