Résistance comparée de l'épinette blanche et du sapin baumier au renversement

2002 ◽  
Vol 32 (4) ◽  
pp. 642-652 ◽  
Author(s):  
S Meunier ◽  
J -C Ruel ◽  
G Laflamme ◽  
A Achim
Keyword(s):  
Tree Species ◽  
Picea Glauca ◽  
Abies Balsamea ◽  
White Spruce ◽  
Diameter Ratio ◽  
Balsam Fir ◽  
Species Vulnerability ◽  
Mesic Site ◽  
Linear Regressions ◽  
Tree Characteristics

Information on eastern Canadian tree species vulnerability to windthrow is scarce. Some statements on relative species vulnerability have been made but they rely on empirical observations, which are often difficult to generalize. In this context, a study was conducted to compare the overturning resistance of balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) on a mesic site. To establish which tree characteristics would best explain the critical turning moment, simple linear regressions were calculated using tree dendrometric data. The best regressions were obtained with stem weight. With this variable, resistance to overturning did not differ between the two species. Only regressions involving total height showed a significantly greater resistance for white spruce. This difference can be explained by a difference between the species in height–diameter relationships. For a similar height, spruce has a greater diameter, involving a higher stem weight and thus a greater resistance. Decay did not play a major role in our experiment as trees with external defects were excluded. Our results suggest that to minimize losses from windthrow, silvi cultural treatments on mesic sites should try to increase the proportion of trees of either species with the lowest height/diameter ratio.

Variations in the foliar amino acid composition of flowering and non-flowering balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) in relation to outbreaks of the spruce budworm (Choristoneura fumiferana (Clem))

1971 ◽  
Vol 49 (7) ◽  
pp. 1005-1011 ◽  
Author(s):  
J. P. Kimmins
Keyword(s):  
Amino Acids ◽  
Picea Glauca ◽  
Host Plants ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Apparent Correlation

The amino acids of new and old foliage of flowering and non-flowering balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) were investigated using two-dimensional descending paper chromatography. The data were analyzed for variation associated with age of foliage, age of tree, and flowering condition. The concentration of foliar amino acids was greater in balsam fir than in white spruce, and greater in new foliage than old foliage.The difference in concentration between foliage of flowering and non-flowering trees was smaller. However, the new foliage of flowering fir had higher levels of most of the amino acids examined than any other foliage category. This appears to reflect the known suitability of these foliage categories for spruce budworm larvae. While the data presented do not quantify the ecological significance of this apparent correlation, they do support the theory that variations in the nutritional quality of host plants play a very important role in the dynamics of herbivore populations.

scholarly journals EFFECTS OF DEFOLIATION BY SPRUCE BUDWORM (CHORISTONEURA FUMIFERANA CLEM.) ON RADIAL GROWTH AT BREAST HEIGHT OF BALSAM FIR (ABIES BALSAMEA (L.) MILL.) AND WHITE SPRUCE (PICEA GLAUCA (MOENCH) VOSS.)

1958 ◽  
Vol 34 (1) ◽  
pp. 39-47 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
Picea Glauca ◽  
Radial Growth ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
First Year ◽  
Growth Ratio ◽  
Breast Height

The relationship between spruce budworm defoliation and radial growth at breast height for balsam fir and white spruce trees of merchantable size was studied in various stands in northwestern Ontario. Defoliation was recorded yearly for these stands from the beginning of the infestation, and radial growth measurements were obtained from increment cores. The first year of radial growth suppression was calculated by comparing the growth of the affected species with that of jack pine and red pine trees by means of a growth-ratio technique. Apparent suppression in balsam fir and white spruce varied between stands, and, generally, occurred at the earliest in the second year and at the latest in the fourth year of severe defoliation. A wide ring at the base of the tree coinciding with the first year of suppression as reported by Craighead was non-existent.

