Research Database
Displaying 121 - 140 of 1585
Intensifying Fire Season Aridity Portends Ongoing Expansion of Severe Wildfire in Western US Forests
Year: 2025
Area burned by wildfire has increased in western US forests and elsewhere over recent decades coincident with warmer and drier fire seasons. However, high–severity fire—fire that kills all or most trees—is arguably a more important metric of fire activity given its destabilizing influence on forest ecosystems and direct and indirect impacts to human communities. Here, we quantified area burned and area burned severely in western US forests from 1985 to 2022 and evaluated trends through time. We also assessed key relationships between area burned, extent and proportion burned severely…
Publication Type: Journal Article
Extreme Weather Magnifies the Effects of Forest Structure on Wildfire, Driving Increased Severity in Industrial Forests
Year: 2025
Despite widespread concern over increases in wildfire severity, the mechanisms underlying this trend remain unclear, hampering our ability to mitigate the severity of future fires. There is substantial uncertainty regarding the relative roles of extreme weather conditions, which are exacerbated by climate change, and forest management, in particular differences between private industrial timber companies and public land agencies. To investigate the effects of extreme weather and forest management on fire severity, we used light detection and ranging (LiDAR) data to characterize pre-fire…
Publication Type: Journal Article
Projections of Lightning-Ignited Wildfire Risk in the Western United States
Year: 2025
Cloud-to-ground (CG) lightning is a major source of summer wildfire ignition in the western United States (WUS). However, future projections of lightning are uncertain since lightning is not directly simulated by most global climate models. To address this issue, we use convolutional neural network (CNN)-based parameterizations of daily June-September CG lightning. CNN parameterizations of daily CG lightning occurrence at each grid cell use fields of three thermodynamic variables—ratio of surface Moist Static Energy (MSE) to 500 hPa saturation MSE, 700–500 hPa lapse rate, and 500…
Publication Type: Journal Article
Morphological and physiological response of conifer seedlings to drought conditioning
Year: 2025
Increased frequency, severity, and duration of droughts and increased wildfire severity are impacting many conifer forests globally. Reforestation in these changing disturbance regimes requires tree seedlings capable of establishing in hotter and drier climates. We evaluated the morphological and physiological effects of drought conditioning on second-year ponderosa pine (Pinus ponderosa), western white pine (Pinus monticola), and western larch (Larix occidentalis) seedlings. Treatments included a well-watered control (75% of container capacity) and a water-limited…
Publication Type: Journal Article
Long-range PM2.5 pollution and health impacts from the 2023 Canadian wildfires
Year: 2025
Smoke from extreme wildfires in Canada adversely affected air quality in many regions in 20231,2. Here we use satellite observations, machine learning and a chemical transport model to quantify global and regional PM2.5 (particulate matter less than 2.5 μm in diameter) exposure and human health impacts related to the 2023 Canadian wildfires. We find that the fires increased annual PM2.5 exposure worldwide by 0.17 μg m–3 (95% confidence interval, 0.…
Publication Type: Journal Article
Showy dragonflies are being driven extinct by warming and wildfire
Year: 2025
Rising temperatures may disrupt reproduction before becoming lethal; thus mating traits could define species vulnerability to warming. Here, using >1,600 estimates of local extinction for 60 dragonfly species, we show that species with mating-associated wing ornamentation experienced more extinctions and lost more habitat under warming and following wildfire burn than non-ornamented species. By contrast, sensitivity was not affected by ecological traits, such as thermal limits, habitat specialization or body size.
