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The relationship between forest stand composition in southern interior British Columbia and fluorescent pseudomonad bacteria populations was investigated using seedling bioassays. The objectives of this study were to (i) compare the relative population sizes of fluorescent pseudomonads baited from soils in pure paper birch (Betula papyrifera Marsh.), pure Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and mixed stands of the two species and (ii) determine if fluorescent pseudomonads from these soils have inhibitory effects against the root pathogen Armillaria ostoyae (Romagn.) Herink in vitro. Soil from birch stands supported four times more pseudomonads on seedling baits than soil from Douglas-fir stands, with the mixed stands intermediate. Soil from young stands yielded twice as many rhizosphere pseudomonads as soil from mature stands. Pseudomonad population size was positively correlated with percent cover and density of birch, and negatively correlated with basal area of Douglas-fir, percent cover of Douglas-fir, and carbon/nitrogen ratio of the soil. Greater than 50% of the fluorescent isolates reduced radial growth of A. ostoyae by more than 20% and greater than 90% reduced biomass of the fungus in dual culture tests. Cell-free bacterial culture filtrates added to the growth medium also reduced growth of A. ostoyae. This study provides evidence that paper birch provides a more favorable environment for fluorescent pseudomonads than Douglas-fir and suggests a mechanism by which paper birch can positively influence the susceptibility of managed forest stands to Armillaria root disease. [ABSTRACT FROM AUTHOR]

Reports on the measured rates of decomposition at three sites representing the major mixedwood forest types of British Columbia: (i) boreal forests of white spruce (Picea glauca (Moench) Voss) and trembling aspen (Populus tremuloides Michx.), (ii) coastal forests of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnus rubra Bong.), and (iii) a wet interior forest of Douglas-fir, paper birch (Betula papyrifera Marsh.), and lodgepole pine (Pinus contorta Doug. ex Loud.). Mass loss of litter of each species (both pure and in combination with the other species) that was measured in forests of each species to determine (i) if broadleaf litter decomposed faster than needle litter, (ii) if litter decomposed faster in broadleaf or mixedwood forests than in coniferous forests, and (iii) if mixing with broadleaf hastened decomposition of needle litter; Broadleaf litters that decomposed faster than needles during the first year but, thereafter, decomposed more slowly; Litter that tended to decompose faster in the broadleaf forests than in the coniferous forests; No evidence to indicate that the addition of broadleaf litter hastened decomposition of needle litter; Results that indicate that the mixing of needle litter with broadleaf litter is unlikely to hasten decomposition in mixedwood forests of British Columbia.

In 1996 we initiated a study to evaluate several techniques for measuring light under broadleaf canopies. Hourly average photosynthetic photon flux density and percent transmittance were measured 1 m above the ground at four points in each of three canopy densities created by a spacing experiment in a 35-year-old paper birch (Betula papyrifera Marsh.) dominated stand located near Prince George, B.C. At each point, fisheye photographs were taken and LAI-2000 plant canopy analyzer (LAI-2000), spherical densiometer, and competition index (Lorimer'sindex) measurements were made. Percent transmittance measurements onan overcast day (1-h average), transmittance measured over periods of 3 h or longer on a clear day, LAI-2000 diffuse noninterceptance measurements, and gap light index determined from fisheye photographs were strongly correlated with growing season percent transmittance (r2>= 0.96) as was competition index (r2 = 0.928). Concave spherical densiometer measurements and midday percent transmittance measurements on clear days were also well correlated with measured percent transmittance (r2>= 0.89). Estimates of understory light by the LITE model were strongly correlated with growing season percent transmittance. Correlations improved with increasing length of the period simulated (r2 = 0.755 for a point measurement on a clear day; r2 = 0.936 for an entire sunny day;and, r2 = 0.953 for the entire growing season). However, this version of the model underestimated percent transmittance in these spaced birch stands by 34-90%. [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Climate change interacts with ecological processes leading to changes in tree and forest growth rate, biome shifts and species composition, all of which are influenced by disturbances. This study explores future overarching climate trends of eight of Canada's ecozones containing managed forests. For the 2071 to 2100 period, climate projections indicate a warming trend of up to an additional 5.5 °C and an overall increase in annual precipitation. Future trends suggest marked contrast between coastal and interior forests and polarization between western and eastern forests. Warmer temperatures, accumulating degree-days above 5 °C and frost-free days suggest longer and drier growing seasons and greater risk of drought particularly in moisture-limited areas such as montane cordillera, taiga shield and boreal shield ecozones. Warmer temperatures and rising precipitation combined with less snow suggest shorter and wetter future winters. This indicates greater risk of rain-on-snow and freeze-thaw events, flooding and landslides particularly in coastal ecozones. We discuss how these projections are likely to result in shifts in dominant species and abundance, which when coupled with the cumulative effects of future disturbances, is likely to alter future forest dynamics and impact harvestable wood volumes for Canada's forestry industry. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