Windthrow as an important process for white spruce regeneration

2002 ◽  
Vol 78 (5) ◽  
pp. 732-738 ◽  
Author(s):  
Jean-Claude Ruel ◽  
Marius Pineau
Keyword(s):  
Key Words ◽  
Picea Glauca ◽  
Abies Balsamea ◽  
White Spruce ◽  
Balsam Fir ◽  
Differential Mortality ◽  
Important Process ◽  
Mature Stands

White spruce (Picea glauca (Moench.) Voss.) is frequently found in association with balsam fir (Abies balsamea (L.) Mill.) in virgin stands. However, its regeneration is less aggressive than that of balsam fir. The persistance of white spruce in the canopy might be explained by differential mortality and windthrow. Windthrow could play an important role in creating favourable seedbeds and providing increased light. This paper examines the contribution of windthrow for white spruce regeneration in balsam fir-dominated forests. Experimental windthrows were created and regeneration establishment monitored for three seasons. Windthrow greatly modified the availability of seedbeds and enhanced white spruce establishment. Older natural windthrows were sampled to conclude that this effect was still evident more than five years after windthrow occured. We also noticed that white spruce benefited more from the disturbance than did balsam fir. Finally, sampling conducted in mature stands showed that mature white spruce stems were more abundant on the mounds created by old uprootings, indicating that this effect is maintained in the long term. Even though balsam fir also benefited from windthrow, the benefit was proportionally greater for white spruce. Key words: Picea glauca, Abies balsamea, windthrow, microtopography, regeneration

Foliage architecture explains oviposition preference of spruce budworm (Lepidoptera: Tortricidae) for white spruce over balsam fir

2006 ◽  
Vol 138 (2) ◽  
pp. 198-204 ◽  
Author(s):  
Gary G. Grant
Keyword(s):  
Picea Glauca ◽  
Choristoneura Fumiferana ◽  
Oviposition Preference ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Spatial Arrangement ◽  
Balsam Fir

AbstractI conducted dual-choice oviposition bioassays to test the hypothesis that spruce budworm, Choristoneura fumiferana (Clemens), prefer the foliage architecture (spatial arrangement of foliage needles) of white spruce (Picea glauca (Moench) Voss; Pinaceae) to that of balsam fir (Abies balsamea (L.) P. Mill.; Pinaceae). Needles of white spruce radiate around the twig axis, giving the foliage a round architecture. Needles of balsam fir typically radiate bilaterally from the twig axis, giving the foliage a flat architecture, although on some trees foliage needles radiate around the twig axis, giving the foliage a round architecture. In bioassays, females showed a 2.4:1 preference for white spruce over "flat" balsam fir foliage, but this preference was reduced significantly to a 1.2:1 ratio when balsam fir had a round architecture. Given a choice between "round" and "flat" balsam fir foliage, females preferred the "round" foliage by a 2.2:1 margin. A similar preference for the round architecture was also observed when artificial (plastic) foliage with the two types of needle arrangements were compared. I conclude that the spatial arrangement of foliage needles is a major factor responsible for the oviposition preference of spruce budworm for white spruce over balsam fir.

The effect of light availability and basal area on cone production in Abies balsamea and Picea glauca

2002 ◽  
Vol 80 (4) ◽  
pp. 370-377 ◽  
Author(s):  
David F Greene ◽  
Christian Messier ◽  
Hugo Asselin ◽  
Marie-Josée Fortin
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Light Availability ◽  
Abies Balsamea ◽  
Basal Area ◽  
White Spruce ◽  
Balsam Fir ◽  
Forest Edges ◽  
Cone Production ◽  
Effect Of Light

Mean annual seed production is assumed to be proportional to basal area for canopy trees, but it is not known if subcanopy trees produce fewer seeds than expected (given their size) because of low light availability. Ovulate cone production was examined for balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) in 1998 and for balsam fir in 2000 in western Quebec using subcanopy stems, near or far from forest edges, or (at one site) planted white spruce trees in fully open conditions. A very simple light model for transmission through mature trembling aspen (Populus tremuloides Michx.) crowns and through boles near forest edges was developed to account for the effect of light receipt on cone production. The enhanced light near forest edges (e.g., recent clearcuts) leads to about a doubling of cone production for subcanopy stems. The minimum subcanopy height for cone production far from an edge is about 10 m for balsam fir and 14 m for white spruce, with these minima decreasing near edges. By contrast, the minimum height for white spruce in a plantation (full light) is about 3 m. Accounting for light receipt leads to an increase in the explained variance.Key words: balsam fir, cone production, light model, regressions, subcanopy stems, white spruce.

