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Conservation Genetics

, Volume 16, Issue 1, pp 209–221 | Cite as

Landscape genetics and genetic structure of the southern torrent salamander, Rhyacotriton variegatus

  • Sarah L. Emel
  • Andrew Storfer
Research Article

Abstract

Landscape genetic methods can be used to identify the most effective conservation measures to maintain functional connectivity among populations. Analyses of habitat factors that facilitate or restrict gene flow are particularly useful for species with specific habitat requirements and low dispersal rates. Rhyacotriton variegatus is a salamander species with low desiccation tolerance and a restricted geographic range, limited to the Pacific Northwest. Thus, we predicted that genetic distance would be positively correlated with climate and landscape variables that increase risk of desiccation. Two genetic distance measures, pairwise FST and proportion of shared alleles (DPS), suggested that gene flow was low among 19 sampling localities (367 total individuals) and genetic structure was high overall (DPS = 0.636 ± 0.010, FST = 0.330 ± 0.011; mean ± SD). Using both least-cost path and Circuitscape models of landscape resistance, we found that low stream cover, low canopy cover, high heat-load index, and short frost-free period all restricted gene flow among populations. We suggest that the conservation status of this species be revisited given this evidence of high genetic structure within the species, the level of habitat fragmentation in their range, and their reliance on dense canopy cover for dispersal. Maintaining stream corridors with buffers of dense canopy cover may maximize connectivity despite the pressures of timber harvest and urbanization.

Keywords

Landscape genetics Genetic structure Conservation Microsatellites Salamander Rhyacotriton variegatus 

Notes

Acknowledgments

We would like to thank the American Museum of Natural History Theodore Roosevelt Memorial Fund, Sigma Xi Grants-in-Aid of Research, and the Washington State University Elling Foundation for funding the project. M. Adams, A. Caldwell, E. Dunn, K. Emel, Z. Emel, B. Hogberg, and J. Miller assisted with tissue collection. P. Frias, R. M. Larios, S. Micheletti, S. Spear, D. Trumbo, and G. Zancoli provided guidance with laboratory and computer analyses. Finally, we thank B. Epstein, S. Micheletti, L. Shipley, D. Trumbo, and L. Waits for providing comments on the manuscript.

Supplementary material

10592_2014_653_MOESM1_ESM.docx (159 kb)
Supplementary material 1 (DOCX 158 kb)

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© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  1. 1.School of Biological SciencesWashington State UniversityPullmanUSA

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