The term “aboriginal forestry” is used increasingly to describe the evolving role of First Nations peoples in Canadian forestry over the last 30 years. This paper reviews a diversity of experiences and identifies issues that have important implications for governments, forest planners, and First Nations: a forestry regime that reflects the interests of governments and industry rather than those of First Nations; variable implementation of aboriginal rights in forestry practice; benefits and problems of economic partnerships; limitations on consultation, traditional knowledge, and comanagement in forestry; and finally, different forestry paradigms. Among these experiences and issues, we recognise different visions for the participation of First Nations peoples in Canadian forestry. At one end of the spectrum, “forestry excluding First Nations” is no longer accepted. The most common form may be “forestry by First Nations,” representing a role for First Nations within existing forestry regimes. Other options include “forestry for First Nations,” in which forest managers seek to incorporate aboriginal values and knowledge in management activities and “forestry with First Nations,” in which aboriginal peoples are equal partners in forest management. However, aboriginal forestry is better understood as a potential new form of forestry that uses knowledge and techniques drawn from both traditions and conventional forestry and is based on aboriginal rights, values, and institutions. Au Canada, le terme « foresterie autochtone »gagne en popularité pour décrire le rôle grandissant des Premières nations en foresterie au cours des trente dernières années. Cet article passe en revue de nombreuses expériences et identifie des enjeux aux conséquences importantes pour les gouvernements, les gestionnaires forestiers et les Premières nations. Un régime forestier qui reflète les intérêts des gouvernements et des industriels plutôt que ceux des Premières nations, la reconnaissance inégale des droits autochtones dans les pratiques forestières, les bénéfices et les problèmes associés aux partenariats d’affaires, les limites propres à la consultation, la place des savoirs traditionnels et de la cogestion en foresterie et enfin, la variété des paradigmes forestiers composent ces enjeux. Parmi ces expériences et enjeux, nous reconnaissons l’expression de différentes façons de concevoir la participation autochtone à la foresterie canadienne. À un bout du spectre, « une foresterie qui exclut les Premières nations »n’est plus une option acceptable. La vision la plus répandue est probablement celle d’« une foresterie par les Premières nations »signifiant que celles-ci ont un rôle à jouer dans les régimes forestiers existants. Une autre conception est celle de « la foresterie pour les Premières nations »lorsque les gestionnaires forestiers tentent d’intégrer des valeurs et des savoirs autochtones à leurs activités d’aménagement. Enfin, les situations où les autochtones sont partenaires à part entière dans l’aménagement de la forêt s’inscrivent sous la rubrique « la foresterie avec les Premières nations ». Cependant, la foresterie autochtone est mieux comprise lorsqu’elle implique la possibilité d’une nouvelle foresterie qui a recours à des savoirs et des techniques inspirés à la fois des traditions et de la foresterie conventionnelle et qui est fondée sur des droits, des valeurs et des institutions autochtones. [ABSTRACT FROM AUTHOR]

