Search

Regional analyses assessing the vulnerabilities of forest ecosystems and the forest sector to climate change are key to considering the heterogeneity of climate change impacts as well as the fact that risks, opportunities, and adaptation capacities might differ regionally. Here we provide the Regional Integrated Assessment of climate change on Quebec's forests, a work that involved several research teams and focused on climate change impacts on Quebec's commercial forests and on potential adaptation solutions. Our work showed that climate change will alter several ecological processes within Quebec's forests. These changes will result in important modifications in forest landscapes. Harvest will cumulate with climate change effects to further alter future forest landscapes, which will also have consequences on wildlife habitats (including woodland caribou habitat), avian biodiversity, carbon budget, and a variety of forest landscape values for Indigenous peoples. The adaptation of the forest sector will be crucial to mitigate the impacts of climate change on forest ecosystem goods and services and improve their resilience. Moving forward, a broad range of adaptation measures, notably through reducing harvest levels, should be explored to help strike a balance among social, ecological, and economic values. We conclude that without climate adaptation, strong negative economic and ecological impacts will likely affect Quebec's forests. Key words: Quebec, boreal forest, synthesis, ecosystem services, regional analyses Les analyses regionales evaluant la vulnerabilite des ecosystemes forestiers et du secteur forestier aux changements climatiques sont essentielles pour prendre en compte l'heterogeneite des impacts des changements climatiques, mais aussi le fait que les risques, les opportunites et les capacites d'adaptation peuvent differer d'une region a l'autre. Nous presentons ici l'evaluation regionale integree des changements climatiques sur les forets du Quebec, un travail qui a implique plusieurs equipes de recherche et qui s'est concentre sur les impacts des changements climatiques sur les forets commerciales du Quebec et sur les solutions d'adaptation a ces changements. Nos travaux montrent que les changements climatiques pourraient modifier plusieurs processus ecologiques dans les forets du Quebec. Ces changements entraineront d'importantes modifications des paysages forestiers. La recolte forestiere pourrait s'additionner aux changements climatiques pour modifier davantage les futurs paysages forestiers, ce qui pourrait egalement avoir des consequences sur les habitats fauniques (notamment ceux du caribou forestier), la biodiversite aviaire, le bilan carbone et les valeurs des paysages forestiers pour les Peuples autochtones. Nous preconisons que l'adaptation du secteur forestier sera essentielle afin d'attenuer les impacts des changements climatiques sur plusieurs biens et services ecosystemiques forestiers. Ces strategies devraient ameliorer la resilience des services ecosystemiques. Par exemple, la reduction de la recolte pourrait permettre de maintenir l'habitat du caribou, favoriser la biodiversite aviaire, bonifier la capacite de stockage du carbone et profiter aux activites traditionnelles autochtones. La reduction des taux de recolte du bois pourrait aussi aider a reduire les echecs de regeneration apres les feux dans les regions oU ceux-ci sont actuellement communs, ou dans celles qui seront a risque dans le futur. Sur la base de nos travaux, nous concluons qu'omettre de mettre en oeuvre des options d'adaptation aux changements climatiques pourrait representer des impacts economiques et ecologiques negatifs importants pour les forets du Quebec. Mots-cles : Quebec, foret boreale, synthese, services ecosystemiques, analyses regionales, 1. Introduction The science is clear: human-caused climate change has been warming the planet by 1.1[degrees]C since 1880, with a recent rate of increase of 0.18[degrees]C per decade since 1981 [...]

Over one billion people in the world depend on forests to meeting livelihood needs and more than half of them engage in community-based forest management. Community forestry has the potential of making important contributions in achieving the sustainable development goals; however, their positive effects on local livelihoods have been questioned. Actors, with their interests and power balance, can be important factors explaining the success of community forestry by shaping the decisionmaking process. Hence, the aim of our study was to analyze the economic performance of community forestry across the world, through its contribution to poverty reduction and explain how the economic outcome relates to the interests of the powerful actors. Community forestry from seven countries was analyzed including cases in Asia (Nepal, Indonesia, Vietnam), Africa (Namibia and Cameroon), and Europe (Germany and Albania). Data were collected with a sequence design method aiming to identify the participating actors and their power. A multivariate principal components analysis was conducted to capture the power dynamics within each community forestry. Results showed that community forestry programs do not always lead to poverty alleviation. The economic outcomes can be linked to the interests of the most powerful actors which in most cases do not desire a high economic outcome but rather promote contributions up to subsistence level. Key words: comparative study, livelihoods, decentralization, poverty reduction, co-management, Introduction Over one billion people in the world depend on forests as a contribution to meeting their livelihood needs (Hajjar et al. 2020). As a consequence, multiple forest use can [...]

Intraregional trade of forest products is a critical component of regional and subregional timber markets in terms of supply chain planning and locating forest product manufacturing facilities. Based on a gravity trade model, we evaluated the various factors driving the interstate flows of softwood sawlog and roundwood pulpwood in the 13 southern US states: AL, AR, FL, GA, KY, LA, MS, NC, OK, SC, TN, TX, and VA. Biennial state-level panel data from 2011 to 2019 in 13 southern states were employed to estimate empirical sawlog and pulpwood trade models. The results suggest that state gross domestic product (GDP) of importing states, exporter and importer production, importer consumption, the distance between the trading partners, and the electronic logging device mandate are influential factors of softwood sawlog trade between the states. Similarly, state GDP, exporter pulpwood production, importer consumption, the distance between the trading partners, delivered timber prices, and pellet mill capacity in each state are found to be significant determinants of softwood pulpwood trade between the partners across the state borderlines. The findings provide forest managers and policy makers with additional insights on the growing bilateral timber trade dynamics in regional and subregional markets in the southern United States. Key words: forest products, intraregional trade, Hausman-Taylor estimator, pellet mill capacity, Introduction Timber inventories are vitally important for decision makers in the forest products industry, particularly in supply chain planning and locating forest product mills. Interstate shipments of raw stumpage products [...]

Statistical confidence in estimates of timber volume, carbon storage, and other forest attributes depends, in part, on the uncertainty in field measurements. Surprisingly, measurement uncertainty is rarely reported, even though national forest inventories routinely repeat field measurements for quality assurance. We compared measurements made by field crews and quality assurance crews in the Forest Inventory and Analysis program of the U.S. Forest Service, using data from 2790 plots and 51740 trees and saplings across the 24 states of the Northern Region. We characterized uncertainty in 12 national core tree-level variables; seven tree crown variables used in forest health monitoring; three variables describing seedlings; and 11 variables describing the site, such as elevation, slope, and distance from a road. Discrepancies in measurement were generally small but were higher for some variables requiring judgment, such as tree class, decay class, and cause of mortality. When scaled up to states, forest types, or the region, uncertainties in basal area, timber volume, and aboveground biomass were negligible. Understanding all sources of uncertainty is important to designing forest monitoring systems, managing the conduct of the inventory, and assessing the uncertainty of forest attributes required for making regional and national forest policy decisions. Key words: carbon accounting, Forest Inventory and Analysis, forest inventory, measurement uncertainty, forestry, 1. Introduction Forest inventories have historically been performed for many purposes (Labau et al. 2007), including estimating merchantable timber, determining risk of fire, evaluating habitat for wildlife, and assessing biodiversity. [...]

