Research Database
Displaying 181 - 200 of 300
Severe fire has impacted populations of the California spotted owl more than fuels management or drought-related tree mortality
Year: 2025
Reducing fuel densities is the primary tool available to improve forest resilience to intensifying disturbance, but implementation is constrained by concern of effects to mature-forest associated species, such as spotted owls (Strix occidentalis). While the negative effects of severe fire on spotted owls are well studied, the influence of drought and fuels management on populations is uncertain, impeding fuels management. We integrated a novel dataset of California disturbance history with passive acoustic monitoring to compare the effects of severe fire, drought, and fuels…
Publication Type: Journal Article
Perspectives: The pace and scale challenge: Leveraging wildfire footprints to increase forest resilience to future high-severity fire
Year: 2025
In historically frequent fire forests, wildfires are burning larger areas and driving forest loss across western North America, yet they also produce extensive low- to moderate-severity effects that can be leveraged to harden landscapes against future high-severity fire. Here, we operationalize prior conceptual calls by presenting a framework that identifies opportunities to leverage recent wildfire footprints via three management pathways to increasing resistance to high-severity fire: create (use burned edges as containment lines to treat adjacent unburned forest), enhance…
Publication Type: Journal Article
Forest floor properties in pine forests of the southeastern and western United States
Year: 2025
BackgroundWildland fuels are fundamental variables in modeled predictions of fire behavior and effects. In forest ecosystems, accumulated forest floor layers, including recently fallen litter and highly decomposed organic material (i.e., duff), often constitute most surface fuel—biomass and stored carbon. Associated error in estimated litter and duff biomass can thus propagate to major sources of uncertainty in predicted fire effects, including tree mortality and smoke production. Distributions of forest floor biomass are difficult to measure, and estimates of litter and duff…
Publication Type: Journal Article
Fire refugia in forest ecosystems of the Pacific Northwest, USA: Science and applications for conservation, adaptation, and stewardship
Year: 2025
Concepts and models of fire refugia are increasingly important components of forest management and adaptation discussions in the context of wildland fire, forest and habitat conservation, and global change. Recent stand-replacing fires in mature and old-growth forests of the Pacific Northwest (PNW) region of the western United States have increased land manager and scientific interest in fire refugia that can provide important ecosystem services. Here we provide an overview of fire refugia concepts and products being actively developed and applied in forests of the PNW (Washington, Oregon,…
Publication Type: Journal Article
Wildfire recovery in Pacific Northwest Latine communities: how community capitals shape disaster resilience
Year: 2025
Wildfires are increasingly affecting people’s lives in the Pacific Northwest. Latine populations, in particular, often face unique challenges in their recovery process. This study examines individual Latine wildfire recovery experiences to understand the strengths and barriers in the community’s post-fire recovery process in two wildfire-affected areas in Oregon and Washington. Perceptions of recovery of Latine community members and community-based organizations that serve these populations were collected through focus groups, semi-structured interviews, and participant observation at…
Publication Type: Journal Article
A post-fire reforestation assessment and prioritization tool for the Western United States
Year: 2025
BackgroundIncreasing wildfire area burned has left millions of hectares in the western United States (US) in need of reforestation. Recent federal legislation allows for increased investments in tree planting to address the backlog of planting needs in previously burned areas. To support post-fire planning and assessment, we developed Regenmapper, a web-based decision support system (DSS) that provides spatial information on natural regeneration potential within post-fire environments. The program is freely available from a web browser (…
Publication Type: Journal Article
The Diffusion of Risk Management Assistance for Wildland Fire Management in the United States
Year: 2025
