Population Genetic Structure and Dispersal of the Reticulated Flatwoods Salamanders (Ambystoma bishopi) on Eglin Air Force Base

Determining how landscape connectivity affects the distribution and abundance of species is vital for conservation efforts. The reticulated flatwoods salamander (Ambystoma bishopi) is an endangered pond-breeding species restricted to pine flatwoods habitats of Georgia and Florida. Some of the most extensive remaining habitat occurs on Eglin Air Force Base in Okaloosa County, Florida. We characterized variation of 12 microsatellite DNA loci among larval salamanders at 12 ponds on Eglin. Our objectives were to 1) delineate population genetic structure, 2) estimate dispersal rates among ponds, and 3) estimate the effective numbers of breeders contributing to each pond. We found an expected pattern of isolation-by-distance, with nearby groups of ponds showing higher connectivity and distant comparisons showing greater genetic differentiation. Connectivity also was reduced by anthropogenic landscape features such as roads and impervious surfaces as well as invasive vegetative overgrowth. Effective population sizes at ponds were small at most ponds, suggesting that few breeders contribute to a typical cohort. These findings will assist the Air Force with implementing effective habitat management measures on Eglin.