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Biotic disturbance agents are important factors influencing forest dynamics; incorporating them into management planning requires a detailed understanding of their distribution, prevalence, and effects on stand dynamics. However, this information can be difficult to collect in remote forest systems, such as lowland black spruce (Picea mariana (Mill.) B.S.P.) forests affected by eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck, hereafter ESDM). In such cases, predictive modeling is often needed to inform management decisions and address forest health questions. Here, we used two publicly available datasets to predict areas where black spruce is more likely to be infested with ESDM in northeastern Minnesota, USA. Using random forest modeling and logistic regression, we found location, stand age, basal area, site index, average diameter, and metrics of species composition to be among the most important predictors of ESDM occurrence. Predictions showed two regions of greater likelihood of infestation with distinct ecological characteristics and ownership patterns. By understanding how stand structural characteristics relate to ESDM infestations, managers can improve monitoring and management of ESDM at the stand and landscape scales. Additionally, our approach of using multiple datasets and modeling methods can serve as a framework for decision-making on other forest health concerns. [ABSTRACT FROM AUTHOR]

White spruce (Picea glauca (Moench) Voss) plantations have historically been an important source of high-quality forest products in the Great Lakes Region of North America. Thinning in spruce plantations is a common silvicultural practice for reducing competition and promoting resiliency to forest health threats such as eastern spruce budworm (Choristoneura fumiferana Clemens), a native forest pest of eastern North America. Spruce budworm larvae feed on the foliage of trees, which reduces growth and potentially causes mortality during an outbreak. There has been continual spruce budworm defoliation in northern Minnesota, U.S.A., since the mid-1950s, with higher levels of defoliation in the late 1990s. This research modeled the diameter growth response of white spruce 18 years after initial thinning in stands that presently range between 44 and 64 years old. Some stands received a second thinning in recent years. We used generalized nonlinear least squares and nonlinear mixed-effects models to estimate annual diameter growth using common tree and stand metrics. Growth model performance was improved by including thinning and frequency of spruce budworm defoliation as modifiers of diameter growth. Results of this study highlight how thinning in combination with insect disturbance affect diameter growth in white spruce plantations of northern Minnesota. Key words: forest health, thinning, growth and yield, plantations, Picea glauca. Les plantations d'epinette blanche (Picea glauca (Moench) Voss) ont traditionnellement ete une importante source de produits forestiers de grande qualite dans la region des Grands Lacs, en Amerique du Nord. L'eclaircie est une pratique sylvicole courante dans les plantations d'epinette pour reduire la competition et augmenter la resilience face aux agents qui menacent la sante de la foret tels la tordeuse des bougeons de l'epinette (Choristoneura fumiferana Clemens), un ravageur forestier indigene de l'est de l'Amerique du Nord. Les larves de la tordeuse se nourrissent du feuillage des arbres, ce qui reduit la croissance et peut causer de la mortalite durant une epidemie. La tordeuse des bougeons de l'epinette a cause une defoliation continue dans le nord du Minnesota, aux Etats-Unis, depuis le milieu des annees 1950 et les defoliations les plus severes sont survenues a la fin des annees 1990. Cette etude consistait a modeliser la reaction de la croissance en diametre de l'epinette blanche 18 ans apres l'eclaircie initiale dans des peuplements dont l'age varie presentement de 44 a 64 ans. Certains peuplements ont recemment subi une deuxieme eclaircie. Nous avons utilise des modeles generalises des moindres carres non lineaires et des modeles non lineaires a effets mixtes pour estimer la croissance annuelle en diametre a l'aide de mesures courantes d'arbre et de peuplement. La performance des modeles de croissance a ete amelioree en incluant l'eclaircie et la frequence de la defoliation par la tordeuse des bourgeons de l'epinette en tant que modificateurs de la croissance en diametre. Les resultats de cette etude font ressortir de quelle facon l'eclaircie combinee a la perturbation causee par les insectes influence la croissance en diametre dans les plantations d'epinette blanche du nord du Minnesota. [Traduit par la Redaction] Mots-cles : etat de sante de la foret, eclaircie, croissance et rendement, des plantations, Picea glauca., 1. Introduction Forest growth and yield models have historically been developed without including observations from stands subjected to biotic disturbances (Woods and Coates 2013). Both biotic and abiotic disturbances can [...]