Vital rates can provide important insights into management effects on wildlife populations. However, for many North American birds, especially woodpeckers (Picidae), vital rates are not well documented. Here, we estimated adult annual survival of the White-headed Woodpecker {Dryobates albolarvatus) across a 10 year period (2011-2021) in managed ponderosa pine (Pimts ponderosa) forests along the eastern slope of the Cascade Range in Washington. USA. We banded male and female woodpeckers with unique color band combinations and resighted them on breeding territories from March to July in each year. We banded 116 woodpeckers, most of which we aged as hatch-year (n = 49) or second-year (n = 32) when banded, and all were past the critical dependence period when mortality is highest. We estimated recapture and annual survival probabilities for 33 breeding males and 24 breeding females using open-population Cormack-Jolly-Seber models that included 2 covariates: age at first capture (AGE) and sex (SEX). We combined birds into 3 AGE classes: class 1 (hatchyear), class 2 (second-year and after hatch-year), and class 3 (> after second-year). Female recapture probabilities were higher than males, although both were >0.85. AGE class 1 birds had the lowest recapture probabilities, but the estimates were imprecise. Survival probabilities were >0.X0 for all birds, regardless of which model we evaluated. These survival estimates could be inflated because some adults that are nonbreeders and dispersed from the study area may have lower rates of survival. We did not find any evidence of differences in survival probabilities by SEX or AGE. Our results suggested that, despite managed ponderosa pine stands having trees smaller in diameter and greater in density than historical stands. Whiteheaded Woodpeckers had a high probability of surviving year to year in this forest type. Received 6 February 2022. Accepted 27 April 21)22. Key words: color bands, mark-recapture, pine stands, survival estimates. Washington. Las tasas vitales pueden provcer una vision de los efectos del mancjo en poblaciones de fauna silvestre. Sin embargo, para muchas aves de Nortcamcrica, especialmente para carpinteros (Picidae), dichas tasas vitales no cstan bien documentadas. Aqui estimamos la sobrevivencia anual del carpintero Dryobates albolanatits a lo largo de un pcriodo de 10 afios (2011-2021) en bosques manejados de pino ponderosa (Pinus ponderosa') en la vcrticnte este de la Cordillera Cascade en Washington. EUA. Anillamos machos y hembras de carpintero con combinaciones unicas de anillos dc colorcs y los re-obscrvamos en sus territories reproductivos de marzo-julio de cada afio. Anillamos 116 carpinteros. la mayoria de los cuales determinamos como del primer ano (n = 49) o del segundo ano (n = 32) al momenlo de scranillados y todos habian pasado c! pcriodo de dependencia critica cuando la mortandad es mas aita. Estimamos probabilidadcs dc recaptura y sobrevivencia anual de 33 machos y 24 hembras reproductivos usando modelos Cormack-Jolly-Seber para poblaciones abierias que incluycron 2 eovariables: cdad dc primera captura (AGE) y sexo (SEX). Combinamos cstas aves en 3 clases de AGE: clase 1 (del primer ano). clase 2 (del segundo ano y despues del segundo ano) y clasc 3 (> despues del segundo ano). Las probabilidadcs dc recaptura dc hembras fueron mas altas que las de los machos, aunquc ambas fucron >0.85. Las aves de la clase 1 de AGE tuvieron la mas baja probabilidad de recaptura. aunque estas estimaciones fueron imprecisas. Las probabilidades de sobrevivencia fucron >0.80 para todas las aves. indcpendicntcmcnte del modelo evaluado. Estas estimaciones de sobrevivencia podrian cstar infladas porque algunos adultos que son noreproductivos y se dispersaron del area de estudio podrian tencr tasas de sobrevivencia mas bajas. No encontramos evidencia de difcrencias en la probabilidad de sobrevivencia por SEX o AGE. Nuestros rcsultados sugieren que. si bien las parcelas con plantaciones de pino ponderosa bajo mancjo ticnen arboles dc diametros menores y mayorcs densidades que las parcelas historical cstos carpinteros tiencn una alta probabilidad de sobrevivencia ano con ano en cste tipo dc bosque. Palabras clave: anillos de colores. captura-recaplura. estimaciones de sobrevivencia. parcelas dc pino. Washington., Woodpeckers are keystone species in forest ecosystems because they create cavities and excavations while nesting and foraging that other species use (Blendinger 1999, Aitken and Martin 2007), help to disperse [...]

Tree-ring reconstructions of past fire activity provide context for forest management and restoration plans. Our primary objective in this study was to develop a new fire history in the Potomac Highlands of West Virginia where published reconstructions are particularly sparse, but efforts to develop prescribed fire plans are on the rise. We produced a 293-year (1727-2019) post-settlement fire history from 57 yellow pine (P. pungens, P. rigida, and P. virginiana) trees spread across five topographically diverse sites on Short Mountain in Hampshire County. The filtered composite mean fire interval was 7-15 years at individual sites, while a landscape-scale analysis indicates that fire frequency did not change over nearly 160years (1855-2011). Fires, however, were significantly less extensive during the 'exclusion era' (post-1930). No conclusive relationships between drought and fire were identified, although the most extensive fire year (1930) was uniquely dry. These findings complement existing regional fire histories and provide a new context for the application of prescribed fire in the Potomac Highlands. KEYWORDS: Fire history, Yellow pine, Dendrochronology, West Virginia, HIGHLIGHTS * The Short Mountain fire history (1727-2019) provides a record of continuous fire occurrence from early Euro-American settlement to the 21st century. * The filtered composite mean fire interval [...]

Traditionally, forest management has focused on forestry-related practices whereas other industries have been managed separately. Forest management requires the integration of all natural resource development activities, along with other anthropogenic and natural forest disturbances (e.g., climate change, pollution, wildfire, pest disturbance) to understand how human activities can change forested ecosystems. The term cumulative effects has been used to describe these attempts to integrate all disturbances to develop an understanding of past, current, and future impacts on environmental, social, and economic components of the system. In this review, we focus on the science required to understand the past, current, and future impacts of the cumulative effects of anthropogenic and natural disturbances on forested ecosystems or their components. We have primarily focused on the terrestrial system with an emphasis on northern forests in Canada. Our paper is not intended to be a comprehensive review of all cumulative effects science but a synthesis of the challenges and approaches currently being used. Central repositories were identified as an approach to deal with issues of availability of remotely sensed data on anthropogenic and natural disturbances. Data integration projects, open data, and well-designed large-scale data collection efforts are needed to provide sufficient data on environmental responses to cumulative effects. As well, large-scale integrated, modularized ecosystem models are needed to bring stressor and environmental response data together to explore responses to, and interactions between, multiple stressors to project these effects into the future and to identify future data collection needs. Key words: Cumulative effects, natural disturbance, anthropogenic disturbance, integrated natural resource management, forest management, environmental stressor. Traditionnellement, la gestion des forets s'est concentree sur les pratiques liees a la foresterie, alors que les autres industries ont ete gerees separement. La gestion des forets necessite l'integration de toutes les activites de developpement des ressources naturelles, parallelement aux autres perturbations anthropiques et naturelles des forets (par exemple, le changement climatique, la pollution, les incendies de foret, les perturbations dues aux phytoravageurs) pour comprendre comment les activites humaines peuvent modifier les ecosystemes forestiers. Le terme <>a ete utilise pour decrire ces tentatives d'integration de toutes les perturbations afin de developper une comprehension des impacts passes, presents et fiiturs sur les composantes environnementales, sociales et economiques du systeme. Dans cette synthese, les auteurs se concentrent sur la science requise pour comprendre les effets passes, actuels et futurs des effets cumulatifs des perturbations anthropiques et naturelles sur les ecosystemes forestiers ou leurs composantes. Ils se sont principalement concentres sur le systeme terrestre, en mettant l'accent sur les forets du nord du Canada. Leur document ne se veut pas un examen exhaustif de toute la science des effets cumulatifs, mais une synthese des defis et des approches actuellement utilisees. Les depots centraux ont ete identifies comme approche pour traiter les questions de disponibilite des donnees de teledetection sur les perturbations anthropiques et naturelles. Des projets d'integration des donnees, des donnees ouvertes et des efforts bien concus de collecte de donnees a grande echelle sont necessaires pour fournir suffisamment de donnees sur les reponses environnementales aux effets cumulatifs. De meme, des modeles d'ecosystemes integres et modulaires a grande echelle sont necessaires pour rassembler les donnees sur les facteurs de stress et les reponses environnementales afin d'explorer les reponses a de multiples facteurs de stress et les interactions entre eux, de projeter ces effets dans le futur et d'identifier les besoins futurs en matiere de collecte de donnees. [Traduit par la Redaction] Mots-cles : effets cumulatifs, perturbation naturelle, perturbation anthropique, gestion integree des ressources naturelles, gestion forestiere, facteur de stress environnemental., 1. Introduction 1.1. Context Forests cover more than 347 million ha of the Canadian landscape (Natural Resources Canada 2017), providing many benefits, but balancing economic, cultural, and ecological values is [...]

