Larval feeding behaviour affects the impact of staminate flower production on the suitability of balsam fir trees for spruce budworm

Oecologia ◽  
1996 ◽  
Vol 105 (1) ◽  
pp. 126-131 ◽  
Author(s):  
�ric Bauce ◽  
Nathalie Carisey
Keyword(s):  
Feeding Behaviour ◽  
Staminate Flower ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Larval Feeding ◽  
Flower Production ◽  
The Impact

Rate of defoliation of balsam fir in relation to spruce budworm attack and timing of spray application

1979 ◽  
Vol 9 (3) ◽  
pp. 354-361 ◽  
Author(s):  
J. Robert Blais
Keyword(s):  
Feeding Behaviour ◽  
Spruce Budworm ◽  
Early Spring ◽  
Fourth Instar ◽  
Balsam Fir ◽  
Larval Feeding ◽  
Progressive Damage ◽  
Spray Application ◽  
The Relationship ◽  
Very High

Studies were conducted in 1976 and 1977 to determine feeding behaviour and progressive damage to balsam fir (Abiesbalsamea (L.) Mill.) throughout the larval feeding period of the spruce budworm (Choristoneurafumiferana Clem.).Four plots had high populations of approximately 30 larvae and four had very high populations of over 100 larvae per 45-cm branch tip at peak L2. In early spring emerging second-instar larvae mined needles of old foliage; few buds were attacked prior to third instar. Defoliation of current year's growth was between 70 and 80% in plots with high populations and close to 100% in those with very high populations. In the high-population plots the 25% level of foliage destruction occurred close to peak fifth instar and the 50% level just before peak sixth instar. In plots with very high populations 25% defoliation occurred close to peak third instar and 50% defoliation close to peak fourth instar. The relationship between defoliation patterns and best timing of insecticide application is discussed.

Stochastic simulation of growth loss in thinned balsam fir stands defoliated by the spruce budworm in Newfoundland

1998 ◽  
Vol 28 (5) ◽  
pp. 703-710 ◽  
Author(s):  
Erhard John Dobesberger
Keyword(s):  
Stochastic Simulation ◽  
Larval Density ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Damage Function ◽  
Balsam Fir ◽  
Negative Exponential Function ◽  
Attack Pattern ◽  
Growth Loss ◽  
The Impact

A stochastic simulation model was developed to derive a damage function for the spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), and balsam fir, Abies balsamea (L.) Mill., herbivore interaction at the stand level for open-grown trees. Both aggregated and uniform models of attack pattern by late-instar larvae based on k of the negative binomial were evaluated to determine the impact of larval density and attack pattern on the loss in stemwood volume increment of young, thinned balsam fir stands in Newfoundland. Percentage loss in stemwood increment was a nonlinear, negative exponential function of initial larval density. Implementation of control measures to prevent 50% defoliation that is caused by about 14 larvae/branch tip would result in saving 24% of the annual stemwood increment after 1 year of defoliation and about 32% after 2 years of cumulative defoliation. Aggregation of spruce budworm larvae among trees within a forest stand results in less growth loss compared with a uniform pattern of attack. The nonlinear damage function may suggest tolerance and possibly compensatory growth after herbivory by low population levels of the spruce budworm.

Impact de la tordeuse des bourgeons de l'épinette [Choristoneura fumiferana (Clem.)] sur la régénération des sapinières après la coupe à blanc

1993 ◽  
Vol 69 (2) ◽  
pp. 163-172 ◽  
Author(s):  
J.-C. Ruel ◽  
M. Huot
Keyword(s):  
Key Words ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Dominant Position ◽  
The Impact ◽  
Coupe À Blanc

An analysis of over 100 balsam fir [Abies balsamea (L.) Mill.] stands has shown some effects of spruce budworm defoliation on regeneration after clearcutting. Even though softwood stocking was consistently high prior to harvesting operations, longer infestation periods or more severe defoliation levels led to a decrease in the stocking of softwood stems above 50 cm height and to the establishment and development of hardwood advance growth. Hardwoods were more often in a dominant position in the most severely damaged stands and the budworm effect was still persistent on the regeneration structure even 5 years after logging. Cutovers with less than 60% stocking were also more frequent in the most severely devastated fir stands. This situation seemed directly related to the impact of the spruce budworm on balsam fir advance growth. Key words: balsam fir, Choristoneura fumiferana, advance growth, clearcutting

scholarly journals Impact of a spruce budworm outbreak in balsam fir and subsequent stand development over a 40-year period

