Li, Mingke2023-03-012023-03-012019Thesis 10464https://unbscholar.lib.unb.ca/handle/1882/14562A spruce budworm (Choristoneura fumiferana Clem.; SBW) outbreak in Québec spread southward into New Brunswick in 2014. This thesis used spatial analyses of 5 years of SBW population data in northern New Brunswick and tree defoliation data in Québec to examine spatial patterns and factors influencing SBW infestation. Local previous-year SBW population level, proximity to outbreak hot-spots, and April degree-days were important in predicting SBW population levels in New Brunswick, although relationships were inconsistent across years. Models incorporating spatial stuctures [sic] explained 68–79% of the annual variance, and performed better than non-spatial models. A combined-year model with R [squared] = 0.53 consistently underestimated upcoming-year populations. Defoliation patterns quantified in 57 plots in Québec were clustered in 28-47% of cases, which had higher plot-level defoliation and higher deviations. Plot-level defoliation and basal area explained 80% of the variance in individual-tree-defoliation. The thesis contributed to efficient sampling allocation and insecticide treatment targeting infestation.text/xmlxi, 129 pageselectronicen-CAhttp://purl.org/coar/access_right/c_abf2master thesis2020-11-25MacLean, DavidForestry and Environmental Management