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We report on a 60-year-old red pine (Pinus resinosa Aiton) spacing trial experiment located in Ontario, Canada, that included the combinations between six initial spacings (from 1.2 to 3.0 m) and the presence or absence of a commercial thinning (CT) regime, as well as their impacts on quadratic mean diameter (QMD) and stand volume yield. The CT regime, initiated at age 30, targeted a residual basal area (BA) of 38 [m.sup.2] * [ha.sup.-1] after each of four entries. Without thinning, as initial spacing increased, QMD increased; gross and net volume production peaked in the 2.1-2.4 m spacings. With thinning, similar trends with spacing were evident for QMD, although piece sizes were larger and differences between spacings were lower. The immediate increase of mean tree size caused by tree selection explained most of the differences in QMD between thinned and unthinned plots. Thinning to a common target BA resulted in similar standing volume across spacings. Cumulative gross yield was similar between spacings of Key words: silviculture, stand density management, plantation, thinning, Pinus resinosa, long-term silviculture experiment. Cette etude porte sur un dispositif experimental d'espacement initial de pin rouge (Pinus resinosa Aiton) plante en Ontario, au Canada, il y a 60 ans. Le dispositif etait compose des combinaisons de six espacements initiaux (de 1,2 a 3,0 m) et de la presence ou de l'absence d'un regime d'eclaircie commerciale (EC) et visait a evaluer l'impact des traitements sur le diametre moyen quadratique (DMQ) et la production en volume du peuplement. Le regime d'EC, qui a debute a 30 ans, visait a obtenir une surface terriere (G) residuelle de 38 [m.sup.2] * [ha.sup.-1] apres chacune des quatre interventions. En l'absence d'eclaircie, le DMQ augmentait avec l'espacement initial alors que les productions en volume brut et net ont atteint des valeurs maximales pour des espacements entre 2,1 et 2,4 m. Quand le regime d'eclaircie etait applique, nous avons observe des tendances similaires d'augmentation du DMQ avec l'espacement, meme si la taille des arbres etait plus grande et que les differences entre les espacements etaient plus faibles. Une grande partie des differences du DMQ entre les placettes eclaircies et non eclaircies etait expliquee par l'augmentation immediate de la taille moyenne des arbres causee par la recolte des arbres selectionnes. La G residuelle commune a toutes les eclaircies a mene a des volumes sur pied similaires, peu importe l'espacement initial. La production brute cumulee etait similaire entre les espacements plus petits que 2,1 m dans le cas des peuplements eclaircis et non eclaircis, et etait plus faible pour les espacements plus grands dans le cas des placettes eclaircies. Une plus grande production en volume net dans les peuplements eclaircis dont les espacements etaient les plus petits indique que la mortalite a ete recoltee. Des productions en volume brut et net plus faibles dans le cas des espacements plus grands indiquent que l'eclaircie a provoque une sous-utilisation de l'espace de croissance. [Traduit par la Redaction] Mots-cles : sylviculture, gestion de la densite des peuplements, plantation, eclaircie, Pinus resinosa, experience sylvicole de longue duree., Introduction Planted forests are estimated to provide about one-third of the world's industrial stemwood production (Jurgensen et al. 2014). This proportion has globally increased over the past two and half [...]

Acadian forests of New Brunswick, Canada, are highly variable both in terms of species composition and quality. This is particularly accurate for hardwoods, for which value recovery is closely influenced by wood quality and a proper understanding of tree attributes. Therefore, based on several databases created between 2012 and 2021, the objectives of this study were to (1) characterize the stand-level distribution of species, size, form, and risk according to site factors and (2) determine the influence of different tree, stand, and site factors on the recovery of merchantable, sawlog, and veneer volumes. In total, 287,984 trees stemming from 9233 plots were analyzed for objective 1. For a subset of trees (743), tree, stand, and site attributes were also related to the product output of harvesting operations through a comprehensive inventory of standing trees and their associated products. Analyses were performed with linear and multinomial logistic regressions as well as factor analysis of mixed data (FAMD). Key results indicated that tree attributes and product recovery were significantly influenced by (1) environmental factors (soil, temperature, and precipitation), summarized by ecoregion in this study and (2) tree size and form. These findings suggest that the inclusion of site factors in supply planning could improve product recovery during forest operations. [ABSTRACT FROM AUTHOR]

Ref: Can. J. For. Res. 51(2): 181-189 (2021) https://doi.org/10.1139/cjfr-2020-0246. The authors noticed that some numbers in the main text were not updated after conducting new analyses requested during the review [...]

