scholarly journals Dynamique et estimation du rendement des strates de retour après coupe totale dans la sapinière à bouleau jaune

2006 ◽  
Vol 82 (5) ◽  
pp. 675-689 ◽  
Author(s):  
Julie Dubois ◽  
Jean-Claude Ruel ◽  
Jean-Gabriel Elie ◽  
Louis Archambault
Keyword(s):  
Soil Type ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Type Structure ◽  
Balsam Fir ◽  
Stand Dynamics ◽  
Advance Regeneration ◽  
Second Growth ◽  
Spruce Stands ◽  
Stand Type

A total of 48 plots originating from clearcuts were studied in the balsam fir-yellow birch ecological domain of the province of Quebec, Canada, using dendrochronology. The aim of the study was to assess the effect of pre-cut stand type, structure and abundance of regeneration after logging, and soil type on stand dynamics. Results indicate a relationship between pre-cut stand type and the composition of second-growth stands. Ecological characteristics must be taken into account in order to estimate the abundance of advance regeneration and predict the evolution of stocking. Results also show that the structure of regeneration, described by a diameter index, can help in predicting yield at age 38. Devastation by the spruce budworm played a major role in second-growth stand dynamics making it difficult to predict balsam fir yield. The study has also shown an increase in intolerant hardwoods and a low softwood production on rich sites. Black spruce stands came back to black spruce.Key words: mixedwoods, succession, regeneration survey, yield, Choristoneura fumiferana

Évolution de la régénération de peuplements résineux et mélangés au cours des 30 années après coupe à blanc mécanisée

1998 ◽  
Vol 74 (3) ◽  
pp. 428-443 ◽  
Author(s):  
Jean-Claude Ruel ◽  
François Ouellet ◽  
Roch Plusquellec ◽  
Chhun-Huor Ung
Keyword(s):  
Black Spruce ◽  
Jack Pine ◽  
Balsam Fir ◽  
Stand Dynamics ◽  
Mixed Stands ◽  
Significant Component ◽  
Advance Regeneration ◽  
Second Growth ◽  
Spruce Stands ◽  
Coupe À Blanc

This paper presents results from a 30 year monitoring of 15 clearcut areas. Study areas were located before cutting in stands having an abundant advance regeneration. Four study areas were initially dominated by black spruce, four by balsam fir, three by jack pine and the last four comprised a mix of species. Stand inventories and regeneration surveys were conducted before harvesting. Harvesting was done in regular logging operations, without any special care to protect the advance growth. Regeneration surveys were taken again after harvesting, 5 years, 10 years, 20 years and 30 years after harvesting. Black spruce stands regenerated to black spruce dominated stands. Balsam fir, which was sometimes abundant in the advance regeneration, did not invade the stands and the abundance of hardwoods was temporary. In some cases a reduction in yield is to be expected. In balsam fir stands, harwoods were more aggressive. A reduction in softwood yield is predicted for three of the four cutovers. The presence of a tall regeneration seems to lead to higher yields in black spruce and balsam fir stands. The evolution of jack pine and mixed stands is quite variable. In some jack pine stands, hardwoods will constitute a significant component of the new stand. In some mixed stands, softwoods are not very abundant whereas in others they form an important part of the stand at 30 years. This study has shown an urgent need for a better understanding of stand dynamics in young stands. Such an understanding is necessary for an adequate forecast of the yield of second growth stands.

scholarly journals Vulnerability of Conifer Regeneration to Spruce Budworm Outbreaks in the Eastern Canadian Boreal Forest

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 850 ◽  
Author(s):  
Janie Lavoie ◽  
Miguel Montoro Girona ◽  
Hubert Morin
Keyword(s):  
Boreal Forests ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Management Strategies ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Insect Outbreaks ◽  
Spruce Stands ◽  
Canadian Boreal Forest

