Project on Spruce Budworm

Spruce budworm outbreaks devastate fir and spruce forests in the northern U.S. and southern Canada. The last big outbreak in the east started in the 1970s, and a new incipient outbreak is being suppressed currently in s.e. Canada. Spruce budworms follow a general pattern of outbreaks every 40-ish years, and there are data available on outbreak-vs. -not for about 300 years. There are multiple mechanistic and phenomenological models of outbreaks of this species, but none that are effective predictors of outbreaks. One proposed model predicts alternate stable states for budworm populations (outbreak & low numbers), but they might be phase shifts caused by changed environmental conditions. Shifts in inter-outbreak intervals could be affected by nationwide declines in bird populations (they eat caterpillars), climate change, and human actions (wood demand & suppression). We would like to delve into the problems of budworm outbreak modeling to see if we can come up with an effective predictive model.