Knowledge of the long-term effects of silviculture treatments is crucial to forest management. The long-term effects of thinning, a common and widely used silviculture treatment, is little documented for upland black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) stands. We revisited a partial cutting experiment installed in 1961 in a 65-year-old unmanaged upland black spruce stand. The aim was to document the long-term effects of thinning on tree and stand growth and to complete previously published results of the first 15 years of response to thinning by determining its influence in terms of merchantable volume. Free thinning was applied following three intensities: 0%, 25%, and 50% of total basal area removal. The retrospective analysis of growth rings showed that the response over the first 15 years was less significant when determined in net merchantable volume instead of net total volume. Heavily thinned plots, nonetheless, showed a net stand merchantable volume increment 33% greater than that of the unthinned plots. In the longer term, a spruce budworm (Choristoneura fumiferana Clemens) outbreak affected the site; nevertheless, the heavily thinned plots maintained a superior tree growth rate and did not show senescence mortality like the other plots, allowing stand volume to catch up to that of the unthinned plots after 33 years. Results suggested that thinning upland black spruce stands may be useful in mitigating reductions in volume production associated with growing stands to longer rotations as called for by certain ecosystem-based management approaches. Resume: La connaissance des effets a long terme des traitements sylvicoles est importante pour l'amenagement forestier. Les effets a long terme de l'eclaircie, un traitement sylvicole communement applique, sont peu documentes pour les peuplements d'epicea noir (Picea mariana (Mill.) Britton, Sterns & Poggenb.) bien draines. Nous avons revisite une experience de coupe partielle effectuee en 1961 dans un peuplement d'epicea noir bien draine, age de 65 ans et non amenage. Les objectifs etaient de documenter les effets a long terme de l'eclaircie sur la croissance des arbres et du peuplement et de completer les resultats publies precedemment sur la reaction a l'eclaircie au cours des 15 premieres annees en determinant son influence en termes de volume marchand. Une eclaircie neutre a ete appliquee selon trois intensites: l'enlevement de 0%, 25% et 50% de la surface terriere totale. L'analyse retrospective des cernes de croissance indique que la reaction etait moins significative en termes de volume marchand net qu'en termes de volume total net au cours des 15 premieres annees. Neanmoins, les placettes fortement eclaircies etaient associees a un accroissement net en volume marchand 33% plus grand que celui des placettes non eclaircies. Par la suite, une epidemie de tordeuse des bourgeons de l'epinette (Choristoneura fumiferana Clemens) a affecte le peuplement. Toutefois, les arbres des placettes fortement eclaircies ont maintenu un taux de croissance plus eleve et n'ont pas subi de mortalite par senescence comme dans les autres placettes, ce qui a permis au peuplement d'atteindre le meme volume que celui des placettes non eclaircies apres 33 ans. Les resultats indiquent qu'une eclaircie appliquee dans un peuplement d'epicea noir bien draine peut etre utile pour attenuer les reductions de production en volume associees a l'allongement de la rotation des peuplements, tel que le preconisent certaines approches d'amenagement ecosystemique. [Traduit par la Redaction], Introduction Partial cutting methods, such as commercial thinning or shelterwood, are often considered in forest management strategies either for intensive wood production (Pelletier and Pitt 2008) or for close-to-nature ecosystem [...]

