Research Database
Displaying 1 - 20 of 151
COVID‐19 Fueled an Elevated Number of Human‐Caused Ignitions in the Western United States During the 2020 Wildfire Season
Year: 2025
The area burned in the western United States during the 2020 fire season was the greatest in the modern era. Here we show that the number of human-caused fires in 2020 also was elevated, nearly 20% higher than the 1992–2019 average. Although anomalously dry conditions enabled ignitions to spread and contributed to record area burned, these conditions alone do not explain the surge in the number of human-caused ignitions. We argue that behavioral shifts aimed at curtailing the spread of COVID-19 altered human-environment interactions to favor increased ignitions. For example, the number of…
Publication Type: Journal Article
Mental health risk for wildland firefighters: a review and future directions
Year: 2025
Wildland fire is increasingly a consequence of the climate crisis, with growing impacts on communities and individuals. Wildland firefighters are critical to the successful management of wildland fire, yet very limited research has considered mental health in this population. Although a wealth of research in mental health risk and associated risk and protective factors exists for structural firefighters, unique demands of wildland firefighting such as the seasonal nature of work, the length and intensity of shifts, and the often geographically isolated working conditions, among other factors…
Publication Type: Journal Article
Extreme Fire Spread Events Burn More Severely and Homogenize Postfire Landscapes in the Southwestern United States
Year: 2025
Extreme fire spread events rapidly burn large areas with disproportionate impacts on people and ecosystems. Such events are associated with warmer and drier fire seasons and are expected to increase in the future. Our understanding of the landscape outcomes of extreme events is limited, particularly regarding whether they burn more severely or produce spatial patterns less conducive to ecosystem recovery. To assess relationships between fire spread rates and landscape burn severity patterns, we used satellite fire detections to create day‐of‐burning maps for 623 fires comprising 4267 single‐…
Publication Type: Journal Article
Fine Particulate Matter From 2020 California Wildfires and Mental Health–Related Emergency Department Visits
Year: 2025
Importance: A growing body of research suggests that exposure to fine particulate matter (PM2.5; particle size 2.5 microns or smaller) may be associated with mental health outcomes. However, the potential impact of wildfire-specific PM2.5 exposure on mental health remains underexplored.Objective: To investigate whether wildfire-specific PM2.5 exposure may be associated with emergency department (ED) visits for mental health conditions, including all-cause and for psychoactive substance use, nonmood psychotic disorders, anxiety, depression, and other mood-affective disorders during the…
Publication Type: Journal Article
Enhancing fire emissions inventories for acute health effects studies: integrating high spatial and temporal resolution data
Year: 2025
Background: Daily fire progression information is crucial for public health studies that examine the relationship between population-level smoke exposures and subsequent health events. Issues with remote sensing used in fire emissions inventories (FEI) lead to the possibility of missed exposures that impact the results of acute health effects studies.Aims: This paper provides a method for improving an FEI dataset with readily available information to create a more robust dataset with daily fire progression.Methods: High temporal and spatial…
Publication Type: Journal Article
Long-term influence of prescribed burning on subsequent wildfire in an old-growth coast redwood forest
Year: 2025
Background: Prescribed burning is an effective tool for reducing fuels in many forest types, yet there have been few opportunities to study forest resilience to wildfire in areas previously treated. In 2020, a large-scale high-intensity wildfire burned through an old-growth coast redwood (Sequoia sempervirens) forest with a mixed land management history, providing a rare opportunity to compare early post-wildfire data between areas with and without previous application of prescribed burning. The purpose of this study was to analyze the differences between these two treatments in…
Publication Type: Journal Article
Enhancing fire emissions inventories for acute health effects studies: integrating high spatial and temporal resolution data
Year: 2025