This paper uses survey information to examine several common assertions about the institutional prerequisites for successful profitability when a First Nation enters an economic enterprise either independently or in joint effort with an outside firm. In the winter of 2004–2005, we interviewed managers on both the First Nations and private sides of joint ventures and other business alliances in Canada, to determine what affected their recent profitability experience. We gathered information on the ages, sizes, and activities of the firms. We also gathered information about the firms’ management structures and relationship with the First Nation, and the characteristics of the government of the First Nation. With a sample size of 40 firms that responded, we found that several institutional characteristics affected profit positively: strong separation of management from band governance, participation in management planning, and the use of staggered terms in band council elections. We found that the likelihood of profitability decreased if the band had been in third party management as well as if there was formal participation of elders or hereditary chiefs in decision making. We offer interpretations of these results. Cet article utilise les données d’un sondage réalisé au cours de l’hiver 2004–2005 afin d’examiner plusieurs assertions courantes au sujet des préalables institutionnels requis pour atteindre la profitabilité des entreprises initiées par des Premières nations agissant seules ou en partenariat avec des acteurs privés. Nous avons interviewé des gestionnaires impliqués dans de tels partenariats d’affaires au Canada et provenant tant des Premières nations que du secteur privé. Nous voulions déterminer ce qui affectait la profitabilité qu’ils avaient connue récemment. Nous avons rassemblé de l’information sur l’âge, la taille et les activités des entreprises. Nous avons aussi recueilli des données sur la structure de gestion des entreprises, les relations avec les Premières nations et les caractéristiques de la gouvernance en vigueur dans les communautés d’accueil. Un échantillon, regroupant les quarante entreprises qui ont répondu, nous permet d’observer que plusieurs caractéristiques institutionnelles, comme la séparation claire entre la gestion des projets et la gouvernance des communautés, la participation dans la planification managériale et le recours à des mandats échelonnés lors des élections au conseil de bande, affectent positivement les profits. Nous avons aussi remarqué que les chances de profitabilité diminuent si les conseils de bandes jouent un rôle en tant que de tierce partie dans la gestion des entreprises et si les aînés ou les chefs héréditaires participent formellement au processus décisionnel. Nous tentons d’interpréter ces résultats. [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

The Canadian boreal logging industry has attracted little or no attention from economic researchers in spite of its importance for the competitiveness and long-term survival of other forest-based industries. This article uses a panel data set covering the period from 1977 to 1995 to analyze technical efficiency, technical change, and total factor productivity growth in the logging industries for six boreal provinces. The production technology is represented using a data envelopment analysis model. A transitive measure of productivity change that combines technical progress and changes in the degree of productive efficiency is computed. The empirical investigation reveals that logging activities in the boreal region are characterized by substantial efficiency differentials among the regions. Results from a Tobit analysis of efficiency differentials indicate that forest resource characteristics such as forest density and proportion of hardwood production were found to have positive effects. There was also evidence of significant positive scale effects. Engineering construction per area seems to be negatively related to efficiency. Total factor productivity in the boreal logging industry progressed at an average annual rate of 1.56%.L'industrie de la récolte forestière en forêt boréale canadienne a suscité peu ou pas d'intérêt de la part de chercheurs en écon omie et ce malgré son importance pour la compétitivité et la survie à long terme des industries de transformation du bois. Cet article utilise des données en panel couvrant la période de 1977 à 1995 afin d'analyser l'efficience technique, les changements technologiques et le gain global de productivité de l'industrie de la récolte dans six provinces de la zone boréale. La technologie de production est représentée à l'aide d'un modèle d'analyse par enveloppement des données. Une mesure transitive du changement de productivité qui combine le progrès technologique ainsi que les changements dans le niveau d'efficience est présentée. L'approche empirique a révélé que des différences substantielles caractérisaient l'efficience des activités de récolte parmi les régions de la zone boréale. Les résultats d'une analyse Tobit sur les différences d'efficience indiquent que les caractéristiques de la ressource forestière telles que la densité et la proportion des essences feuillues avaient des effets positifs. Des rendements d'échelle positifs ont également été détectés. Les travaux d'ingénierie par superficie traitée semblent affecter négativement l'efficience. La productivité globale dans l'industrie de la récolte en forêt boréale a progressée à un taux annuel moyen de 1,56 %.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

