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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]

Abstract 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.

Detailed information about the historical range of variability in wildfire activity informs adaptation to future climate and disturbance regimes. Here, we describe one of the first annually resolved reconstructions of historical (1500–1900 ce) fire occurrence in coast Douglas‐fir dominated forests of the west slope of the Cascade Range in western Oregon. Mean fire return intervals (MFRIs) across 16 sites within our study area ranged from 6 to 165 years. Variability in MFRIs was strongly associated with average maximum summer vapor pressure deficit. Fire occurred infrequently in Douglas‐fir forest stands seral to mountain hemlock or silver fir, but fire frequency was much shorter than predicted by theory in other forest types. MFRIs within Douglas‐fir stands seral to western hemlock or grand fir ranged from 19 to 45 years, and MFRIs in stands seral to Douglas‐fir ranged from 6 to 11 years. There was little synchrony in fire occurrence or tree establishment across 16 sites separated by 4 km. The lack of synchrony in fire suggests that large, wind‐driven fire events that are often considered to be characteristic of coast Douglas‐fir forests were not an important driver of succession in our study area during the last ~400–500 years. Climate was more arid than normal during fire years in most forest types, but historical fire in stands seral to Douglas‐fir was strongly associated with antecedent moisture and less strongly associated with drought. We interpret the extraordinary tempo of fire we observed in stands seral to Douglas‐fir and the unique climate pattern associated with fire in these stands to be indicative of Indigenous fire stewardship. This study provides evidence of far more frequent historical fire in coast Douglas‐fir forests than assumed by managers or scientists—including some of the most frequent fire return intervals documented in the Pacific Northwest. We recommend additional research across the western Cascades to create a comprehensive account of historical fire in highly productive forests with significant cultural, economic, and ecological importance. [ABSTRACT FROM AUTHOR]

Abstract Detailed information about the historical range of variability in wildfire activity informs adaptation to future climate and disturbance regimes. Here, we describe one of the first annually resolved reconstructions of historical (1500–1900 ce) fire occurrence in coast Douglas‐fir dominated forests of the west slope of the Cascade Range in western Oregon. Mean fire return intervals (MFRIs) across 16 sites within our study area ranged from 6 to 165 years. Variability in MFRIs was strongly associated with average maximum summer vapor pressure deficit. Fire occurred infrequently in Douglas‐fir forest stands seral to mountain hemlock or silver fir, but fire frequency was much shorter than predicted by theory in other forest types. MFRIs within Douglas‐fir stands seral to western hemlock or grand fir ranged from 19 to 45 years, and MFRIs in stands seral to Douglas‐fir ranged from 6 to 11 years. There was little synchrony in fire occurrence or tree establishment across 16 sites separated by 4 km. The lack of synchrony in fire suggests that large, wind‐driven fire events that are often considered to be characteristic of coast Douglas‐fir forests were not an important driver of succession in our study area during the last ~400–500 years. Climate was more arid than normal during fire years in most forest types, but historical fire in stands seral to Douglas‐fir was strongly associated with antecedent moisture and less strongly associated with drought. We interpret the extraordinary tempo of fire we observed in stands seral to Douglas‐fir and the unique climate pattern associated with fire in these stands to be indicative of Indigenous fire stewardship. This study provides evidence of far more frequent historical fire in coast Douglas‐fir forests than assumed by managers or scientists—including some of the most frequent fire return intervals documented in the Pacific Northwest. We recommend additional research across the western Cascades to create a comprehensive account of historical fire in highly productive forests with significant cultural, economic, and ecological importance.

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]

Indigenous fire stewardship enhances ecosystem diversity, assists with the management of complex resources, and reduces wildfire risk by lessening fuel loads. Although Indigenous Peoples have maintained fire stewardship practices for millennia and continue to be keepers of fire knowledge, significant barriers exist for re-engaging in cultural burning. Indigenous communities in Canada have unique vulnerabilities to large and high-intensity wildfires as they are predominately located in remote, forested regions and lack financial support at federal and provincial levels to mitigate wildfire risk. Therefore, it is critical to uphold Indigenous expertise in leading effective and socially just fire stewardship. In this perspective, we demonstrate the benefits of cultural burning and identify five key barriers to advancing Indigenous fire stewardship in Canada. We also provide calls to action to assist with reducing preconceptions and misinformation and focus on creating space and respect for different knowledges and experiences. Despite growing concerns over wildfire risk and agency-stated intentions to establish Indigenous Peoples as partners in wildfire management, power imbalances still exist. The future and coexistence with fire in Canada needs to be a shared responsibility and led by Indigenous Peoples within their territories.