Regeneration of northern white-cedar (Thuja occidentalis L.) is often deficient after harvesting in mixedwood stands growing on mesic sites even where browsing pressure is low. We compared the effectiveness of silviculture treatments on early regeneration of white-cedar after single-tree selection cutting (25% of basal area removed), shelterwood seed cut (50% of basal area removed), and group selection cutting (gaps of 625 m2) in three yellow birch (Betula alleghaniensis Britt.) - softwood uneven-aged stands in Quebec, Canada. Three years after harvesting, the combination of factors that maximized abundance of white-cedar seedlings was single-tree selection cutting with artificial seeding on exposed mineral seedbeds (68.8% of plots with the presence of white-cedar). Early growth of planted white-cedar seedlings (40 cm tall) and biomass production were proportional to light availability, i.e., best under group selection cutting (mean height increment = 14.8 cm/year, mean root collar diameter increment = 3.0 mm/year). Browsing pressure has regional impacts depending on herbivore occupancy of the area. Our study was conducted near the northern limit of white-tailed deer (Odocoileus virginianus (Zimmerman, 1780)), and deer were locally absent, while snowshoe hare (Lepus americanus Erxleben, 1777) did not have a consistent effect on seedling abundance and early survival, limiting height growth only during the first year following planting. Resume: La regeneration du thuya occidental (Thuja occidentalis L.) est souvent deficiente sur les stations mesiques exploite es ou il se retrouve en melange avec d'autres especes, meme si la pression de broutement est faible. Trois betulaies jaunes (Betula alleghaniensis Britt.) resineuses inequiennes ont donc ete selectionnees dans la partie nord de l'aire de distribution du cerf de Virginie (Odocoileus virginianus (Zimmerman, 1780)) (Quebec, Canada), afin d'etudier l'efficacite d'une coupe de jardinage par pied d'arbre (25% de la surface terriere recoltee), d'une coupe de jardinage par trouees (trouees de 625 m2) et d'une coupe progressive d'ensemencement (50% de la surface terriere recoltee) pour la regeneration du thuya. Trois ans apres la recolte, la meilleure combinaison de conditions pour la regeneration du thuya est la coupe de jardinage par pied d'arbre avec un ensemencement artificiel sur un sol mineral expose (68,8% des parcelles ont au moins un semis de thuya). Quant a la croissance et la production de biomasse des semis plantes de thuya mesurant 40 cm initialement, elles sont proportionnelles a la disponibilite de la lumiere, c.-a-d. la meilleure apres la coupe de jardinage par trouees (accroissement moyen en hauteur = 14,8 cm/an, accroissement moyen en diametre au collet = 3,0 mm/an). Le broutement a un impact variable selon les regions, dependamment de la densite des populations d'herbivores. Le cerf etait absent du territoire d'etude, tandis que le lievre d'Amerique (Lepus americanus Erxleben, 1777) n'a pas eu un effet syste-matique sur l'etablissement et la survie des semis. Il a seulement limite la croissance en hauteur des plants durant la premie re annee suivant la plantation., Introduction Northern white-cedar (Thuja occidentalis L.) occurs across a wide variety of habitats (Scott and Murphy 1987). It can reproduce on organic soils, but its development is best on mesic [...]

We present the 6 year effects of different cutting patterns (patch-selection cutting with 20, 30, and 40 m diameter gaps, 1 ha patch clear-cut, and uncut control) and spot scarification, on seedbed coverage and regeneration dynamics in yellow birch (Betula alleghaniensis Britton)--conifer stands in eastern Quebec, Canada. After 3 years, yellow birch had established better in cutting patterns with gaps than in the patch clear-cut and in the control, while its density was 7 times higher in scarified than in nonscarified subplots. After 6 years, scarified openings and the borders of openings had 3-5 times more seedlings >30 cm in height than nonscarified openings and the understory between the gaps. The loss of advance growth in openings was the main result for conifer species, although recruitment of new balsam fir (Abies balsamea (L.) Mill.) seedlings was accelerated by scarification. Despite the abundance of red spruce (Picea rubens Sarg.) seed-trees on the site, our treatment combinations failed to promote its natural regeneration. Varying gap size did not change the total density of competing vegetation but modified the composition of this shrub layer. Our 6 year results suggest that maintaining conifer species, and the mixed composition of the stands, is uncertain over the long term. Resume: Nous presentons les effets apres six ans de differents patrons de coupe (jardinage avec trouees de 20, 30 et 40 m de diametre, coupe en parquet de 1 ha, et temoin non coupe) et du scarifiage en placeaux, sur le recouvrement des lits de germination et la dynamique de regeneration dans des peuplements de bouleau jaune (Betula alleghaniensis Britton) et coniferes de l'est du Quebec, au Canada. Apres trois ans, le bouleau jaune setait mieux etabli dans les patrons de coupe avec trouees que dans le parquet et le temoin, alors que sa densite etait sept fois plus elevee dans les sous parcelles scarifie es que dans les sous parcelles non scarifiees. Apres six ans, les ouvertures scarifiees et les lisieres des ouvertures contenaient trois a cinq fois plus de semis >30 cm de hauteur que les ouvertures non scarifiees et le sous-bois entre les trouees. La perte de regeneration preetablie dans les ouvertures a ete le principal resultat pour les coniferes, bien que le scarifiage ait accelere l'etablissement de nouveaux semis de sapin baumier (Abies balsamea (L.) Mill.). Meme si des semenciers d'epinette rouge (Picea rubens Sarg.) etaient abondants sur le site, notre combinaison de traitements n'a pas favorisesa re-generation naturelle. La variation de la grandeur des trouees n'a pas change la densite totale des especes de competition, mais elle a modifie la composition de cette strate arbustive. Nos resultats apres six ans suggerent que le maintien des coniferes et de la composition mixte des peuplements est incertain a long terme., Introduction In transition between the broad-leaved and the coniferous (boreal) forest of Quebec, Canada (Saucier et al. 2009), the balsam fir (Abies balsamea (L.) Mill.)--yellow birch (Betula alleghaniensis Britton) domain [...]

