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Wildfires are increasing in importance in many regions of the Canadian boreal forest and are an ongoing risk for forest management activities. We simulated the effects of fires on long-term harvest levels on the 59 forest management units of the province of Quebec, Canada, for the 2020-2100 period. Different climate change pathways (stable, RCP 4.5 or 8.5) and salvage logging rates (20% or 70% of mature burned stands) were simulated. Changes in forest flammability due to climate change, species migration, and forest management were also considered. Under stable climatic conditions, the decline in potential harvest levels due to fire, based on 50 simulations per scenario, ranged between 3% and 33% (mean = 11%) when high salvage logging rates were simulated, compared to 6%-45% (mean = 20%) for low salvage rates. Climate change caused increases in burn rates between -3% and 39% for RCP 4.5 and between 33% and 69% for RCP 8.5 at the end of the 21st century, depending on fire zones. However, the effects of these modified burn rates on harvest levels did not differ substantially from those of baseline burn rates, probably because the projected burn rates were highest during the later part of the simulations (2070- 2100), when their impacts on harvest level calculations were limited. This study indicates that potential harvest levels calculated without considering wildfires are likely to be non-sustainable. Key words: forest landscape modelling, harvest level, wildfire, climate change, salvage logging, 1. Introduction Wildfires have an important influence on forest management activities. In the short term, fire suppression is expensive (Stocks and Martell 2016), as are post-fire silvicultural interventions to restore [...]

Wildfire-mediated changes to forests have prompted numerous studies on post-fire forest recovery of coniferous forests. Given climate change, a growing body of work demonstrates that conifer regeneration in temperate and boreal forests is declining, a phenomenon often termed 'regeneration failure.' However, the definition and parameters are numerous and variable. Characterization of drought also varies greatly, thus hindering the ability to compare results among areas. This review discusses new perspectives on conifer regeneration failure and places these studies into the context of drought and fire activity. We focus this review on three forest types where conifer regeneration failure is well documented: western boreal forests, cold mixed-conifer forests, and dry pine forests. To place the challenges to conifer tree regeneration in the context of regional climate trends, we present a novel regional analysis that summarizes drought conditions prior, during, and following the year of a large wildfire. We demonstrate the need to assess failure in the context of specific forest dynamics and well-defined metrics. For example, tree establishment may historically occur over longer periods, and current and future climate may exacerbate this and not promote pre-fire forest structure and composition. Many forests are undergoing rapid change and the type, magnitude, and causes of changes need to be compared among areas. As such, we should be cautious of quantifying 'regeneration failure' and drought without providing spatial and temporal context. Key words: tree regeneration, drought, climate change, forest conversion, regeneration failure, wildfires Les modifications des forets provoquees par les incendies de foret ont suscite de nombreuses etudes sur la regeneration des forets de coniferes apres un incendie. Compte tenu des changements climatiques, un nombre croissant de travaux demontre que la regeneration des coniferes dans les forets temperees et boreales est en declin, un phenomene souvent appele << accident de regeneration >>. Cependant, la definition et les parametres sont nombreux et variables. La caracterisation du phenomene de secheresse varie egalement beaucoup, ce qui entrave la capacite de comparer les resultats entre les regions. Cet article presente de nouvelles perspectives sur les accidents de regeneration des coniferes et place ces etudes dans le contexte des secheresses et des incendies. Nous nous concentrons sur trois types de forets ou les accidents de regeneration des coniferes sont bien documente : les forets boreales de l'Ouest, les forets mixtes froides de coniferes et les forets seches de pins. Pour placer les defis de la regeneration des coniferes dans le contexte des tendances climatiques regionales, nous presentons une nouvelle analyse regionale qui resume les conditions de secheresse avant, pendant et apres l'annee d'un grand incendie de foret. Nous demontrons la necessite d'evaluer l'accident de regeneration dans le contexte de dynamiques forestieres specifiques et de mesures bien definies. Par exemple, l'etablissement des arbres peut historiquement se produire sur des periodes plus longues, et le climat actuel et futur peut exacerber ce phenomene et ne pas favoriser la structure et la composition de la foret avant l'incendie. De nombreuses forets subissent des changements rapides et le type, l'ampleur et les causes de ces changements doivent etre compares entre les differentes regions. En tant que tel, nous devrions etre prudents dans la quantification des << accidents de regeneration >> et des secheresses sans fournir un contexte spatial et temporel. [Traduit par la Redaction] Mots-cles : regeneration des arbres, secheresse, changement climatique, conversion des forets, echec de la regeneration, incendies de foret, Introduction The composition, structure, and ecological function of forests, which occupy around 30% of the global landmass, are strongly patterned by landform and climate (Bond et al. 2005). Worldwide, forest [...]