The wildland fire management system is increasingly complex and uncertain, which challenges suppression actions and increases stress on an already strained system. Researchers and managers have called for the use of strategic, risk-informed decision making and decision support tools (DSTs) in wildfire management to manage complexity and mitigate uncertainty. This paper evaluated the use of an emerging wildfire DST, the Risk Management Assistance (RMA) dashboard, during the 2021 and 2022 wildfire seasons. We used a mixed-method approach, consisting of an online survey and in-depth interviews…
Publication Type: Journal Article
Large projected increases in area burned and wildfire frequency by 2050 in Utah, USA
Year: 2025
Changes in wildfire regimes may disrupt ecosystem processes as wildfires burn larger areas or burn more frequently than the recent natural range of variability. The climatic drivers of wildfire behavior may change in strength, but these effects are not likely to be uniform across space and different vegetation types. Increased understanding of how weather and climate influence patterns of burn area and frequency across vegetation types may assist in better predicting and managing future wildfire regimes. We examined a dataset of all 1469 wildfires ≥40 ha from 1984 - 2021 in Utah, USA, and…
Publication Type: Journal Article
Awareness and Social Interactions Influence Natural Resource Professionals’ Recommendations for Prescribed Fire Use
Year: 2025
Restoring fire in fire-adapted ecosystems is necessary to curtail woody plant expansion, enhance biodiversity, and reduce wildfire risks, yet prescribed fire is promoted less by federal agencies than other grassland conservation practices. The U.S. Department of Agriculture…
Fire and Rangelands, Prescribed Burning, Public Perceptions of Fire and Smoke, Restoration and Hazardous Fuel Reduction
Publication Type: Journal Article
The hidden variable: Impacts of human decision-making on prescribed fire outcomes
Year: 2025
This study investigates the key drivers influencing prescribed fire effects across 16 sites in northern and central California, with particular emphasis on how operational decisions by fire practitioners shape burn outcomes. Data from the California Prescribed Fire Monitoring Program revealed that prescribed fires reduced total fuel loads by an average of 60 %, with greater consumption of postfrontal smoldering fuels (coarse fuels, 65 %) compared to frontline spreading fuels (fine fuels, 49.0 %).Crown scorch height showed a strong relationship to crown base height (R2 =…
Fire Effects and Fire Ecology, Fuels and Fuel Treatments, Prescribed Burning, Restoration and Hazardous Fuel Reduction
Publication Type: Journal Article
Rising rates of wildfire building destruction in the conterminous United States
Year: 2025
Many regions of the world have seen an increase in highly destructive wildfires, driven by well-documented increases in burned area and growth of housing in the wildland–urban interface (WUI), which exposes more homes to fire. However, it is unclear whether wildfires are also becoming more destructive due to changes in wildfire behavior or in the development patterns of exposed communities. Here, we assessed trends in wildfire building exposure and destruction rates in the conterminous United States from 2002 to 2022. We mapped destroyed and surviving buildings within 100 m of all wildfires…
Publication Type: Journal Article
Yosemite’s Merced Grove of giant sequoias: critical restoration continues despite legal challenges
Year: 2025
BackgroundGiant sequoias are the most massive individual trees on earth, and among the longest-lived. They also have a limited distribution, covering ~10,000 ha across ~70 distinct groves. Severe wildfires in 2020 and 2021 impacted 82% of the range, killing roughly 13-19% of the entire population of these irreplaceable trees. Within the giant sequoia range, the Merced Grove is one of the most at risk of burning at high severity. Located in Yosemite National Park, it has no recorded wildfire history and has received minimal restoration treatment, most of which occurred…
Public Perceptions of Fire and Smoke, Restoration and Hazardous Fuel Reduction, Social and Community Impacts of Fire
Publication Type: Journal Article
Emissions from burned structures in wildfires as significant yet unaccounted sources of US air pollution
Year: 2025
Structure fires in the wildland–urban interface (WUI) are becoming more frequent and destructive, yet their emissions of air pollutants remain poorly quantified and are not included in national inventories. Here we present a conterminous-scale inventory of WUI-related structure fire emissions in the United States from 2000 to 2020. A small number of highly destructive events dominate structure fire emissions—the 20 most destructive fires account for 68% of total carbon monoxide emissions. Structure fire emissions are more spatially concentrated than vegetation fire emissions, and in several…