Emerald ash borer (EAB; Agrilus planipennis Fairmaire, 1888) has been a persistent disturbance for ash forests in the United States since 2002. Of particular concern is the impact that EAB will have on the ecosystem functioning of wetlands dominated by black ash (Fraxinus nigra Marsh.). In preparation, forest managers need reliable and complete maps of black ash dominated stands. Traditionally, forest survey data from the United States Forest Inventory and Analysis (FIA) Program have provided rigorous measures of tree species at large spatial extents but are limited when providing estimates for smaller management units (e.g., stands). Fortunately, geospatial data can extend forest survey information by generating predictions of forest attributes at scales finer than those of the FIA sampling grid. In this study, geospatial data were integrated with FIA data in a randomForest model to estimate and map black ash dominated stands in northern Minnesota in the United States. The model produced low error rates (overall error = 14.5%; area under the curve (AUC) = 0.92) and was strongly informed by predictors from soil saturation and phenology. These results improve upon FIA-based spatial estimates at national extents by providing forest managers with accurate, fine-scale maps (30 m spatial resolution) of black ash stand dominance that could ultimately support landscape-level EAB risk and vulnerability assessments. Key words: compound topographic index (CTI), remote sensing, black ash, emerald ash borer, forest inventory. L'agrile du frene (AF; Agrilus planipennis Fairmaire, 1888) est une source de perturbation persistante dans les forets de frene depuis 2002 aux Etats-Unis. L'impact que l'AF aura sur le fonctionnement de l'ecosysteme des milieux humides domines par le frene noir (Fraxinus nigra Marsh.) est particulierement preoccupant. Pour se preparer, les gestionnaires forestiers ont besoin de cartes exhaustives et fiables des peuplements domines par le frene noir. Traditionnellement, les donnees d'inventaire forestier du programme d'analyse et d'inventaire forestier (AIF) des Etats-Unis ont fourni des mesures rigoureuses concernant les especes arborescentes pour de vastes etendues mais elles sont limitees lorsqu'il s'agit de fournir des estimations pour de plus petites unites d'amenagement (p. ex des peuplements). Heureusement, les donnees geospatiales peuvent etendre la portee des informations de l'inventaire forestier en generant des predictions des attributs forestiers a des echelles plus fines que la grille d'echantillonnage du programme d'AIF. Dans cette etude, des donnees geospatiales ont ete integrees avec des donnees du programme d'AIF dans une foret d'arbres decisionnels pour estimer et cartographier les peuplements domines par le frene noir dans le nord du Minnesota, aux Etats-Unis. Le modele a produit de faibles taux d'erreur (erreur globale = 14,5 %; surface sous la courbe (AUC) = 0,92) et etait fortement informe par des predicteurs ayant trait a la saturation du sol et a la phenologie. Ces resultats ameliorent les estimations spatiales fondees sur le programme d'AIF a l'echelle nationale en fournissant aux gestionnaires forestiers des cartes precises et a petite echelle (resolution spatiale de 30 m) des peuplements domines par le frene noir qui pourraient en fin de compte servir de base a l'evaluation des risques et de la vulnerabilite a l'AL. [Traduit par la Redaction] Mots-cles : indice topographique compose (CTI), teledetection, frene noir, agrile du frene, inventaire forestier., 1. Introduction A variety of exotic flora, fauna, and pathogens induce ecological changes to forest ecosystems worldwide, ultimately disrupting ecosystem processes and functions, including nutrient cycling, productivity, and wildlife habitat [...]

