Assistant Professor University of Richmond Richmond, Virginia, United States
Background/Question/Methods
Persistence of populations depends on both population size and genetic viability. However, few study systems are able to integrate data on long-term population trends and genetic viability to predict population viability through time. In this study, we directly compared more than a decade of census population size data with genetic estimates of effective population size in 12 populations of the wood frog (Rana sylvatica), and how variation in these population parameters are influenced by ecological and environmental attributes of the temporary ponds they occupy. The wood frog life history and breeding phenology provide a useful system to link the predictive utility of genetic tools to population size. Specifically, we tested how well estimates of effective population size obtained from 15 genetic loci and two estimation methods predict long-term demographic trends across 12 populations. We also predicted that several ecological attributes could influence population size dynamics.
Results/Conclusions
We found a strong association between genetic and census estimates of population size, while populations with more variance in census size across years had weaker association between census and genetic estimates of population size. We also predicted that several ecological attributes could influence population size, however only pond water depth was associated with population size, while canopy cover, surface area, and isolation on the landscape were not linked with population dynamics. While there is no replacement for long-term monitoring of populations, our data suggest that genetic estimates can offer a rapid and robust assessment of both population size and genetic viability in some systems. Considering that conservation management often requires timely information on imperiled populations, efficiencies gained during the assessment phase can provide an important advantage for the conservation of amphibians and other taxa.