2008 ◽  
Vol 84 (1) ◽  
pp. 60-69 ◽  
Author(s):  
David A MacLean ◽  
Allison R Andersen
Keyword(s):  
Stand Structure ◽  
Abies Balsamea ◽  
Basal Area ◽  
Stand Density ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Stand Development ◽  
Wide Range ◽  
Break Up ◽  
The Impact

Nine 0.04-ha plots were established in 1956 (age 35 years) in a balsam fir (Abies balsamea [L.] Mill.) stand in northwestern New Brunswick, Canada to determine the impact of an uncontrolled spruce budworm (Choristoneura fumiferana [Clem.]) outbreak on stand development. The plots were measured annually from 1956 to 1961 and at five-year intervals from 1965 to 1995. Moderate to severe defoliation occurred from 1951 to 1957 and again in 1975 to 1977, 1981, and 1986 to 1988. Budworm-caused mortality from 1956 to 1961 (age 35 to 40 years) varied considerably among plots, reducing volume by 35 to 113 m3/ha (34%-84%), and resulting in a wide range of post-outbreak plot densities. Plots were grouped into three post-budworm outbreak (1965, age 45 years) basal area classes, of ≤ 20 m2/ha, 21 to 27 m2/ha, and ≥ 28 m2/ha, to examine stand recovery. Recovery of volume up to age 60 years ranged from 72 to 132 m3/ha, in the lowest to highest basal area classes, respectively. From age 60 to 75 years, five plots declined in volume due to the onset of stand break-up and four plots increased in volume. By age 60 years, survivor growth was greatest in the high basal area plots, ranging from 6.2 to 9.0 m3/ha/yr in seven plots, versus 2.6 to 3.2 m3/ha/yr in two low basal area plots. From age 60 to 75 years, survivor growth averaged only 2.8 to 5.2 m3/ha/yr, and the stand exhibited major decline, with 63%, 74%, and 78% mortality of fir ≤ 15 cm DBH in the low to high basal area plots, respectively. Budworm-caused "thinning" in the 1950s largely determined subsequent stand development and the rate of stand break-up 25 to 35 years later. The timing and rate of natural stand decline was strongly influenced by post-outbreak stand density. Key words: budworm-caused mortality, stand structure, stand development, growth, mortality, stand density

Les forêts de la Côte Nord au Québec sont-elles sujettes aux déprédations par la tordeuse?

1983 ◽  
Vol 59 (1) ◽  
pp. 17-20 ◽  
Author(s):  
J. Robert Blais
Keyword(s):  
Tree Mortality ◽  
Growth Ring ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
North Shore ◽  
The North ◽  
River Region ◽  
Saguenay River ◽  
The Impact

Quebec's North Shore is a vast region comprising about one third of productive forests in the province. The impact of the spruce budworm (Choristoneura fumiferana (Clem.)) in this remote region was not welt known. In the summer of 1981, ground and aerial surveys were conducted to determine the extent to which fir stands had been affected during the current bud-worm outbreak. It was possible to confirm that defoliation had been severe for several successive years prior to 1978, and that since then, insect populations had diminished considerably. Available information on balsam fir mortality indicated only two areas: one in Saguenay River region in the extreme southwest of the study area, and the other in the vicinity of Baie Comeau. The 1981 surveys revealed that varying quantities of fir had succumbed to budworm attack in many stands occurring for hundreds of kilometers east of Baie Comeau. The spruce budworm maintained high populations sufficiently long to cause pockets of tree mortality over a widespread area on the North Shore. Growth-ring measurements on several old balsam fir and white spruce trees from many localities indicated that no other widespread budworm outbreak had occurred on the North Shore since the end of the nineteenth century.

Soil drainage class, host tree species, and thinning influence host tree resistance to the spruce budworm

2012 ◽  
Vol 42 (10) ◽  
pp. 1771-1783 ◽  
Author(s):  
Alvaro Fuentealba ◽  
Éric Bauce
Keyword(s):  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Host Tree ◽  
Balsam Fir ◽  
Thinning Intensity ◽  
Drainage Class ◽  
Tree Resistance ◽  
Commercial Thinning ◽  
The Impact