Abstract: This paper examined the impact of commercial thinning on selected wood properties of jack pine (Pinus banksiana Lamb.). Wood properties evaluated include wood density (ring density, earlywood ring density, [...]

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Highlights • Mature and old-growth forest stages are important to sustain ecosystem functions. • Commonly used forest planning models do not value old-growth forests adequately. • Planning models that retain old-growth forest may lower economic returns. • Accounting for the potential impact of fires may reduce high-value sustained supply. • We propose a new planning model that reduces fire risk to the ecosystem and economy. Abstract The maintenance of old-growth stands is important for sustaining natural forest ecosystems, but fire disturbances and commonly-used timber harvest practices exert adverse impacts on the retention of old-growth forests. Forest management planning prescribes harvest levels based on the planning policy and models, but the impact of the management strategies on the retention of old-growth forests has not been well studied. The objectives of this study were to examine: a) the impact of implementing three different harvest policies on the retention of old-growth forest and b) the impact of implementing a policy of maintaining a targeted minimum of 20% old-growth area on the harvest revenue that would be generated over a long planning horizon. To simulate the implementation of these policies, we developed three strategic timber harvest-scheduling models. The first model (Model 1) maximizes harvest timber volume; Model 2 maximizes the net present value (NPV) of the timber harvested; and Model 3 maximizes the NPV of value-added products at the primary processing mills. The value-added products we considered were lumber, chips and sawdust. The models were solved for three forest management units with different fire regimes. Solutions to models that did not include a strict constraint on old-growth forest area retention did not retain the targeted level of old-growth forest over a 150-year planning horizon. When an old-growth constraint was implemented, Model 3 produced the greatest revenue with the least variation by 5-year period over the planning horizon. The probability of finding a feasible solution to our optimization Model 3 with an old-growth forest constraint increased to 0.87–1.0 compared with 0.71–0.83 using Model 1, and 0.78–0.87 using Model 2. We conclude that the value-added policy model increases the probability of sustaining the bioeconomy while preserving forest ecosystems initiated by disturbance. [ABSTRACT FROM AUTHOR]

Forest regeneration is a key element in achieving sustainable forest management. Partial harvest methods have been used extensively in temperate broadleaf and mixedwood ecosystems to promote regeneration on poorly stocked sites and to maintain forest composition and productivity. However, their effectiveness in promoting conifer establishment has yet to be demonstrated in unmanaged boreal forests, especially those dominated by black spruce (Picea mariana (Mill.) BSP) where constraints for regeneration differ from those found in more meridional regions. We aimed to evaluate conifer seedling density and dimensions, 10 years after the onset of a gradient of silvicultural treatments varying in harvesting intensities, and to identify the critical factors driving the regeneration process. Study blocks of even-aged black spruce stands in the eastern Canadian boreal forest were submitted to three variants of shelterwood harvesting: a seed-tree harvest, a clear-cut and an untreated control. Shelterwood and seed-tree harvesting were combined with spot scarification to promote regeneration. Shelterwood and seed-tree harvesting produced a density of conifer regeneration sufficient to maintain forest productivity, but they did not promote seedling growth. Black spruce was the predominant species in terms of regeneration density, with proportions 3–5× higher than that for balsam fir (Abies balsamea (L.) Mill.). Ten years after treatment, seed-origin black spruce seedlings were abundant in skidding trails, while layers dominated the residual strips. Balsam fir density was not influenced by treatment nor by tree position relative to skidding trails. Balsam fir and black spruce had different responses to treatment in terms of height and diameter, the former exhibiting a better growth performance and larger diameter in the residual strips. Spot scarification created micro-sites that had a significant impact on the regeneration process. Overall, our results support that shelterwood and seed-tree harvesting combined with scarification enable adequate regeneration in black spruce stands, confirming these treatments as viable silvicultural alternatives to clear-cutting when required by sustainable forest management objectives. [ABSTRACT FROM AUTHOR]

