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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 [...]

As wildfires are increasingly causing negative impacts to communities and their livelihoods, many communities are demanding more proactive and locally driven approaches to address wildfire risk. This marks a shift away from centralized governance models where decision-making is concentrated in government agencies that prioritize reactive wildfire suppression. In British Columbia (BC), Canada, Community Forests—a long-term, area-based tenure granted to Indigenous and/or local communities—are emerging as local leaders facilitating proactive wildfire management. To explore the factors that are enabling local governance approaches to managing wildfire risk, we conducted semi-structured interviews with 26 Community Forest managers across BC. Managers highlighted financial and social capacity, especially trust and relationships with both community members and government agencies, as crucial factors influencing their ability to undertake proactive management. These factors enable Community Forests to address wildfire risk not only within their own tenure area, but also at household, community, and landscape scales, while balancing diverse community values, objectives for forest management, and legal and policy obligations. Despite ongoing challenges, Community Forests emphasized the importance of scaling up their efforts to address wildfire risk and are a critical form of local wildfire governance that can help advance proactive wildfire management across BC. [ABSTRACT FROM AUTHOR]

Anthropogenic influences are altering fire regimes worldwide, resulting in an increase in the size and severity of wildfires. Simultaneously, throughout western North America, there is increasing recognition of the important role of Indigenous fire stewardship in shaping historical fire regimes and fire‐adapted ecosystems. However, there is limited understanding of how ecosystems are affected by or recover from contemporary "megafires," particularly in terms of understory plant communities that are critical to both biodiversity and Indigenous cultures. To address this gap, our collaborative study, in partnership with Secwépemc First Nations, examined understory community recovery following a large, mixed‐severity wildfire that burned in the dry and mesic conifer forests of British Columbia, Canada, with a focus on plants of high cultural significance to Secwépemc communities. To measure the effect of a continuous gradient of fire severity across forest types, we conducted field assessments of fire severity and sampled understory plants 4 years postfire. We found that native species richness and richness of species of high cultural significance were lowest in areas that burned at high severity, with distinct compositional differences between unburned areas and those that burned at high severity. These findings were consistent across forest types characterized by distinct historical fire regimes. In contrast, richness of exotic species increased with increasing fire severity in the dominant montane interior Douglas‐fir forests, with exotic species closely associated with areas that burned at high severity. Our study indicates that recent megafires may be pushing ecosystems outside their historical range of variability, with negative implications for ecosystem recovery and cultural use across these fire‐affected landscapes. We also found consistently higher plant diversity, and both native and cultural species richness, in subalpine forests. Collectively, our results provide strong evidence of the ecological and cultural significance of low‐ to moderate‐severity fire and subalpine forests, and the longstanding and ongoing role of Indigenous peoples in shaping these landscapes. As wildfires continue to impact ecosystems and human communities, this study offers novel insights into the recovery of important ecological and cultural values, while highlighting the need to support ethical research collaborations with Indigenous communities and Indigenous‐led revitalization of fire and plant stewardship. [ABSTRACT FROM AUTHOR]

