Landscape Connectivity and Metapopulation Dynamics

Abstract

The wholesale destruction and fragmentation of habitat by humans has precipitated a global extinction crisis in which species are going extinct faster than at any other time since the last mass extinction event occurred some 65 million years ago (Wilcox and Murphy, 1985). Besides resulting in an absolute loss of available habitat, habitat destruction may also fragment the landscape. The process of habitat fragmentation involves the dissection of remaining habitat into a greater number of smaller and increasingly more isolated patches. Habitat fragmentation disrupts landscape connectivity, which may interfere with dispersal, leading to more isolated populations, and thereby enhancing extinction risk for species. Although habitat destruction may ultimately have a greater effect on populations than fragmentation (Fahrig, 1997), habitat fragmentation may exacerbate or hasten the effects of habitat loss. There has thus been considerable interest within the field of conservation biology in predicting the consequences of habitat loss and fragmentation for species persistence. This lab explores how quantitative methods and theory derived from landscape ecology can be used to predict the consequences of landscape connec-tivity for metapopulation persistence. This lab will enable students to 1. develop species' perceptions of landscape connectivity by using neutral landscape models to quantify critical thresholds of habitat fragmentation for species with different gap-crossing abilities (Part 1);