Understanding the patterns of tree recruitment is essential to quantifying the future health and productivity of forest ecosystems. Using national forest inventory information, we incorporated browse impact measurements into models of sapling (2.5-12.7 cm diameter at breast height (DBH)) and overstory tree (>12.7 cm DBH) ingrowth across the northern United States. Ingrowth was modeled with standard and zero-inflated techniques using discrete Poisson and negative binomial distributions. Zero-inflated models using stand attributes and browse impacts provided the best fit statistics for modeling the occurrence and frequency of ingrowth over a 5-year time period. Results indicate that stands with very high browse impact would contain 50.0% fewer ingrowth saplings compared with stands with no browse impact. Greater browse impacts similarly yielded a negative effect on overstory tree ingrowth, but to a lesser degree than saplings. Despite the stochastic nature of ingrowth observations, incorporating browse impacts may be essential in determining accurate levels of ingrowth in forests where herbivory constrains forest regeneration objectives. Key words: herbivory, white-tailed deer, regeneration, ingrowth, Forest Inventory and Analysis. Il est essentiel de comprendre les patrons de recrutement des arbres pour quantifier l'etat de sante et la productivity futures des ecosystemes forestiers. A partir des informations tirees de l'inventaire forestier national, nous avons incorpore des mesures d'impact du broutage dans des modeles de recrutement des gaules (2,5- 12,7 cm de diametre a hauteur de poitrine (DHP)) et des tiges ([greater than or equal to] 12,7 cm au DHP) dans l'etage dominant a travers le nord des Etats-Unis. Le recrutement a ete modelise a l'aide de techniques standards et avec une surrepresentation de zeros en utilisant les distributions de Poisson et binomiale negative. Les modeles avec une surrepresentation de zeros utilisant les attributs du peuplement et les impacts du broutage fournissaient les statistiques les mieux ajustees pour modeliser l'occurrence et la frequence du recrutement sur une periode de 5 ans. Les resultats indiquent que les peuplements severement impactes par le broutage contiendraient 50,0 % moins de recrues comparativement aux peuplements exempts de broutage. Des impacts plus importants dus au broutage ont de facon similaire eu un effet negatif sur le recrutement des tiges dans l'etage dominant, mais a un degre moindre que dans le cas des gaules. Malgre la nature stochastique des observations au sujet du recrutement, l'introduction des impacts du broutage peut s'averer essentiel pour determiner le degre exact de recrutement dans les forets ou le broutage menace les objectifs de regeneration forestiere. [Traduit par la Redaction] Mots-cles: broutage, cerf de Virginie, regeneration, recrutement, Analyse et Inventaire Forestier., Introduction Tree recruitment is the accretion of newly established trees of a certain size in forest stands. Quantifying tree recruitment is essential to forest managers and is an integral component [...]

White-tailed deer (Odocoileus virginianus Zimmerman) present numerous challenges for maintaining the health of forests in the US Lake States. Although many sources of data exist that provide coarse estimates of deer-browse impacts on plant survival and abundance (e.g. national forest inventories) or examine areas where deer are excluded (e.g. exclosures), few studies exist that use detailed tree seedling measurements across diverse stand conditions and forest types. This study evaluated four years of citizen science data collected in the Assessing Vegetation Impacts from Deer (AVID) program in Minnesota, USA. Results showed that average annual height growth of seedlings for nine browse-palatable species was 1.9 cm. For four of these tree species, annual height growth was not significantly different from zero. These results point to the challenges for the growth and survival of browse-palatable tree species in Minnesota under current deer population levels. Engaging the public through a citizen science project such as AVID showcases the importance of evaluating browse impacts on trees from white-tailed deer while simultaneously providing information to managers and decision makers about this important conservation concern. Study Implications : Citizen scientists can collect data on important conservation issues with ecological implications. This study showcases data provided by volunteers in Minnesota's Assessing Vegetation Impacts from Deer (AVID) program. These results showed that the growth of nine browse-palatable species grew minimally over a four-year span. Citizen science data like these can be used by state wildlife agencies to better understand forest-wildlife interactions and establish wildlife population harvest goals. Measurements of deer browse can also assist researchers by reducing the costs of data collection and providing a geographically diverse data set with detailed measurements of deer impacts to forest vegetation. [ABSTRACT FROM AUTHOR]

