A landscape genetics approach to amphibian conservation
January 2006 - December 2007
- University of Maine
Amphibians are now more threatened globally than birds or mammals as a result of habitat destruction and fragmentation. Most conservation strategies have not halted amphibian declines due to focusing on individual wetlands rather than landscape-scale pressures such as decreased connectivity among wetlands. Preserving wetland connectivity is crucial for maintaining amphibian genetic diversity and population persistence. It is not clear, however, how anthropogenic and natural landscape variables affect amphibian movement, and therefore connectivity, among wetlands. Our research uses landscape genetics to determine spatial connectivity among populations of an amphibian species, spotted salamanders, known to breed in ephemeral wetlands as well as naturally fishless and stocked lakes. Unlike traditional mark-recapture techniques that often are limited by scale and recapture rates, genetics allows us to examine multiple scales of connectivity over several generations. By measuring differentiation, or how genetically different populations of these species are from one another in a single landscape, we can better define the spatial scale at which genetic exchange is occurring and what landscape features affect this flow. Ultimately, we will develop conservation recommendations for preserving gene flow for species with life histories represented by these three species that recognize landscape barriers and conduits to movement among wetlands. These recommendations will assist resource managers planning landscape-scale amphibian conservation strategies by determining the realistic spatial scale at which long-term conservation efforts should focus.