The knowledge of natural disturbance dynamics and preindustrial landscapes is essential to implement sustainable forest management. Recent findings identify the lack of a forest dynamics model, different from the standard cyclic model of Baskerville (1975. For. Chron. 51: 138–140), for balsam fir (Abies balsamea (L.) Mill.) ecosystems of maritime eastern Canada. With the use of historical forest maps and dendrochronology, we reconstructed the range of variability of the preindustrial landscape (6798 km2) and inferred on the natural disturbance dynamics of the balsam fir forest of Anticosti Island. The preindustrial landscape was characterized by a forest matrix of overmature softwood stands with inclusions of younger softwood stands ranging from 0.1 to 7837 ha in size. Widespread stand-initiating events were apparently rare in the preindustrial landscape over the last 160 years. Since our results were not well represented by the cyclic model, which predicts the occurrence of a mosaic of stands in different age classes, we proposed an alternative forest dynamics model for eastern balsam fir ecosystems near the Gulf of St. Lawrence. Forest management inspired by this alternative model may be more appropriate to maintain or restore ecological characteristics of balsam fir forests of this region within their range of natural variability. La connaissance de la dynamique des perturbations naturelles et des paysages préindustriels est essentiel à la réalisation de l’aménagement forestier durable. Des travaux récents ont identifié le besoin d’un nouveau modèle de dynamique forestière, différent du modèle cyclique standard de Baskerville (1975. For. Chron. 51 : 138–140), pour les sapinières (Abies balsamea (L.) Mill.) maritimes de l’est du Canada. Au moyen de l’analyse de cartes forestières historiques et de la dendrochronologie, nous avons reconstruit les limites de variabilité du paysage préindustriel (6 798 km2) et inféré sur la dynamique naturelle des perturbations des sapinières de l’île d’Anticosti. Le paysage préindustriel était caractérisé par une matrice de peuplements résineux surannés avec des inclusions de peuplements résineux plus jeunes, d’une superficie variant de 0,1 à 7 837 ha. L’occurrence de perturbations initiatrices de nouveaux peuplements semble avoir été faible durant les derniers 160 ans. tant donné que les résultats ne sont pas bien représentés par le modèle cyclique, qui prédit l’occurrence d’une mosaïque de peuplements d’âges différents, nous proposons un modèle alternatif de dynamique forestière pour les sapinières de l’est du Canada localisées près du golfe du Saint-Laurent. L’aménagement forestier inspiré par ce modèle alternatif pourrait être plus approprié pour maintenir ou restaurer les caractéristiques écologiques des sapinières de cette région à l’intérieur de leurs limites de variabilité naturelle. [ABSTRACT FROM AUTHOR]

Examines the economic impact of policy changes in a forested region of the province of Alberta known as the Foothills Model Forest (FMF). Effects of policy changes in various sectors that are analyzed in terms of all sectors of the regional economy with particular emphasis on the forestry sector; Study that uses a computable general equilibrium (CGE) framework rather than a fixed-price framework to analyze economy-wide impacts of land use or forest policy changes; Application of this technique on a regional scale that is rare in the scientific literature; Model results that indicate that a decrease in forestry output somewhat offsets the positive economic impact generated by increased visitor activity; Failure to consider these trade-off impacts in the analysis that will result in erroneous conclusions; Outcomes from timely policy scenarios that are examined; Results from the CGE framework that suggest that policy makers face a greater degree of complexity than in current economic impact frameworks.