Burn severity is an important component of the fire regime that has not yet been fully characterized for the forests of Canada. The objectives of this study were to (i) create a Canada-wide geospatial database of burn severity for wildland fires across forested regions of Canada from 1985 to 2015, and (ii) use this database to evaluate seasonal and annual trends in burn severity across Canada and regionally using two different regional units (ecozones and Homogeneous Fire Regime zones). We developed the 30 m resolution geospatial Canadian Landsat Burn Severity (CanLaBS) product from Landsat imagery, using values of pre-fire to post-fire differences in normalized burn ratios (dNBRs) for nearly 60 Mha of area burned across Canada's forests from 1985 to 2015, complemented with estimates of pre-fire forest composition, crown closure, and biomass. Our results suggest that burn severity is generally lower in spring fires than in summer ones nationally and in almost every regional unit. We found no consistent relationship between burn severity and annual area burned across ecozones. Finally, we observed a small but significant decrease in burn severity from 1985 to 2015 across Canada, although this is regionally variable. The CanLaBS database is publicly available at https://doi.org/10.23687/b1f61b7e-4ba6-4244-bc79-c1174f2f92cd. Key words: dNBR, fire regime, fire database, fire severity, Landsat. La severite des incendies forestiers est une composante importante du regime des feux qui n'a pas encore ete completement definie au Canada. Les objectifs de cette etude etaient d'abord de creer une base de donnees geospatiales pancanadienne sur la severite des feux pour ensuite l'utiliser afin d'evaluer l'existence de tendances dans la severite des feux au fil des saisons ou des annees. Pour ce faire, les analyses ont ete realisees a l'echelle du Canada ou encore en utilisant deux types de regionalisation (les ecozones ou les zones de regimes de feux homogenes). La base de donnees (CanLaBS) a ete developpee a une resolution de 30 m a partir de donnees de Landsat permettant de calculer la difference des indices normalises de brulage sur 60 Mha de territoire incendie entre 1985 et 2015 dans les zones forestieres du Canada. L'ensemble de donnees est complete avec des donnees sur la situation anterieure au feu (composition, degre de fermeture du couvert et biomasse). Nos resultats d'analyse indiquent que la severite des feux est generalement moindre au printemps qu'a l'ete a l'echelle du Canada Canada comme dans presque toutes les regions analysees. Nous n'avons pas observe de relation entre la severite des feux et l'aire annuelle brulee. En outre, dans l'ensemble du Canada et dans quelques regions, la severite des feux a decru entre 1985 et 2015. Notre base de donnees est accessible au public a https://doi.org/10.23687/b1f61b7e-4ba64244-bc79-c1174f2f92cd. Mots-cles : dNBR, regime de feux, base de donnees sur les feux de foret, severite des feux, Landsat., 1. Introduction Fire is the dominant disturbance type in Canada's forests, with an average of about 8000 fires burning close to 2 Mha per year (1959-2015; Hanes et al. 2019). [...]