Dead wood pools are strongly influenced by natural disturbance events, stand development processes, and forest management activities. However, the relative importance of these influences can vary over time. In this study, we evaluate the role of these factors on dead wood biomass pools across several forest management alternatives after 60 years of treatment on the Penobscot Experimental Forest in central Maine, USA. After accounting for variation in site quality, we found significant differences in observed downed coarse woody material (CWM; ≥ 7.6 cm small-end diameter) and standing dead wood biomass among selection, shelterwood, and commercial clear-cut treatments. Overall, total dead wood biomass was positively correlated with live tree biomass and was negatively correlated with the average wood density of nonharvest mortality. We also developed an index of cumulative harvest severity, which can be used to evaluate forest attributes when multiple harvests have occurred within the same stand over time. Findings of this study highlight the dynamic roles of forest management, stand development, and site quality in influencing dead wood biomass pools at the stand level and underscore the potential for various outcomes from the same forest management treatment applied at different times in contrasting stands. Key words: silviculture, tree mortality, spruce budworm, harvest severity index, woody debris. Les reservoirs de bois mort sont fortement influences par les perturbations, les processus de developpement des peuplements et les activites d'amenagement forestier. Cependant, l'importance relative de ces facteurs peut varier dans le temps. Dans cette etude, nous evaluons le role de ces facteurs sur les reservoirs de biomasse de bois mort en fonction de plusieurs options d'amenagement forestier apres 60 annees de traitement a la foret experimentale de Penobscot, dans le centre du Maine, aux Etats-Unis. Apres avoir tenu compte de la variation dans la qualite de station, nous avons observe des differences significatives dans les debris ligneux grossiers au sol (DLG; diametre au fin bout [greater than or equal to] 7,6 cm) et la biomasse de bois mort sur pied entre la coupe de jardinage, la coupe progressive et la coupe rase commerciale. Globalement, la biomasse totale de bois mort etait correlee positivement avec la biomasse des arbres vivants et negativement avec la densite moyenne du bois mort non recolte. Nous avons aussi developpe un indice d'intensite cumulative de recolte, qui peut etre utilise pour evaluer les attributs de la foret lorsque de multiples recoltes sont survenues avec le temps dans le meme peuplement. Les resultats de cette etude mettent en evidence les roles dynamiques de l'amenagement forestier, du developpement des peuplements et de la qualite de station quant a leur influence sur les reservoirs de biomasse de bois mort a l'echelle du peuplement et souligne la possibilite que le meme traitement d'amenagement forestier applique a differents moments dans differents peuplements produise differents resultats. [Traduit par la Redaction] Mots-cles : sylviculture, mortalite des arbres, tordeuse des bourgeons de l'epinette, indice d'intensite de recolte, debris ligneux., Introduction Dead wood is an important component of ecosystem structure and function (Harmon et al. 1986; McComb and Lindenmayer 1999; Siitonen 2001). Specifically, dead wood plays a key role in [...]

Red maple (Acer rubrum L.), historically a common but not abundant tree species in North America, has increased in abundance throughout its range over the last several decades; however, it has received little attention in growth and yield studies. The objectives of this study were to (i) evaluate the effects of stocking level and stand density on overall patterns of red maple stand productivity and (ii) quantify these relationships across a wide range of stand age, site quality, geographic location, and climatic conditions. We used long-term measurements from 52 sites in Wisconsin and Michigan to examine growth responses of even-aged red maple stands to various levels of thinning. Using linear, mixed-effects modeling, future stand-level red maple basal area was modeled as a function of stand and plot characteristics and climatic variables. Growing season precipitation and its interaction with initial red maple basal area were significant predictors; however, they only collectively reduced the mean squared error by 2.1% relative to a base model containing solely stand and plot factors. Model projections indicated there was little difference in predicted future basal