Context: In fire-excluded forests across western North America, recent intense wildfire seasons starkly contrast with fire regimes of the past. The last 100 years mark a transition between pre-colonial and modern era fire regimes, providing crucial context for understanding future wildfire behavior. Objectives: Using the greatest time depth of digitized fire events in Canada, we identify distinct phases of wildfire regimes from 1919 to 2019 by evaluating changes in mapped fire perimeters (> 20-ha) across the East Kootenay region (including the southern Rocky Mountain Trench), British Columbia. Methods: We detect transitions in annual number of fires, burned area, and fire size; explore the role of lightning- and human-caused fires in driving these transitions; and quantify departures from historical fire frequency at the regional level. Results: Relative to historical fire frequency, fire exclusion has created a significant fire deficit in active fire regimes, with a minimum of 1–10 fires missed across 46.4-percent of the landscape. Fire was active from 1919 to 1939 with frequent and large fire events, but the regime was already altered by a century of colonization. Fire activity decreased in 1940, coinciding with effective fire suppression influenced by a mild climatic period. In 2003, the combined effects of fire exclusion and accelerated climate change fueled a shift in fire regimes of various forest types, with increases in area burned and mean fire size driven by lightning. Conclusions: The extent of fire regime disruption warrants significant management and policy attention to alter the current trajectory and facilitate better co-existence with wildfire throughout this century. [ABSTRACT FROM AUTHOR]

Our understanding of forest dynamics and successional pathways in coastal Douglas-fir (Pseudotsuga menziesii var menziesii) forests with relatively frequent mixed-severity fires is limited by a lack of annually precise dendroecological reconstructions that combine records of historical fires and tree establishment. The processes by which old-forest heterogeneity developed under historical fire regimes with recurrent low- and moderate-severity fires has not been well studied at fine temporal scales and across spatial scales. We developed crossdated multi-century records of fire and tree establishment histories in old forests (170 – 550 years) at 34 plots distributed across six sites. Study sites include warm-dry to cool-moist Douglas-fir forest types found in the southern west Cascades of Oregon, USA. Spatial variability in historical fire frequency and fire effects resulted in tremendous diversity in forest developmental histories, age structure, and forest conditions. Most historical fire intervals were very frequent (<10 years) to frequent (<25 years) in dry Douglas-fir forests. Exceptionally high fire frequency and an abrupt decrease in fire frequency after European colonization in dry Douglas-fir forests adds to growing evidence and recognition of Indigenous fire stewardship in montane Douglas-fir forests. In moist forests where Douglas-fir is seral to western hemlock, fire intervals were frequent to moderately frequent (<50 years), but intervals varied substantially over time. Relatively young moist forests burned frequently while mature moist forests had long fire intervals (50–160 years). Nearly all tree establishment cohorts were preceded by either stand-replacing (28 %) or non-stand-replacing fires (64 %). However, tree cohorts only provided evidence of 16 % of historical fire events that we reconstructed from cambial fire scars. This study demonstrates that frequent fire can be an important driver of forest development and in some contexts shapes the structure of coastal old-growth Douglas-fir forests, which are often characterized as developing from endogenous disturbances during long fire-free periods. The high level of pyrodiversity we observed was associated with variation in and interactions of micro-climate, topography, fuels, and Indigenous fire stewardship. We recommend rigorous dendroecological reconstructions across the coastal Douglas-fir region to refine our understanding of the geography of fire-mediated forest developmental dynamics in this important forest type, to inform forest management, conservation, and ecocultural restoration. • Fires were historically frequent to moderately frequent in moist Douglas-fir forests. • Non-stand-replacing fires shaped the development of old-growth forests. • Fire frequency was higher when moist forests were relatively young. • Non-stand-replacing fire was a gap creation process that facilitated tree establishment. • Indigenous fire stewardship shaped historical fire regimes and forest conditions. [ABSTRACT FROM AUTHOR]