Fire regime zonation systems are critical tools for research and management activities. In this study, we develop a hierarchical framework that applies both qualitative and quantitative approaches to create a two-level fire regime zonation system for Canada. The finer scale level, Fire Regime Units (FRUs), was created through a stepwise synthesis of fire regime metrics based on 1970-2016 fire records, environmental attributes such as topographic features and vegetation, literature review, and expert advice. Each of these 60 FRUs exhibits an internal homogeneity in fire regime. As non-contiguous units can show similar patterns in fire-related measurements, we performed a clustering analysis on the FRUs to define 15 broad-scale Fire Regime Types (FRTs). Each type is characterized by a unique set of indices related to fire activity, seasonality, and ignition cause. This two-level fire regime zonation system has a large range of applications (e.g., modeling, gradient analysis) and is flexible enough to be updated with new data or when notable shifts in fire dynamics occur. Key words: wildland fire regime, Canada, spatial analysis, boreal forest, zonation. Les systemes de zonation des regimes de feux sont des outils indispensables pour les activites de recherche et d'amenagement. Dans cette etude, nous developpons un cadre hierarchique qui utilise des approches qualitatives et quantitatives pour creer un systeme de zonation a deux niveaux des regimes de feux au Canada. Le niveau correspondant a l'echelle la plus fine, les unites de regime des feux (URFs), a ete cree par une synthese progressive des metriques de regime des feux sur la base des donnees sur les feux de 1970 a 2016, des attributs environnementaux tels que les caracteristiques topographiques et la vegetation, ainsi qu'une revue de la litterature et des conseils d'expert. Chacune de ces 60 URFs possede une homogeneite interne du regime des feux. Etant donne que des unites non contigues peuvent avoir des composantes de regime de feux similaires, nous avons effectue une analyse de regroupement sur les URFs pour definir 15 types de regime des feux (TRFs) a plus grande echelle. Chaque type est caracterise par un ensemble unique d'indices relatifs a l'activite, la saisonnalite et la cause d'allumage du feu. Cette zonation des regimes de feux a deux niveaux a une vaste gamme d'applications (p. ex., modelisation, analyse de gradient) et est assez flexible pour etre mise a jour avec de nouvelles donnees ou lorsque des changements importants surviennent dans la dynamique des feux. Mots-cles: regime des feux de foret, Canada, analyse spatiale, foret boreale, zonation., 1. Introduction From coastal rain forests to tundra barrens, as well as the vast boreal biome, Canada displays a wide range of fire regimes. While wildland fire is an inherently [...]

Protecting wildlife within areas of resource extraction often involves reducing habitat fragmentation. In Canada, protecting threatened woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) populations requires preserving large areas of intact forest habitat, with some restrictions on industrial forestry activities. We present a linear programming model that assesses the trade-off between achieving an objective of habitat protection for caribou populations while maintaining desired levels of harvest in forest landscapes. The habitat-protection objective maximizes the amount of connected habitat that is accessible by caribou, and the forestry objective maximizes net revenues from timber harvest subject to even harvest flow, a harvest target, and environmental sustainability constraints. We applied the model to explore the habitat protection and harvesting scenarios in the Cold Lake caribou range, a 6726 [km.sup.2] area of prime caribou habitat in Alberta, Canada. We evaluated harvest scenarios ranging from 0.1 [Mm.sup,3] * [year.sup.-1] to maximum sustainable harvest levels over 0.7 [Mm.sup,3] * [year.sup.-1] and assessed the impact of habitat protection measures on timber supply costs. Protecting caribou habitat by deferring or reallocating harvest increases the timber unit cost by Can$1.1-2.0 [m.sup.-3]. However, this impact can be partially mediated by extending the harvest to areas of oil and gas extraction to offset forgone harvest in areas of prime caribou habitat. Key words: caribou recovery, network flow model, mixed-integer programming, Steiner network, landscape connectivity, harvest scheduling model I, wildlife habitat protection, Canada. La protection de la faune dans les zones ou on procede a l'extraction des ressources implique souvent la reduction de la fragmentation de l'habitat. Au Canada, la protection des populations de caribou des bois (Rangifer tarandus caribou (Gmelin, 1788)) exige la preservation de vastes zones d'habitat forestier intact et l'imposition de certaines restrictions sur les activites forestieres industrielles. Nous presentons un modele de programmation lineaire qui permet d'evaluer le compromis entre la realisation des objectifs de protection de l'habitat pour les populations de caribou tout en maintenant les niveaux souhaites de recolte dans les paysages forestiers. L'objectif de protection de l'habitat maximise la quantite d'habitat non fragmente accessible au caribou et l'objectif de la foresterie maximise les revenus nets provenant de la recolte de bois, sujets a un volume regulier de recolte, une cible de recolte et a des contraintes de durabilite environnementale. Nous avons applique le modele pour explorer des scenarios de protection de l'habitat et de recolte dans le territoire du caribou du lac Cold, un excellent habitat pour le caribou d'une superficie de 6726 [km.sup.2] situe en Alberta au Canada. Nous avons evalue des scenarios de recolte variant de 0,1 [Mm.sup.3] * [an.sup.-1] a des niveaux maximum de recolte durable de plus de 0,7 [Mm.sup.3] * [an.sup.-1] et nous avons evalue l'impact des mesures de protection de l'habitat sur les couts d'approvisionnement en bois. La protection de l'habitat du caribou par le report ou la reaffectation de la recolte augmente le cout unitaire du bois de 1,1 a 2,0 Can$ [m.sup.-3]. Cependant, on peut en partie attenuer l'impact en etendant la recolte aux zones d'extraction d'huile et de gaz pour compenser la recolte perdue dans les zones qui offrent un habitat ideal pour le caribou. Mots-cles : retablissement du caribou, modele de flux de reseau, programmation partiellement en nombres entiers, reseau de Steiner, connectivite des paysages, modele de calendrier de recolte I, protection de l'habitat faunique, Canada., Introduction Woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) is designated a threatened species under Canada's Species at Risk Act (SARA) and Alberta's provincial Wildlife Act (Committee on the Status of [...]

