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

2005 ◽  
Vol 62 (3) ◽  
pp. 261-267 ◽  
Author(s):  
David Pothier ◽  
Daniel Mailly ◽  
Stéphane Tremblay
1960 ◽  
Vol 92 (5) ◽  
pp. 384-396 ◽  
Author(s):  
J. R. Blais

A spruce budworm outbreak started in Quebec and adjoining parts of New Brunswick in 1949 and spread each year until by 1955 most balsam fir stands within an area of 32,000 square miles were attacked. Approximately 45 per cent of this area was in the Lower St. Lawrence and Gaspe regions of Quebec. In Quebec, important population reductions took place in various sectors of the outbreak area as a result of unfavourable weather conditions in 1956 and 1957 (Blais, 1958a, 1958b), and the final collapse occurred in 1958 when populations returned to the endemic level throughout the area (Blais and Martineau, 1958). In New Brunswick, a relatively small outbreak area remained at the end of the summer in 1958 (Webb et al., 1959). The large-scale aerial applications of DDT begun in New Brunswick in 1952, and in Quebec in 1954, were continued until 1958. Biological studies in connection with the spraying were carried out in both provinces. In Quebec these studies consisted of assessing spruce budworm population fluctuations in both sprayed and unsprayed areas and in determining, where possible, the causes for these fluctuations. All factors associated with changes in population could not be adequately measured over such a large territory, but a real attempt was made to obtain information on parasitism. The present paper deals with this aspect of the studies.


2004 ◽  
Vol 34 (11) ◽  
pp. 2351-2362 ◽  
Author(s):  
Wayne E MacKinnon ◽  
David A MacLean

The species composition of surrounding forest and site characteristics have been postulated to influence growth loss caused by eastern spruce budworm (Choristoneura fumiferana Clem.) defoliation. Forty spruce (Picea spp.) and balsam fir (Abies balsamea (L.) Mill.) stands located in north-central New Brunswick, Canada, were measured for defoliation and tree growth and used to determine the effects of surrounding forest (softwood, mixedwood), site (wet soil – nutrient poor; moist soil – nutrient rich), and species group (balsam fir, spruce) on growth reduction caused by spruce budworm. Stem analysis of six trees per stand (total 240 trees) determined mean specific volume increment (SVI) per year in 1973–1993. There was relatively little defoliation during the 1989–1993 measurement period, and regression analyses showed that SVI was significantly (p = 0.0299) related to mean defoliation for only one of eight treatment classes: balsam fir on moist–rich sites in mixedwood forests. However, two periods of earlier growth reduction were evident, and analysis of variance showed that balsam fir on wet–poor sites sustained 12% greater (p = 0.0071) reduction in SVI from 1987 to 1990 than balsam fir on moist–rich sites. White spruce (Picea glauca (Moench) Voss) sustained 13% greater (p = 0.0198) reduction in SVI from 1973 to 1978 than red spruce (Picea rubens Sarg.) – black spruce (Picea mariana (Mill.) BSP). Surrounding forest type did not significantly affect SVI reduction from 1973 to 1978 or from 1987 to 1990, but from 1973 to 1978 stands in softwood forest sustained 5%–8% more growth reduction than those in mixedwood forest.


1996 ◽  
Vol 72 (5) ◽  
pp. 533-540 ◽  
Author(s):  
David A. MacLean ◽  
Eldon S. Eveleigh ◽  
Tony L. Hunt ◽  
Mervyn G. Morgan

The effect of cumulative defoliation caused by spruce budworm (Choristoneura fumiferana [Clem.]) from 1981 to 1987 on tree growth was assessed in a 35-year-old balsam fir (Abies balsamea [L.] Mill.) stand. After six years of moderate to severe defoliation, specific volume increment was reduced by an average of 11, 55, 83, 70, and 83% for trees with visual cumulative defoliation ratings, in 1987, of 1–25%, 26–50%, 51–75%, 76–90%, and 91–100%, respectively. Following defoliation, mean specific volume increment ranged from 0.02 cm3 cm−2 year−1 for trees with >90% cumulative defoliation to 0.16 cm3 cm−2 year for trees with <25% defoliation. Specific volume increment and percentage growth reduction were significantly related to the cumulative defoliation rating, with regression equations explaining 72 and 64%, respectively, of the variability among trees. It was concluded that onetime visual ratings of cumulative defoliation caused by spruce budworm can be used in assessing balsam fir growth rates and growth reduction. Key words: growth reduction, specific volume increment, stem analysis, Choristoneura fumiferana, Abies balsamea


2021 ◽  
Author(s):  
Marion Germain ◽  
Daniel Kneeshaw ◽  
Louis De Grandpré ◽  
Mélanie Desrochers ◽  
Patrick M. A. James ◽  
...  

