Chronologie de la croissance chez des semis de sapin baumier (Abies balsamea (L.) Mill.) après une coupe à blanc avec protection de la régénération

2002 ◽  
Vol 78 (6) ◽  
pp. 876-885 ◽  
Author(s):  
Sylvain Parent ◽  
Jean-Claude Ruel
Keyword(s):  
Abies Balsamea ◽  
Ring Width ◽  
Complete Removal ◽  
Moisture Stress ◽  
Height Growth ◽  
Balsam Fir ◽  
White Birch ◽  
Strong Response ◽  
Seedling Bank ◽  
Wide Range

The method of harvesting with protection of the advanced regeneration consists of a complete removal of the main canopy to release a seedling bank established under the overstory shade. After harvesting, seedlings acclimated to understory conditions could suffer from moisture stress, especially the small, juvenile seedlings (less than six years). The objective of the study is to determine the capacity of understory-acclimated balsam fir seedlings to respond positively and immediately to release. The response to release was studied in two seedling populations belonging to two distinct climatic regions of Quebec, the Western and the Eastern sections of the balsam fir-white birch ecological domain. Results show that the response patterns were similar in both populations. Response to release occurred in two steps. One year after harvesting, basal ring width was on the average five times larger than prior to harvesting (p > 0.001). Height growth only became significantly higher the second year after release (p < 0.001). On average, juveniles showed higher height growth rates (height growth/height) than older seedlings. This rate was negatively correlated to seedling height at harvesting (r = -0,68, p < 0.001). Our study clearly shows that balsam fir seedlings can respond immediately and positively to large openings. The strong response of juvenile seedlings to release indicates that these can contribute significantly to the future stand. The geographic and climatic differences between the two stands under study suggest that these observations apply to a wide range of balsam fir stands. Key words: advance growth, balsam fir, release

Effects of fenitrothion on the arthropod food of tree-foraging forest songbirds

1990 ◽  
Vol 68 (11) ◽  
pp. 2235-2242 ◽  
Author(s):  
Rhonda L. Millikin
Keyword(s):  
Active Ingredient ◽  
Significant Relationship ◽  
Tree Species ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Betula Papyrifera ◽  
White Birch ◽  
Forest Songbirds ◽  
The Impact

The impact of fenitrothion on the arthropod food of songbirds was measured using white birch (Betula papyrifera Marsh.) and balsam fir (Abies balsamea (L.) Mill.) branch sample and drop trays. Following ground application of fenitrothion at 293 g active ingredient/ha, there was a significant decrease in the biomass of arthropods as determined using branch samples from both tree species, but not until 5 days after the application (29% reduction for balsam fir, 35% for white birch). Samples from drop trays indicated an immediate kill of arthropods not associated with the tree. Most remaining arthropods on treated balsam fir trees were dead. These dead arthropods would not be suitable food for birds that require movement to detect their prey. There was no significant relationship between amount of deposit (treated trees only) and the reduction of arthropods for either tree species.

scholarly journals Dynamique d'établissement d'un peuplement bi-étagé de bouleau blanc et de sapin baumier en zone boréale

1993 ◽  
Vol 69 (2) ◽  
pp. 173-177 ◽  
Author(s):  
Louis Bélanger ◽  
Daniel Allard ◽  
Philippe Meek
Keyword(s):  
Age Structure ◽  
Initial Period ◽  
Abies Balsamea ◽  
Floristic Composition ◽  
Balsam Fir ◽  
White Birch ◽  
Vegetation Dynamic ◽  
Local Conditions ◽  
Regeneration Pattern ◽  
Seed Sources

The age structure of a boreal two-storied stand formed by an upperstory of white birch (Betula papyrifera Marsh.) with an understory of balsam fir (Abies balsamea (L.) Mill.) was analysed. The establishment of this 50-year stand followed a burn that ran through a cut-over area. The objective was to verify if the establishment of the fir understory followed the traditional succession model or the initial floristic composition model. The age structure analysis indicated an immediate and rapid establishment of white birch during a period of 6 years after the fire. Establishment of fir, however, was initiated only 16 years after the fire. Peak establishment was 33 years after the fire. Fir regeneration followed a cycle. The regeneration pattern was characterized by the absence of fir establishment the first 16 years after the fire, followed by sporadic fir regeneration the next 12 years, then by a 13-year period of abundant regeneration after which there was a complete halt to fir regeneration. So, in this case, the successional model was more fit to describe the dynamics of balsam fir. The absence of fir regeneration during the initial period after the fire could be explained by the absence of the nearby fir seed sources due to harvesting. However, the total absence of fir establishment during the last period is more difficult to explain. Seedbed evolution since the fire could possibly be in cause. This and other studies indicate that in the boreal balsam fir-white birch ecoclimatic domain vegetation dynamic after fire does not limit itself to one pathway. Stand regeneration after fire is significantly affected by local conditions.

