Dendrochronological reconstruction of spruce budworm (Choristoneura fumiferana) outbreaks in southern Quebec for the last 400 years¹This article is one of a selection of papers from the 7th International Conference on Disturbance Dynamics in Boreal Forests.

Abstract

It is argued that spruce budworm (Choristoneura fumiferana (Clemens)) (SBW) outbreaks have tended to be more frequent, severe, and spatially synchronized since the beginning of the 20th century. However, few studies have assessed the long-term (>200 years) variations in SBW outbreak dynamics. We reconstructed the SBW outbreak history at the northern limit of the temperate forest in southern Quebec using dendrochronological material from old buildings and five old-growth stands. Our regional tree-ring chronology represents one of the longest and most replicated insect outbreak reconstructions in North America. Nine potential outbreaks were identified (

Environmental-mediated relationships between tree growth of black spruce and abundance of spruce budworm along a latitudinal transect in Quebec, Canada

“…Therefore, the synchrony between tree growth and SBW dynamics is useful in order to 81 understand the evolution and intensity of outbreaks, and the effect of severe infestation on 82 stand productivity (Boulanger et al 2012). Using the predictions of the effects of climate 83 change on SBW outbreaks, models are required that describe how SBW defoliation dynamics 84 interact with tree growth patterns across seasons and landscapes, and how they could affect the 85 future productivity of forests (Krause et al 2012).…”

Natural root grafting in Picea mariana to cope with spruce budworm outbreaks

“…Similarly, insect defoliation in black spruce were noticed by dendrochronology and photointerpretation in lakes Libéral and Onatchiway between 1976and 1979(Krause and Morin 1999 and in Lac Lamandonis around 1980 (Bouchard et al 2007). At a wider spatial scale, this event corresponds to the well-documented last spruce budworm outbreak in Quebec in the 20th century (e.g., Morin et al 1993Morin et al , 2007Krause and Morin, 1999;Bouchard et al 2007;Simard et al 2008;Boulanger et al 2012;Fierravanti et al 2015).…”

“…is the most damaging insect in boreal forests in eastern North America (Morin et al 2007). Insect outbreaks have a periodicity of 30-40 years (Boulanger and Arseneault 2004;Boulanger et al 2012) and cause extensive mortality, e.g., the latest spruce budworm outbreak destroyed up to 238 million m 3 of softwood in Quebec (Boulet et al 1996). Larval feeding on foliage can cause tree growth reductions above 40% (Krause and Morin 1999;Pothier et al 2005) and, eventually, tree death.…”

“…Canopy gaps are progressively filled by growth releases of surviving trees, and they trigger recruitment and post-outbreak colonization (Morin 1994). Therefore, spruce budworm outbreaks are widely recognized as main drivers of forest dynamics in eastern North America (Morin et al 1993(Morin et al , 2007Morin 1994;Bouchard et al 2007;Boulanger et al 2012;Fierravanti et al 2015).…”

Dynamique spatio-temporelle des épidémies de la tordeuse des bourgeons de l'épinette dans la pessière à mousses au cours XXième siècle /

“…Les épidémies identifiées dans les chronologies d'épinette noire présentent, en général, un pourcentage d'arbres affectés moins important que sur les peuplements de sapin baumier étudiés antérieurement Boulanger et Arseneault, 2004 ;Boulanger et al, 2012).…”