Monday, August 6, 2007 - 2:50 PM

COS 10-5: Predicting connectivity using circuit analysis: Theory and applications in conservation planning

Brad H. McRae, NCEAS, Brett G. Dickson, ForestERA Project, and Rick A. Hopkins, Live Oak Associates, Inc.

Models from electronic circuit theory have broad applicability to analyses of ecological connectivity in complex landscapes.  The models represent raster landscapes as grids of nodes connected by resistors, with resistance levels corresponding to movement probabilities or costs in different habitat types.  Resistance, current, and voltage calculated across the grids can then be related to ecological processes, such as individual movement and gene flow, across landscapes.  Because the models are based in connections between circuit theory and random walks, they are better justified in many cases than commonly applied connectivity models.  We’ll review basic circuit theory, discuss relationships between circuit and random walk theories, and describe efficient algorithms that can accommodate millions of raster cells.  We’ll provide examples of how circuit models can be used to predict animal movement patterns and identify important habitat patches and movement corridors for conservation planning.