Contemporary fire regimes of Canadian forests have been well documented based on forest fire records between the late 1950s to 1990s. Due to known limitations of fire datasets, an analysis of changes in fire-regime characteristics could not be easily undertaken. This paper presents fire-regime trends nationally and within two zonation systems, the homogeneous fire-regime zones and ecozones, for two time periods, 1959-2015 and 1980-2015. Nationally, trends in both area burned and number of large fires ([greater than or equal to]200 ha) have increased significantly since 1959, which might be due to increases in lightning-caused fires. Human-caused fires, in contrast, have shown a decline. Results suggest that large fires have been getting larger over the last 57 years and that the fire season has been starting approximately one week earlier and ending one week later. At the regional level, trends in fire regimes are variable across the country, with fewer significant trends. Area burned, number of large fires, and lightning-caused fires are increasing in most of western Canada, whereas human-caused fires are either stable or declining throughout the country. Overall, Canadian forests appear to have been engaged in a trajectory towards more active fire regimes over the last half century. Key words: fire regime, wildfire, trend analysis, Canadian forests. Les regimes contemporains des feux dans les forets canadiennes ont ete bien documentes selon les archives portant sur les feux de foret, accumulees depuis la fin des annees 1950 jusqu'aux annees 1990. A cause des limitations connues des jeux de donnees sur les feux, on ne pouvait facilement entreprendre une analyse des changements survenus dans les caracteristiques des regimes des feux. Cet article presente l'evolution des regimes des feux a l'echelle nationale et a l'interieur de deux systemes de zonage, la zone ou les regimes des feux sont homogenes et les ecozones, pour deux periodes, soit de 1959 a 2015 et de 1980 a 2015. A l'echelle nationale, dans les deux zones, les superficies brnlees et le nombre de grands feux ([greater than or equal to]200 ha) ont significativement augmente depuis 1959, ce qui pourrait etre du a une augmentation des feux causes par la foudre. Par contre, les feux d'origine humaine ont diminue. Les resultats indiquent que la taille des grands feux a augmente au cours des 57 dernieres annees et que la saison des feux debute environ une semaine plus tot et se termine une semaine plus tard. A l'echelle regionale, l'evolution des regimes des feux varie d'un endroit a l'autre et on observe moins de tendances significatives. Les superficies brUlees, le nombre de grands feux et les feux causes par la foudre sont en augmentation presque partout dans l'ouest du Canada, tandis que les feux d'origine humaine sont soit stables ou en diminution partout dans le pays. Dans l'ensemble, les forets canadiennes semblent engagees sur une trajectoire vers des regimes des feux plus actifs au cours des 50 dernieres annees. [Traduit par la Redaction] Mots-cles : regime des feux, feu de foret, analyse des tendances, forets canadiennes., 1. Introduction The fire-regime concept is composed of fire-related characteristics that describe the occurrence and impact of fires over space and time. In Canada, the fire regime is commonly characterized [...]