British Columbia experienced three years with notably large and severe wildfires since 2015. Multiple stand-replacing wildfires occurred in coastal-transitional forests, where large fires are typically rare, and thus, information on post-fire carbon is lacking. Because of their carbon storage potential, coastal-transitional forests are important in the global carbon cycle. We examined differences in surface fuel carbon among fire severity classes in 2016, one year after the Boulder Creek fire, which burned 6 735 ha of coastal-transitional forests in 2015. Using remotely sensed indices (dNBR), we partitioned the fire area into unburned (control), low-, moderate-, and high-severity classes. Field plots were randomly located in each class. At each plot, surface fuel carbon was quantified by type, namely coarse, small, and fine woody material, duff, and litter, and carbon mass by fuel type was compared among severity classes. Total surface fuel carbon did not differ significantly between burned and unburned plots; however, there was significantly less duff and litter carbon in burned plots. Remotely sensed severity classes did not properly capture wildfire impacts on surface fuels, especially at lower severities. Pre-fire stand characteristics are also important drivers of surface fuel loads. This case study provides baseline data for examining post-fire fuel carbon dynamics in coastal-transitional British Columbia. Key words: wildfire, forest carbon, fire severity, forest floor, surface fuels. Depuis 2015 la Colombie-Britannique a connu trois annees durant lesquelles sont survenus des feux de forets particulierement vastes et severes. De multiples feux de foret qui entrainent le renouvellement des peuplements sont survenus dans les forets transitionnelles cotieres oU de tels feux sont typiquement rares et oU l'information sur le carbone apres feu est par consequent inexistante. Etant donne leur capacite a emmagasiner le carbone, les forets transitionnelles cotieres sont importantes dans le cycle global du carbone. Nous avons etudie les differences dans la quantite de carbone contenu dans les combustibles de surface parmi les classes de severite du feu en 2016, un an apres le feu de Boulder Creek qui a brule 6735 ha de foret transitionnelle cotiere en 2015. A l'aide d'indices determines par teledetection (reflectance des zones brulees), nous avons decoupe la region touchee par le feu en fonction de la classe de severite du feu : nulle (temoin non brule), faible, moderee, elevee. Des places echantillons ont ete localisees au hasard sur le terrain dans les zones correspondant a chacune des classes de severite. Dans chaque place echantillon, le carbone des combustibles de surface a ete quantifie par type : materiel ligneux grossier, petit et fin, humus et litiere. La masse de carbone par type de combustibles a ete comparee parmi les classes de severite. La quantite totale de carbone dans les combustibles de surface n'etait pas significativement differente que les places echantillons aient ete brulees ou non. Cependant il y avait significativement moins de carbone dans l'humus et la litiere dans les places echantillons brulees. Les classes de severite determinee par teledetection ne refletaient pas adequatement les impacts des feux de foret sur les combustibles de surface, particulierement dans le cas des feux de faible severite. Les caracteristiques du peuplement avant feu sont egalement d'importants determinants des charges de combustibles de surface. Cette etude de cas fournit les donnees de base pour etudier la dynamique du carbone apres feu dans la zone transitionnelle cotiere en Colombie-Britannique. [Traduit par la Redaction] Mots-cles : feu de foret, carbone forestier, severite du feu, couverture morte, combustibles de surface., Introduction Wildfire is a common disturbance in many forest ecosystems, with historical fire regimes ranging from frequent surface fires that cause minimal overstory tree mortality to infrequent but intense stand-replacing [...]

The western spruce budworm (WSB; Choristoneura freemani Razowski) shapes Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests throughout western North America with periodic, severe landscape-level defoliation events. The largest and most continuous recorded defoliation occurred in the 2000s, largely centered in the Williams Lake and 100 Mile House WSB outbreak regions, peaking in 2007 at 847 000 ha defoliated in British Columbia (B.C.). Unique WSB outbreak regions in south-central B.C. are described using biogeoclimatic ecosystem classification, geography, 106 years of documented defoliation, and 46 stand-level Douglas-fir host tree-ring chronologies. Since the 1980s, recorded defoliation in B.C. has shifted from coastal ecosystems and become a dominant disturbance in drier, colder, interior Douglas-fir ecosystems. Defoliation records demarcate four outbreaks from 1950-2012 and up to three growth suppression events