Forest ecosystem management heads towards the use of partial cuttings. However, the wide variation in growth response of residual trees remains unexplained, preventing a suitable prediction of forest productivity. The aim of the study was to assess individual growth and identify the driving factors involved in the responses of residual trees. Six study blocks in even-aged black spruce [Picea mariana (Mill.) B.S.P.] stands of the eastern Canadian boreal forest were submitted to experimental shelterwood and seed-tree treatments. Individual-tree models were applied to 1039 trees to analyze their patterns of radial growth during the 10 years after partial cutting by using the nonlinear Schnute function on tree-ring series. The trees exhibited different growth patterns. A sigmoid growth was detected in 32% of trees, mainly in control plots of older stands. Forty-seven percent of trees located in the interior of residual strips showed an S-shape, which was influenced by stand mortality, harvested intensity and dominant height. Individuals showing an exponential pattern produced the greatest radial growth after cutting and were edge trees of younger stands with higher dominant height. A steady growth decline was observed in 4% of trees, represented by the individuals suppressed and insensitive to the treatment. The analyses demonstrated that individual nonlinear models are able to assess the variability in growth within the stand and the factors involved in the occurrence of the different growth patterns, thus improving understanding of the tree responses to partial cutting. This new approach can sustain forest management strategies by defining the best conditions to optimize the growth yield of residual trees. [ABSTRACT FROM AUTHOR]

Partial cutting is thought to be an alternative to achieve sustainable management in boreal forests. However, the effects of intermediate harvest intensity (45%-80%) on growth remain unknown in black spruce (Picea mariana (Mill.) B.S.P.) stands, one of the most widely distributed boreal species with great commercial interest. In this study, we analysed the effect of three experimental shelterwood and one seed-tree treatments on tree radial growth in even-aged black spruce stands, 10 years after intervention. Our results show that radial growth response 8-10 years after cutting was 41% to 62% higher than in untreated plots, with stand structure, treatment, tree position relative to skidding trails, growth before cutting and time having significant interactions. The stand structure conditioned tree growth after cutting, being doubled in younger and denser stands. Tree spatial position had a pronounced effect on radial growth; trees at the edge of the skidding trails showed twice the increase in growth compared to interior trees. Dominant trees before cutting located close to the skidding trails manifested the highest growth response after cutting. This research suggests that the studied treatments are effective to enhance radial wood production of black spruce especially in younger stands, and that the edge effect must be considered in silvicultural management planning. [ABSTRACT FROM AUTHOR]

Northern white-cedar (Thuja occidentalis) is a species of high commercial and ecological value, the abundance of which has been declining since the middle of the 19th century. Very little information regarding its silviculture in mixedwood stands is currently available, even though a significant portion of wood resources comes from these stands. The present study is a retrospective analysis of white-cedar growth in partially harvested mixedwood stands of western Quebec, Canada. Eight stands distributed across two regions were analyzed. Dendrochronological approaches examined long-term diameter growth for sample white-cedar trees and stems of associated species. These approaches were used to reconstruct stand characteristics at the time of harvesting, together with local harvesting intensity. The study demonstrated white-cedar's capacity to maintain good growth for long periods of time and at large tree sizes. Accession to the upper canopy positions occurs through repeated episodes of suppression/release, most of which seem to be associated with spruce budworm (Choristoneura fumiferana) outbreaks. White-cedar response to partial harvesting varies with tree size, residual basal area and species composition. Growth response was generally stronger for small trees, even though large trees still maintained the best diameter growth. Growth of white-cedar was negatively affected by an increase in softwood proportion in basal area. Growth responses to harvesting could be sustained for a period of 20 years. [ABSTRACT FROM AUTHOR]

In eastern Canada, past diameter-limit cutting left a legacy of low-density and heterogeneous hardwood stands. The complex stand structure and variahle density hinders the application of uniform treatments for stand regeneration and rehabilitation. This article describes an innovative approach called the "multiple-treatment irregular shelterwood system." Two variants of the method are presented to achieve extended irregular shelterwood and continuous cover irregular shelterwood. The silvicultural prescription recognizes microstands that are grouped into microtypes based mainly on sapling stocking and tree canopy closure. For each microstand, harvesting of mature trees is allowed if the understory has sufficient stocking of saplings. If not, partial cutting and/or soil scarification is prescribed to promote regeneration. The design of the trail system and the sequence of entries are adapted for each irregular shelterwood variant. Results from two field trials show that this method is operationally feasible. Existing advance regeneration was adequately protected, and favorable microsite conditions were created when sufficient regeneration was lacking. Half of the volume of wood was harvested from test sites with no high grading of species composition or tree quality, while maintaining a high degree of structural heterogeneity. [ABSTRACT FROM AUTHOR]