We celebrate the 50th anniversary of the Canadian Journal of Forest Research by reflecting on the considerable progress accomplished in select areas of Canadian wildland fire science over the past half century. Specifically, we discuss key developments and contributions in the creation of the Canadian Forest Fire Danger Rating System; the relationships between wildland fire and weather, climate, and climate change; fire ecology; operational decision support; and wildland fire management. We also discuss the evolution of wildland fire management in Banff National Park as a case study. We conclude by discussing some possible directions in future Canadian wildland fire research including the further evaluation of fire severity measurements and effects; the efficacy of fuel management treatments; climate change effects and mitigation; further refinement of models pertaining to fire risk analysis, fire behaviour, and fire weather; and the integration of forest management and ecological restoration with wildland fire risk reduction. Throughout the paper, we reference many contributions published in the Canadian Journal of Forest Research, which has been at the forefront of international wildland fire science. Key words: Banff National Park, Canadian Forest Fire Danger Rating System, fire ecology, wildland fire, wildfire. La science des incendies forestiers a connu des progres considerables au cours du dernier demi-siecle, avec des avancees dans tous les principaux domaines d'investigation. Dans cet article, nous celebrons le 50e anniversaire de la Revue canadienne de recherche forestiere en reflechissant a l'histoire de la recherche scientifique sur les incendies de foret au Canada. Nous examinons l'evolution de cette science au cours des 50 dernieres annees au Canada, notamment pour les principaux developpements et contributions dans la conception de la Methode canadienne d'evaluation des dangers d'incendie de foret, la climatologie-meteorologie des incendies, le changement climatique, l'ecologie des incendies et la gestion operationnelle des incendies. Nous presentons, a titre d'exemple, une etude de cas sur l'evolution de la gestion des incendies dans le parc national Banff. Nous concluons en discutant des orientations des recherches futures sur les incendies de foret au Canada, notamment pour ce qui est de l'evaluation future de la gravite des incendies et de leurs effets, de l'efficacite des traitements de gestion des combustibles et des effets et de l'attenuation du changement climatique, ainsi que du developpement de l'analyse des risques d'incendie de meme que des modeles de comportement des incendies. Nous constatons egalement qu'il est toujours necessaire de mieux integrer la gestion des forets et la restauration ecologique a la reduction des risques d'incendie. Tout au long de l'article, nous faisons reference aux nombreuses contributions publiees dans la Revue canadienne de recherche forestiere, qui a ete a la pointe de la science internationale en matiere d'incendies de foret. Mots-cles : parc national Banff, Methode canadienne d'evaluation des dangers d'incendie de foret, ecologie de feu, feux de forets., Introduction Wildland fire has been a persistent feature of the Canadian landscape for millennia (Richard 1993; Price et al. 2013). On average, fires have burned 1.96 Mha per year in [...]

Forest management inventories (FMIs) provide critical information, usually at the stand level, for forest management planning. A typical FMI includes (i) the delineation of the inventory area to stands by applying auxiliary information; (ii) the classification of the stands according to categorical attributes such as age, site fertility, main tree species, and stand development; and (iii) measurement, modelling, and prediction of stand attributes of interest. The emergence of wall-towall remote-sensing data has enabled a paradigm change in FMIs from highly subjective, visual assessments to objective, model-based inferences. Previously, optical remote-sensing data were used to complement visual assessments, especially in stand delineation and height measurements. The evolution of airborne laser scanning (ALS) has made objective estimation of forest characteristics with known accuracy possible. New optical and Lidar-based sensors and platforms will allow further improvements of accuracy. However, there are still bottlenecks related to species-specific stand attribute information in mixed stands and assessments of tree quality. Here, we concentrate on approaches and methods that have been applied in the Nordic countries in particular. Key words: airborne laser scanning, forest management planning, inventory by compartments, relascope, tree species. Les inventaires d'amenagement forestier (IAF) fournissent des informations essentielles, generalement a l'echelle du peuplement, pour la planification de la gestion forestiere. Un IAF typique comprend (i) la delimitation des peuplements de la zone d'inventaire a l'aide d'informations auxiliaires, (ii) la classification des peuplements en fonction d'attributs categoriques, tels que l'age, la fertilite du site, les principales essences d'arbres et le developpement du peuplement, et (iii) la mesure, la modelisation et la prediction des attributs des peuplements qui presentent un interet. L'emergence des donnees de teledetection couvrant la totalite d'un territoire a permis un changement de paradigme dans les IAF, passant d'evaluations visuelles tres subjectives a des inferences objectives fondees sur des modeles. Auparavant, les donnees optiques de teledetection etaient utilisees pour completer les evaluations visuelles, en particulier pour la delimitation des peuplements et les mesures de la hauteur. L'evolution du balayage laser aeroporte (BLA) a rendu possible l'estimation objective des caracteristiques des forets avec une precision connue. De nouveaux capteurs et plates-formes, optiques et bases sur le BLA, permettront d'ameliorer encore la precision. Cependant, des contraintes persistent quant a l'information sur les attributs des peuplements propres a chaque espece dans les peuplements mixtes et a l'evaluation de la qualite des arbres. Nous nous concentrons ici sur les approches et les methodes qui ont ete appliquees dans les pays scandinaves en particulier. [Traduit par la Redaction] Mots-cles : balayage laser aeroporte, planification de la gestion forestiere, inventaire par compartiments, relascope, essences d'arbres., Introduction The National Forest Inventory (NFI) and the forest management inventory (FMI) are the two main types of forest inventories. The main aim of the NFI is to provide sample-based [...]

Stem taper equations, which predict the change in stem form from ground to tip, have become the primary means for estimating bole volume. Stem taper equations can provide predictions with similar levels of accuracy as volume equations, but with greater flexibility, a wider range of potential uses, and consistency between taper and volume. This review is a synthesis of the current state of knowledge on stem taper equations and an assessment of challenges for future model refinement. It includes the history and evolution of stem taper model forms, which have received tremendous attention and focus over the last several decades. Additional focal areas covered are (i) the use of additional covariates beyond tree diameter at breast height (DBH) and total height; (ii) alternative statistical methods for developing stem taper equations such as parametric, semiparametric, and nonparametric approaches; (iii) key considerations for proper development, application, and use of stem taper equations such as sample size requirements, local calibration, and evaluation; and (iv) a synthesis of key findings, future opportunities, and ongoing challenges. Current and developing technologies such as terrestrial laser scanning (TLS) offer an unprecedented opportunity to measure stem form in much greater detail at significantly lower costs and time requirements than traditional methods. Overall, continued development, refinement, and application of stem taper equations will remain important given the critical nature of tree volume for science, accurate inventories, and ultimately, sustainable forest management. Key words: bole volume, stem form, forest inventory, parametric, semiparametric, nonparametric, regression. Les equations de defilement des tiges, qui predisent les changements dans la forme des tiges du sol jusqu'a l'extremite, sont devenues le principal moyen pour estimer le volume du tronc. Les equations de defilement des tiges peuvent fournir des predictions avec des niveaux de precision semblables aux equations de volume, mais avec une plus grande flexibilite, un eventail d'usages potentiels plus grand et une coherence entre le defilement et le volume. Cet article est une synthese de l'etat actuel des connaissances sur les equations de defilement et une evaluation des defis a surmonter pour raffiner les futurs modeles. Cela inclut l'historique et l'evolution des formes de modeles de defilement, qui a suscite beaucoup d'interet et recu beaucoup d'attention au cours des quelques dernieres decennies. Les zones additionnelles d'interet couvertes sont (i) l'utilisation de covariables additionnelles autres que le diametre des arbres a hauteur de poitrine (dhp) et la hauteur totale; (ii) les methodes statistiques alternatives pour elaborer des equations de defilement des tiges telles que les approches parametriques, semi-parametriques et non parametriques; (iii) les princ ipales considerations pour le developpement, l'application et l'utilisation appropries des equations de defilement des tiges telles que les exigences concernant la taille de l'echantillon, la calibration locale et l'evaluation; et (iv) une synthese des principales constatations, des opportunites futures et des defis actuels. Les technologies courantes et en voie de developpement, telles que le balayage laser terrestre, offrent des opportunites sans precedents de mesurer la forme des tiges de facon beaucoup plus detaillee a des couts significativement plus faibles et beaucoup plus rapidement que les methodes traditionnelles. Globalement, l'application, le raffinement et le developpement continu des equations de defilement des tiges vont demeurer importants etant donne le caractere crucial du volume des arbres pour la science, la precision des inventaires et ultimement l'amenagement forestier durable. [Traduit par la Redaction] Mots-cles : volume du tronc, forme de la tige, inventaire forestier, parametrique, semi-parametrique, non parametrique, regression., 1. Introduction Tree volume, particularly merchantable volume, is a primary attribute that strongly influences forest management and planning. However, tree volume is difficult to measure and assess directly because of [...]

