Role of Ecological Corridors in Supporting Wildlife Movement and Genetic Connectivity Across Fragmented Habitats

Abstract

Isolation of wildlife populations through habitat fragmentation not only limits mobility among patches, but through time, decreases the gene flow required for maintenance of genetic diversity and species viability. Ecological corridors, which are structurally continuous habitat connections between fragmented patches, have emerged as one of the most popularly utilized conservation strategies for fragmentations; however, doubts persist regarding their effectiveness for mobility and gene flow purposes. The following paper provides an overview of existing data based on experimental,                    meta-analytic and molecular genetics studies in order to examine how well ecological corridors perform in these two areas. Meta-analysis of 78 studies has demonstrated that corridors enhance               inter-patch mobility by 50% on average in plants and animals, while long-term experimental research has shown that this positive effect translates to greater species richness in connected habitats. Studies of molecular genetics offer some of the most direct evidence for connectivity effects, as one example, a major freeway in southern California has been observed to severely hinder gene flow in bobcats and coyotes even though there have been rare cases of successful crossings. Furthermore, the presence of artificial wildlife bridges across highways in Canada was enough to provide gene flow that ensured that black bears were not genetically isolated, showing that connectivity engineering could be used effectively to replace the role of natural corridors in landscapes, if done appropriately. Corridors not only ensure presence but also perform other ecological roles such as pollination which is disrupted in isolated fragments.