scholarly journals Coefficients de distribution de la régénération, cinq ans après des coupes avec protection des petites tiges marchandes appliquées dans des sapinières et des pessières noires du Québec

2011 ◽  
Vol 87 (05) ◽  
pp. 669-683 ◽  
Author(s):  
Martin Riopel ◽  
Jean Bégin ◽  
Jean-Claude Ruel
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Annual Rainfall ◽  
Deciduous Species ◽  
Partial Cutting ◽  
Coniferous Species ◽  
Breast Height ◽  
Silvicultural Treatments ◽  
Heavy Equipment

For certain mature forests dominated by balsam fir (Abies balsamea [L.] Mill.) or black spruce (Picea mariana [Mill.] BSP), it may be preferable to harvest trees with diameter at breast height greater than 15 cm while conserving smaller ones. This treatment, called harvesting with protection of small merchantable trees, produces strips, where partial cutting is applied, alternating with corridors, which are disturbed by heavy equipment during harvesting. This project studied stocking levels five years after treatment on 4896 sub-plots of 4 m2 in 22 blocks. Stocking coefficients (SC) for coniferous and deciduous species were modeled in order to identify variables affecting stocking. The strips had well-distributed coniferous regeneration, while SC in the corridors were more variable and lower, occasionally less than 60%. Black spruce-dominated sites were not as well stocked as balsam fir-dominated sites. Stocking levels of protected coniferous merchantable trees positively influence coniferous and deciduous SC in the corridors. The presence of coniferous species is also affected by harvest season and total annual rainfall. Alternative silvicultural treatments applicable in certain corridors are presented.

scholarly journals A multiscale analysis of the effects of alternative silvicultural treatments on windthrow within balsam fir dominated stands

2015 ◽  
Vol 45 (12) ◽  
pp. 1739-1747 ◽  
Author(s):  
Kenneth Agbesi Anyomi ◽  
Jean-Claude Ruel
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Basal Area ◽  
Natural Disturbance ◽  
Balsam Fir ◽  
Partial Cutting ◽  
Selection Cutting ◽  
Silvicultural Treatments ◽  
Block Level ◽  
And Control

Boreal ecosystem functioning is largely controlled by disturbance dynamics. There have been efforts at adapting forest management approaches to emulate natural disturbance effects, as this is expected to maintain ecosystem resilience. In many instances, this involves resorting to partial cutting strategies that are likely to increase windthrow losses. The objective of this study was to determine the effects of alternative silvicultural practices on windthrow damage and how these effects vary with the scale of treatment. The study was conducted in the Quebec North Shore region (Canada), an area dominated by balsam fir (Abies balsamea (L.) Mill.) and accompanied by black spruce (Picea mariana (Mill) B.S.P.). Four different silvicultural treatments (overstory removal, heavy partial cutting, and two patterns of selection cutting) and control areas were implemented in 2004 and 2005. The experiment used a nested approach where treatment at the plot level was independent and yet nested within the block-level treatment. At the block level, treatments were applied over 10–20 ha units, leaving a small portion of the block for a smaller application of each treatment (plot scale, 2500 m2). Inventory was carried out before harvesting and monitoring was done yearly after harvesting, with the aim to better understand the plot- and block-level factors that drive windthrow damage levels and the effects of alternative silvicultural treatments. Results after 6–7 years show that basal area proportion windthrown differs substantially between treatments, as well as between treated sites and control sites. Windthrow levels were higher under heavy cuts relative to selection cuts and also increased with balsam fir proportion. Windthrow proportions were better correlated to block-level treatment than plot-level treatment, showing that the environment surrounding the treated plot can have an important effect on windthrow losses. Overall, the selection cutting system, particularly SC2, retains the most green-tree basal area and thus best meets the management objective of retaining old-growth attributes. A simple empirical model was calibrated that could aid in hazard rating.

scholarly journals Mixed Regional Shifts in Conifer Productivity under 21st-Century Climate Projections in Canada’s Northeastern Boreal Forest

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 248
Author(s):  
Tyler Searls ◽  
James Steenberg ◽  
Xinbiao Zhu ◽  
Charles P.-A. Bourque ◽  
Fan-Rui Meng
Keyword(s):  
Climate Change ◽  
Model Validation ◽  
21St Century ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Acer Rubrum ◽  
Forest Growth ◽  
Balsam Fir ◽  
Growth And Yield ◽  
Climate Projections

