Pierce McNie

Metacommunity Dynamics of the Spruce Budworm in Novel Habitats

Pierce McNie, Daniel Kneeshaw, Élise Filotas

Two important disturbances are affecting forest ecosystems today: climate change and landscape fragmentation. Species ranges across the planet are changing due to climate change, with range shifts towards the poles, or higher in altitude becoming more and more apparent. In turn, a majority of forests today are extremely fragmented, with the effect of reducing species abilities to respond to the changing climate through changing their ranges. The spruce budworm, a herbivorous insect pest of balsam fir (Abies balsamea), white spruce (Picea glauca) and black spruce (Picea mariana) is also expected to expand its range with increasing temperatures. This will create new assemblages of species which have not existed previously: novel ecosystems. Fragmentation and climate change are likely to influence the community dynamics and outbreak patterns of the SBW and its parasitoid community. It is important and interesting to consider how the SBW expansion might look and how human activities may shape the future of this species. This project asks the questions: How will the food web dynamics of spruce budworm metacommunities be altered by fragmentation and climate change, and, how will these changes to the food web affect the outbreak patterns and population dynamics of the SBW? We will construct a spatially explicit metacommunity model to examine the relative effects of different immigration capacity and habitat heterogeneity on the community dynamics of the SBW and its associated parasitoids and hyperparasitoids. Given a range of climate change scenarios the model will examine potential impacts of warming, increased weather variability, changes in species phenology, and dispersal ability of the SBW and its parasitoids.