This study compares the financial return of converting old-growth boreal stands into even-aged stands to that of two approaches of selection cutting in Quebec (Canada). In this region, old-growth stands are usually harvested by completely removing the canopy while protecting the abundant advance regeneration, an approach known as careful logging around advance growth (CLAAG). These approaches were compared using a time frame of over 200 years. Consideration is given to the majority of the operating costs leading to end products. The financial analysis integrates Monte Carlo simulations, making it possible to consider the uncertainty associated with variables. The net present values (NPVs) are then associated with a distribution of probabilities. The results show that the probabilities of obtaining positive NPVs are high for all treatments, suggesting that selection cutting approaches can be appropriate alternatives to CLAAG for some stands. Depending on the criteria used, the CLAAG cut or one of the selection cuts show the best performances. In fact, the results of the financial study show that in the future, selection cutting approaches will be more profitable than CLAAG but still less than present CLAAG operations. This occurs because, according to the current yield curves and rotation ages, future stands managed with CLAAG will have smaller and less valuable trees than in the primary forest and in stands managed with the selection system. [ABSTRACT FROM AUTHOR]

Many hardwood or mixedwood stands of northeastern North America have been high graded in the past and need restoration treatments to bring them back to an acceptable level of production. Even when early seedling establishment can be secured, further development may be compromised by many factors. This study looks at the effect of seedbed, browsing, and competition on the growth and survival of yellow birch (Betula alleghaniensis Britt.) seedlings that became established after a brushing and scarification treatment applied in high-graded mixedwood stands of Quebec, Canada. The seedbed types studied include 1-m-wide scarified patches, 2-m-wide scarified patches, and mounds. Browsing impact was assessed by placing fences around half of the plots. Half of the plots were released from competing vegetation. Browsing by hare (Lepus americanus) was seen as a major factor controlling seedling development between 3 and 6 years after scarification. It reduced both survival and growth and obscured the effect of other factors. In the absence of browsing, competition had a major effect on mounds but not on scarified patches. Mounds were found to have the best growth potential when competition and browsing were controlled. The scarified patches had the best growth when competition and browsing were allowed. Even though mortality was somewhat higher on scarified patches, initial densities were very high and still provide more seedlings than required. [ABSTRACT FROM AUTHOR]

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents a method for preparing wood sections and reading tree rings in diffuse-porous hardwoods that is more efficient than the standard sanding method. The planing of fresh samples and the use of an ultraviolet light source in conjunction with a fluorescent dye reduced the preparation time by 39%. No significant differences were found between the two methods for the time needed for ring count. The fluorescent method can be used for both wood sections and cores, and it can be applied to coniferous species. [ABSTRACT FROM AUTHOR]

Investigates the mortality pattern in black spruce stands from Quebec. Reference to mortality of fire or clear-cut origin; Reconstitution of the stands; Impact of spruce budworm outbreak on the mortality of the stands; Correlation between the mortality rates and the occurrence of outbreaks.

Investigates the evolution pattern of the diameter structure of boreal black spruce stands originating from fire or logging in Quebec. Comparison of stands originating from fire and from logging; Impact of the widespread careful logging on the stands; Reconstitution of the dynamics of 40- to 90-year-old stands.

• Experts had to list and rank ecological issues related to second-growth forest. • The old-growth forest rarefaction was selected as the most important issue. • Protection of woodland caribou was the second most important issue. • Participant's affiliation did not influence the issues ranking scores. The Eastern boreal forests of Quebec, Canada, have been extensively harvested over the past decades. Second-growth stands originating from sites harvested between 1920 and 1950 will soon reach the stage allowing for a second harvest. In order to guide the decision-makers responsible for ecosystem-based management of these forests, their specific management issues must be identified, based on the best knowledge available. In this context, we used the Delphi method and asked experts to identify and prioritize the main ecological issues related to the management of second-growth forests. Fourteen experts participated in at least one round of the process, out of an initial population of 30 known experts. After three rounds of questions, experts identified the maintenance of old-growth forests as the most important issue related to second-growth forest management in this region. The protection of woodland caribou and its habitat, and land fragmentation by forest roads were the second and third most important issues identified by the Delphi survey participants. These issues are not unique to second-growth forests, but should be given priority in considering management strategies associated with second-growth stands. [ABSTRACT FROM AUTHOR]