area for the range of climate conditions experienced by these stands highlighting red maple's wide tolerance of environmental conditions across the region. Key words: Acer rubrum, basal area growth, climate, Great Lakes region. Historiquement l'erable rouge (Acer rubrum L.) etait une espece d'arbre commune mais peu abondante en Amerique du Nord. Malgre que son abondance ait augmente partout dans son aire de distribution au cours des dernieres decennies, cette espece a suscite peu d'interet dans les etudes de croissance et de rendement. Les objectifs de cette etude etaient (i) d'evaluer les effets de la surface terriere et de la densite des peuplements sur la trajectoire de productivite des peuplements d'erable rouge et (ii) de quantifier ces relations pour une vaste gamme d'age de peuplement, de qualite de station, de situation geographique et de conditions climatiques. Nous avons utilise des mesures a long terme provenant de 52 stations au Wisconsin et au Michigan pour etudier la reaction de croissance de peuplements equiennes d'erable rouge soumis a differentes intensites d'eclaircie. A l'aide d'un modele lineaire a effets mixtes, la future surface terriere de l'erable rouge a l'echelle du peuplement a ete modelisee en fonction de caracteristiques des peuplements et des parcelles, ainsi que des variables climatiques. Les precipitations pendant la saison de croissance et leur interaction avec la surface terriere initiale de l'erable rouge etaient des variables predictives significatives. Cependant, ces variables ont collectivement diminue l'erreur quadratique moyenne de seulement 2,1 % comparativement a un modele de base ne contenant que des variables propres aux peuplements et aux parcelles. Les projections du modele indiquaient que la future surface terriere qui a ete predite variait peu en fonction de la gamme de conditions climatiques observees dans ces peuplements, ce qui met en evidence la grande tolerance de l'erable rouge aux conditions environnementales de cette region. [Traduit par la Redaction] Mots-cles: Acer rubrum, croissance en surface terriere, climat, region des Grands Lacs., Introduction Red maple (Acer rubrum L.) is one of the most widespread tree species in North America in terms of both geographic range and ecological amplitude (Walters and Yawney 1990). [...]

Estimating the amount of standing deadwood in forests is crucial for assessing wildlife habitat and determining carbon stocks. In this analysis, snags (standing dead trees) in various stages of decay were inventoried across eight silvicultural treatments in eastern spruce-fir forests in central Maine nearly 60 years after treatments were initiated. Several modeling strategies were developed to estimate number of snags per hectare in various stages of decay. An unmanaged reference area displayed the highest basal area and volume of snags (5.4 [+ or -] 3.1 [m.sup.2] * [ha.sup.-1] and 29.4 [+ or -] 23.6 [m.sup.3] * [ha.sup.-1], respectively, (mean [+ or -] standard deviation)), while the lowest basal area and volume (0.9 [+ or -] 1.0 [m.sup.2] * [ha.sup.-1] and 3.1 [+ or -] 5.2 [m.sup.3] * [ha.sup.-1]) were observed in selection system with a 5-year cutting cycle. Models indicated that snag abundance was related to stand density, depth to water table, and the average harvest interval of the treatment. At a fixed stand density, approximately 140% more snags were predicted to occur in treatments with an average harvest interval of 55 compared with 5 years. An index of error reflecting the number of snags found in certain decay classes was reduced by 40% when predictions from count regression models fit with a mixed modeling strategy were used over ordinal regression. Results from these analyses can help to reduce the disparities between observed and modeled snag stocking levels and further our understanding of the relationships between live and standing dead trees inherent to eastern spruce-fir forests. Resume: Il est essentiel d'estimer la quantite de bois mort debout dans les forets pour evaluer l'habitat faunique et determiner les stocks de carbone. Dans cette etude, les chicots (arbres morts debout) a differents stades de decomposition ont ete inventories dans huit traitements sylvicoles dans des peuplements melanges d'epicea et de sapin situes dans le centre du Maine, presque 60 ans apres le debut des traitements. Plusieurs strategies de modelisation ont ete developpees pour estimer le nombre de chicots a l'hectare rendus a differents stades de decomposition. Une zone temoin non amenagee avait la surface terriere et le volume les plus eleves de chicots, soit respectivement (moyenne [+ or -] ecart type) 5,4 [+ or -] 3,1 [m.sup.2]*[ha.sup.-1] et 29,4 [+ or -] 23,6 [m.sup.3]*[ha.sup.-1], tandis que la surface terriere et le volume les plus faibles (0,9 [+ or -] 1,0 [m.sup.2]*[ha.sup.