Modelling landscape genetic connectivity of the mountain pine beetle in western Canada

• Author(s) / Creator(s)

  • Wittische, Julian
  • Janes, Jasmine K.
  • James, Patrick M. A.

• The current mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins, 1902) outbreak has reached more than
  25 million hectares of forests in North America, affecting pine species throughout the region and substantially changing
  landscapes. However, landscape features that enhance or limit dispersal during the geographic expansion associated with the
  outbreak are poorly understood. One of the obstacles in evaluating the effects of landscape features on dispersal is the
  parameterization of resistance surfaces, which are often constructed based on biased expert opinion or by making assumptions in the calculation of ecological distances. In this study, we assessed the impact of four environmental variables on MPB genetic connectivity across western Canada. We optimized resistance surfaces using genetic algorithms and models of maximum likelihood population effects, based on pairwise genetic distances and ecological distances calculated using random-walk commute-time distances. Unlike other methods for the development of resistance surfaces, this approach does not make a priori assumptions about the direction or shape of the relationships between environmental features and their cost to movement. We found highest support for a composite resistance surface including elevation and climate. These results further the understanding of MPB movement during an outbreak. Additionally, we demonstrated how to use our results for management purposes.

• Date created

  2019-01-01

• Subjects / Keywords

  • Range expansion
  • Gene flow
  • Random walk resistance
  • Linear mixed-effect model
  • Insect outbreaks

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/r3-4yhg-qs87

• License

  Attribution-NonCommercial 4.0 International