from 1937-2012. Outbreak duration was shorter in the north and far south of B.C., with recovery periods (no trees showing growth suppression) shorter over all WSB outbreak regions in the 2000s, suggesting that trees may be increasingly susceptible to each successive defoliation event. Knowing the regional outbreak periodicity may facilitate early detection of incipient WSB populations, which is critical for management as many of our low-elevation Douglas-fir forests become more stressed with changing and unpredictable climate regimes. Key words: western spruce budworm, British Columbia outbreak history, aerial overview records, dendrochronology, Douglas-fir. La tordeuse occidentale de l'epinette (TOE; Choristoneura freemani Razowski) faconne les forets de douglas de Menzies (Pseudotsuga menziesii (Mirb.) Franco) partout dans l'ouest de l'Amerique du Nord par l'entremise d'episodes de defoliation severes et periodiques a l'echelle du paysage. La defoliation la plus vaste et la plus continue est survenue dans les annees 2000; elle etait surtout concentree dans les zones d'epidemie de TOE du lac Williams et de 100 Mile House et a culmine en 2007 apres avoir defolie 847 000 ha en Colombie-Britannique (C.-B.). Les zones uniques d'epidemie de TOE dans le centre-sud de la C.-B. sont caracterisees al'aide de la classification biogeoclimatique des ecosystemes, de lageographie, des defoliations repertoriees depuis 106 ans et de 46 series dendrochronologiques de douglas de Menzies hotes a l'echelle du peuplement. Depuis les annees 1980, les donnees indiquent que la defoliation en C.-B. a migre des ecosystemes cotiers vers les ecosystemes de douglas de Menzies de l'interieur plus secs et plus froids ou elle est devenue une perturbation dominante. Les donnees de defoliation delimitent quatre epidemies de 1950 a 2012 et jusqu'a trois episodes de suppression de la croissance de 1937 a 2012. La duree des epidemies etait plus courte dans le nord et loin dans le sud de la C.-B., avec des periodes de recuperation (periodes durant lesquelles aucun arbre ne subit de suppression de la croissance) plus courtes dans toutes les regions touchees par les epidemies dans les annees 2000, ce qui indique que les arbres pourraient devenir de plus en plus sensibles a chaque episode successif de defoliation. Le fait de connaitre la periodicite des epidemies regionales peut faciliter la detection precoce des populations pre-epidemiques de TOE, ce qui est essentiel pour l'amenagement etant donne que plusieurs de nos forets de douglas de Menzies situees a basse altitude subissent plus de stress a cause des regimes climatiques changeant et imprevisibles. [Traduit par la Redaction] Mots-cles : tordeuse occidentale de l'epinette, Colombie-Britannique, historique des epidemies, rapports de survol aerien, dendrochronologie, douglas de Menzies., Introduction The western spruce budworm (WSB; Choristoneura freemani Razowski, formerly Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae)) is a native defoliator that periodically experiences often long lasting, landscape-level population outbreaks throughout its [...]

Indigenous land stewardship and mixed‐severity fire regimes both promote landscape heterogeneity, and the relationship between them is an emerging area of research. In our study, we reconstructed the historical fire regime of Ne Sextsine, a 5900‐ha dry, Douglas fir–dominated forest in the traditional territory of the T'exelc (Williams Lake First Nation) in British Columbia, Canada. Between 1550 and 1982 CE, we found median fire intervals of 18 years at the plot level and 4 years at the study‐site level. Ne Sextsine was characterized by an historical mixed‐severity fire regime, dominated by frequent, low‐severity fires as indicated by fire scars, with infrequent, mixed‐severity fires indicated by cohorts. Differentiating low‐ from mixed‐severity plots over time was key to understanding the drivers of the fire regime at Ne Sextsine. Low‐severity plots were coincident with areas of highest use by the T'exelc, including winter village sites, summer fishing camps, and travel corridors. The high fire frequency in low‐severity plots ceased in the 1870s, following the smallpox epidemic, the forced relocation of Indigenous peoples into small reserves, and the prohibition of Indigenous burning. In contrast, the mixed‐severity plots were coincident with areas where forest resources, such as deer or certain berry species, were important. The high fire frequency in the mixed‐severity plots continued until the 1920s when