-1] et 3,1 [+ or -] 5,2 [m.sup.3]*[ha.sup.-1]) ont ete observes dans la coupe de jardinage avec une rotation de cinq ans. Les modeles indiquaient que l'abondance de chicots etait reliee a la densite du peuplement, a la profondeur de la nappe phreatique et a la l'intervalle moyen entre les recoltes. Avec une densite de peuplement fixe, les modeles predisaient approximativement 140% plus de chicots dans les traitements dont l'intervalle entre les recoltes etait de 55 ans comparativement a cinq ans. Un indice d'erreur refletant le nombre de chicots observes dans certaines classes de decomposition a ete reduit de 40% lorsqu'on utilisait les predictions des modeles de regression de variables explicatives de denombrement ajustes avec une strategie de modelisation mixte plutot que la regression ordinale. Les resultats de ces analyses peuvent contribuer a reduire les ecarts entre les niveaux observes de densite relative des chicots et ceux qui sont predits par les modeles et ameliorer notre comprehension des relations entre les arbres vivants et les arbres morts sur pied propres aux forets melangees d'epicea et de sapin. [Traduit par la Redaction], Introduction Snags (standing dead trees) play an important role in forest carbon dynamics (Harmon et al. 2011) and are key elements for maintaining forest biodiversity and providing a heterogeneous forest [...]

: Tree basal area (ba) or diameter at breast height (dbh) are universally used to represent tree secondary growth in individual tree based growth models. However, the long-term implications of using either ba or dbh for predictions are rarely fully assessed. In this analysis, Dba and Ddbh increment equations were fit to identical datasets gathered from six conifer and four hardwood species grown in central Maine. The performance of Dba and Ddbh predictions from nonlinear mixed-effects models were then compared with observed growth measurements of up to 29 years via a Monte Carlo simulation. Two evaluation statistics indicated substantial improvement in forecasting dbh using Ddbh rather than Dba. Root mean squared error (RMSE) and percentage mean absolute deviation (MAD%) were reduced by 14% and 15% on average, respectively, across all projection length intervals (5-29 years) when Ddbh was used over Dba. Differences were especially noted as projection lengths increased. RMSE and MAD% were reduced by 24% when Ddbh was employed over Dba at longer projection lengths (up to 29 years). Simulations found that simulating random effects rather than using local estimates for random effects performed as well or better at longer interval lengths. These results highlight the implications that selecting a growth model dependent variable can have and the importance of incorporating model uncertainty into the growth projections of individual tree based models. Resume: La surface terriere de l'arbre (G) ou le diametre o hauteur de poitrine (D) sont universellement utilises pour repre-senter la croissance secondaire dans les modeles de croissance d'arbre individuel. Cependant, les implications o long terme de l'emploi de G ou D pour les predictions sont rarement pleinement evaluees. Dans cette analyse, les equations d'accroissement DG et DD ont ete ajustees o des ensembles de donnees identiques recueillies o partir de six coniferes et quatre feuillus dans le centre du Maine. La performance des predictions de DG et DD o l'aide des modeles non lineaires o effets mixtes a ete comparee aux mesures de croissance prises sur une periode de 29 ans en utilisant une simulation de Monte Carlo. Deux statistiques d'evaluation indiquent une amelioration substantielle de la prediction de D en utilisant DD plutot que DG. Lorsque DD a ete utilise o la place de DG, l'ecart type residuel et l'ecart moyen absolu en pourcentage ont ete reduits respectivement de 14 et 15 % en moyenne pour tous les horizons de projection (5-29 ans). Ces differences etaient particulierement marquees lorsque les horizons de projection s'allongeaient. En effet, l'ecart type residuel et l'ecart moyen absolu en pourcentage ont ete reduits de 24 % lorsque DD a ete employe au lieu de DG pour les horizons de projection plus longs (jusqu'o 29 ans). Les simulations ont montre que la simulation des effets aleatoires performe aussi bien sinon mieux que les estimations locales des effets aleatoires lorsque les horizons sont longs. Ces resultats mettent en evidence, d'une part, les impacts causes par la selection de la variable dependante pour un modele de croissance et, d'autre part, l'importance d'inte-grer l'incertitude des modeles dans les projections de croissance par des modeles d'arbre individuel. [Traduit par la Redaction], Introduction Diameter (at breast height, dbh) or basal area (ba) can be used to predict secondary growth of individual trees in forest growth models. The circumference of the tree at [...]