Larval diet prior to and following virus ingestion influences the efficacy of two nucleopolyhedroviruses in whitemarked tussock moth (Orgyia leucostigma) caterpillars

2012 ◽  
Vol 144 (3) ◽  
pp. 447-457 ◽  
Author(s):  
Garrett Brodersen ◽  
Rob Johns ◽  
Renée Lapointe ◽  
David Thumbi ◽  
Graham Thurston ◽  
...  
Keyword(s):  
Artificial Diet ◽  
Viral Infections ◽  
Abies Balsamea ◽  
Field Studies ◽  
Balsam Fir ◽  
Betula Papyrifera ◽  
White Birch ◽  
Tussock Moth ◽  
Orgyia Leucostigma ◽  
Whitemarked Tussock Moth

AbstractFood quality can influence the performance of immature insects and their interactions with pathogens, such as viruses. In manipulative field studies, virus-free caterpillars of the whitemarked tussock moth (WMTM) (Orgyia leucostigma (Smith)) had higher survival, more female-biased sex ratios, and were larger when feeding on white birch (Betula papyrifera Marshall) versus balsam fir (Abies balsamea (Linnaeus) Miller) or red spruce (Picea rubens Sargent). Subsequent laboratory studies with two nucleopolyhedroviruses, derived from WMTMs and Douglas-fir tussock moths, indicated that caterpillars fed high quality food (i.e., artificial diet) prior to infection had less mortality associated with virus infection than those feeding on lower quality foliage (i.e., birch). In field studies, caterpillars fed birch following infection had significantly lower mortality than those feeding on relatively lower quality foliage (i.e., balsam fir). We postulate that higher nutritional quality in artificial diet relative to birch (previrus-ingestion nutrition) and in birch relative to balsam fir foliage (postvirus-ingestion nutrition) has a positive effect on the ability of tussock moth caterpillars to resist or recover from viral infections, although the specific mechanisms responsible for observed resistance remain unclear.

Long-term impact of fire on high-altitude balsam fir (Abies balsamea) forests in south-central Quebec deduced from soil charcoal

2013 ◽  
Vol 43 (2) ◽  
pp. 188-199 ◽  
Author(s):  
Pierre-Luc Couillard ◽  
Serge Payette ◽  
Pierre Grondin
Keyword(s):  
Boreal Forest ◽  
High Altitude ◽  
Tree Species ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Forest Landscape ◽  
White Birch ◽  
Soil Charcoal ◽  
Fire Activity

Extensive balsam fir (Abies balsamea (L.) Mill.) stands across the southern boreal forest are ecosystems likely more influenced by insect outbreaks and windthrows than by fire. To what degree the dominance of balsam fir stands reflects past and present disturbance dynamics associated with fire is not well documented. To answer this question, we focused on the reconstruction of the long-term fire history of high-altitude balsam fir forests of southern Quebec. The reconstruction was based on botanically identified and radiocarbon-dated soil charcoal particles in 19 sites covering successional stages from white birch (Betula payrifera Marsh.) to mixed white birch – balsam fir stands. Fire activity commenced early after deglaciation, about 9600 calibrated years before present when the first boreal tree species were established. Fire occurred recurrently during the following 5000 years with a forest landscape composed of the principal tree species common to the boreal forest, including jack pine (Pinus banksiana Lamb.). Fire activity ceased more or less abruptly about 4500 years ago due to less fire-conducive, more humid conditions. Then, the forest landscape progressively changed towards a larger representation of white birch – balsam fir forests and the disappearance of jack pine. Whereas several balsam fir stands have not burned over the last 4500 years, scattered fires occurred in particular over the last 250 years when 1815 and 1878 fires, probably man-made, burned 50% of the forest, thus causing a major change in the composition of the forest landscape. It is concluded that the high-altitude forest landscape of southern Quebec changed profoundly over the Holocene in close association with a time-transgressive dry-to-wet climatic gradient.

