Integrated landscape genetics of the mountain pine beetle system
The mountain pine beetle (MPB; Dendroctonus ponderasae) outbreak in western Canada has had significant ecological and economic consequences. Outbreak dynamics are the product of interactions among the beetle itself, associated pathogenic fungi (Ophiostoma spp.), host trees (Pinus spp.), physical landscape features, and climate. As part of the TRIA project, a large interdisciplinary NSERC Strategic Network, this research uses genetic data to investigate the spatial interactions among species in the beetle-fungi-pine complex and relate them to landscape features to better understand the causes and consequences of outbreaks and to inform risk management models.
We are also interested in the question of whether rapid evolution has played a role in the expansion of the MPB into novel habitats. The first step to address such a question is to identify loci that are potentially under selection. However, demographic processes such as rapid range expansion can create spatial patterns in allele frequencies that mimic those created by adaptive processes. Landscape genomics endeavours to identify loci potentially under selection through correlations between allele frequencies and environmental heterogeneity but do not necessarily consider the influence of this potentially confounding demographic context. Using a simulation approach, we are examining how range expansion, population dynamics, and spatial context affect our capacity to meaningfully identify loci under selection.
Students: Julian Wittische, Paul Mayrand
Collaborators: see the TRIANet Website
Scanning electron microscopy image of an adult mountain pine beetle, Dendroctonus ponderosae. Photo credit: Janice Cooke