Spruce budworm (Choristoneura fumiferana) is the main defoliator of conifer trees in North American boreal forests, affecting extensive areas and causing marked losses of timber supplies. In 2017, spruce budworm affected more than 7 million ha of Eastern Canadian forest. Defoliation was particularly severe for black spruce (Picea mariana (Mill.) B.S.P.), one of the most important commercial trees in Canada. During the last decades, intensive forest exploitation practices have created vast stands of young balsam fir (Abies balsamea (L.) Mill.) and black spruce. Most research focused on the impacts of spruce budworm has been on mature stands; its effects on regeneration, however, have been neglected. This study evaluates the impacts of spruce budworm on the defoliation of conifer seedlings (black spruce and balsam fir) in clearcuts. We measured the cumulative and annual defoliation of seedlings within six clearcut black spruce stands in Quebec (Canada) that had experienced severe levels of defoliation due to spruce budworm. For all sampled seedlings, we recorded tree species, height class, and distance to the residual forest. Seedling height and species strongly influenced defoliation level. Small seedlings were less affected by spruce budworm activity. As well, cumulative defoliation for balsam fir was double that of black spruce (21% and 9%, respectively). Distance to residual stands had no significant effect on seedling defoliation. As insect outbreaks in boreal forests are expected to become more severe and frequent in the near future, our results are important for adapting forest management strategies to insect outbreaks in a context of climate change.

Growth dynamics of black spruce in stands located between the 51st and 52nd parallels in the boreal forest of Quebec, Canada

2011 ◽  
Vol 41 (9) ◽  
pp. 1769-1778 ◽  
Author(s):  
Marie-Josée Tremblay ◽  
Sergio Rossi ◽  
Hubert Morin
Keyword(s):  
Boreal Forests ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Ring Width ◽  
Growth Dynamics ◽  
Stand Dynamics ◽  
Stand Development ◽  
Insect Outbreaks ◽  
Spruce Stands ◽  
Ecological Importance

Despite their ecological importance, the role and effects of insect outbreaks on stand dynamics of the northern boreal forests in North America have still to be demonstrated. The study was conducted between the 51st and 52nd parallels in Quebec, Canada, to identify mechanisms governing regeneration of high-latitude stands by investigating variations in growth of trees during stand development. Chronologies of tree-ring width and individual dynamics of growth in height and volume were assessed in black spruce ( Picea mariana (Mill.) B.S.P) of one even-aged and five uneven-aged stands. Uneven-aged stands contained trees up to 340 years old and representing almost every age class. Several growth reductions were observed that were synchronized between stands and were characterized by high amplitudes but different percentages of affected trees. These reductions were followed by marked growth releases. Even if the absence of nonhost species prevented the building of chronologies that could confirm the origin of growth reductions, the findings suggested that spruce budworm ( Archips fumiferana Clemens [syn.: Choristoneura fumiferana (Clemens)]) outbreaks contribute to the formation and maintenance of the uneven-aged structure of older black spruce stands at high latitudes.

scholarly journals Sample Sizes Required To Estimate Defoliation of Spruce and Balsam Fir Caused by Spruce Budworm Accurately

1998 ◽  
Vol 15 (3) ◽  
pp. 135-140 ◽  
Author(s):  
David A. MacLean ◽  
Wayne E. MacKinnon
Keyword(s):  
Black Spruce ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Sample Sizes ◽  
Preliminary Assessment ◽  
Travel Costs ◽  
Host Trees ◽  
Sampling Protocols ◽  
Spruce Stands ◽  
Number Of Branches

Abstract Data from the assessment of current defoliation levels on 172,000 individual shoots from 6890 midcrown branches sampled from balsam fir and spruce stands were used to define sampling protocols for assessing defoliation caused by spruce budworm. The method was based on sampling one midcrown branch from each of x host trees per stand, and assessing defoliation of y individual shoots per branch. Both the number of shoots per branch and the number of branches required per stand varied with host species (balsam fir, white spruce, or red-black spruce) and with average defoliation level. Sample sizes required to estimate mean defoliation with 90% confidence that the confidence interval is ±10% ranged from 7 to 24 branches per stand and from 17 to 58 shoots per branch, with the largest samples required at moderate (31-70%) defoliation levels. Estimated costs of shoot and branch sampling and processing ranged from $40-110/stand, based on a 90% confidence level salary rate of $12(Can.)/hr, and excluding travel costs. Results can be applied using a preliminary assessment to determine the general defoliation level, which along with species, determines the required sample size. North. J. Appl. For. 15(3):135-140.

