Towards robust corridors – a novel validation framework to more efficiently create corridors

Abstract

Context Ecological corridors are one of the most recommended ways to mitigate biodiversity loss. With growing recognition of corridor importance, robust, quantitative validation methods lag behind the use of corridor modeling. Objective We propose a post-hoc corridor validation framework, considering the range of methods across data needs and statistical intensity. We aim to demonstrate the importance of post-hoc corridor validation by testing several validation methods on different corridor model outputs, using the same input data. Methods We used three different transformations on a Florida black bear (Ursus americanus floidanus) habitat suitability model to create different resistance grids, independent GPS collar data from a Florida black bear study population, and Circuitscape to create corridor models. We used several validation methods, including a novel method, to compare resulting corridors with management objectives. Results Transformed resistance grids were all correlated, yet differing validation and resistance grids resulted in different corridor recommendations. The use of one resistance surface and one validation category can result in the selection of inefficient or ineffective corridors. At a minimum, modelers should determine what proportion of an independent population falls within resulting corridors and should move towards more robust, documented methods as resources allow. The use of multiple validation methods can ensure greater confidence of modeling results. Conclusions We encourage the addition and development of the framework presented here to create more robust, effective corridors. If validation methods are not improved, the ecological and economic cost of poor corridor science will continue to increase with increasing biodiversity loss.