Reports that forest policymakers in Canada are considering the allowable cut effect (ACE) as a potential mechanism to provide tenure holders with incentives to practice enhanced forest management. To investigate the incentives created by the ACE, this paper estimates returns to ACE investments for a trembling aspen (Populus tremuloides Michx.) - white spruce (Picea glauca (Moench) Voss) mixedwood forest in Alberta. A timber supply model is used to optimize harvesting schedules to maximize net present values over a 200-year planning horizon. A number of scenarios are investigated with variations in intensity of silvicultural investments, beginning age-class distributions, levels of flexibility around the allowable annual cut (AAC), calculations of AACs based on coniferous and mixedwood volumes, and green-up constraints. In our simulations, it was difficult to find positive returns to the ACE. Positive returns only occurred when operating under harvesting constraints with a mature starting forest and AAC calculations that ignored deciduous volumes. In those limited cases where there were positive returns to the ACE, returns were higher for extensive, rather than intensive investments. Combining these results with other potential impediments to the ACE, previously identified in the literature, the probability of tenure holders having incentives to undertake ACE investments is low.

Provides information on the 4th International Workshop on Disturbance Dynamics in Boreal Forest held at the University of Northern British Columbia on August 9 to 12, 2002. Issues involving forest management discussed at the event; Keynote speakers who were present in the workshop; Discussion on the importance and role of disturbance in shaping boreal forest.

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Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Although the public advisory committee has become a very common tool for involving local people in forest management decisions, it does not necessarily broaden the base of public input and may simply replicate the challenges of access, representation, and capacity to participate that are found in wider society. As a category of social exclusion, this study explores why women are significantly underrepresented on forest management advisory committees in Canada and how these committees function as gendered units. Research involved 25 semistructured interviews with members (and former members) of two forest management advisory committees: Tembec in Manitoba and NewPage in Nova Scotia. The strongest evidence in our study suggests that these committees operate within male-dominated institutions and particular masculine norms that are simply taken for granted. Thus, social relations based on gender often go unacknowledged. Findings also showed that the lack of critical mass of women often limited the active participation of the small number of women involved in committee activities. Our empirical observations suggest that unless we attend to gender when involving communities in establishing strategies for forest management, we will reinforce gender disadvantage and exclusion and overrepresent industrial and utilitarian interests of forestry over other community and ecocentric values. Bien que les comités directeurs soient devenus des outils de participation du public auxquels on recourt de plus en plus afin d'inclure les populations locales dans le processus décisionnel en aménagement forestier, cela n'élargit pas nécessairement la contribution du public et peut simplement reproduire les défis qu'on retrouve à la grandeur de la société concernant l'accès, la représentation et la capacité à participer. Sous le thème de l'exclusion sociale, cette étude explore pourquoi les femmes sont fortement sous-représentées dans les comités directeurs en aménagement forestier au Canada et comment ces comités fonctionnent en tant qu'entités sexuées. La recherche s'appuie sur 25 entrevues semi-dirigées avec des membres (et ex-membres) de deux comités directeurs en aménagement forestier, soit ceux de Tembec au Manitoba et de NewPage en Nouvelle-Écosse. Le constat le plus manifeste de notre étude indique que ces comités fonctionnent dans le cadre d'institutions à prédominance masculine et où des normes masculines particulières sont tout simplement prises pour acquises. Ainsi, les relations sociales fondées sur le genre passent souvent inaperçues. Les résultats montrent aussi que l'absence de masse critique féminine limite souvent la participation active du petit groupe de femmes qui collaborent aux activités de ces comités. Nos observations empiriques indiquent que, faute de considérer le genre dans la contribution des communautés lors de l'établissement des stratégies d'aménagement, le désavantage envers les femmes et l'exclusion seront renforcés alors que les intérêts industriels et utilitaristes seront surreprésentés au détriment des autres communautés et des valeurs éco-centriques. [ABSTRACT FROM AUTHOR]