Sustaining the structure, function, and services provided by forest ecosystems in the face of changing climate and disturbance regimes represents a grand challenge for forest managers and policy makers. To address this challenge, a range of adaptation approaches have been proposed centered on conferring ecosystem resilience and adaptive capacity; however, considerable uncertainty exists regarding how to translate these broad and often theoretical adaptation frameworks to on-the-ground practice. Complicating this issue has been movement away, in some cases, from other recent advances in forest management, namely ecological silviculture strategies that often focus on restoration. In this paper, we highlight the areas of compatibility and conflict between these two frameworks by reviewing the four principles of ecological silviculture (continuity, complexity and diversity, timing, and context) from the perspective of global change adaptation. We conclude that given many commonalities between the outcomes of ecological silviculture and conditions conferring adaptive capacity, the four principles remain a relevant starting point for guiding operationalization of often theoretical adaptation strategies. Key words: variable retention, biological legacies, variable density thinning, ecosystem complexity, emulation of natural disturbance regimes. Face aux changements climatiques et aux regimes de perturbations, le maintien de la structure, des fonctions et des services fournis par les ecosystemes forestiers represente un defi majeur pour les amenagistes forestiers et les responsables politiques. Plusieurs approches adaptatives ont ete proposees pour relever ce defi, mais elles sont toutes axees sur le renforcement de la resilience et de la capacite d'adaptation des ecosystemes. Cependant, il existe une incertitude considerable quant a la maniere de mettre en pratique ces larges cadres d'adaptation qui sont souvent theoriques. Pour compliquer ce probleme, on s'est parfois eloigne d'avancees recentes en matiere d'amenagement forestier, comme les strategies de sylviculture ecologique qui se concentrent souvent sur la restauration. Dans cet article, nous mettons en evidence les zones de compatibilite et de conflit entre ces deux cadres d'adaptation en passant en revue les quatre principes de la sylviculture ecologique (continuite, complexite et diversite, moment d'intervention, et contexte) dans une optique d'adaptation aux changements globaux. Nous concluons qu'etant donne les nombreux points communs entre les resultats de la sylviculture ecologique et les conditions qui conferent une capacite d'adaptation, les quatre principes demeurent un point de depart pertinent pour guider la mise en oeuvre de strategies d'adaptation qui sont souvent theoriques. [Traduit par la Redaction] Mots-cles : retention variable, legs biologiques, eclaircie a densite variable, complexite de l'ecosysteme, emulation des regimes de perturbations naturelles., Introduction Recent and anticipated changes in climate and disturbance regimes have magnified the challenges facing the long-term sustainability of forest habitats and ecosystem services (McDowell et al. 2020). The novelty [...]

In recent history, both a growing awareness of how scientific and societal uncertainty impacts management decisions and of the intrinsic value of nature have suggested new approaches to forest management, with a growing debate in forest science over the need for a paradigmatic shift from the classic conventional world view, based on determinism, predictability, and output-oriented management, towards a world view that has roots in complex adaptive systems theory and is consistent with a nature-based ethic. A conceptual framework under this context is provided by systemic silviculture. In this discussion, we analyze how this approach can be linked to three fundamental moments of the history of forestry and forest science: the Dauerwald theory, Gurnaud's control method, and the origins of environmental ethics. Relationships with the recent history of forest management science and current research perspectives are also highlighted. Key words: silviculture, complex adaptive systems, Dauerwald system, Gurnaud's control method, environmental ethics. Dans l'histoire recente, la facon dont l'incertitude scientifique et societale influence les decisions de gestion ainsi que la valeur intrinseque de la nature sont de plus en plus l'objet d'une prise de conscience qui ouvre la voie a de nouvelles approches en gestion forestiere. Cette situation engendre un debat qui s'intensifie en science forestiere au sujet de la necessite d'un changement de paradigme : d'une conception classique conventionnelle du monde fondee sur le determinisme, la previsibilite et la gestion axee sur la production vers une vision du monde qui a ses racines dans la theorie des systemes adaptatifs complexes et est compatible avec une ethique fondee sur la nature. Dans ce contexte, la sylviculture systemique offre un cadre de travail conceptuel. Dans ce document de reflexion, nous analysons comment cette approche peut etre reliee a trois moments fondamentaux de l'histoire de la foresterie et des sciences forestieres : le concept de la foret perenne de Dauerwald, la methode de controle de Gurnaud et les origines de l'ethique environnementale. Les relations avec l'histoire recente en science de la gestion forestiere et les perspectives courantes de recherche sont egalement mises en valeur. [Traduit par la Redaction] Mots-cles : sylviculture, systemes adaptatifs complexes, systeme de Dauerwald, la methode de controle de Gurnaud, ethique environnementale., Introduction Forests have a long history of management worldwide, which has shaped their structure and composition to answer a wide and changing range of social and economic needs, following the [...]

The United States Department of Agriculture Forest Service established three regional Institutes of Forest Genetics in the United States in the 1950s to improve trees for reforestation and improve the management of forests. The institute in Rhinelander, Wisconsin, started in 1956 as part of the Lake States Forest Experiment Station. Since that time, the 'Rhinelander Lab' has undergone changes in research priorities, organizational changes, and name changes while becoming an international center of forest scientific excellence. Many of the researchers' key findings over the years were published in the Canadian Journal of Forest Research. In this paper, for the 50th anniversary edition of the Journal, we reflect upon one part of those accomplishments: the history of the contributions of Populus L. research at Rhinelander. We discuss major research programs and the scientists conducting this work, including (i) physiology of wood formation, (ii) short rotation intensive culture and short rotation woody crops, (iii) intensively cultured plantations, (iv) physiology and utilization of short rotation poplar yields, (v) breeding and selection, (vi) biotechnology and molecular genetics, (vii) atmospheric pollution and climate change, (viii) phytotechnologies, and (ix) ecosystem services. Also, we describe four major international conferences held in Rhinelander and (or) hosted by Rhinelander researchers. Key words: Aspen FACE, bioenergy, biofuels, biomass, carbon allocation, carbon dioxide, hybrid poplar, tropospheric ozone, photosynthesis, phyto-recurrent selection, phytoremediation, poplar silviculture, water use efficiency. Dans les annees 1950, le Service des forets du departement de l'Agriculture des Etats-Unis a cree trois instituts regionaux de genetique forestiere aux Etats-Unis pour l'amelioration des arbres destines au reboisement et pour ameliorer l'amenagement des forets. L'institut situe a Rhinelander, au Wisconsin, a ete mis sur pied en 1956 en tant qu'organisme affilie au Lake States Forest Experiment Station. Depuis ce temps, le laboratoire de Rhinelander a connu des changements dans ses priorites de recherche, des changements organisationnels et des changements de nom tout en devenant un centre international d'excellence scientifique en foresterie. Au cours des annees plusieurs resultats cles des chercheurs ont ete publies dans la Revue canadienne de recherche forestiere. A l'occasion du 50e anniversaire de publication de la Revue, nous nous penchons dans cet article sur une facette de ces accomplissements : l'histoire des contributions a la recherche sur Populus L. a Rhinelander. Nous traitons des principaux programmes de recherche et des scientifiques qui effectuent ce travail, incluant : (i) la physiologie de la formation du bois, (ii) la culture intensive a courte rotation et la ligniculture a rotation courte, (iii) les plantations en culture intensive, (iv) la physiologie et l'utilisation de la production de peuplier a courte rotation, (v) la reproduction et la selection, (vi) la biotechnologie et la genetique moleculaire, (vii) la pollution atmospherique et le changement climatique, (viii) les phytotechnologies, et (ix) les services de l'ecosysteme. De plus, nous decrivons quatre conferences internationales majeures tenues a Rhinelander et organisees par les chercheurs de Rhinelander. [Traduit par la Redaction] Mots-cles : systeme experimental d'enrichissement en dioxyde de carbone a l'air libre, bioenergie, biocarburant, biomasse, allocation du carbone, dioxyde de carbone, peuplier hybride, ozone tropospherique, photosynthese, selection phytorecurrente, phytoremediation, sylviculture du peuplier, efficacite de l'utilisation de l'eau., Introduction At the end of the 19th century and beginning of the 20th century, the forests of the northern Lake States of the United States were heavily logged for lumber [...]

