Canadian Forest Service Publications

The relationship between biogeoclimatic zones and defoliation by the two-year cycle spruce budworm in Central British Columbia. 2001. Shand, A.; Alfaro, R.I.; Taylor, S.P.; Low, B.; Quenet, R.V. Pages 144-151 in A.M. Liebhold, M.L. McManus, I.S. Otvos, and S.L.C. Fosbroke Proceedings - Integrated management and dynamics of forest defoliating insects, August 15-19, 1999, Victoria BC, Canada. USDA Forest Service, Northeastern Research Station, Newtown Square, PA, General Technical Report NE-277.

Year: 2001

Available from: Pacific Forestry Centre

Catalog ID: 18315

Language: English

Series: USDA General Technical Report

CFS Availability: Order paper copy (free)

Abstract

The two-year cycle spruce budworm (Choristoneura biennis (Freeman)) (Lepidoptera: Tortricidae) is a major defoliator of Engelmann spruce (Picea engelmannii (Parry)), white Spruce (P. glauca (Moench) Voss), an Engelmann-white spruce hybrid, and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in the interior of British Columbia, Canada. Repeated defoliation causes top kill, tree mortality, and a loss of timber volume. A Geographic Information System analysis of the biogeoclimatic ecosystem classifications, leading tree species, and stand ages associated with budworm defoliation was used to investigate environmental and stand characteristics associated with susceptibility to outbreaks of this budworm. The biogeoclimatic designation of the stand was an important indicator of susceptibility to two-year cycle budworm defoliation. Stands that experienced repeated defoliation were predominantly in the wet, cool Sub-Boreal Spruce and moist, very cold Engelmann Spruce-Subalpine Fir biogeoclimatic classifications. Within these susceptible biogeoclimatic designations, those forest stands leading in the host species were the most likely to experience defoliation.

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