Although the southwestern region of France has not experienced a major wildfire in several decades, the wildfire potential of this area remains high. This threat not only represents a matter of human safety, especially given the substantial influx of tourists during the summer season, but also endangers the important forest resources of this region. Widely used in North America, modelling wildfire probability at the landscape level is now a proven method for wildfire risk mapping. The aim of this study is to adapt Burn-P3, a Canadian simulation model for burn probability mapping, to the geographic context of the Landes department, France, in order to calculate wildfire probability and potential fire intensity (considered together as the two main components of wildfire hazard) for several weather scenarios. This exercise involved a conversion of the vegetation of the Landes region to the forest fuel types derived from the Canadian method. Results reveal a highly heterogeneous wildfire probability and head fire intensity across the study landscape, with the two modelled components exhibiting divergent spatial configurations. They also show a rapid and nonlinear increase in wildfire risk according to the severity of weather conditions. These findings represent the first detailed mapping of wildfire risk in southwestern France using a probabilistic simulation model. This product can be readily integrated in risk analysis and guide targeted mitigation actions to improve human safety and optimize the protection of forest resources.Keywords: Keywords: wildfire probability, fire intensity, fire meteorology, ignitions, simulation model, Landes department.Le sud-ouest de la France n'a pas connu d'incendie majeur depuis plusieurs decennies, mais il presente un fort potentiel de feu de grande ampleur. Cette menace concerne la securite de la population qui augmente significativement lors de la saison estivale touristique, ainsi que les ressources forestieres considerables de cette region. Largement utilisee en Amerique du Nord, la modelisation de la probabilite d'incendies de vegetation a l'echelle du paysage est desormais une methode eprouvee pour la cartographie du risque de feu de foret. La presente etude vise a adapter le modele de probabilite canadien Burn-P3 au contexte geographique du departement des Landes, en France, afin de calculer la probabilite d'incendie et la puissance potentielle (consideres ici comme les deux composantes majeures de l'alea) des feux pour divers scenarios meteorologiques. Pour ce faire, le principal defi fut de convertir les formations vegetales du secteur landais en combustibles forestiers issus de la methode canadienne. Les resultats montrent une probabilite d'incendie et une puissance du front de flamme tres variables a travers le paysage, ces deux composantes ayant des configurations spatiales fort differentes. De plus, l'alea feu de foret augmente rapidement et de facon non lineaire en fonction de la severite croissante des conditions meteorologiques. Ces resultats representent une premiere cartographie detaillee de la probabilite de feux de forets dans le sud-ouest de la France, realisee a l'aide d'un modele de simulation probabiliste. Celui-ci pourra etre utilise a des fins d'analyse des risques et pour guider des actions de mitigation ciblees afin d'ameliorer la securite des personnes et optimiser la protection du massif forestier.Mots-cles : probabilite d'incendie, puissance du feu, meteorologie des incendies, allumages, modele de simulation, departement des Landes., IntroductionDe nombreuses regions du monde naturellement adaptees a un regime de feux actif n'ont connu que peu, voire aucun grand feu depuis des decennies, parfois des siecles (Marlon et al. [...]