Coarse woody debris (CWD) in the form of logs, downed wood, stumps and large tree limbs is an important structural habitat feature for many small mammal species, including the American marten (Martes americana). At a long-term experimental trial in northern temperate hemlock-cedar forests of British Columbia, Canada, we analysed the impact of varying amounts of overstory basal area retention: 0% (clearcut), 40%, 70%, and 100% (unharvested) on CWD volume, decay class, and inputs from windthrow over 27 years. We used CWD attributes (diameter, length, decay class, and height above the ground) known to be favourable for martens to create an index for assessing the impact of harvesting intensity on CWD habitat features. Stands with 70% retention had CWD attributes that resulted in CWD habitat features similar to unharvested stands. Clearcuts contained pieces that were smaller, more decayed, and closer to the ground, which contributed to a habitat that was less valuable, compared with stands that had higher retention. Over the 27-year period, windthrown trees were the majority of CWD inputs, and volume change was positively related to percent retention. Our results highlight that forest management influences CWD size and input dynamics over multiple decades, and the need for consideration of these impacts when undertaking long-term multiple-use forestry planning. Key words: coarse woody debris, partial cutting, mustelids, American marten habitat, retention forestry, windthrow. Les debris ligneux grossier (DLG) sous forme de billes, de bois au sol, de souches et de grosses branches d'arbre constituent une importante caracteristique structurale de l'habitat de plusieurs petits mammiferes, incluant la marte d'Amerique (Martes americana). Dans le cadre d'un essai experimental a long terme dans des forets temperees nordiques de pruche et de thuya de la Colombie-Britannique, au Canada, nous avons analyse l'impact de la retention de differents niveaux de surface terriere : 0 (absence de recolte), 40,70 et 100 % (coupe rase) sur le volume, la classe de decomposition et les apports de DLG provenant des chablis sur une periode de 27 ans. Nous avons utilise les attributs (diametre, longueur, classe de decomposition et hauteur au-dessus du sol des DLG) censes etre favorables a la marte pour creer un indice permettant d'evaluer l'impact de l'intensite de la coupe sur les caracteristiques de l'habitat de DLG. Les peuplements avec 70 % de retention avaient des DLG dont les attributs correspondaient aux caracteristiques de l'habitat de DLG similaires a ce qu'on observe dans les peuplements non recoltes. Les coupes rases contenaient des pieces plus petites, plus decomposees et situees plus pres du sol qui constituaient un habitat moins interessant comparativement aux peuplements oU le taux de retention etait plus eleve. Durant la periode de 27 ans, la majorite des apports de DLG sont venus des arbres renverses par le vent et le changement de volume etait positivement relie au taux de retention. Nos resultats mettent en evidence l'influence de l'amenagement forestier sur la taille et la dynamique d'apport des DLG au cours de multiples decennies et le besoin de tenir compte de ces impacts lorsqu'on entreprend la planification a long terme de l'amenagement forestier polyvalent. [Traduit par la Redaction] Mots-cles: debris ligneux grossier, coupe partielle, mustelides, habitat de la marte d'Amerique, foresterie avec retention, chablis., Introduction Coarse woody debris (CWD) is an important component of many forest ecosystem functions (Harmon et al. 1986), and there is increasing recognition that CWD dynamics need to be considered [...]

Postfire salvage logging is used to reduce economic losses; however, burned trees are rapidly colonized by wood-boring insects, which reduce the merchantable value of the wood. This study aims to predict wood borer (Monochamus Megerle in Dejean, 1821) attacks after wildfire as a function of rapidly available variables such as tree basal area, stem diameter, and burn severity using the differenced normalized burn ratio (dNBR). In 2011, we sampled 60 black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) or jack pine (Pinus banksiana Lamb.) plots in five burns from 2010 in the Haute-Mauricie region of Quebec, Canada. A 50 cm bole section was debarked on seven trees in each plot to estimate wood borer attack density. Wood borer attacks were more abundant in black spruce than in jack pine. As a continuous variable, dNBR unveiled a quadratic effect of burn severity on attack density in black spruce, which was higher at moderate burn severity. In jack pine, the highest levels of attack density were found at high burn severity. Models produced in this article will help forest managers to better prioritize areas for salvage logging and thus reduce economic losses due to wood borer activity. Key words: Monochamus, wildfire, salvage logging, wormhole, boreal forest. La coupe de recuperation est utilisee pour reduire les pertes economiques apres un feu de foret. Cependant, les arbres brules sont rapidement colonises par des insectes xylophages, ce qui reduit la valeur marchande du bois. L'objectif de cette etude consistait a predire la densite des attaques de xylophages (Monochamus Megerle dans Dejean, 1821) apres feu, en fonction de variables rapidement disponibles, soit la surface terriere par essence, le diametre de la tige et la severite du feu, a l'aide du << differenced normalized burn ratio (dNBR) >>. En 2011, nous avons echantillonne 60 sites d'epinette noire (Picea mariana (Mill.) Britton, Sterns et Poggenb.) et de pin gris (Pinus banksiana Lamb.) dans cinq brulis de 2010, en Haute-Mauricie au Quebec, Canada. Sur sept arbres par site, une section de tronc de 50 cm fut ecorcee afin d'estimer la densite des attaques de xylophages. Les attaques de xylophages etaient plus abondantes sur l'epinette noire que sur le pin gris. L'utilisation du dNBR en tant que variable continue a revele un effet quadratique de la severite du feu sur la densite des attaques sur l'epinette noire, qui etait plus elevee apres un feu de severite moderee. Dans le pin gris, la densite maximale des attaques de xylophages etait associee a un feu de severite elevee. Les modeles produits dans cet article aideront les amenagistes forestiers a mieux prioriser les secteurs pour des coupes de recuperation et ainsi reduire les pertes economiques dues aux activites des insectes xylophages. Mots-cles: Monochamus, feu de foret, coupe de recuperation, trous de vers, foret boreale., Introduction Large wildfires generate tremendous numbers of dead trees, which are increasingly salvaged to reduce economic losses resulting from this natural disturbance (Lindenmayer et al. 2008). However, most postfire stands [...]

Recent interest in continuous cover forest management of longleaf pine (Pinus palustris Mill.) ecosystems raises questions of long-term sustainability because of uncertainty in rates of canopy recruitment of longleaf pine trees. We destructively sampled 130 naturally regenerated, midstory longleaf pines across an 11300 ha, second-growth longleaf pine landscape in southwestern Georgia, United States, to reconstruct individual tree height growth patterns. We tested effects of stand density (using a competition index) and site quality (based on two site classifications: mesic and xeric) on height growth and demographics of midstory trees. We also compared height growth of paired midstory and overstory trees to infer stand regeneration and recruitment dynamics. In low-density stands, midstory trees were younger and grew at greater rates than trees within high-density stands. Midstory trees in low-density stands were mostly from a younger regeneration cohort than their paired overstory trees, whereas midstory-overstory pairs in high-density stands were mostly of the same cohort. Our results highlight the importance of releasing midstory longleaf pine trees from local competition for sustained height growth in partialharvesting management systems. They also demonstrate patterns of long-term persistence in high-density stands, indicating flexibility in the canopy recruitment process of this shade-intolerant tree species. Key words: canopy recruitment, Pinus palustris, stem analysis, suppression, uneven-aged silviculture. L'interet recent pour l'amenagement forestier a couvert permanent des ecosystemes de pin des marais (Pinus palustris Mill.) souleve des questions sur sa durabilite a long terme en raison de l'incertitude du taux de recrutement du pin des marais dans le couvert dominant. Nous avons echantillonne de maniere destructive 130 pins des marais regeneres naturellement et situes dans l'etage intermediaire d'un paysage de seconde venue de 11300 ha domine par le pin des marais dans le sud- ouest de la Georgie, aux Etats-Unis, pour reconstituer le patron de croissance en hauteur des arbres individuels. Nous avons teste les effets de la densite du peuplement (a l'aide d'un indice de competition) et de la qualite de la station (en tenant compte de deux classes de station : mesique et xerique) sur la croissance en hauteur et la demographie des arbres de l'etage intermediaire. Nous avons aussi compare la croissance en hauteur de paires d'arbres provenant des etages superieur et intermediaire pour deduire les dynamiques de regeneration et de recrutement des peuplements. Dans les peuplements a faible densite, les arbres de l'etage intermediaire etaient plus jeunes et croissaient plus rapidement que les arbres des peuplements a forte densite. Les arbres de l'etage intermediaire dans les peuplements a faible densite provenaient principalement d'une cohorte de regeneration plus jeune que leurs homologues de l'etage dominant, alors que les arbres apparies des etages superieur et intermediaire des peuplements a forte densite appartenaient generalement a la meme cohorte. Nos resultats soulignent l'importance de degager les pins des marais de l'etage intermediaire de la competition immediate pour obtenir une croissance en hauteur soutenue dans les systemes d'amenagement utilisant des coupes partielles. Ils demontrent aussi une persistance a long terme du pin des marais dans les peuplements a forte densite, ce qui fait ressortir la flexibilite du processus de recrutement du couvert dominant de cette espece arboree intolerante a l'ombre. [Traduit par la Redaction] Mots-cles: recrutement du couvert dominant, Pinus palustris, analyse de tige, oppression, sylviculture inequienne., Introduction Temporal patterns of forest stand development have been widely studied, and several variants in the classification of patterns of forest dynamics have been developed (e.g., Bormann and Likens 1979; [...]