Models of forest growth and yield (G&Y) are a key component in long-term strategic forest management plans. Models leveraging the industry-standard “empirical” approach to G&Y are frequently underpinned by an assumption of historical consistency in climatic growing conditions. This assumption is problematic as forest managers look to obtain reliable growth predictions under the changing climate of the 21st century. Consequently, there is a pressing need for G&Y modelling approaches that can be more robustly applied under the influence of climate change. In this study we utilized an established forest gap model (JABOWA-3) to simulate G&Y between 2020 and 2100 under Representative Concentration Pathways (RCP) 2.6, 4.5, and 8.5 in the Canadian province of Newfoundland and Labrador (NL). Simulations were completed using the province’s permanent sample plot data and surface-fitted climatic datasets. Through model validation, we found simulated basal area (BA) aligned with observed BA for the major conifer species components of NL’s forests, including black spruce [Picea mariana (Mill.) Britton et al.] and balsam fir [Abies balsamea (L.) Mill]. Model validation was not as robust for the less abundant species components of NL (e.g., Acer rubrum L. 1753, Populus tremuloides Michx., and Picea glauca (Moench) Voss). Our simulations generally indicate that projected climatic changes may modestly increase black spruce and balsam fir productivity in the more northerly growing environments within NL. In contrast, we found productivity of these same species to only be maintained, and in some instances even decline, toward NL’s southerly extents. These generalizations are moderated by species, RCP, and geographic parameters. Growth modifiers were also prepared to render empirical G&Y projections more robust for use under periods of climate change.

Black spruce decline triggered by spruce budworm at the southern limit of lichen woodland in eastern Canada

2001 ◽  
Vol 31 (12) ◽  
pp. 2160-2172 ◽  
Author(s):  
Martin Simard ◽  
Serge Payette
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Jack Pine ◽  
Growth Patterns ◽  
Balsam Fir ◽  
Eastern Canada ◽  
Southern Limit ◽  
Epiphytic Lichen ◽  
Spruce Decline

Black spruce (Picea mariana (Mill.) BSP) is the dominant tree species of the southernmost (48°N) lichen woodlands in eastern Canada. Most spruce trees in mature lichen woodlands appear to be declining, as shown by the massive invasion of the epiphytic lichen Bryoria on dead branches of dying trees. A dendroecological study was undertaken to identify the main causal factors of the decline. A decline index based on the abundance of Bryoria on spruce trees was used to distinguish healthy from damaged lichen–spruce woodlands and to select sampling sites for tree-ring measurements. Three conifer species (black spruce, balsam fir (Abies balsamea (L.) Mill.), and jack pine (Pinus banksiana Lamb.)) were sampled to compare their growth patterns in time and space. In the late 1970s and mid-1980s, black spruce and balsam fir experienced sharp and synchronous radial-growth reductions, a high frequency of incomplete and missing rings, and mass mortality likely caused by spruce budworm (Choristoneura fumiferana (Clem.)) defoliation. Jack pine, a non-host species, showed no such trend. Because black spruce layers were spared, lichen woodlands will eventually regenerate unless fire occurs in the following years. Black spruce decline can thus be considered as a normal stage in the natural dynamics of the southern lichen woodlands.

Growth intercept models for black spruce, jack pine and balsam fir in Quebec

2005 ◽  
Vol 81 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Daniel Mailly ◽  
Mélanie Gaudreault
Keyword(s):  
Pinus Banksiana ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Site Index ◽  
Jack Pine ◽  
Balsam Fir ◽  
Practical Significance ◽  
Interim Testing ◽  
Growth Intercept ◽  
Mean Square Errors

The objective of this study was to develop variable growth intercept models for coniferous species of major importance in Quebec using Nigh's (1997a) modelling technique. Eighty-three, 68, and 70 stem analysis plots of black spruce (Picea mariana [Mill.] BSP), jack pine (Pinus banksiana Lamb.) and balsam fir (Abies balsamea (L.) Mill) were used, respectively. The growth intercept models for black spruce were the most precise, followed by those for jack pine and finally by those for balsam fir, based on the root mean square errors. Results indicated that the accuracy of the models was good, relative to those previously published for other species in Canada. Interim testing of the models revealed a low mean error for all three species that may not be of practical significance for site index determination, although more data should be obtained to further test the models. Key words: balsam fir, black spruce, growth intercept, jack pine, model, nonlinear regression, site index

Linking deadwood-associated beetles and fungi with wood decomposition rates in managed black spruce forests1This article is one of a selection of papers from the International Symposium on Dynamics and Ecological Services of Deadwood in Forest Ecosystems.