Worldwide, Indigenous peoples are leading the revitalization of their/our cultures through the restoration of ecosystems in which they are embedded, including in response to increasing "megafires." Concurrently, growing Indigenous‐led movements are calling for governments to implement Indigenous rights, titles and treaties, and many settler‐colonial governments are committing to reconciliation with Indigenous peoples and to implementing the United Nations Declaration on the Rights of Indigenous Peoples. Yet, despite growing recognition that just and effective conservation is only possible through partnerships with, or led by, Indigenous peoples, decolonizing approaches to restoration have received insufficient attention. However, reconciliation will be incomplete without Indigenous‐led restoration of Indigenous lands, knowledges, and cultures. In this article, we introduce the concept of "walking on two legs" to guide restoration scientists and practitioners in advancing the interconnected processes of Indigenous‐led restoration and reconciliation in Indigenous territories. As an action‐oriented framework articulated by Secwépemc Elder Ronald E. Ignace, "walking on two legs" seeks to bring Indigenous knowledges into balance with western scientific knowledge in service of upholding an Indigenous stewardship ethic that is embedded in Indigenous ways of relating to land and embodies principles of respect, reciprocity, and responsibility. Grounding this discussion in the context of fire‐adapted ecosystems of western Canada and unceded and traditional Secwépemc territory, Secwepemcúl̓ecw, we argue that walking on two legs, along with principles of reconciliation, offers a pathway to uphold respectful relationships with Indigenous peoples, knowledges, and territories through Indigenous‐led restoration. [ABSTRACT FROM AUTHOR]

With the growing challenge of addressing modern fire risk, land managers and researchers are increasingly looking to Indigenous knowledge as a primary source of information for enabling resilience of fire-dependent social-ecological systems (SES). Although this is an important step forward for recognizing the contribution of Indigenous peoples to fire-dependent landscapes, current SES research in fire contexts views knowledge as detached from power, reflecting a critique in SES resilience research more broadly. Integrating Indigenous knowledge into dominant colonial management paradigms (such as "command and control" management of fire) without attention to these power asymmetries will lead to inequitable solutions to modern wildfire challenges. To address this gap, we employ the concept of situated resilience--which views knowledge as a process contextualized within power dynamics--to a case study of a fire-dependent SES in the traditional territory of the T'exelc (Williams Lake First Nation), in the land now known as British Columbia, Canada. Through a "collaborative experiment" research design that incorporated iterative, long-term, ethical research relationships guiding knowledge co-production in forest walks, we engaged with T'exelc Elders, archaeologists, and forest managers to explore the context of Indigenous fire knowledge and situate Indigenous definitions of resilience in future forest management. Results indicate that for the T'exelc, the intentional use of fire to support their livelihoods was lost due to colonialism. This colonial context disrupted place-based, intergenerational knowledge transmission and resulted in forest management devoid of respect. However, employing the concept of situated resilience moved us beyond a preoccupation with the content of fire knowledge toward actively shifting the colonial context in which T'exelc knowledge was embedded. Through our collaborative experiment, and the trust built among T'exelc Elders, archaeologists, and forest managers, future forest management will more directly work to restore intergenerational knowledge exchange and respect and situate Indigenous-led resilience to modern wildfire challenges. [ABSTRACT FROM AUTHOR]

Increasingly, severe wildfires have led to declines in biodiversity across all of Earth's vegetated biomes [D. B. McWethy et al., Nat. Sustain. 2, 797-804 (2019)]. Unfortunately, the displacement of Indigenous peoples and place-based societies that rely on and routinely practice fire stewardship has resulted in significant declines in biodiversity and the functional roles of people in shaping pyrodiverse systems [R. Bliege Bird et al., Proc. Natl. Acad. Sci. U.S.A. 117, 12904-12914 (2020)]. With the aim of assessing the impacts of Indigenous fire stewardship on biodiversity and species function across Earth's major terrestrial biomes, we conducted a review of relevant primary data papers published from 1900 to present. We examined how the frequency, seasonality, and severity of humanignited fires can improve or reduce reported metrics of biodiversity and habitat heterogeneity as well as changes to species composition across a range of taxa and spatial and temporal scales. A total of 79% of applicable studies reported increases in biodiversity as a result of fire stewardship, and 63% concluded that habitat heterogeneity was increased by the use of fire. All studies reported that fire stewardship occurred outside of the window of uncontrollable fire activity, and plants (woody and nonwoody vegetation) were the most intensively studied life forms. Three studies reported declines in biodiversity associated with increases in the use of high-severity fire as a result of the disruption of Indigenous-controlled fire regimes with the onset of colonization. Supporting Indigenous-led fire stewardship can assist with reviving important cultural practices while protecting human communities from increasingly severe wildfires, enhancing biodiversity, and increasing ecosystem heterogeneity. [ABSTRACT FROM AUTHOR]