Abstract Context Although the spatiotemporal dynamics of spruce budworm outbreaks have been intensively studied, forecasting outbreaks remains challenging. During outbreaks, budworm-linked warblers (Tennessee, Cape May, and bay-breasted warbler) show a strong positive response to increases in spruce budworm, but little is known about the relative timing of these responses. Objectives We hypothesized that these warblers could be used as sentinels of future defoliation of budworm host trees. We examined the timing and magnitude of the relationships between defoliation by spruce budworm and changes in the probability of presence of warblers to determine whether they responded to budworm infestation before local defoliation being observed by standard detection methods. Methods We modelled this relationship using large-scale point count surveys of songbirds and maps of cumulative time-lagged defoliation over multiple spatial scales (2–30 km radius around sampling points) in Quebec, Canada. Results All three warbler species responded positively to defoliation at each spatial scale considered, but the timing of their response differed. Maximum probability of presence of Tennessee and Cape May warbler coincided with observations of local defoliation, or provided a one year warning, making them of little use to guide early interventions. In contrast, the probability of presence of bay-breasted warbler consistently increased 3–4 years before defoliation was detectable. Conclusions Early detection is a critical step in the management of spruce budworm outbreaks and rapid increases in the probability of presence of bay-breasted warbler could be used to identify future epicenters and target ground-based local sampling of spruce budworm.


2021 ◽  
Vol 496 ◽  
pp. 119408
Author(s):  
Djidjoho Julien Houndode ◽  
Cornelia Krause ◽  
Hubert Morin
Keyword(s):  

Author(s):  
Marc Rhainds ◽  
Ian DeMerchant ◽  
Pierre Therrien

Abstract Spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is the most severe defoliator of Pinaceae in Nearctic boreal forests. Three tools widely used to guide large-scale management decisions (year-to-year defoliation maps; density of overwintering second instars [L2]; number of males at pheromone traps) were integrated to derive pheromone-based thresholds corresponding to specific intergenerational transitions in larval densities (L2i → L2i+1), taking into account the novel finding that threshold estimates decline with distance to defoliated forest stands (DIST). Estimates of thresholds were highly variable between years, both numerically and in terms of interactive effects of L2i and DIST, which limit their heuristic value. In the context of early intervention strategy (L2i+1 &gt; 6.5 individuals per branch), however, thresholds fluctuated within relatively narrow intervals across wide ranges of L2i and DIST, and values of 40–200 males per trap may thus be used as general guideline.


1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais

Nearly all forest regions in the Province of Quebec where balsam fir (Abies balsamea (L.) Mill.) is an important tree component have been subjected to severe defoliation by the spruce budworm, Choristoneura fumiferana (Clem.), during the past 20 years. These outbreaks have followed an easterly direction beginning near the Ontario-Quebec border in 1939 and ending in the Gaspé Peninsula in 1958.


1996 ◽  
Vol 26 (9) ◽  
pp. 1620-1628 ◽  
Author(s):  
Qiong Su ◽  
Ted D. Needham ◽  
David A. MacLean

Changing stand composition by increasing hardwood content has been suggested as a long-term method for reducing susceptibility and vulnerability of balsam fir (Abiesbalsamea (L.) Mill.) to spruce budworm (Choristoneurafumiferana (Clem.)). Twenty-five mixed balsam fir–hardwood stands were selected in northern New Brunswick, with five stands in each 20% hardwood class (0–20, 21–40%, etc.). Defoliation each year from 1989 to 1993 was significantly (p < 0.0001) related to hardwood content, with r2 ranging from 0.57 to 0.81. As hardwood content increased, defoliation of balsam fir decreased. From 1989 to 1992, the years of moderate to severe defoliation, balsam fir stands with <40% hardwoods sustained 58–71% defoliation, on average, versus 12–15% defoliation in stands with >80% hardwood. A generalized model combining hardwood content and the estimated defoliation in pure softwood stands in a given year explained 77% of the variation in defoliation over stands and years. This study indicated that mixed balsam fir–hardwood stand management, with hardwood content >40%, could substantially reduce losses during spruce budworm outbreaks. Further research is warranted to elucidate the mechanism involved, but our working hypothesis is that greater hardwood content increased the diversity or populations of natural enemies such as birds and parasitoids.


1986 ◽  
Vol 62 (2) ◽  
pp. 96-100 ◽  
Author(s):  
D. J. McRae

Recent spruce budworm (Choristoneura fumiferana [Clem.]) infestations have resulted in widespread areas of balsam fir (Abies balsamea [L.] Mill.) mortality in Ontario, and there is growing interest in reestablishing these areas quickly as productive forests. One technique being used is prescribed fire after a salvage and bulldozer tramping operation. A 445-ha prescribed burn was carried out under moderate fire danger conditions in northern Ontario. The site, which was covered by balsam fir fuel that had been killed by spruce budworm, was tramped to improve fire spread. Weather, fuel consumption, and fire effects are reported. The burn effectively reduced heavy surface fuel loadings and consequently planting on the site was easier. Key words: Prescribed burning, fire, spruce budworm. Choristoneura fumiferana, balsam fir, Abies balsamea, fuel consumption, site preparation, tramping, stand conversion.


1992 ◽  
Vol 96 (4) ◽  
pp. 281-286 ◽  
Author(s):  
Larry A. Calhoun ◽  
John A. Findlay ◽  
J. David Miller ◽  
Norman J. Whitney
Keyword(s):  

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