Stand conditions influence the partitioning of Biomass to stem, needle, branch, and root components. Using data from 4- to 6-year-old loblolly pine (Pinus taeda L.) trees grown in a miniature-scale spacing trial, this study determined the effect of initial spacing on the Biomass partitioning of loblolly pine. Multivariate analysis of variance procedures concluded that row and column spacing did not have a significant effect on the relative amount of Biomass among tree components. Root/shoot and height/diameter ratios, however, differed across densities, indicating that allometric-based partitioning tradeoffs occurred. Results from the miniature-scale trees showed trends similar to those observed with mature-sized trees at operational spatial scales. Stem and woody roots were 70% and 14% of total mass, respectively. Since these trees were physiologically young at the time of harvest, the allocation of mass to needle continued to be a priority, accounting for 10% of the total mass. Initial planting spacing did not directly affect partitioning patterns; however, allometric ratios offered some evidence that partitioning may have changed between above- and below-ground tree components. This analysis offers insight into using principles from similarity analysis to analytically relate Biomass partitioning from miniature to operational spatial scales. La situation dans un peuplement influence la repartition de la biomasse entre la tige, les aiguilles, les branches et les racines. A (aide de donnees provenant de tiges de pin a encens (Pinus taeda L.) agees de 4 a 6 ans et croissant dans un test d'espacement a echelle reduite, cette etude a determine les effets de l'espacement initial sur la repartition de la biomasse chez le pin a encens. L'analyse de variance multivariee a permis de conclure que l'espacement des rangees et des colonnes n'a pas eu d'effet significatif sur la quantite relative de biomasse parmi les composantes de (arbre. Cependant, les rapports racines/tige et hauteur/diametre differaient selon la densite, indiquant que la repartition de la biomasse a fait (objet de compromis bases sur l'allometrie. Les resultats provenant du test a echelle reduite ont montre des tendances similaires a celles qui ont ete observees chez les arbres matures a une echelle spatiale operationnelle. La tige et les racines ligneuses representaient respectivement 70 % et 14 % de la masse totale. Etant sonne que ces arbres etaient physiologiquement jeunes au moment de la recolte, l'allocation de biomasse vers les aiguilles, qui representait 10 % de la masse totale, continuait a etre prioritaire. L'espacement initial n'a pas directement affecte les patrons de repartition. Cependant, les rapports allometriques fournissaient quelques indices que la repartition entre les composantes aerienne et souterraine pouvait avoir change. Cette analyse fournit un apercu de l'utilisation des principes de l'analyse de similarite pour relier de facon analytique la repartition de la biomasse en passant d'une echelle spatiale reduite a une echelle spatiale operationnelle. [Traduit par la Redaction], Introduction Biomass partitioning in forests is controlled by tree growth patterns and environmental conditions. One environmental condition that is under direct control of loblolly pine (Pinus taeda L.) plantation managers [...]

Innovation and knowledge exchange are critical to foster adaptive management and continual learning. Across the spectrum of knowledge exchange, ranging from peer-reviewed research to anecdotes, there is a largely untapped middle ground: real-world silvicultural case studies implemented and documented by foresters. The University of Minnesota Great Lakes Silviculture Library is a novel, freely available platform designed to enable foresters to exchange these case studies. Five years after its launch, we conducted focus groups with foresters from Minnesota and Wisconsin, USA, and Ontario, Canada, to explore the platform's usage and value. Participants valued having access to examples of silvicultural treatments and their outcomes that they could easily digest, apply, and share. They gained new knowledge from management across administrative boundaries. They also appreciated the consistent, relatable case study format. However, participants noted that limited time was the primary barrier to wider authorship and readership. The Library enables information exchange across agencies and disciplines within natural resources, giving greater voice to practicing foresters and supplementing other sources of forestry knowledge. [ABSTRACT FROM AUTHOR]