Demography and spatial dynamics in balsam fir stands after a spruce budworm outbreak

2011 ◽  
Vol 41 (5) ◽  
pp. 1112-1120 ◽  
Author(s):  
Sergio Rossi ◽  
Hubert Morin
Keyword(s):  
Choristoneura Fumiferana ◽  
Spatial Scales ◽  
Spatial Dynamics ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Permanent Plots ◽  
Random Pattern ◽  
Advance Regeneration ◽  
Competition For Resources

The renewal of balsam fir (Abies balsamea (L.) P. Mill.) stands is related to the recurrent spruce budworm (Archips fumiferana Clemens [syn.: Choristoneura fumiferana (Clemens)]) outbreaks that favour the growth of the regeneration following death of the dominant trees. The aim of this study was to investigate the population demography and the spatial relationships among individuals in four permanent plots of the boreal forest of Quebec, Canada, after a spruce budworm outbreak. This was realized by collecting data on trees and saplings every five years from 1994 to 2004 and by using Ripley’s K statistics. The younger plots showed recruitment of up to 90 new trees·ha–1·year–1, and mortality following competition among individuals affected up to 27% and 50% of the trees and saplings, respectively. In the plot with the lowest tree density, sapling recruitment was estimated as 378 new individuals·ha–1·year–1. Saplings were aggregated at all spatial scales, whereas trees showed a random pattern of stem distribution. A significant tendency to separation between saplings and trees was observed. The specific stand dynamics observed in balsam fir are connected to an abundant advance regeneration and an age-dependent competition for resources in a heterogeneous environment with different levels of resource availability.

Comparative responses of small mammals, vegetation, and food sources to natural regeneration and conifer release treatments in boreal balsam fir stands of Quebec

1999 ◽  
Vol 29 (7) ◽  
pp. 1128-1140 ◽  
Author(s):  
Nancy Gagné ◽  
Louis Bélanger ◽  
Jean Huot
Keyword(s):  
Small Mammals ◽  
Natural Regeneration ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Rubus Idaeus ◽  
Balsam Fir ◽  
Food Sources ◽  
Ground Vegetation ◽  
Growing Seasons ◽  
Advance Regeneration

Abundance and species diversity of small mammals were compared among three regeneration methods used in boreal balsam fir (Abies balsamea (L.) Mill.) forests. Those methods were natural regeneration after "careful logging" to retain advance regeneration and planting (black spruce, Picea mariana (Mill.) BSP) followed by herbicide (Vision®) release or brushsaw cutting release. Deciduous vegetation was reduced for two growing seasons in both plantation types after treatment, and foliar arthropods decreased for one growing season. In herbicide-treated plantations, red raspberry (Rubus idaeus L.) shrub cover, near-ground vegetation, and production of berries were reduced for two growing seasons. After herbicide release, the abundance of the red-backed vole (Clethrionomys gapperi (Vigors)) was significantly lowered for two growing seasons. This negative effect was associated with reduced cover during the first two post-treatment growing seasons. In the short term, herbicide-treated plantations constitute poorer red-backed vole habitats than brushsaw plantations. In early successional boreal balsam fir stands, planting did not markedly affect small mammals probably because natural regeneration was common in these plantations.

Ten-year results of strip clear-cutting in Quebec black spruce stands

2000 ◽  
Vol 30 (1) ◽  
pp. 59-66 ◽  
Author(s):  
David Pothier
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Height Growth ◽  
Clear Cutting ◽  
Advance Regeneration ◽  
Spruce Stands ◽  
Harvesting Method ◽  
Cost Efficient ◽  
One Year ◽  
Cutting System

Regeneration of first-cut strips in a two-cut system of strip clear-cutting was compared to that of large clear-cutting in four different areas representative of the black spruce (Picea mariana (Mill.) BSP) stands of the boreal forest of Quebec. Seedlings were more evenly distributed in clearcut strips than in large clearcuts. Differences of about 10 000 black spruce seedlings per hectare and 20% of stocking were observed in favour of clearcut strips compared to large clearcuts. Black spruce stocking was about 14% larger on lowland than on upland sites but height growth was better on upland sites. A regeneration problem similar to that of large clearcuts was observed when the second strips were cut. One year after cutting these second strips, winter harvesting resulted in a 23% gain in black spruce stocking as compared to summer harvesting. Even if black spruce stocking marginally increased during the years following winter harvesting, the height advantage of the preserved advance growth justifies the application of this harvesting method. The strip clear-cutting system effectively improved the stocking of former black spruce stands but if the stocking level of advance growth is adequate, careful harvesting to preserve advance regeneration should be the preferred method since it would be more cost-efficient.