Background: Daily fire progression information is crucial for public health studies that examine the relationship between population-level smoke exposures and subsequent health events. Issues with remote sensing used in fire emissions inventories (FEI) lead to the possibility of missed exposures that impact the results of acute health effects studies.Aims: This paper provides a method for improving an FEI dataset with readily available information to create a more robust dataset with daily fire progression.Methods: High temporal and spatial resolution burned area information from two FEI…
Publication Type: Journal Article
Complexities in post-wildfire governance: lessons from Colorado’s 2020 wildfires
Year: 2025
Background: The increasing size and severity of western U.S. wildfires in recent years has generated greater attention towards post-wildfire response and recovery. Post-fire governance requires coordinating response and recovery capacities across jurisdictions, landscapes, and time scales. The presence of wildfire on federal public lands necessitates federal agency involvement in both suppression and recovery efforts, and program coordination with lower levels of government and non-governmental organizations. Using semi-structured interviews, we investigated experiences of leaders across the…
Publication Type: Journal Article
Short-term impacts of operational fuel treatments on modelled fire behaviour and effects in seasonally dry forests of British Columbia, Canada
Year: 2025
Background: In response to increasing risk of extreme wildfire across western North America, forest managers are proactively implementing fuel treatments.Aims: We assessed the efficacy of alternative combinations of thinning, pruning and residue fuel management to mitigate potential fire behaviour and effects in seasonally dry forests of interior British Columbia, Canada.Methods: Across five community forests, we measured stand attributes before and after fuel treatments in 2021 and 2022, then modelled fire behaviour and effects using the…
Publication Type: Journal Article
Assessing costs and constraints of forest residue disposal by pile burning
Year: 2025
Pile burning of thinned residues is a critical tool to dispose of fuels and to reduce wildfire risk in overstocked, fire-prone forests globally. However, cost estimates of pile burning are limited. In the Western United States, where fuel reduction and pile burning are key strategies to mitigate risk of severe wildfire, previous reports estimate that the average cost of pile burning after machine treatment is $543 ac−1 ($1,343 ha−1). There is, however, limited information on the costs of hand thinning and pile burning. In response, this study quantified the costs of cutting and yarding,…
Publication Type: Journal Article
Long-term soil nutrient and understory plant responses to post-fire rehabilitation in a lodgepole pine forest
Year: 2025
Wildfires and other disturbances play a fundamental role in regenerating lodgepole pine forests. Though severe, stand-replacing fires are typical of this ecosystem, they can have dramatic impacts on soil properties and biogeochemical processes that influence the rate and composition of vegetation recovery. Organic soil amendments are often applied to manage post-fire erosion, but they can also improve soil moisture and nutrient retention and potentially alter the trajectory of post-fire revegetation. We compared change in soil nutrients, microbial communities, and understory plant cover and…
Publication Type: Journal Article
Small-scale fire refugia increase soil bacterial and fungal richness and increase community cohesion nine years after fire
Year: 2025
Small-scale variation in wildfire behavior may cause large differences in belowground bacterial and fungal communities with consequences for belowground microbial diversity, community assembly, and function. Here we combine pre-fire, active-fire, and post-wildfire measurements in a mixed-conifer forest to identify how fine-scale wildfire behavior, unburned refugia, and aboveground forest structure are associated with belowground bacterial and fungal communities nine years after wildfire. We used fine-scale mapping of small (0.9–172.6 m2) refugia to sample soil-associated burned and…
Publication Type: Journal Article
Household needs among wildfire survivors in the 2017 Northern California wildfires
Year: 2025
Wildfires are impacting communities globally, with California wildfires often breaking records of size and destructiveness. Knowing how communities are affected by these wildfires is vital to understanding recovery. We sought to identify impacted communities' post-wildfire needs and characterize how those needs change over time. The WHAT-Now study deployed a survey that was made publicly available for communities affected by the October 2017 Northern California wildfires or the accompanying smoke at beginning approximately four months post-fire with the vast majority completed by nine months…
Publication Type: Journal Article
Wildland Firefighters Suffer Increasing Risk of Job-Related Death
Year: 2025