Although it is increasingly accepted that young (e.g., [less than or equal to]30 years) stands originating from wildfire are considerably less flammable than older stands in the boreal forest of North America, the role of fuel availability and structure in this phenomenon has not been thoroughly investigated. As a regional study in a high-frequency fire regime, detailed wildfire fuel loading and structure were measured in 66 sites including both wetlands and uplands in the Boreal Plains landscape of Wood Buffalo National Park in northwestern Canada. Overall, a significant increase in total flammable biomass occurred in upland sites over 97 years, but this increase was not consistently observed in wetlands, except where there was dense tree cover. Fuel accumulation was highly moderated by canopy fuels, as surface fuels were relatively constant across differing site types and time since fire, averaging 0.4 kg * [m.sup.-2]. Significant but gradual canopy fuel accumulation was observed in moist conifer upland forests dominated by mature black spruce (Picea mariana (Mill.) B.S.P.) or white spruce (Picea glauca (Moench) Voss) over 100 years since fire. Outside of these mature moist conifer uplands, there was no difference in total fuel loading between other upland forests and across the gradient of treed to open wetlands. Key words: boreal, wildfire, wetlands, fuels, vegetation structure. Bien qu'il soit de plus en plus accepte que les jeunes (p. ex. [less than or equal to]30 ans) peuplements issus de feux sont beaucoup moins inflammables que les peuplements plus vieux dans la foret boreale de l'Amerique du Nord, le role que jouent la structure et la disponibilite des combustibles dans ce phenomene n'a pas ete etudie a fond. Dans le cadre d'une etude regionale sur le regime de feux a haute frequence, la structure et la charge des combustibles des feux ont ete mesurees en detail a 66 endroits, incluant tant des zones humides que bien drainees dans le paysage de plaines boreales du parc national Wood Buffalo dans le nord-ouest canadien. Dans l'ensemble, une augmentation importante de la biomasse inflammable totale est survenue dans les stations bien drainees apres 97 ans mais cette augmentation n'a pas systematiquement ete observee dans les zones humides, a l'exception des endroits oU le couvert arborescent etait dense. L'accumulation de combustibles etait fortement temperee par les combustibles dans le couvert forestier etant donne que les combustibles de surface etaient relativement constants parmi differents types de stations et temps ecoules depuis le feu, atteignant en moyenne 0,4 kg * [m.sup.-2]. Une accumulation importante mais graduelle de combustibles dans le couvert a ete observee dans les forets humides bien drainees de coniferes dominees par l'epinette noire (Picea mariana (Mill.) B.S.P.) ou l'epinette blanche (P. glauca (Moench) Voss) depuis plus de 100 ans apres un feu. A l'exception de ces stations humides bien drainees dominees par des coniferes matures, il n'y avait pas de difference dans la charge totale de combustibles entre d'autres forets bien drainees ainsi que le long du gradient allant de zones humides boisees a ouvertes. [Traduit par la Redaction] Mots-cles : boreal, feux de foret, zones humides, combustibles, structure de la vegetation., 1. Introduction Paleoecological reconstructions from tree rings (Wallenius et al. 2011) and charcoal and pollen (Larsen and MacDonald 1998) in boreal western Canada indicate a historic fire return interval that [...]

The Canadian Journal of Forest Research published a collection focusing on changing wildfire regimes, their impacts, and the path forward, inspired by the unprecedented 2023 wildfire season in Canada. The 2023 fire season was characterized by extreme weather conditions, leading to record-breaking area burned and severe logistical challenges. The season highlighted the urgent need for transformational changes in urban and land planning, wildfire and forest management, and governance to coexist with wildfires in the future, with a particular focus on collaboration with Indigenous communities and incorporation of Traditional Knowledge. [Extracted from the article]

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Accurate and fine-scale forest data are essential to improve natural resource management, particularly in the face of climate change. Here, we present SCANFI, the Spatialized CAnadian National Forest Inventory, which provides coherent, 30 m resolution 2020 wall-to-wall maps of forest attributes (land cover type, canopy height, crown closure, aboveground tree biomass, and main species composition). These maps were developed using the NFI photo-plot dataset, a systematic regular sample grid of photo-interpreted high-resolution imagery covering all of Canada's non-arctic landmass. SCANFI was produced using temporally harmonized summer and winter Landsat spectral imagery along with hundreds of tile-level regional models based on a multiresponse k-nearest neighbours and random forest imputation method. This tile-level approach revealed the importance of radiometric variables in predicting vegetation attributes, namely winter radiometry, as the large-scale climate gradients were controlled at the tile-level. SCANFI was validated with rigorous cross-validation analyses, which revealed robust model performance for structural attributes (biomass R2 = 0.76; crown closure R2 = 0.82; height R2 = 0.78) and tree species cover (e.g., Douglas fir R2 = 0.60). SCANFI attributes were also validated with several independent external products, ranging from ground plot-based tree species cover (e.g., black spruce R2 = 0.53) to satellite LiDAR height data products (e.g., crown closure R2 = 0.71). SCANFI total aboveground biomass trends also followed those published by other studies. The methodology presented herein can be used to map time series of these attributes, identify the original training points used to make any given prediction, as well as map additional variables associated with the NFI photo-plots that are challenging to map using traditional remote sensing approaches. [ABSTRACT FROM AUTHOR]