Although many studies have focused on factors influencing treeline advance with climate change, less consideration has been given to potential changes in tree spatial pattern across the forest-tundra ecotone. We investigated trends in spatial pattern across the forest-tundra ecotone and geographical variation in the Yukon, Manitoba, and Labrador, Canada. Tree cover was measured in contiguous quadrats along transects up to 100 m long located in Forest, Ecotone, and Tundra sections across the forest-tundra transition. Spatial patterns were analyzed using new local variance to estimate patch size and wavelet analysis to determine the scale and amount of aggregation. Compared with the Forest, tree cover in the Ecotone was less aggregated at most sites, with fewer smaller patches of trees. We found evidence that shorter trees may be clumped at some sites, perhaps due to shelter from the wind, and we found little support for regular spacing that would indicate competition. With climate change, trees in the Ecotone will likely become more aggregated as patches enlarge and new patches establish. However, results were site-specific, varying with aspect and the presence of krummholz (stunted trees); therefore, strategies for adaptation of communities to climate change in Canada's subarctic forest would need to reflect these differences. Alors que plusieurs études ont mis l'accent sur les facteurs qui influencent la progression de la limite des arbres due aux changements climatiques, peu d'attention a été accordée aux changements potentiels du patron de répartition spatiale des arbres dans l'écotone entre la forêt et la toundra. Nous avons étudié les changements de la répartition spatiale dans l'écotone entre la forêt et la toundra de même que sa variation géographique au Yukon, au Manitoba et au Labrador, au Canada. Le couvert forestier a été mesuré dans des quadrats contigus établis le long de transects pouvant atteindre 100 m de longueur et situés dans les sections de forêt, d'écotone et de toundra dans la zone de transition entre la forêt et la toundra. Les patrons spatiaux ont été analysés avec les méthodes de la nouvelle variance locale pour estimer la taille des îlots de forêt et avec l'analyse par ondelettes pour déterminer l'échelle et le degré d'agrégation. Comparativement à la forêt, le couvert forestier de l'écotone était moins groupé dans la plupart des stations, ce qui s'est traduit par des îlots de forêt plus petits et moins nombreux. Nous avons trouvé des preuves que les petits arbres peuvent être regroupés dans certaines stations, probablement pour se protéger du vent, et nous avons trouvé peu de signes d'espacement régulier qui auraient indiqué la présence de compétition. Avec les changements climatiques, les arbres établis dans l'écotone se regrouperont probablement davantage par l'agrandissement des îlots et par l'établissement de nouveaux îlots. Cependant, ces résultats sont spécifiques aux stations puisqu'ils varient selon leur orientation et en fonction de la présence de krummholz (arbres prostrés). Ainsi, les stratégies d'adaptation des communautés aux changements climatiques dans la forêt subarctique canadienne devraient refléter ces différences. [ABSTRACT FROM AUTHOR]

We present the effects, 10 years after treatment, of different cutting intensities (removal of 0%, 35%, 50%, 65%, and 100% of basal area (BA)) on the response of residual trees in a 60-year-old mixed aspen–conifer stand in Quebec, Canada. While decennial mortality reached 170 stems·ha–1 under natural conditions (control, 24 m2·ha–1 BA), the removal of mature trembling aspen (Populus tremuloides Michx.) trees reduced hardwood losses to 125, 105, and 0 stems·ha–1, respectively, in the 35%, 50%, and 65% cuttings, without affecting losses of coniferous species (≤25 stems·ha–1). The growth response of conifers was generally higher than that of broad-leaved species. For hardwoods, the decennial gains in merchantable BA decreased with respect to the control (3.2 m2·ha–1), to 1.2 m2·ha–1 in the 35% cut and to 0.9 m2·ha–1 in the 50% cut, but increased under the 65% cut (2.5 m2·ha–1). For conifers, gains were proportional to removal in partial cuts (2.6–4.9 m2·ha–1) and lower in the control (1.7 m2·ha–1). As a whole, our results suggest that partial cutting may be an effective means of increasing growth of the softwood proportion occupying the intermediate and suppressed strata in a mixed aspen-dominated stand. Nous présentons les résultats de coupes de différentes intensités effectuées il y a 10 ans (prélèvements de 0, 35, 50, 65 et 100 % de la surface terrière (ST)) sur la réaction des tiges résiduelles d’un peuplement mixte de 60 ans, constitué de tremble et de conifères, au Québec, Canada. Alors que la mortalité décennale a atteint 170 tiges·ha–1 en conditions naturelles (témoin, 24 m2·ha–1 de ST), le prélèvement prioritaire du peuplier faux-tremble (Populus tremuloides Michx.) mature a permis de diminuer les pertes de feuillus à 125, 105 et 0 tiges·ha–1, respectivement dans les coupes à 35, 50 et 65 %, sans affecter les pertes de résineux (≤25 tiges·ha–1). La réaction de croissance des conifères a généralement été meilleure que celle des feuillus. Pour les feuillus, les gains décennaux en ST marchande ont diminué par rapport au témoin (3,2 m2·ha–1), à 1,2 m2·ha–1 dans la coupe à 35 % et à 0,9 m2·ha–1 dans la coupe à 50 %, pour remonter dans la coupe à 65 % (2,5 m2·ha–1). Pour les conifères, les gains ont été directement proportionnels au prélèvement dans les coupes partielles (2,6 à 4,9 m2·ha–1), et moins élevés dans le témoin (1,7 m2·ha–1). Dans l’ensemble, nos résultats indiquent que la coupe partielle peut être efficace pour augmenter la croissance de la fraction résineuse des étages intermédiaire et opprimé dans un peuplement mixte dominé par le tremble. [ABSTRACT FROM AUTHOR]