Thinning has frequently been recommended for reducing damage caused by spruce budworm ( Choristoneura fumiferana (Clemens)). It is believed that this technique enhances the mechanisms of resistance of trees (antibiosis and tolerance) to this insect. However, various research projects that have focused upon effects of this silvicultural tool on host tree resistance have yielded equivocal results. A better understanding of the effects of this technique on host tree resistance and budworm performance can help us to reduce the impact of this insect while respecting the ecological integrity of the forests. We examined the effects of stand commercial thinning and drainage class on balsam fir ( Abies balsamea (L.) Mill.)), white spruce ( Picea glauca (Moench) Voss), and black spruce ( Picea mariana (Mill.) Britton, Sterns & Poggenb.) resistance to spruce budworm 3 years after thinning. We wanted to determine if this technique could be used as preventive tool against insect defoliators. Field-rearing experiments of spruce budworm were conducted, together with foliar chemical analyses, along a gradient of stand thinning intensity (0% (control), 25% (light), and 40% (heavy)) and drainage class (rapidly drained, class 2; mesic with seepage, class 3; subhygric, class 4; and hydric, class 5). Despite having favoured budworm performance (high pupal mass) and winter survival, heavy thinning increased balsam fir and white spruce tolerance (amount of current-year foliage remaining) to a level that resulted in overall increased host tree resistance to the insect. This response was caused by strong foliage production in reaction to the thinning treatment. Light thinning did not increase host tolerance, except in balsam fir and white spruce that were growing on hydric and subhygric sites, respectively, demonstrating the importance of this variable in determining host tree resistance. These results suggest that heavy thinning may be used as a preventive measure during the low-density phase of budworm populations, since this technique increased foliar production in balsam fir and white spruce, rendering them more resistant to attack by this insect.

Balsam fir (Abies balsamea) establishment dynamics during a spruce budworm (Choristoneura fumiferana) outbreak: an evaluation of the impact of aging techniques

2001 ◽  
Vol 31 (3) ◽  
pp. 373-376 ◽  
Author(s):  
Sylvain Parent ◽  
Hubert Morin ◽  
Christian Messier
Keyword(s):  
Conventional Method ◽  
Seedling Recruitment ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Adult Mortality ◽  
Balsam Fir ◽  
Tree Age ◽  
Terminal Bud ◽  
The Impact

The effects of recurrent spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks on balsam fir (Abies balsamea (L.) Mill.) mortality have been extensively studied in Canada. Most studies report substantial seedling recruitment of balsam fir during outbreaks when reproductive trees are dying. According to previous research, this contradiction could be due to inaccuracies in the conventional aging method. Counting the maximum number of growth rings found at the tree base would significantly underestimate tree age. Counting terminal bud scars found on the entire trunk, including buried stem, would give a more accurate tree age. In this study, we compare recruitment dynamics obtained for aging seedlings in two balsam fir populations (about 500 km apart) using (i) the conventional method and (ii) bud scar counts. For both populations, the conventional method shows substantial recruitment during adult mortality, while the second aging technique reveals reduced recruitment during the epidemic phase of the spruce budworm outbreak.

scholarly journals Oil and Flower Production in Rosa damascena trigintipetala Dieck under Salinity Stress in Taif Region, Saudi Arabia

2021 ◽  
Vol 13 (8) ◽  
pp. 4547
Author(s):  
Mohamed E. El-Sharnouby ◽  
Metwally M. Montaser ◽  
Sliai M. Abdallah
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Salinity Stress ◽  
Growth Parameters ◽  
Industrial Applications ◽  
Rosa Damascena ◽  
Flower Production ◽  
Survival Percentage ◽  
The Impact ◽  
Tolerance To Salinity

The flower industry depends on oil and fragrance, which is addressed in the current work. Different concentrations of NaCl (0, 250, 500, 1000, and 1500 ppm) were applied to Taif rose plants (Rosa damascena var. trigintipetala Dieck) to evaluate their effects on growth and essential oil content. Results clearly indicated the highest survival percentage (98.3%) was seen in untreated plants compared to plants under salinity stress. Moreover, increasing the NaCl levels induced an adverse effect on the growth parameters of Taif rose plants, while some essential oil contents were increased to the maximum degree of their tolerance to salinity stress. The extracted essential oils were analyzed using GC/MS. The essential oils of Taif rose plants treated with 500 ppm NaCl recorded the highest values of citronellol, geraniol and phenylethyl alcohol contents (16.56, 8.67 and 9.87%), respectively. NaCl at 250 ppm produced the highest values of heneicosane (13.12%), and then decreased to the lowest value (7.79%) with the increase of NaCl to 1500 NaCl, compared to the control and other NaCl levels. The current results could highlight the impact of salinity stress on Rosa damascena Miller var. trigintipetala Dieck for better economic and industrial applications.

scholarly journals Predicting balsam fir mortality in boreal stands affected by spruce budworm

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