industrial‐scale grazing and logging began, facilitated by the establishment of a nearby railway. T'exelc oral histories and archeological evidence at Ne Sextsine speak to varied land stewardship, reflected in the spatiotemporal complexity of low‐ and mixed‐severity fire plots. Across Ne Sextsine, 63% of cohorts established and persisted in the absence of fire after colonial impacts beginning in the 1860s, resulting in a dense, homogeneous landscape that no longer supports T'exelc values and is more likely to burn at uncharacteristic high severities. This nuanced understanding of the Indigenous contribution to a mixed‐severity fire regime is critical for advancing proactive fire mitigation that is ecoculturally relevant and guided by Indigenous expertise. [ABSTRACT FROM AUTHOR]

Maps depicting historic fire regimes provide critical baselines for sustainable forest management and wildfire risk assessments. However, given our poor understanding of mixed-severity fire regimes, we asked if there may be considerable errors in fire-regime classification systems used to create landscape-level maps. We used dendrochronological field data (fire scars and tree establishment dates) from 20 randomly selected sites in southern British Columbia to evaluate two classification systems (Natural Disturbance Type (NDT) and Historical Natural Fire Regime (HNFR)) used by managers to map fire regimes. We found evidence of mixed-severity fires at 55% of sites. Each classification system made considerable and contrasting errors predicting mixed-severity regimes (relative to field data), and the discrepancies varied with elevation. The NDT system underrepresented low-to-moderate-severity fires at lower elevations, whereas the HNFR system overpredicted their occurrence at higher elevations. Errors are attributed to underlying assumptions about disturbances in the two classification systems, as well as limitations of the research methods used to estimate fire frequency in mixed-severity regimes (i.e., methods more relevant to high- versus low-severity regimes). Ecological heterogeneity created by mixed-severity regimes potentially influences decisions related to conservation, silviculture, wildfire, and fuel mitigation. Thus, understanding underlying assumptions and errors in mapping fire regimes is critical. Resume: Des cartes representant les regimes des feux passes fournissent des bases pour l'amenagement durable des forets et l'evaluation des risques de feu de foret. Cependant, etant donne notre mauvaise comprehension des regimes des feux d'intensite mixte, nous soulevons la possibilite que les systemes de classification des regimes des feux, utilises pour produire des cartes a l'echelle du paysage, comportent d'importantes erreurs. Nous avons utilise des donnees dendrochronologiques recoltees sur le terrain (annees de formation des cicatrices de feu et de l'etablissement des arbres), dans 20 stations choisies au hasard dans le nord de la Colombie-Britannique, pour evaluer deux systemes de classification (type de perturbation naturelle (NDT) et regime des feux naturels passes (HNFR)) utilises par les amenagistes pour cartographier les regimes des feux. Nous avons decouvert des indices de feux de severite mixte dans 55 % des stations. Chaque systeme de classification a produit des erreurs majeures et differentes dans la prediction des regimes des feux de severite mixte (par rapport aux donnees terrain) et les divergences variaient avec l'altitude. Le systeme NDT sous-representait les feux de severite faible a moderee a basse altitude tandis que le systeme HNFR en surestimait l'occurrence a plus haute altitude. Les erreurs sont attribuables aux hypotheses sous-jacentes concernant les perturbations dans les deux systemes de classification, ainsi qu'aux limites des methodes de recherche utilisees pour estimer la frequence des feux dans les regimes de severite mixte (c.-a-d. des methodes plus adaptees aux regimes de severite faible vs elevee). L'heterogeneite ecologique creee par les regimes des feux de severite mixte pourrait influencer les decisions reliees a la conservation, la sylviculture, la faune et l'attenuation des combustibles. Par consequent, il est essentiel de comprendre les hypotheses sous-jacentes et les erreurs pour cartographier les regimes des feux. [Traduit par la Redaction], Introduction Traditionally, fire regimes have been categorized as dominated by either infrequent severe fires or frequent low-severity fires (Perry et al. 2011). With improved understanding of wildfire complexity in mountain [...]