Present address: Institute of Terrestrial Ecosystems, Swiss Federal Institute of Technology (ETH), Zürich 8092, Switzerland.
Using connectivity metrics in conservation planning – when does habitat quality matter?
Article first published online: 9 MAR 2009
© 2009 Blackwell Publishing Ltd
Diversity and Distributions
Volume 15, Issue 4, pages 602–612, July 2009
How to Cite
Visconti, P. and Elkin, C. (2009), Using connectivity metrics in conservation planning – when does habitat quality matter?. Diversity and Distributions, 15: 602–612. doi: 10.1111/j.1472-4642.2009.00564.x
- Issue published online: 10 JUN 2009
- Article first published online: 9 MAR 2009
- conservation planning;
- graph theory;
- habitat quality;
Aim The objective of conservation planning is often to prioritize patches based on their estimated contribution to metapopulation or metacommunity viability. The contribution that an individual patch makes will depend on its intrinsic characteristics, such as habitat quality, as well as its location relative to other patches, its connectivity. Here we systematically evaluate five patch value metrics to determine the importance of including an estimate of habitat quality into the metrics.
Location We tested the metrics in landscapes designed to represent different degrees of variability in patch quality and different levels of patch aggregation.
Methods In each landscape, we simulated population dynamics using a spatially explicit, continuous time metapopulation model linked to within patch logistic growth models. We tested five metrics that are used to estimate the contribution that a patch makes to metapopulation viability: two versions of the probability of connectivity index, two versions of patch centrality (a graph theory metric) and the metapopulation capacity metric.
Results All metrics performed best in environments where patch quality was very variable and high quality patches were aggregated. Metrics that incorporated some measure of patch quality did better in all environments, but did particularly well in environments with high variance of patch quality and spatial aggregation of good quality patches.
Main conclusions Including an estimate of patch quality significantly increased the ability of a given connectivity metric to rank correctly habitat patches according to their contribution to metapopulation viability. Incorporating patch quality is particularly important in landscapes where habitat quality is highly variable and good quality patches are spatially aggregated. However, caution should be used when applying patch metrics to homogeneous landscapes, even if good estimates of patch quality are available. Our results demonstrate that landscape structure and the degree of variability in patch quality need to be assessed prior to selecting a suitable method for estimating patch value.