Dynamique de la sapinière à bouleau jaune de l'est après une épidémie de tordeuse des bourgeons de l'épinette

1999 ◽  
Vol 75 (3) ◽  
pp. 515-534 ◽  
Author(s):  
Pierre Pominville ◽  
Stéphane Déry ◽  
Louis Bélanger
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
The Other ◽  
Balsam Fir ◽  
Betula Alleghaniensis ◽  
White Birch ◽  
Yellow Birch ◽  
Mixed Stands ◽  
The Dead

An outbreak of spruce budworm, Choristoneura fumiferana (Clem.), occurred between 1974 and 1987, in Quebec, in the eastern balsam fir, Abies balsamea (L.) Mill, - yellow birch, Betula alleghaniensis Britton, ecoclimatic sub-domain. The effect of this disruption has been assessed in mesic balsam fir stands killed during the outbreak, in mesic balsam fir stands partially damaged and in the following stands, also partially damaged: mesic yellow birch – balsam fir stands, mesic white birch, Betulapapyrifera Marsh., - balsam fir stands, mesic balsam fir – yellow birch stands, mesic balsam fir – white birch stands and xeric balsam fir stands. To that effect, surveys were led before, immediately after, and about five years after the outbreak in two blocks that have not been protected with insecticides. These blocks, located in Charlevoix and in Shipshaw management units, are second growth stands originating from clearcuts which occured about 50 years ago. Approximately five years after the outbreak, abundant coniferous regeneration was found everywhere except in the mesic yellow birch –balsam fir stand and in the dead mesic balsam fir stand, where softwood represented less than 50% of the regeneration. On the other hand, young softwood stems were located under the regeneration of white birch and of mountain maple, Acer spicatum Lam, in dead balsam fir stands, in balsam fir – white birch stands, as well as in living balsam fir stands and under mountain maple in yellow birch – balsam fir stands and in balsam fir – yellow birch stands. Our age structures indicate that softwood advance growth was relatively rare in these stands. Thus, during the opening of the canopy by the spruce budworm, intolerant hard-woods and shrubs invaded the still available microsites. In the dead balsam fir stands, stocking of the dominant hardwood regeneration stems is equivalent to that of softwood. Thus, dead balsam fir stands are turning to mixed stands. Xeric stands will remain softwood stands since they show luxuriant softwood regeneration dominating in height. In the other stands, we will have to wait the harvest period before we can adequately assess succession.

Recent impact of fire on high-altitude balsam fir forests in south-central Quebec1This article is one of a selection of papers from the 7th International Conference on Disturbance Dynamics in Boreal Forests.

2012 ◽  
Vol 42 (7) ◽  
pp. 1289-1305 ◽  
Author(s):  
Pierre-Luc Couillard ◽  
Serge Payette ◽  
Pierre Grondin
Keyword(s):  
High Altitude ◽  
Fire Regime ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Stand Age ◽  
Forest Types ◽  
Plant Composition ◽  
White Birch ◽  
South Central

The dynamics of high-altitude balsam fir ( Abies balsamea (L.) Mill.) forests is mainly driven by insect outbreaks and windthrows. However, very little work has been done on the role of fire on the development and maintenance of this ecosystem. In this study, we document the role of fire in the high-altitude balsam fir forests of the Réserve Faunique des Laurentides (RFL), southern Quebec. Sixteen sites were sampled among six different forest types described according to plant composition and fire evidence. At each site, the diameter structure was recorded and stand age was calculated based on tree-ring dating of individual trees and radiocarbon-dated surficial charcoal samples. Fire played a major role in the recent dynamics of high-altitude fir forests in the RFL. Over the last 250 years, nearly 50% of the study area burned during two fire conflagrations, i.e., around 1815 and in 1878. The fires triggered gradual changes in plant composition and forest structure, as shown by a succession of forest types ranging from white birch ( Betula papyrifera Marsh.) to spruce–fir types. Absence of surficial charcoal older than 300 years suggests that high-altitude forests of the RFL area were not subjected to a constant fire regime. It is possible that recent fires were caused by human activity.

Early seedling demography in balsam fir seedling banks

1999 ◽  
Vol 29 (10) ◽  
pp. 1502-1509 ◽  
Author(s):  
Robin Duchesneau ◽  
Hubert Morin
Keyword(s):  
Seed Dispersal ◽  
Abies Balsamea ◽  
Ecological Factors ◽  
Balsam Fir ◽  
Permanent Plots ◽  
Seedling Mortality ◽  
Dispersal Pattern ◽  
Seedling Demography ◽  
Seedling Bank ◽  
Early Establishment