We studied how different thinning regimes and initial age structures of a Norway spruce (Picea abies (L.) Karst.) forest landscape affect the radiative forcing of forest biomass production and use. We considered the effects of forest carbon sequestration, substitution of materials and fossil fuels with forest biomass, and timber use efficiency. The initial age structures of our hypothetical forest landscapes in the middle boreal zone in Finland were young, middle-aged, and mature. Forest landscapes were thinned using either the current thinning recommendations (baseline) or maintaining 20% higher or 20% lower stocking over the 80-year study period. We employed forest ecosystem model simulations together with a life cycle assessment tool. The highest carbon sequestration was obtained by maintaining higher stocking in the landscapes. The initially middle-aged and mature age structures resulted in the strongest cooling of the climate in the first three decades of the simulation, but the highest cooling was found in the young age structure. However, radiative forcing was less sensitive to the thinning than to the substitution or timber use efficiency. Our results indicate that modeled climate impacts are affected by both initial age structure and forest management, which should be considered when generalizing the climate change mitigation potential of forests and forestry. Key words: climate cooling impact, displacement factor, forest landscape, initial age structure, mitigation efficiency, radiative forcing. Nous avons etudie comment differents regimes d'eclaircie et differentes structures d'age initiales d'un paysage forestier domine par l'epicea commun (Picea abies (L.) Karst.) influencent le forcage radiatif de la production et de l'utilisation de la biomasse forestiere. Nous avons examine les effets de la sequestration du carbone forestier, de la substitution des materiaux et des combustibles fossiles par la biomasse forestiere, et de l'efficacite d'utilisation du bois de construction. La structure d'age initiale de nos paysages forestiers hypothetiques du milieu de la zone boreale finlandaise etait jeune, moyenne ou mature. Les paysages forestiers ont ete eclaircis en utilisant les recommandations d'eclaircie en vigueur (scenario de reference), ou en faisant varier de plus ou moins 20% la surface terriere de reference avec un horizon de simulation de 80 ans. Nous avons utilise les simulations d'un modele d'ecosysteme forestier conjointement a un outil devaluation du cycle de vie. La plus forte sequestration du carbone a ete obtenue en maintenant une surface terriere plus elevee dans les paysages. Les structures d'age initiales moyenne et mature ont produit le plus grand refroidissement du climat au cours des 30 premieres annees de la simulation, mais le refroidissement le plus eleve a ete observe dans la structure d'age jeune. Cependant, le forcage radiatif etait moins sensible a l'eclaircie qu'a la substitution ou qu'a l'efficacite d'utilisation du bois de construction. Nos resultats indiquent que les impacts climatiques modelises sont influences par la structure d'age initiale et l'amenagement forestier qui devraient donc etre pris en compte pour generaliser le potentiel d'attenuation des changements climatiques par les forets et les activites forestieres. [Traduit par la Redaction] Mots-cles : impact du refroidissement climatique, facteur de deplacement, paysage forestier, structure d'age initiale, efficacite d'attenuation, forcage radiatif., 1. Introduction Using harvested wood products (HWPs) and the energy in the biomass from sustainably managed forests has great potential in terms of long-term climate change mitigation (Lundmark et al. [...]

This study analyzes the effects of adopting an adaptive harvest strategy in even-aged forest management under timber price uncertainty on the production of nontimber goods. We use the reservation price strategy ('harvest when the observed timber prices are higher than the reservation prices') on a longleaf pine (Pinus palustris Mill.) stand and employ the Faustmann-Hartman model as a benchmark. We assume that a longleaf pine stand can be managed for timber production, water production, carbon sequestration, and pine straw raking, depending on the planting density. Our results indicate that the reservation price strategy leads to longer expected harvest age when planting density is high. The reservation price strategy does not lead to increases in water production and carbon sequestration with low planting density. With high planting density, the reservation price strategy leads to increases in the amount of in situ carbon sequestered by 14.4-24.7 Mg * [ha.sup.-1]. Our findings suggest that managing longleaf pine forests in good- or poor-quality sites is a profitable alternative and enables water production and carbon sequestration. Key words: reservation price strategy, price uncertainty, nontimber benefits, Faustmann-Hartman, land expectation values. Cette etude s'interesse aux effets sur la production de produits forestiers non ligneux qu'engendre l'adoption d'une strategie de recolte adaptative dans la gestion de forets equiennes en situation d'incertitude des prix du bois. Nous utilisons la strategie du prix de reserve (recolter lorsque les prix observes sont plus eleves que les prix de reserve) dans un peuplement de pin des marais (Pinuspalustris Mill.) et nous employons le modele de Faustmann-Hartman a titre de reference. Nous supposons qu'un tel peuplement peut etre amenage pour la production de matiere ligneuse, la production d'eau, la sequestration de carbone et pour le ratissage des aiguilles, selon la densite de la plantation. Nos resultats demontrent que la strategie du prix de reserve retarde l'age de la recolte lorsque la densite de la plantation est elevee. La strategie du prix de reserve n'accroit pas la production d'eau ni la sequestration de carbone dans les plantations de faible densite. Dans les plantations plus denses, la strategie du prix de reserve entraine des augmentations de la quantite de carbone sequestre in situ de 14,4 a 24,7 Mg * [ha.sup.-1]. Nos resultats indiquent que la gestion des forets de pin des marais dans les sites de bonne ou de mauvaise qualite est une alternative rentable et permet de produire de l'eau et de sequestrer du carbone. Mots-cles: strategie du prix de reserve, incertitude des prix, benefices des produits non ligneux, Faustmann- Hartman, valeur actualisee des terres., Introduction The Faustmann formula (1849) has long been the main framework to model the optimal forest rotation by maximizing the land value of an even-aged stand for timber production. More [...]

In southeast Alaska, United States, multiple-use forest management objectives include both timber production and wildlife habitat. Following stand-replacing disturbances such as clear-cutting, Sitka spruce (Picea sitchensis (Bong.) Carriere) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) naturally regenerate and competitively dominate resources, excluding understory biomass and biodiversity. Thinning may mitigate the effects of canopy closure and permit understory development, but evidence of the effect on understories 8-10 years after thinning is lacking. We report results 4-5 and 8-10 years after thinning experiments on the Tongass National Forest to demonstrate the effects of precommercial thinning (thinned versus control), stand age (15-25, 25-35, and 35-50 years), and weather on understory dynamics and Sitka black-tailed deer (Odocoileus hemionus sitkensis Merriam, 1898) forage availability. Stand density negatively affected understory biomass, whereas temperature and precipitation positively interacted to increase biomass. Thinning had an enduring effect on understories, with biomass at least twice as great in thinned versus unthinned stands through year 10. We identified compositional differences from thinning as stand age class increased. Deer forage responded similarly to biomass, but thinning-induced differences faded with increased winter snowfall scenarios, especially in older stands. This study aids the understanding of stand overstory and understory development following silvicultural treatments in the coastal temperate rain forest of Alaska and suggests management implications and applications for balancing objectives throughout the forest type. Key words: Tongass-Wide Young-Growth Studies, Sitka spruce (Picea sitchensis), western hemlock (Tsuga heterophylla), FRESH-deer model, understory diversity. Dans le sud-est de l'Alaska, aux Etats-Unis, les objectifs de l'amenagement forestier polyvalent incluent a la fois la production de matiere ligneuse et l'habitat faunique. A la suite d'une perturbation majeure, telle la coupe rase, l'epinette de Sitka (Picea sitchensis (Bong.) Carriere) et la pruche de l'Ouest (Tsuga heterophylla (Raf.) Sarg.) se regenerent naturellement et dominent les ressources de facon competitive, excluant la biodiversite et la biomasse du sous-bois. L'eclaircie peut attenuer les effets de la fermeture du couvert et permettre le developpement du sous-bois, mais nous n'avons pas d'indices que l'effet de l'eclaircie puisse s'etendre sur 8-10 ans. Nous presentons les resultats d'eclaircies experimentales apres 4-5 ans et 8-10 ans dans la foret nationale de Tongass pour illustrer les effets de l'eclaircie precommerciale (eclaircie versus temoins), de l'age du peuplement (15-25, 25-35 et 35-50 ans), ainsi que des conditions meteorologiques sur la dynamique du sous-bois et la disponibilite de nourriture pour le cerf de Sitka (Odocoileus hemionus sitkensis Merriam, 1898). La densite du peuplement affectait negativement la biomasse du sous-bois tandis que la temperature et la precipitation interagissaient pour augmenter la biomasse. L'eclaircie a eu un effet durable sur le sous-bois : jusqu'a l'age de 10 ans il y avait deux fois plus de biomasse dans les peuplements eclaircis que dans les peuplements non eclaircis. Nous avons identifie des differences de composition a la suite d'une eclaircie a mesure que la classe d'age du peuplement augmentait. La nourriture du cerf de Sitka reagissait comme la biomasse mais les differences causees par l'eclaircie s'estompaient avec les scenarios d'augmentation des chutes de neige durant l'hiver, particulierement dans les peuplements plus vieux. Cette etude aide a comprendre le developpement de l'etage dominant et du sous-bois a la suite de traitements sylvicoles dans la foret pluvieuse temperee cotiere de l'Alaska et a des repercussions sur l'amenagement et des applications pour equilibrer les objectifs a travers les types de foret. [Traduit par la Redaction] Mots-cles : etudes portant sur la repousse de seconde venue dans la foret de Tongass, epinette de Sitka (Picea sitchensis), pruche de l'Ouest (Tsuga heterophylla), systeme d'evaluation des ressources alimentaires dans l'habitat du cerf--un modele interactif, diversite du sous-bois., Introduction The temperate rain forest of the Pacific Northwest in North America stretches from southcentral Alaska through to British Columbia and as far south as northern California. Cool, wet maritime [...]

