Spruce budworm outbreaks in eastern Quebec over the last 450 years

Abstract

In this study we used dendrochronology to reconstruct the history of eastern spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks over the last 450 years in the Bas-Saint-Laurent region of southeastern Quebec. In total, 260 tree cores were sampled from 204 beams in seven historic buildings and 12 trees in a virgin forest stand. Eight previously documented outbreaks (1975–1992, 1947–1958, 1914–1923, 1868–1882, 1832–1845, 1805–1812, 1752–1776, 1710–1724) and three presumed previous outbreaks (1678–1690, 1642–1648, 1577–1600) were identified based on periods of growth reduction. Of these 11 confirmed or presumed outbreaks, six were documented for the first time in eastern Quebec. Such data suggest that outbreak frequency has remained quite stable, with a mean interval of about 40 years between the midpoint of successive outbreaks since the mid-16th century. In addition, together with previous studies, our results indicate a strong spatial synchrony of spruce budworm outbreaks across central and eastern Quebec during the last 300 years. Consequently, our study does not support the hypothesis that spruce budworm outbreak frequency and synchrony increased during the 20th century.

Predicting balsam fir growth reduction caused by spruce budworm using large-scale historical records of defoliation

“…4) that correspond to the four classes of defoliation impact proposed by Gray et al [14]. For a period of 30 years, a time roughly equivalent to the return interval of the recent spruce budworm outbreak [9], these volume losses were estimated at 2, 8, 15 and 24% for the negligible, light, moderate, and severe classes of defoliation impact, respectively. Similar results have been derived from a process-based model developed by Baskerville and Kleinschmidt [3] for balsam fir stands subjected to defoliation by spruce budworm in north-central Maine and New Brunswick.…”

“…B.S.P.). A recent historical study based on tree-ring analyses have shown that the frequency of spruce budworm outbreaks has remained quite stable over the last four centuries [9], presumably because of the continuous abundance of balsam fir stands [8,24,25]. Since fir-dominated stands are still abundant and are expected to remain so into the future, sustained management of these forests must consider the impact of future insect defoliation by integrating estimation of wood losses in volume prediction models.…”

Microsporidia Biological Control Agents and Pathogens of Beneficial Insects

“…For example, in the conifer forests of northern North America, Nosema fumiferanae is a microsporidium that is considered a regulating component of outbreaks of the eastern spruce budworm, Choristoneura fumiferana (Régnière 1984;van Frankenhuyzen et al 2007). Extensive defoliating outbreaks of this moth occur in 35-40 year cycles (Royama 1984;Boulanger & Arseneault 2004), in which N. fumiferanae and other entomopathogens and parasites increase and decrease with host density and can dampen the outbreaks (Eveleigh et al 2007). In the extended periods between budworm outbreaks, N. fumiferanae maintains infection across seasonal generations via transovarial transmission (Eveleigh et al 2012).…”

Commercial Thinning to Meet Wood Production Objectives and Develop Structural Heterogeneity: A Case Study in the Spruce-Fir Forest, Quebec, Canada

“…The natural disturbance regime was characterized by recurring spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks, which can lead to small or major disturbances [27]. The site was part of the Fir-Yellow Birch (Betula alleghaniensis Britt.)…”