Following the 1995 mast year, we conducted detailed seedling demography surveys to characterize some ecological factors affecting germination and early establishment in understory balsam fir (Abies balsamea (L.) Mill.) seedling banks and verify if recruitment from a cohort can potentially renew the balsam fir seedling bank. Twenty-five seed traps paired with 32 demography subplots were located in each of four permanent plots and regularly monitored over a 2-year period. Spatial patterns of newly emerged seedlings generally corresponded to those found for seed dispersal. However, at the end of the monitoring period, the spatial pattern of surviving seedlings was independent of the seed dispersal pattern. Seedbed types and understory light environments were the main factors explaining seedling mortality. Sphagnum mosses and decaying wood were the most favorable seedbeds for early establishment. The 0- to 25-cm seedling populations grew in size because of the addition of new recruits. If, in the years to come, mortality rates of the 1995 cohorts were similar to those of already established 0- to 25-cm seedlings, mast years of seed production, at least during endemic periods, would be crucial for recruitment and renewal of balsam fir seedling banks.

Effect of gibberellic acid on growth and photosynthesis in Abies balsamea

1975 ◽  
Vol 53 (17) ◽  
pp. 1805-1810 ◽  
Author(s):  
C. H. A. Little ◽  
K. Loach
Keyword(s):  
Gibberellic Acid ◽  
Abies Balsamea ◽  
Foliar Spray ◽  
Weight Ratio ◽  
Normal Growth ◽  
Net Photosynthesis ◽  
Height Growth ◽  
Balsam Fir ◽  
Root Weight ◽  
Productive Capacity

The hypothesis that exogenous gibberellic acid (GA3) increases height growth in tree species partly because it stimulates the rate of net photosynthesis (PN) was investigated in the conifer balsam fir (Abies balsamea L.). In long-term experiments, the normal growth pattern of 4- and 5-year-old potted trees was changed by GA3 applied in both an aqueous soil drench (20 mg per tree, thrice weekly; or 50 mg per tree, twice weekly) and a foliar spray (1000 ppm, weekly) for about 3 months. Effects included increased longitudinal and radial growth in the leader and longest lateral in the uppermost whorl, enhancement of shoot apical dominance, increased needle length, and decreased root weight – top weight ratio. Nevertheless, the Pn and productive capacity of the current and 1-year-old needles in the GA3-treated and control trees were the same, measured during and at the end of the treatment period. In short-term experiments, the 1000-ppm GA3 spray did not affect PN of current-year needles, measured 3 h up to 7 days after one or two applications. PN of current-year cuttings also was not altered by feeding through the basal end (1) 0.25, 2.5, 25, or250 ppm GA3 for 4 h; or(2) 10 or 100 ppm GA3 for24 h. Feeding25 or250 ppm GA3 for 48 h through the distal portion of an attached, current shoot decreased PN in the proximal portion. Collectively, the results indicate that exogenous GA3 increases height growth in balsam fir by altering the normal distribution of photosynthate, not through increasing photosynthate production.

Establishment of natural regeneration under severe browsing pressure from white-tailed deer after group seed-tree cutting with scarification on Anticosti Island

2009 ◽  
Vol 39 (3) ◽  
pp. 596-605 ◽  
Author(s):  
Julien Beguin ◽  
Marcel Prévost ◽  
David Pothier ◽  
Steeve D. Côté
Keyword(s):  
Negative Impact ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
White Birch ◽  
Conifer Species ◽  
Double Pass ◽  
Advance Regeneration ◽  
Anticosti Island ◽  
The Impact ◽  
Tree Group

The use of large clearcuts with protection of advance regeneration is inappropriate for regeneration of balsam fir ( Abies balsamea (L.) Mill.) under severe browsing from white-tailed deer ( Odocoileus virginianus (Zimmermann)). However, little is known about the effects of tree-retention methods along with scarification on the establishment of balsam fir in a context of severe herbivory. Consequently, we hypothesized that seed-tree-group cutting in conjunction with soil scarification creates favourable conditions for balsam fir regeneration. In 1998 and 1999 we set up three circular forest groups of different sizes (40, 60, and 80 m in diameter) surrounded by three different intensities of scarification (no treatment, single pass, double pass) in two balsam fir stands on Anticosti Island, Quebec, Canada. Moreover, we used a network of fenced and unfenced regeneration plots to evaluate the impact of white-tailed deer browsing. The results showed that up to 7 years after harvest, seed-tree-group cutting did not improve the establishment of conifer species. Scarification had a negative impact on the abundance of conifer species, whereas white birch ( Betula papyrifera Marshall) density was significantly higher in areas scarified twice than in unscarified areas. Overall, the development of palatable tree species appears unlikely at deer densities >20 individuals/km2.

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