White spruce (Picea glauca) traits affecting the success of spruce beetles (Dendroctonus rufipennis) in the southwest Yukon
Abstract
A major outbreak of spruce beetle (Dendroctonus rufipennis) occurred in the southwest Yukon between 1990 and 2007. I determined how white spruce (Picea glauca) allocation to growth, defence and reproduction affected spruce beetle population growth, and how climate mediated these interactions. Spruce beetle population growth was greatest in years when spruce grew more slowly and had fewer cones, with no detectable effect of mean summer or winter temperature. For individual spruce trees, the probability of being attacked by spruce beetles increased with decreasing relative growth rates, increasing tree diameter, and increasing number of resin ducts produced in the previous five years; cone production did not affect attack probability. Once attacked, the probability of tree death increased with both decreasing relative growth rate and number of induced resin ducts produced in the attack year. These results show that tree growth and defence but not reproduction determined spruce beetle susceptibility.
Description
Keywords
Forestry and Wildlife, Ecology, Environmental Sciences
Citation
Goulding, M. (2017). White spruce (Picea glauca) traits affecting the success of spruce beetles (Dendroctonus rufipennis) in the southwest Yukon (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/28703