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

Fungi are primary agents of coarse woody debris (CWD) decay in boreal forests, playing an essential role in nutrient cycling and carbon storage. We compared fungal community assemblages using alpha and beta diversity metrics, and physical and chemical properties of CWD across three tree species (trembling aspen [Populus tremuloides], black spruce [Picea mariana], and jack pine [Pinus banksiana]), five decay classes, and two stand development stages, differing in time since stand replacing disturbance in Ontario's boreal forest region. We sampled 180 individual CWD logs from 6 independent stands, with 3 replicates per each species × decay class combination at each site. Using high-throughput sequencing of marker DNA, we found that fungal community structure significantly differed across tree species, decay stage, and stand age. Fungal diversity was highest in decay class 4 CWD. We found that Mn and K concentrations, total carbon, C/N ratio, N/P ratio, and moisture content were important predictors of fungal composition across CWD species and/or decay stage. This study suggests that forest management guidelines that consider both deadwood quantity and quality will support a broader range of fungal species and communities through post-disturbance stand development. [ABSTRACT FROM AUTHOR]

Industrial forestry activities can increase landscape fragmentation, impacting wildlife populations, particularly Canada's woodland caribou, Rangifer tarandus caribou. To protect caribou in areas with forestry activities, the province of Ontario, Canada, implemented a Dynamic Caribou Harvest Schedule (DCHS). The DCHS spatially aggregates harvest disturbance into regions and distributes them across the landscape to maintain forest patch size–age distributions consistent with a natural variation range. However, the DCHS may negatively impact the cost of timber supply. We compared the DCHS with an alternative zoning approach that assigned the harvest deferral and operational management zones within a large forest area. We compared these approaches using an optimization model that combined harvest scheduling, access road construction, and caribou protection sub-problems. We formulated the protection of caribou habitat and road construction as network flow problems, while the harvesting problem incorporated the ecological constraints prescribed by the forest management plan. We compared the DCHS and zoning approaches in the Wabadowgang Noopming Forest of Ontario, a boreal area within the caribou distribution zone. For the same volume of sustainable harvest, the zoning approach protected less total area but more habitat and old-growth stands over the long term, and yielded lower timber costs by 1.2–2.2 $·m−3 than the DCHS. [ABSTRACT FROM AUTHOR]

Information about post-disturbance regeneration success and successional dynamics is critical to predict forest ecosystem resistance and resilience to disturbances and climate change. Our objective was to identify and classify post-disturbance empirical research conducted by the Canadian Forest Service (CFS) of Natural Resources Canada and their collaborators to provide guidance on future research needs, improving our understanding of post-disturbance recovery in a Canadian context. To achieve our objective, we collected and classified peer-reviewed and non-published literature produced by the CFS between 1998 and 2020 that concerned post-disturbance ecology. We focused on research addressing natural or anthropogenic disturbances, such as wildfires, pest outbreaks, windthrows, forest management, seismic lines, and those that studied processes related to soil, vegetation, fauna, hydrology, and microbial communities. We found that forest harvesting was the disturbance most studied by CFS between 1998 and 2020, followed by fire. Despite the fact that large, forested areas are affected annually by pests, studies on recovery after pest outbreaks were scarce. Other disturbances, such as mining and seismic lines or other abiotic disturbances were rare in CFS literature. Most studies (70%) examined changes in vegetation related to forest management and fire and they were mainly focussed on post-disturbance tree regeneration success. Post-disturbance changes in understory species diversity were also well-studied. Our results provide a geographic overview of CFS research on post-disturbance recovery in Canada and enable the identification of key knowledge gaps. Notably, research focusing on recovery after natural disturbances was underrepresented in the assessed literature compared to studies centered around harvesting. Long-term research sites, chronosequences that substitute space for time, and studies focused on consecutive disturbances are especially important to maintain and establish sustainable forest management strategies in the face of climate change. [ABSTRACT FROM AUTHOR]