Interactions among defoliation level, species, and soil richness determine foliage production during and after simulated spruce budworm attack

2020 ◽  
Vol 50 (6) ◽  
pp. 565-580
Author(s):  
Yuanyuan Wu ◽  
David A. MacLean ◽  
Chris Hennigar ◽  
Anthony R. Taylor
Keyword(s):  
Picea Glauca ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Shoot Length ◽  
Balsam Fir ◽  
Site Quality ◽  
Number Of Shoots

Defoliation level and site type are thought to influence tree response during spruce budworm (Choristoneura fumiferana (Clemens)) outbreaks. We determined the effects of four manual defoliation treatments (0%, 50%, 100%, and 100% + bud removal of current foliage) for 3 years on foliage production of balsam fir (Abies balsamea (L.) Mill.), black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.), and white spruce (Picea glauca (Moench) Voss) trees on four site-quality classes. After 3 years of defoliation and 2 years of recovery, foliage biomass was reduced by 34%–98%. During defoliation, the number of shoots generally increased and shoot length of spruce generally decreased, especially on rich sites. During recovery, the number of shoots increased substantially, shoot length decreased, and bud destruction reduced the number of shoots by about 50% compared with that of trees that received the 100% defoliation treatment. Defoliation did not substantially affect needle length. Trees on rich sites had two- to fourfold greater foliage production than trees on poor sites. Effects of site and defoliation differed among species, but site quality, especially nutrition, played an important role in production of shoots and needles and the tree’s ability to withstand defoliation. Black spruce had more limited ability to recover foliage biomass, only producing more shoots, whereas balsam fir and white spruce had stronger ability to recover needle and shoot length, respectively.

EFFICACY AND FIELD PERSISTENCE OF BACILLUS THURINGIENSIS AFTER GROUND APPLICATION TO BALSAM FIR AND WHITE SPRUCE IN WISCONSIN

1984 ◽  
Vol 116 (2) ◽  
pp. 153-158 ◽  
Author(s):  
R. C. Reardon ◽  
K. Haissig
Keyword(s):  
Bacillus Thuringiensis ◽  
Picea Glauca ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir

AbstractBacillus thuringiensis was applied at three dosages (1.0 BIU/tree, 0.1 BIU/tree, and.01 BIU/tree) to balsam fir, Abies balsamea (L.) Mill., and white spruce, Picea glauca (Moench) Voss, with mist blowers. Crystalline proteins were detected on balsam fir foliage for a maximum of 16 days (d) after B. thuringiensis was applied at 1.0 BIU/tree. Higher levels of crystalline proteins were detected on white spruce foliage treated with Thuricide 16B than on that treated with Dipel 4L. On balsam fir, the situation was the opposite. Mist-blower-treated foliage collected for up to 16 d posttreatment caused mortality of spruce budworm, Choristoneura fumiferana (Clemens), larvae. Viable endospores of B. thuringiensis were recovered on white spruce foliage collected 1 year after treatment.

Effet d'une coupe d'ensemencement et du milieu de germination sur la régénération des sapinières boréales riches de seconde venue du Québec

2000 ◽  
Vol 76 (4) ◽  
pp. 643-652 ◽  
Author(s):  
Patricia Raymond ◽  
Jean-Claude Ruel ◽  
Marius Pineau
Keyword(s):  
Picea Glauca ◽  
Forest Cover ◽  
Seedling Survival ◽  
Mineral Soil ◽  
Abies Balsamea ◽  
Basal Area ◽  
White Spruce ◽  
Balsam Fir ◽  
Paper Birch ◽  
Cutting System

Stand regeneration failures, sometimes observed in rich second growth balsam fir stands, prompted a study in 1991 to assess the effects of the shelterwood cutting system on regeneration of balsam fir (Abies balsamea (L.) Mill.), white spruce (Picea glauca (Moench) Voss) and paper birch (Betula papyrifera Marsh). The factorial experiment design (split-plot) includes forest cover reduction (0% and 25% of basal area) in main plots and germination substrate (mineral soil, litter removed and control) in subplots. Results of five growing seasons showed that germination substrate was the main factor determining first-year seedling establishment, and that cover reduction became important for seedling survival and long-term establishment of the three species. A 25% canopy reduction combined with mineral seedbed treatment resulted in the best regeneration densities of the three species. Thus far, the results demonstrate the importance of combining humus disturbance to seed cutting in order to achieve regeneration goals set for the future stand. Key words: shelterwood cutting system, balsam fir, white spruce, paper birch, regeneration, seed cutting, germination substrate

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