Forest management generates border effects in mature dense forests. How agaricoid fungi species react to this disturbance depends on climatic and site conditions, as well as forest management system used and its intensity. We compared abundance and richness of ectomycorrhizal and saprophytic species in managed and unmanaged stands in Nothofagus pumilio (Poepp. & Endl.) Krasser forests of Patagonia, Argentina. We found that basidiome abundance and richness of ectomycorrhizal and saprophytic species were favoured by different forest structure and climatic factors. Ectomycorrhizal species basidiome production was significantly correlated to mean relative humidity of the 15 days prior to sampling and tree density (number of trees per hectare) existing prior to management activities. The latter implies that the tree density an ecosystem is capable of sustaining is crucial to the establishment of ectomycorrhizal species. Saprophytic species were favoured by the increased amount of woody material generated by logging together with maximum temperature in the 15 days prior to sampling and mean annual precipitation. Our results indicate that agaricoid fungi are not affected by low- to medium-intensity forest management, establishing the forestry level that fungal community can tolerate without loss of species in Patagonia. Key words: forest use, Agaricomycetes, Nothofagus pumilio, Patagonia, ecology. L'amenagement forestier genere des effets de bordure dans les forets denses a maturite. La facon dont reagissent les especes de champignons agarices a cette perturbation depend des conditions climatiques et stationnelles ainsi que du systeme d'amenagement forestier et de son intensite. Nous avons compare l'abondance et la richesse des especes ectomycorhiziennes et saprophytiques dans des peuplements amenages ou non dans des forets de Nothofagus pumilio (Poepp. & Endl.) Krasser de la Patagonie en Argentine. Nous avons trouve que divers facteurs climatiques et structures forestieres favorisent l'abondance et la richesse des basidiomes des especes ectomycorhiziennes et saprophytiques. La production de basidiomes d'especes ectomycorhiziennes etait significativement correlee a l'humidite relative moyenne durant les 15 jours precedant l'echantillonnage et au densite d'arbres (nombre d'arbres a l'hectare) presents anterieurement aux interventions d'amenagement. Cela implique que le densite d'arbres qu'un ecosysteme peut supporter est crucial pour l'etablissement des especes ectomycorhiziennes. Les especes saprophytiques etaient favorisees par la quantite accrue de materiau ligneux generes par l'exploitation forestiere ainsi que par la temperature maximum durant les 15 jours precedant l'echantillonnage et les precipitations annuelles moyennes. Nos resultats indiquent qu'un amenagement forestier de faible a moyenne intensite n'affecte pas les champignons agarices, ce qui determine le niveau d'activites forestieres que les communautes fongiques peuvent tolerer sans perte d'especes en Patagonie. [Traduit par la Redaction] Mots-cles : utilisation de la foret, Agaricomycetes, Nothofagus pumilio, Patagonie, ecologie., Introduction Nothofagus pumilio (Poepp. & Endl.) Krasser, locally known as lenga, is the dominant species found at the timberline and the most economically exploited species in Patagonia (Hueck 1978). Different [...]

In forest management planning, errors in predicted stand attributes might lead to suboptimal decisions that result in decreased net present value (NPV). Forest inventory data will have higher value if the amount of suboptimal decisions can be decreased. Therefore, the value of information can be measured through the decrease in inoptimality losses, which are the NPV differences between the optimal and suboptimal decisions. In this study, four alternative sample plot selection strategies with different numbers of sample plots were compared in terms of expected mean inoptimality losses. Stand-level mean inoptimality losses varied between 41.1 x [ha.sup.-1] [euro] and 80.7 x [ha.sup.-1] [euro], depending on the sample plot selection strategy and the number of sample plots used as training data in the k-nearest neighbors imputation method. Mean inoptimality losses decreased substantially when the number of sample plots increased from 25 to 100, and the decreasing trend continued until 500 sample plots. Total inoptimality losses can decrease by approximately 1 million [euro] in an inventory area of 100 000 ha when the number of sample plots is increased from 100 to 500. The measurement of more sample plots can be justified as long as the field measurement costs do not exceed the decrease in inoptimality losses. Key words: forest inventory, forest management planning, inoptimality loss, value of information, cost-plus-loss analysis. Lors de la planification de l'amenagement forestier, des erreurs dans les predictions des attributs de peuplement pourraient conduire a des decisions sous-optimales, entrainant une diminution de la valeur actuelle nette (VAN). Les donnees d'inventaire forestier auront une plus grande valeur si elles servent a diminuer le nombre de decisions sous-optimales. Par consequent, la valeur de l'information peut etre mesuree par la diminution des pertes dues a la sous-optimalite, qui correspondent a la difference de VAN entre les decisions optimales et sous-optimales. Dans cette etude, quatre strategies differentes de selection des placettes d'echantillonnage, avec differents nombres de placettes d'echantillonnage, ont ete comparees en termes de moyennes attendues des pertes dues a la sous-optimalite. Les pertes moyennes dues a la sous-optimalite a l'echelle du peuplement ont varie entre 41,1 [euro] et 80,7 [euro] par hectare, en fonction de la strategie de selection des placettes d'echantillonnage et du nombre de celles-ci utilisees comme donnees d'apprentissage dans la methode d'imputation des k-plus proches voisins. Les pertes moyennes dues a la sous-optimalite ont sensiblement diminue lorsque le nombre de placettes d'echantillonnage est passe de 25 a 100, et la tendance a la baisse s'est poursuivie jusqu'a 500 placettes d'echantillonnage. Les pertes totales dues a la sous-optimalite peuvent diminuer d'environ 1 million [euro] dans une zone d'inventaire de 100 000 ha lorsque le nombre de placettes d'echantillonnage augmente de 100 a 500. La mesure d'un plus grand nombre de placettes d'echantillonnage peut etre justifiee a condition que les couts de mesure sur le terrain ne depassent pas la diminution des pertes par sous-optimalite. [Traduit par la Redaction] Mots-cles: inventaire forestier, planification de l'amenagement forestier, perte due a la sous-optimalite, valeur de l'information, analyse combinee de cout plus perte., 1. Introduction Forest inventories based on airborne laser scanning (ALS) usually consist of data acquisition, model-building, and accuracy assessment with training data, the prediction of stand attributes in a wall-to-wall [...]

