Removing barriers: a new perspective on landscape connectivity

New research from Brad McRae and colleagues incorporates new thinking into planning for connectivity: incorporating barriers into analysis. This paper is not just another method to measure landscape connectivity. Typically, researchers identify areas on the landscape that already facilitate animal movement and then decide how to conserve these existing corridors. Researchers use many different algorithms for detecting the best corridors and prioritizing land conservation (see our previous post on the Issues in Ecology connectivity issue). McRae and colleagues flip this approach and ask how we could most improve connectivity by fixing the barriers to movement. This small philosophical shift expands conservation options to include habitat restoration that may create previously-undetected, cost-effective movement corridors.

Using a simplified landscape and a real-world example from the Columbia Plateau in Washington, McRae and colleagues show how barrier-detection works and how it complements existing landscape modeling and reserve selection approaches. A few take-away messages:

1. Restoring barriers may increase overall landscape connectivity beyond what conservation of existing corridors can do.
2. Adjusting the scale of the barriers detected (from the width of a road to acres of land) can find the most effective restoration project for different budgets.
3. Finding and restoring barriers gives land managers alternatives for conservation action that may create new movement corridors in areas that were previously ignored.

This paper introduces a novel method that broadens our perspective of landscape connectivity and provides land managers will a useful tool for evaluating conservation actions. It is also published in an open-access journal, so everyone can read it for free.