Wildland firefighting is a niche specialization in the fire service - inherently dangerous with unique risks. Over the past decade, fatalities amongst all firefighters have decreased; however, wildland firefighter fatalities have increased. This subject has only been described in the grey literature, and a paucity of medical literature exists. The United States Fire Administration's online fatality database was queried for on duty mortality between 1990 and 2022. The year 2001 was excluded due to the 340 deaths that occurred on September 11th. Data collected included demographics, incident…
Publication Type: Journal Article
Effects of long-term ecological research and cognitive biases on the evaluation of scientific information by public land managers in Oregon and Washington, USA
Year: 2025
Natural resource managers (managers) value and use scientific information to inform their decision-making process in a variety of ways. The scientific information managers use depends on a variety of factors, including the source of the information and ease of access. Barriers, such as paywalls, insufficient capacity, and information overload play an important role in determining what scientific information managers have access and attend to. Additionally, characteristics of managers themselves also influence what scientific information they prioritize and implement. Specific factors likely…
Publication Type: Journal Article
Disentangling drivers of annual grass invasion: Abiotic susceptibility vs. fire-induced conversion to cheatgrass dominance in the sagebrush biome
Year: 2024
Invasive annual grasses are often facilitated by fire, yet they can become ecologically dominant in susceptible locations even in the absence of fire. We used an extensive vegetation plot database to model susceptibility to the invasive annual grass cheatgrass (Bromus tectorum L.) in the sagebrush biome as a function of climate and soil water availability variables. We built random forest models predicting cheatgrass presence or dominance (>15 % relative cover) under unburned (37,219 plots) and burned conditions (6340 plots). We mapped predicted probability of cheatgrass…
Publication Type: Journal Article
Mortality Burden From Wildfire Smoke Under Climate Change
Year: 2024
Wildfire activity has increased in the US and is projected to accelerate under future climate change. However, our understanding of the impacts of climate change on wildfire smoke and health remains highly uncertain. We quantify the past and future mortality burden in the US due to wildfire smoke fine particulate matter (PM2.5). We construct an ensemble of statistical and machine learning models that link variation in climate to wildfire smoke PM2.5, and empirically estimate smoke PM2.5-mortality relationships using georeferenced data on all recorded deaths in the US from 2006 to 2019. We…
Publication Type: Report
Drought before fire increases tree mortality after fire
Year: 2024
Fire and drought are expected to increase in frequency and severity in temperate forests due to climate change. To evaluate whether drought increases the likelihood of post-fire tree mortality, we used a large database of tree survival and mortality from 32 years of wildland fires covering four dominant western North American conifers. We used Bayesian hierarchical modeling to predict the probability of individual tree mortality after fire based on species—Pinus contorta (lodgepole pine), Abies concolor (white fir), Pseudotsuga menziesii (Douglas-fir), and Pinus…
Publication Type: Journal Article
Wildfire Smoke Exposure and Incident Dementia
Year: 2024
Importance: Long-term exposure to total fine particulate matter (PM2.5) is a recognized dementia risk factor, but less is known about wildfire-generated PM2.5, an increasingly common PM2.5 source. Objective: To assess the association between long-term wildfire and nonwildfire PM2.5 exposure and risk of incident dementia. Design, Setting, and Participants: This open cohort study was conducted using January 2008 to December 2019 electronic health record (EHR) data among members of Kaiser Permanente Southern California (KPSC), which serves…
Publication Type: Journal Article
Nonstructural carbohydrates explain post-fire tree mortality and recovery patterns
Year: 2024
Trees use nonstructural carbohydrates (NSCs) to support many functions, including recovery from disturbances. However, NSC’s importance for recovery following fire and whether NSC depletion contributes to post-fire delayed mortality are largely unknown. We investigated how fire affects NSCs based on fire-caused injury from a prescribed fire in a young Pinus ponderosa (Lawson & C. Lawson) stand. We assessed crown injury (needle scorch and bud kill) and measured NSCs of needles and inner bark (i.e., secondary phloem) of branches and main stems of trees subject to fire and at an…
Publication Type: Journal Article