Publication Type: Journal Article
The contribution of Indigenous stewardship to an historical mixed-severity fire regime in British Columbia, Canada
Year: 2022
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…
Publication Type: Journal Article
Trends in forest structure restoration need over three decades with increasing wildfire activity in the interior Pacific Northwest US
Year: 2022
Wildfire is a keystone ecological process in many forests worldwide, but fire exclusion and suppression have driven profound shifts in forest structure (e.g., increased density, canopy cover, biomass) that have contributed to increases in large, high-severity fire in many seasonally dry forests and woodlands of the western United States. Comparisons between contemporary and historic range of variability (HRV) in forest structure can quantify the amount and types of restoration that shift landscapes toward structural conditions that have his- torically fostered resilience to fire. However,…
Publication Type: Journal Article
Human- and lightning-caused wildland fire ignition clusters in British Columbia, Canada
Year: 2022
Wildland fire is a common occurrence in western Canada, with record-setting area burned recorded in British Columbia (BC) in the past decade. Here, we used the unsupervised machine learning algorithm HDBSCAN to identify high-density clusters of both human- and lightning- caused wildfire ignitions in BC using data from 2006 to 2020. We found that human-caused ignition clusters tended to occur around population centres, First Nations communities, roads and valleys, and were more common in the southern half of the province, which is more populated. Lightning-ignition clusters were generally…
Publication Type: Journal Article
Comparing two methods to measure oxidative pyrolysis gases in a wind tunnel and in prescribed burns
Year: 2022
Background. Fire models use pyrolysis data from ground samples and environments that differ from wildland conditions. Two analytical methods successfully measured oxidative pyrolysis gases in wind tunnel and field fires: Fourier transform infrared (FTIR) spectroscopy and gas chroma- tography with flame-ionisation detector (GC-FID). Compositional data require appropriate statistical analysis. Aims. To determine if oxidative pyrolysis gas composition differed between analytical methods and locations (wind tunnel and field). Methods. Oxidative pyrolysis gas sample composition collected in wind…
Publication Type: Journal Article
Comparing particulate morphology generated from human- made cellulosic fuels to natural vegetative fuels
Year: 2022
Background: In wildland–urban interface (WUI) fires, particulates from the combustion of both natural vegetative fuels and engineered cellulosic fuels may have deleterious effects on the environment. Aims: The research was conducted to investigate the morphology of the particulate samples generated from the combustion of oriented strand board (OSB). Findings were compared to the particulate samples collected from the combustion of noble-fir branches. Methods: The exposure conditions were varied to induce either smouldering combustion or flaming combustion of the specimens. Particulate samples…
Publication Type: Journal Article
Growing impact of wildfire on western US water supply
Year: 2022
Streamflow often increases after fire, but the persistence of this effect and its importance to present and future regional water resources are unclear. This paper addresses these knowledge gaps for the western United States (WUS), where annual forest fire area increased by more than 1,100% during 1984 to 2020. Among 72 forested basins across the WUS that burned between 1984 and 2019, the multibasin mean streamflow was significantly elevated by 0.19 SDs (P < 0.01) for an average of 6 water years postfire, compared to the range of results expected from climate alone. Sig- nificance is…
Publication Type: Journal Article
Tree mortality response to drought-density interactions suggests opportunities to enhance drought resistance
Year: 2022
1. The future of dry forests around the world is uncertain given predictions that rising temperatures and enhanced aridity will increase drought-induced tree mortality. Using forest management and ecological restoration to reduce density and competition for water offers one of the few pathways that forests managers can potentially minimize drought-induced tree mortality. Competition for water during drought leads to elevated tree mortality in dense stands, although the influence of density on heat-induced stress and the durations of hot or dry conditions that most impact mortality remain…
Publication Type: Journal Article