Additions of fire residues in the form of charcoal and wood ash may better emulate natural disturbance processes in managed boreal forests. We examined the effects of a poplar (Populus) wood biochar and a high-carbon wood ash on soil and vegetation in a 3-year experiment in northwestern Ontario, Canada. Both soil amendments increased soil pH and soil Ca levels; high-carbon wood ash also increased soil Cu, Zn, B, S, and Pb. Amendments had large effects on plant community composition, favoring a subset of ruderal species including raspberry (Rubus idaeus L.) and goldenrod (Solidago canadensis L.). The addition of high-carbon wood ash resulted in declines in growth of planted white spruce (Picea glauca (Moench) Voss); a path analysis suggests that this was due to the effects of toxic elements rather than the indirect effects of competition. We conclude that high-carbon wood ash, while qualifying as a type of biochar and having some beneficial effects on soil properties, can enhance toxic metals in boreal forest soils, with negative consequences to early tree growth. Differences in plant species responses to biochars and the potential for toxicity effects and indirect effects mediated by plant competition will require screening and field trials of potential biochars prior to their use in operational forestry and forest restoration. Key words: charcoal, heavy metals, natural disturbance emulation, vegetation, competition. L'ajout de residus de feu sous forme de charbon et de cendre de bois pourrait mieux imiter les processus de perturbation naturelle dans les forets boreales amenagees. Nous avons etudie les effets d'un biocharbon de peuplier (Populus) et d'une cendre de bois a haute teneur en carbone sur le sol et la vegetation pendant trois ans au cours d'une experience dans le nord-ouest de l'Ontario, au Canada. Les deux amendements ont augmente les niveaux de pH et de Ca du sol alors que les cendres de bois a haute teneur en carbone ont aussi augmente la teneur en Cu, Zn, B, S et Pb du sol. Les amendements ont eu des effets importants sur la composition de la communaute vegetale en favorisant un sous-ensemble d'especes ruderales comprenant le framboisier (Rubus idaeus L.) et la verge d'or du Canada (Solidago canadensis L.). L'ajout de cendre de bois a haute teneur en carbone a entraine un ralentissement de la croissance de plants d'epinette blanche (Picea glauca (Moench) Voss). Une analyse des pistes causales indique que ce resultat est attribuable aux effets d'elements toxiques plutot qu'aux effets indirects de la competition. Bien que la cendre de bois a haute teneur en carbone soit consideree comme un type de biocharbon ayant des effets benefiques sur les proprietes du sol, nous concluons qu'elle peut augmenter la teneur en metaux toxiques dans les sols de la foret boreale, ce qui a des consequences negatives sur la croissance des jeunes arbres. Les differences de reactions aux biocharbons selon l'espece de plante, les effets toxiques potentiels associes a leur ajout et les effets indirects induits par la competition entre les plantes necessitent d'effectuer un depistage et des essais sur le terrain des biocharbons potentiels avant de les utiliser de facon operationnelle en foresterie et pour la restauration des forets. [Traduit par la Redaction] Mots-cles: charbon, metaux lourds, imitation de perturbations naturelles, vegetation, competition., Introduction Wildfire is the primary disturbance factor in the boreal forest and a main determinant of ecosystem structure and function. The absence of wildfire due to human-induced fire suppression results [...]

Diameter distributions and tree-lists provide information about forest stocks disaggregated by size and species and are key for informing forest management. Diameter distributions and tree-lists are multivariate responses, which makes the evaluation of methods for their prediction reliant on the use of dissimilarity metrics to summarize differences between observations and predictions. We compared four strategies for selection of k nearest neighbors (k-NN) methods to predict diameter distributions and tree-lists using LiDAR and stand-level auxiliary data and analyzed the effect of the k-NN distance and number of neighbors in the performance of the predictions. Strategies differed by the dissimilarity metric used to search for optimal k-NN configurations and the presence or absence of post-stratification. We also analyzed how alternative k-NN configurations ranked when tree-lists were aggregated using different DBH classes and species groupings. For all dissimilarity metrics, k-NN configurations using random-forest distance and three or more neighbors provided the best results. Rankings of k-NN configurations based on different dissimilarity metrics were relatively insensitive to changes on the width of the DBH classes and the definition of the species groups. The selection of the k-NN methods was clearly dependent on the choice of the dissimilarity metric. Further research is needed to find suitable ways to define dissimilarity metrics that reflect how forest managers evaluate differences between predicted and observed tree-lists and diameter distributions. Key words: tree-lists, diameter distributions, k-NN, Reynolds index, LiDAR. Les distributions de diametre et les listes d'arbres fournissent des informations sur les stocks forestiers, ventilees par taille et par espece, et sont des informations de gestion forestiere essentielles. Les distributions de diametre et les listes d'arbres sont influencees par plusieurs variables, par consequent l'evaluation des methodes servant a les predire depend de l'utilisation de mesures de dissimilarite pour exprimer les differences entre les observations et leurs predictions. Nous avons compare quatre strategies de selection des k plus proches voisins (k-NN) pour predire les distributions de diametre et les listes d'arbres a l'aide de donnees auxiliaires LiDAR et de peuplement. Nous avons egalement analyse les effets de la distance k-NN et du nombre de voisins sur la qualite des predictions. Les strategies differaient par la mesure de dissimilarite utilisee pour obtenir les configurations k-NN optimales et par l'utilisation, ou non, de la post-stratification. Nous avons egalement analyse le classement des differentes configurations de k-NN lorsque les listes d'arbres etaient agregees selon differentes classes de diametre et groupes d'especes. Pour toutes les mesures de dissimilarite, les configurations k-NN utilisant une distance fondee sur les forets d'arbres decisionnels et trois voisins ou plus ont donne les meilleurs resultats. Les classements des configurations k-NN fondees sur differentes mesures de dissimilarite etaient relativement insensibles aux modifications de : l'etendue des classes de diametre et la definition des groupes d'especes. Le choix des methodes k-NN dependait clairement du choix de la mesure de dissimilarite. Des recherches supplementaires sont necessaires pour trouver des moyens appropries de definir des mesures de dissimilarite qui refletent l'evaluation que font les amenagistes forestiers des differences entre les listes d'arbres et les distributions de diametre predites et observees. [Traduit par la Redaction] Mots-cles: liste d'arbres, distribution de diametre, k-NN, indice de Reynolds, LiDAR., 1. Introduction To make informed decisions, forest managers require information about the current state of the forest. Knowledge of the total stand volume or basal area is not enough for [...]

The resilience of resource-based communities facing natural disturbances partly depends on the capacity of a wide diversity of stakeholders to share their expertise, articulate their efforts, and develop solutions that are both effective and equitable. Structural methods from network theory can be used to measure how efficiently and thoroughly collaborations happen among stakeholders and to identify ways to improve information flow. We applied network theory to represent and analyse the collaborations between individuals dealing with a significant mountain pine beetle outbreak in the Jasper- Hinton area of Alberta, Canada. For this, we interviewed and collected relational information from 90 respondents officiating in the area. Our results show unbalanced collaboration patterns among federal, provincial, and municipal institutions, as well as the forestry sector and research institutions, leading to clusters and, as a consequence, to gaps in the flow of information that are only partially bridged by a few actors. Such siloing of information is a key barrier to sustainability in natural resource management that may be addressed more transparently using network theory. Key words: network analysis, mountain pine beetle, stakeholder networks, social-ecological systems, resilience. La resilience des communautes qui dependent des ressources face aux perturbations naturelles depend de la capacite d'une grande diversite d'intervenants de partager leur expertise, d'articuler leurs efforts et d'elaborer des solutions efficaces et equitables. Les methodes structurelles qui decoulent de la theorie des reseaux peuvent etre utilisees pour mesurer a quel point les collaborations entre intervenants sont efficaces et completes et pour identifier les facons d'ameliorer la circulation de l'information. Nous avons applique la theorie des reseaux pour representer et analyser les collaborations entre les individus aux prises avec une importante epidemie de dendroctone du pin ponderosa dans les regions de Jasper et Hinton en Alberta, au Canada. A cette fin, nous avons interroge 90 repondants travaillant dans la region et collecte des informations relationnelles a leur sujet. Nos resultats montrent des schemas de collaboration desequilibres parmi les institutions federales, provinciales, municipales, ainsi que les institutions du secteur forestier et de celui de la recherche, engendrant des regroupements et, par consequent, des lacunes dans la circulation de l'information qui sont seulement partiellement comblees par quelques acteurs. Un tel compartimentage de l'information constitue un obstacle important pour l'amenagement durable des ressources naturelles qui peut etre aborde de facon plus transparente en utilisant la theorie des reseaux. [Traduit par la Redaction] Mots-cles: analyse de reseau, dendroctone du pin ponderosa, reseaux d'interesses, systemes socio-ecologiques, resilience., Introduction The resilience of resource-based communities facing a natural disturbance such as a mountain pine beetle (MPB) outbreak depends on many factors. One of them is the capacity of a [...]

A gaharu (Agarwood) nursery programme in Central Kalimantan, Indonesia, failed mainly because the multiple ecologies of members of an environmental organization and indigenous people conflicted. The former believed that the trees that produced gaharu should be protected for their role in storing carbon emissions, and that the nursery programme should provide a 'cultivated' income opportunity. In contrast, for Punan Murung, searching for and trading in heartwood embedded with resin offers the possibility of economic gain and of autonomy, while also serving as a marker for an indigenous semi-nomadic identity. Consideration of the varied relationships of actors with the environment, as these relations are intertwined with multifocal power structures, can further understanding of failures in participatory forest management programmes. Keywords: Indonesia, Kalimantan, gaharu, political ecology, ontology, conservation, development, participatory forest management., Gaharu is the dense, dark, aromatic, heartwood embedded with resin produced by evergreen tropical forest trees--in Indonesia the genera Aquilaria and Gyrinops--when their wood becomes infected with a certain kind [...]