Landscape Ecology

, Volume 31, Issue 10, pp 2231–2244

Altered functional connectivity and genetic diversity of a threatened salamander in an agroecosystem

  • John A. Crawford
  • William E. Peterman
  • Andrew R. Kuhns
  • Lori S. Eggert
Research Article

DOI: 10.1007/s10980-016-0394-6

Cite this article as:
Crawford, J.A., Peterman, W.E., Kuhns, A.R. et al. Landscape Ecol (2016) 31: 2231. doi:10.1007/s10980-016-0394-6

Abstract

Context

Amphibian metapopulations have become increasingly fragmented in the Midwestern United States, with wetland-breeding salamanders being especially dependent on intact, high-quality forested landscapes. However, the degree to which amphibian populations are isolated, the factors that influence dispersal and, ultimately, functional connectivity remain areas in need of investigation.

Objectives and methods

We combined population demographic and genetic approaches to assess how a landscape fragmented by agriculture influences functional connectivity and metapopulation dynamics of a locally threatened salamander (Ambystoma jeffersonianum).

Results

We found that the allelic richness and heterozygosity of this species was significantly related to the level of connectivity with other occupied breeding wetlands and that decreased connectivity resulted in increased genetic differentiation. We also found that effective population size appears to be declining and, while correlative, our focal landscape has experienced significant losses of forested upland habitats and potential wetland breeding habitats over the last 200 years.

Conclusions

By combining population and landscape genetic analyses with an assessment of regional wetland occupancy, our study has uniquely synthesized genetic and metapopulation processes, while also incorporating the effects of the landscape matrix on dispersal, connectivity, and population differentiation. The significant relationship between connectivity with heterozygosity, allelic richness, and genetic divergence observed in this study reinforces empirical observations of long distance dispersal and movements in ambystomatid salamanders. However, our results show that protection of core habitat around isolated wetlands may not sufficiently minimize genetic differentiation among populations and preserve critical genetic diversity that may be essential for the long-term persistence of local populations.

Keywords

Agriculture Ambystoma jeffersonianum Dispersal Fragmentation Metapopulation Wetland 

Supplementary material

10980_2016_394_MOESM1_ESM.docx (37 kb)
Supplementary material 1 (DOCX 37 kb)

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  • John A. Crawford
    • 1
  • William E. Peterman
    • 2
    • 4
  • Andrew R. Kuhns
    • 3
  • Lori S. Eggert
    • 2
  1. 1.National Great Rivers Research and Education CenterEast AltonUSA
  2. 2.Division of Biological SciencesUniversity of MissouriColumbiaUSA
  3. 3.Illinois Natural History Survey, Prairie Research InstituteUniversity of IllinoisChampaignUSA
  4. 4.School of Environment and Natural ResourcesOhio State UniversityColumbusUSA

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