Croissance en hauteur à long terme de la régénération préétablie dans des pessières noires boréales régénérées par marcottage, au Québec

1992 ◽  
Vol 22 (4) ◽  
pp. 613-621 ◽  
Author(s):  
Raynald Paquin ◽  
René Doucet
Keyword(s):  
Growth Rate ◽  
Black Spruce ◽  
Height Growth ◽  
Growth Patterns ◽  
Dominant Position ◽  
Clear Cutting ◽  
Effective Age ◽  
Second Growth ◽  
Spruce Stands ◽  
To Come

Height-growth patterns of black spruce (Piceamariana (Mill.) B.S.P.) in the boreal forest were studied in layer-origin stands released by clear-cutting in the first half of this century. Most stems responded to release brought about by clear-cutting of the main stand. Initially, small stems responded more rapidly and more strongly, but their height-growth rate culminated between 20 and 30 years following release, the same period when height-growth rate culminated for the taller, older stems. After the culmination period, growth rates were independent of height at the time of release. Consequently, the taller stems at time of release were able to maintain their dominant position. Height growth over the recent years indicates that this position could be maintained in the years to come, and even indefinitely. It seems that second-growth black spruce stands behave like even-aged stands despite their uneven-aged structure. Consequently, years since release and stem height are more accurate measures of stem effective age than total age. Moreover, the taller stems in the understory, which are usually considerably older, should be considered to be as valuable as smaller regeneration when a stand is cut.

EFFICACY OF FORAY 48B (BACILLUS THURINGIENSIS BERLINER) APPLICATIONS AGAINST THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (CLEMENS) (LEPIDOPTERA: TORTRICIDAE), TIMED FOR PHENOLOGICAL DEVELOPMENT OF BALSAM FIR AND BLACK SPRUCE

1993 ◽  
Vol 125 (3) ◽  
pp. 479-488 ◽  
Author(s):  
Beresford L. Cadogan ◽  
Roger D. Scharbach
Keyword(s):  
Bacillus Thuringiensis ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Larval Survival ◽  
Balsam Fir ◽  
Early Instar ◽  
Respective Species ◽  
Respective Host

AbstractThe insecticide Foray 48B (Bacillus thuringiensis var. kurstaki Berliner) was applied undiluted at 30 BIU per ha to control spruce budworm, Choristoneura fumiferana (Clem.), in a mixed boreal forest stand of balsam fir, Abies balsamea (L.) Mill., and black spruce, Picea mariana (Mill.) B.S.P. When the treatment was timed to coincide with the early flushing of balsam fir shoots, the corrected budworm population reductions were 74 and 52% on balsam fir and black spruce, respectively. This treatment resulted in 19 and 8% defoliation on the two respective species. When the insecticide application was timed later to coincide with the late flushing of black spruce shoots the corrected population reductions were 93% on balsam fir and 72% on black spruce. Defoliation of the two species was 29 and 10% respectively, following this treatment. Larval survival on both species after the spray timed for black spruce (0.8 and 2.2 larvae per 45-cm branch on balsam fir and black spruce, respectively) was significantly less (P = 0.05) than that observed after the spray timed for balsam fir (4.6 and 4.2 larvae per 45-cm branch on the respective host species).The data indicate that the spray timed to correspond with the flushing of black spruce was generally more efficacious than the spray timed to impact on newly flushed balsam fir; nevertheless, the results raise the question as to how B. thuringiensis insecticides impact on early-instar budworm larvae when there is no preferred current year foliage on which the insects can feed.

Age and size structure of natural and second-growth peatland Piceamariana stands

1994 ◽  
Vol 24 (2) ◽  
pp. 225-233 ◽  
Author(s):  
Arthur Groot ◽  
Brian J. Horton
Keyword(s):  
Age Structure ◽  
High Frequency ◽  
Size Structure ◽  
Black Spruce ◽  
Forest Harvesting ◽  
Second Growth ◽  
Spruce Stands ◽  
Natural Stands ◽  
Over Time ◽  
Site Types

Age and size structures were determined in 40 stands of black spruce (Piceamariana (Mill.) B.S.P.) growing on peatlands and transitional peatlands in northeastern Ontario, Canada. Natural and second-growth stands representing several site types were examined. The age structure of natural black spruce stands varied from even aged in young stands (<160 years) to uneven aged in older stands. Uneven-aged black spruce stands on nutrient-poor peats appear to be self perpetuating in the absence of intense disturbance. Natural stands on more fertile peats or on transitional peatlands are less likely to escape disturbance and more likely to undergo succession to other species. Second-growth stands, which originated after forest harvesting 50–70 years ago, were uneven-aged, although a high frequency of stems commonly occurred in the age-class associated with the time of harvesting. The age and size structures of second-growth stands currently differ from that of natural stands, but will likely become similar to natural stands over time.

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