Correlations between community diversity and within-species genetic diversity in an amphibian assemblage
McKee, Anna Miriam
MetadataShow full item record
When neutral processes (i.e., drift and dispersal) are responsible for distributions of species and genetic diversity, a positive correlation is expected between these scales of diversity. Under these circumstances, species diversity conservation efforts may also benefit the conservation of genetic diversity. However, habitat alteration can modify the strength of neutral processes, potentially leading to changes in the relationship between species and genetic diversity. The extent to which species are affected by habitat alterations may vary depending vagility and habitat restrictions. I investigated the associations of habitat features with species diversity and genetic diversity in two pond-breeding amphibian species with differing vagilities. In 2008 and 2009, I collected tissue samples from southern leopard frogs (Rana sphenocephala) and dwarf salamanders (Eurycea quadridigitata) from 10 and 9 isolated wetlands, respectively, in a longleaf pine reserve in southwest Georgia. I used microsatellite loci to estimate population genetic diversity and species data collected in 2006 from corresponding wetlands to estimate rarefied species richness. I used model selection to determine which local and landscape scale habitat features were most closely associated species and genetic diversity, as well as the spatial scale of greatest relevance. I also used model averaging to determine the directional association of each habitat feature with species and genetic diversity. Diversity was consistently lower in wetlands with more surrounding roads and generally greater in wetlands with more surrounding forest area. Dwarf salamanders showed greater allelic richness in less isolated wetlands and greater heterozygosity in larger wetlands. Southern leopard frog allelic richness was greatest in wetlands with more surrounding agriculture and heterozygosity was greatest in less isolated wetlands. Species richness was greatest in wetlands with more surrounding forest area. To make this research relevant to a wider audience, I developed an activity for undergraduate students to help them understand the effects of neutral processes on species and genetic diversity. Prior to the activity, students were relatively familiar with the effects of neutral processes on genetic diversity; however they were less familiar with the effects on species diversity. The activity was effective in improving student knowledge of the effects of neutral processes on species diversity.