Publication Type: Journal Article
Comparative Analysis of Ensemble and Deterministic Models for Fire Weather Index (FWI) System Forecasting
Year: 2025
Accurate fire weather forecasting is essential for effective wildfire management, particularly in regions increasingly affected by extreme fire activity such as British Columbia and Alberta, Canada. This study evaluates the predictive performance of three ensemble forecasting systems–the Ensemble Prediction System (ENS), the Global Ensemble Forecast System (GEFS), and the Canadian Global Ensemble Prediction System (GEPS)–and one deterministic model (High Resolution Forecast, HRES) –in forecasting components of the Canadian Fire Weather Index (FWI) System with 1–15 days lead time during the…
Publication Type: Journal Article
A Negative Fire–Vegetation Feedback Substantially Limits Reburn Extent Across the North American Boreal Biome
Year: 2025
The North American boreal biome (NAB) is warming at 2–4 times the mean global rate, contributing to increasing wildfire activity. The degree to which this trend alters biome-level feedbacks to global climate depends on how strongly bottom-up feedbacks between fire and vegetation dampen the effects of climate drivers. As young vegetation recovering from fire covers a growing portion of the landscape, it could resist reburning, buffering against further increases in fire. Resistance to reburning could be particularly strong in the NAB, where slow post-fire fuel accumulation is sometimes…
Publication Type: Journal Article
Housing and Economic Recovery as Interdependent Pathways in the Wake of Wildfires
Year: 2025
Highlights
- Introduced an integrated housing-economic recovery framework that links post-wildfire housing stability to local employment conditions and economic diversity.
- Demonstrated how traditional vulnerability tools like SoVI overlook hidden and dynamic vulnerabilities, especially among renters, seasonal workers, and undocumented residents.
- Employed a mixed-methods approach combining quantitative data (DINS, assessor records, LODES, CDC SoVI) with qualitative interviews and spatial analysis to track recovery in Paradise and Santa Rosa.
- Found a marked rise in…
Publication Type: Journal Article
Combining ecophysiology and combustion traits: a pyro-ecophysiological approach to live fuel moisture prediction in common shrubs
Year: 2025
BackgroundQuantifying fuel moisture content accurately is critical for understanding global vegetation flammability. While models representing changes in dead fuel moisture are relatively advanced, the mechanisms driving fluctuations in live fuel moisture content (LFMC) have been difficult to capture. Living plants make up a large proportion of the fuel complex for wildfires, yet linking plant and combustion science to advance our understanding of wildfire risk has, to date, been limiting. Developing mechanistic approaches to link these two disciplines will confer greater understanding and…
Publication Type: Journal Article
Fitness consequences of catastrophic wildfire are mitigated by behavioral responses of an iconic bird
Year: 2025
Publication Type: Journal Article
Global firestorm: Igniting insights on environmental and socio-economic impacts for future research
Year: 2025
Forests are vital life-preserving assets, essential for biodiversity, human health, climate change mitigation, and economic stability. Yet, they are increasingly threatened by forest fires, which undermine these benefits. In the first half of 2025, forest fires in the United States burned over 810,000 acres, Canada lost 7.3 million hectares, while the 2020 Australian mega-fires, which caused an estimated US $20 billion in economic losses, illustrate the scale and urgency of the problem. Despite such impacts, research integrating the diverse dimensions of forest fires, including suppression…
Publication Type: Journal Article
Exploring Wildfire Preparedness, Perceptions, and Responses in Western Canada: Insights from Valemount, British Columbia
Year: 2025
Climate change and decades of fire suppression are increasing the risk of wildfire in many rural and remote communities across Canada. Yet limited research has been done to better understand how these communities experience wildfire risk. For this research, conducted prior to the catastrophic wildfire season of 2023 in British Columbia, we interviewed 20 key informants living in the village of Valemount in the Robson Valley, British Columbia, about their perceptions of wildfire risk, lived experiences, and management approaches. We further explored barriers to and opportunities for future…
Publication Type: Journal Article
Fatigue in wildland firefighting: relationships between sleep, shift characteristics, and cognitive function
Year: 2025