2012 ◽  
Vol 42 (8) ◽  
pp. 1477-1490 ◽  
Author(s):  
Jenna M. Jacobs ◽  
Timothy T. Work
Keyword(s):  
Stand Structure ◽  
Black Spruce ◽  
Wood Decomposition ◽  
Decomposition Rates ◽  
Partial Cutting ◽  
Saprotrophic Fungi ◽  
Silvicultural Treatments ◽  
Saproxylic Beetle ◽  
Main Effects ◽  
The Relationship

Deadwood-associated insects and saprotrophic fungi are principal agents of wood decomposition in boreal forest. Silvicultural treatments that alter microclimate and availability of deadwood likely affect composition and growth rates of both insect and fungal communities, leading to changes in wood decomposition rates. Here, we relate both saproxylic beetle and dominant polypore assemblages with woody decomposition rates and environmental variables in experimental partial cuts, clearcuts, and uncut controls using a series of causal models to determine the relationship between stand structure, biodiversity, and ecosystem function in black spruce ( Picea mariana (Mill.) BSP) forests. Overall beetle and fungal composition differed between uncut stands and harvested stands. Main effects of harvesting included large increases in wood-feeding beetles and the fungus Gloeophyllum sepiarium (Wul.:Fr.) Karst. We suggest that these species were promoted by specific alterations in microhabitat conditions of deadwood. Within clearcuts specifically, changes in species composition and significantly more fungal degree-days resulted in significantly higher decomposition rates. We concluded that levels of partial cutting in the range of 15%–20% retention were not sufficient to maintain predisturbance communities but were sufficient to maintain wood decomposition rates similar to uncut stands.

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.

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.

scholarly journals Primary and Secondary Branch Growth in Black Spruce and Balsam Fir after Careful Logging around Small Merchantable Stems (CLASS)

Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 500 ◽  
Author(s):  
Audrey Lemay ◽  
Cornelia Krause ◽  
Alexis Achim
Keyword(s):  
Boreal Forest ◽  
Radial Growth ◽  
Black Spruce ◽  
Secondary Growth ◽  
Balsam Fir ◽  
Secondary Branch ◽  
Partial Cutting ◽  
Branch Diameter ◽  
Branch Growth ◽  
Post Class

Careful logging around small merchantable stems (CLASS) is a partial cutting treatment that consists of the harvest of 70%–90% of the merchantable volume of an irregular coniferous stand. In this treatment, regeneration, saplings and small merchantable stems (DBH < 15 cm) are preserved and can continue to grow and develop into the dominant layer of the new stand. The aim of this project was to examine the effects of CLASS on the primary and secondary growth of branches, as well as on branch diameter in black spruce and balsam fir trees in the boreal forest of Quebec, Canada. Primary and secondary growth were measured on five branches per tree while branch diameter was analysed from 15 whorls distributed within the crown of the 48 black spruce and 48 balsam fir trees sampled. Branch primary and secondary growth significantly increased after CLASS in the lower part of the crown in both species, and both types of growth increased proportionally. These findings suggest that CLASS may delay crown recession as the lower branches tend to survive and grow for a longer period. However, although radial growth increased in the years post-CLASS, this did not significantly influence the final branch diameter and should not lead to lumber downgrade.

Estimating forest vulnerability to the next spruce budworm outbreak: will past silvicultural efforts pay dividends?

2015 ◽  
Vol 45 (3) ◽  
pp. 314-324 ◽  
Author(s):  
Guillaume B. Sainte-Marie ◽  
Daniel D. Kneeshaw ◽  
David A. MacLean ◽  
Chris R. Hennigar
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Stand Age ◽  
Disturbance History ◽  
Timber Supply ◽  
Silvicultural Treatments ◽  
Combined Use ◽  
Intensively Managed

Silvicultural treatments recommended to reduce damage by spruce budworm (SBW; Choristoneura fumiferana Clemens) include reducing balsam fir (Abies balsamea (L.) Mill.) abundance and age and increasing spruce (Picea spp.) and hardwood content. To evaluate the effect of these measures on forest timber supply, we assessed stand characteristics, disturbance history, and timber supply for an intensively managed eastern Quebec forest from 1985 to 2004, encompassing a major SBW outbreak. During this time, mean stand age declined from 55 to 51 years, and proportions of areas in balsam fir stands declined (42% to 27%), spruce–fir stabilized (12% to 11%), and mixedwoods increased (32% to 52%). We estimated forest vulnerability using softwood volume reductions following simulated outbreak scenarios of different severity (low, moderate, and high) and different effects of hardwood content in reducing spruce–fir defoliation. Volume reductions for outbreaks simulated to begin in either 1985 or 2004 were similar, ranging from 15%–46% (no hardwood effect in reducing defoliation) to 13%–39% (given a maximum hardwood content effect) for light and severe outbreaks, respectively. Considering the net detrimental effect of increased hardwood content on softwood timber supply, we question the dividends of promoting hardwoods and recommend increasing the combined use of plantations and weeding treatments to increase spruce content.

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