Seismic lines are linear features created by the oil and gas industry for energy exploration. Though individually narrow, collectively seismic lines are a pervasive management challenge, resulting in changes to biogeochemical cycles, plant and animal abundance and behaviour, predator–prey relationships, and forest successional trajectories. These impacts arise from historical construction methods that used bulldozers to remove vegetation and substrate leaving lines as persistent openings in a state of arrested succession. In the mid-1990s, "low-impact seismic" (LIS) line construction began, using mulchers to remove vegetation aboveground to minimize impacts and hasten reforestation. Here, we evaluated the effectiveness of LIS in retention, recruitment, and growth of seedlings in forested peatlands in northeast British Columbia. Retained and recruited trees on LIS lines were found at 69% and 64% of sites, had mean densities of 3400 and 6000 stems/ha, and mean heights of 42 and 11 cm, respectively. These LIS lines appeared to recover along expected trajectories toward tree cover, thereby mitigating challenges typical of older seismic exploration. Our results suggest it is feasible to further fast-forward line recovery by ensuring mulcher drums are kept as high as possible to increase the number and height of trees through the mulching process. [ABSTRACT FROM AUTHOR]

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We investigated the genetic makeup of Lutz spruce, a natural hybrid between white and Sitka spruce on the Kenai Peninsula, Alaska. Microsatellites indicate 72% of individuals sampled had predominantly white spruce ancestry, whereas 14% had predominantly Sitka spruce ancestry; some individuals classified as white spruce had Sitka spruce plastid genotypes. As Picea mitochondria are maternally inherited and plastids are paternally inherited, it appears that white spruce was the ancestral seed parent of nearly all spruce on the western peninsula, whereas Sitka spruce alleles originated from pollen. Pollen records show that white spruce colonized the western peninsula ∼8500 YBP from glacial refugium, whereas Sitka spruce arrived on the eastern peninsula ∼4000 YBP after migrating up the Pacific coast. Our data suggest that Sitka spruce colonization west of the Kenai Mountains may have occurred not via seed dispersal but by long distance transport of wind-borne pollen and subsequent hybridization with established white spruce populations. Hybridization was an important mechanism that allowed Sitka spruce to expand the leading edge of its range in response to historical climate change. As the climate continues to warm, climate envelope modeling suggests Lutz spruce may ultimately displace white spruce on the western peninsula even as Sitka spruce is constrained to the eastern peninsula where it will continue to hybridize. [ABSTRACT FROM AUTHOR]

Airtankers are commonly used for initial attack (IA) to reduce the likelihood of wildland fires escaping containment efforts. We examined IA airtanker dispatch decisions for forest fires in Ontario, Canada, through an analysis of historical fire records from 2001 to 2019. A hurdle modelling approach that predicts the probability of airtanker(s) being dispatched and then the number of airtankers sent was used. Two different hurdle models were considered depending on the timing of the information available to the decision maker: a "fire report model" based upon the information available when a fire is first reported, and an "initial attack model" using information available at the time IA action began. Both models indicated that the most influential covariates for airtanker dispatch are the fire weather index, fuel volatility, observed fire rate of spread, fire size at IA, and cause of ignition. When evaluating the predictive ability of the models on a validation data set, the "initial attack model" performed better than the "fire report model". Our models generally perform well when predicting none, one, or two airtankers on IA, but they generally underpredict when more than two airtankers are dispatched, which suggests risk-averse decision-making in fire management resource dispatching. [ABSTRACT FROM AUTHOR]

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

The article focuses on peat surface compression reduces smouldering fire potential as a novel fuel treatment for boreal peatlands.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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