Frontiers in Genetics (Sep 2015)

How spatio-temporal habitat connectivity affects amphibian genetic structure

  • Alexander Gordon Watts,
  • Peter eSchlichting,
  • Shawn eBillerman,
  • Shawn eBillerman,
  • Brett eJesmer,
  • Brett eJesmer,
  • Steven eMicheletti,
  • Marie-Josee eFortin,
  • Chris eFunk,
  • Paul eHapeman,
  • Erin L Muths,
  • Melanie April Murphy

DOI
https://doi.org/10.3389/fgene.2015.00275
Journal volume & issue
Vol. 6

Abstract

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Heterogeneous landscapes and fluctuating environmental conditions can affect species’ dispersal, population genetics, and genetic structure, yet understanding how biotic and abiotic factors affect population dynamics in a fluctuating environment is critical for species management. We evaluated how spatio-temporal habitat connectivity influences dispersal and genetic structure in a population of boreal chorus frogs (Pseudacris maculata) using a landscape genetics approach. We developed gravity models to assess the contribution of various factors to the observed genetic distance as a measure of functional connectivity. We selected (a) wetland (within-site) and (b) landscape matrix (between-site) characteristics; and (c) wetland connectivity metrics using a unique methodology. Specifically, we developed three networks that quantify wetland connectivity based on: (i) P. maculata dispersal ability, (ii) temporal variation in wetland quality, and (iii) contribution of wetland stepping-stones to frog dispersal. We examined 18 wetlands in Colorado, and quantified 12 microsatellite loci from 322 individual frogs. We found that genetic connectivity was related to topographic complexity, within- and between-wetland differences in moisture, and wetland functional connectivity as contributed by stepping-stone wetlands. Our results highlight the role that dynamic environmental factors have on dispersal-limited species and illustrate how complex asynchronous interactions contribute to the structure of spatially-explicit metapopulations.

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