- Brown, Taisa
University of New Brunswick
Defoliation, egg mass, and hazard maps from the 1972- 1989 spruce budworm outbreak in Maine were digitized. Based on these historic records, representative defoliation patterns were determined using cluster analysis. Approximately 69% of the state variation in the 18-year record could be described by 22 defoliation patterns. These geo-referenced patterns could be incorporated into a decision support system to estimate growth loss and mortality resulting from an outbreak of spruce budworm. The relationships between outbreak impact and the spatial location, ecozone, watershed, and forest composition were assessed. Differences in defoliation and relative budworm density were examined for each geographic zone delineated by the Maine Forest Service.