The Connectivity Analysis Toolkit (CAT) is a freely available software that provides new tools for both linkage mapping and landscape-level 'centrality' analysis. Conservation biologists have long recognized that natural areas that are linked into networks are often more effective than isolated areas at preserving certain components of biodiversity. Although in the past connectivity usually was considered in a static sense as habitat corridors, we now recognize that planning for connectivity requires incorporating process as well as pattern into conservation planning, and that connectivity can be achieved by means other than corridors. Planners and biologists are increasingly recognizing that existing corridor mapping tools, such as included in commercial GIS software, may not be flexible enough to incorporate new knowledge on patterns of animal movement and ecological processes.

Centrality refers to a group of landscape metrics that rank the importance of sites as gatekeepers for flow across a landscape network. Computational advances now allow such metrics to be applied to landscapes of continuous habitat gradients rather than patches in a matrix of unsuitable habitat. The Toolkit's connectivity analysis methods can complement methods commonly available in GIS, and allow planners to better evaluate alternate assumptions on how to represent wildlife movement and ecological processes. Land-use planning for biodiversity conservation necessarily involves decisions that have large economic and social impacts, and thus merits use of the most rigorous and informative tools available.

The Toolkit allows users to develop and compare three contrasting centrality metrics based on input data representing habitat suitability or permeability, in order to determine which areas, across the landscape as a whole, would be priorities for conservation measures that might facilitate connectivity and dispersal. The Toolkit also allows application of these approaches to the more common question of mapping the best habitat linkages between a source and a target patch. The newest version of the Toolkit adds methods for analyzing connectivity across time as habitat shifts under changing climates.

Hundreds of conservation planners around the world have already begun applying this new software to map habitat linkages and rank sites for their contribution to landscape connectivity. These methods can be applied to both conservation plans focus on a single species, such as recovery plans, and to multi-species planning efforts. The methods can be applied at a range of scales from local watersheds to large regions.

Click here to download CAT Manual and Software

References: Carroll, C., B. McRae, and A. Brookes. In review. Centrality analysis of connectivity across regional habitat gradients: Conservation planning for gray wolf in western North America.

Connectivity Analysis Toolkit (CAT, Version 1.0 (c) 2010, Carlos Carroll, Klamath Center for Conservation