BackgroundWildland firefighting requires exposure to long shifts and poor sleep, which may pose a risk to worker safety due to impaired cognitive function.AimsWe investigated the associations between sleep, shift characteristics, and cognitive function in wildland firefighters.MethodsWe conducted a within-subject observational study with 25 wildland firefighters from the British Columbia Wildfire Service, Canada. Data were collected remotely during the 2021 and 2022 fire seasons. Wrist-worn actigraphy and the psychomotor vigilance task served…
Publication Type: Journal Article
Learning from Wildfire Decision Support: large language model analysis of barriers to fire spread in a census of large wildfires in the United States (2011–2023)
Year: 2025
BackgroundBarriers are the landscape features that firefighters leverage to stop wildfire spread. In the United States, decision-makers discuss barrier availability in a framework called the Wildland Fire Decision Support System (WFDSS).AimsThis study analyzes WFDSS text from 6630 large wildfires and examines the barriers identified.MethodsA large language model was trained and validated, then used to detect 13 different barriers. Burn scar and fuel treatment barriers were compared with their availability near each fire.Key results…
Publication Type: Journal Article
Wildland Fire–Related Smoke PM2.5 and Cardiovascular Disease Emergency Department Visits in the Western United States
Year: 2025
BackgroundThe impact of short‐term exposure to fine particulate matter with a diameter ≤2.5 μm (PM2.5) due to wildland fire smoke on the risk of cardiovascular disease (CVD) remains unclear. We investigated the association between short‐term exposure to wildfire smoke PM2.5 and emergency department visits for acute CVD in the western United States from 2007 to 2018.MethodsWe analyzed 49 759 958 emergency department visits for primary or secondary diagnoses of atrial fibrillation (AF), acute myocardial infarction, heart failure, stroke, and total CVD across 5…
Publication Type: Journal Article
Multi-scale assessment of wildfire use on carbon stocks in the Sierra Nevada, CA
Year: 2025
BackgroundThe active use of wildfire to meet forest management objectives is an important tool to increase the scale of forest restoration in dry, historically frequent-fire forests. While there are many benefits of reintroducing fire to these forests, the impact of wildland fire use policies in frequent-fire forests on aboveground carbon stocks has not yet been studied. In this study, we begin to fill this knowledge gap by assessing how fire frequency and severity affected aboveground carbon dynamics in two basins in the Sierra Nevada with a history of wildfire use over the…
Publication Type: Journal Article
Wildland firefighter exposure and female cancer risk: currently available evidence
Year: 2025
The James M. Inhofe National Defence Authorization Act for Fiscal Year 2023 established that certain illnesses and diseases are to be deemed as proximately caused by employment in federal fire protection activities. However, cancers affecting female wildland firefighters were not included on this list and are recommended for further evaluation. We present the best available scientific evidence for the risk of breast and gynaecological cancers associated with exposures that are commonly measured in the wildland fire environment, including benzene, polycyclic aromatic hydrocarbons, and…
Publication Type: Journal Article
Impact of wildfire smoke, heat stress and sleep deprivation on the brain health of wildland firefighters
Year: 2025
Wildland firefighters (WLFFs) face significant brain health risks due to prolonged exposure to smoke, extreme heat, dehydration, physical exertion and irregular sleep patterns. Here, the literature is presented as a narrative review on studies that inform our knowledge on WLFF brain health. The neurotoxic components of wildfire smoke, such as particulate matter, carbon monoxide and polycyclic aromatic hydrocarbons, can disrupt brain function by inducing oxidative stress, neuroinflammation and hypoxia, which can contribute to cognitive decline and increase the risk of neurodegenerative…
Publication Type: Journal Article
Advancing the community health vulnerability index for wildland fire smoke exposure
Year: 2024
Wildland fire smoke risks are not uniformly distributed across people and places, and the most vulnerable communities are often disproportionately impacted. This study develops a county level community health vulnerability index (CHVI) for the Contiguous United States (CONUS) using three major vulnerability components: adaptive capacity, sensitivity, and exposure at the national and regional level. We first calculated sensitivity and adaptive capacity sub-indices using nine sensitivity and twenty adaptive capacity variables. These sub-indices were then combined with an exposure sub-index,…
Publication Type: Journal Article