Determining genetic resistance to jack pine budworm defoliation in jack pine from different geographic seed sources across Ontario

Abstract

Jack pine budworm is an outbreak insect that defoliates jack pine forests across Canada. While it is a native species, the outbreaks can have severe economic impacts, such as loss of timber volume and increased risk of severe forest fires, and may also require expensive spray programs to keep the budworm in check. With the climate warming at a rapid rate, it is expected that the cycle of forest disturbances may increase drastically, therefore increasing the duration and severity of outbreaks and decreasing the time between jack pine budworm outbreaks. In this study, I analyzed the defoliation patterns in a jack pine provenance trial in the Red Lake area in northwestern Ontario which had recently been the victim of the start of a jack pine budworm outbreak. The original trial was created in order to see how well certain seed sources would do under the current rapidly changing climatic conditions. Sources from north-western, central, and southern Ontario were used in the original provenance trial. In my study, I compared defoliation severity between the three source locations. I found that seed sources from the north tolerated jack pine budworm defoliation significantly better than both the central and southern sources, and that seed sources from central Ontario performed better than the south as well. The results of this study imply that forest managers should proceed very cautiously when attempting to start an assisted migration program in hopes to negate the effects of climate change. While it may seem like a good idea to get ahead of the rising temperatures, planting foreign seed sources may have devastating unintended consequences.