The effect of removing lodgepole pine (Pinus contorta Dougl. ex Loud.) and retaining Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) to reduce the risk of disturbance from mountain pine beetle (Dendroctonus ponderosae Hopk.) in mixed conifer stands in southern British Columbia, Canada, on population processes influencing outbreaks of western spruce budworm (Choristoneura occidentalis Free.) was evaluated in 10 paired (open vs. closed) field plots. Overall feeding damage to Douglas-fir was significantly, but only slightly, lower in open stands compared with closed stands. Although open plots tended to recruit more budworms, the losses resulting from the dispersal of spring-emerging budworms in search of feeding sites were significantly greater in open plots. The forest management benefits of these early season losses were mitigated, however, by more mortality of budworms from natural enemies, particularly diseases, in the closed plots during the budworm feeding period. These results are discussed in terms of compensating population processes and balancing objectives in forest pest management. In this case, selective harvesting of lodgepole pine as a mitigation strategy for the mountain pine beetle conserved the midterm timber supply potential represented by associated Douglas-fir even in the presence of an outbreak of the western spruce budworm. Dans les peuplements mélangés de conifères du sud de la Colombie-Britannique, au Canada, on élimine le pin tordu (Pinus contorta Dougl. ex Loud.) en conservant le douglas de Menzies (Pseudotsuga menziesii (Mirb.) Franco) pour réduire les risques de perturbation par le dendroctone du pin ponderosa (Dendroctonus ponderosae Hopk.). L’effet de cette pratique sur les processus démographiques qui influencent les épidémies de tordeuse occidentale de l’épinette (Choristoneura occidentalis Free.) a été évalué dans 10 paires (peuplements ouverts vs peuplements fermés) de parcelles sur le terrain. Globalement, les dommages subis par le douglas de Menzies à cause du broutement étaient, quoique légèrement, significativement plus faibles dans les peuplements ouverts que dans les peuplements fermés. Bien que les peuplements ouverts aient eu tendance à recruter plus de tordeuses, les pertes dues à la dispersion des tordeuses qui émergent au printemps à la recherche d’endroits pour se nourrir étaient plus élevées dans les peuplements ouverts. À la suite de ces pertes en début de saison, les bénéfices de l’aménagement forestier ont cependant été atténués par une plus forte mortalité des tordeuses causée par ses ennemis naturels, particulièrement les maladies, dans les peuplements fermés pendant la période de broutement de la tordeuse. La discussion porte sur la compensation des processus démographiques et l’équilibre entre les objectifs en lien avec le contrôle des ravageurs forestiers. Dans ce cas, la stratégie qui préconise la récolte sélective du pin tordu pour atténuer l’impact du dendroctone du pin ponderosa a permis de maintenir le potentiel d’approvisionnement en bois à mi-terme que constitue le douglas de Menzies associé au pin tordu, même en présence d’une épidémie de tordeuse occidentale de l’épinette. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing 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.)