Research Database
Displaying 1 - 20 of 238
Global Synthesis of Quantification of Fire Behaviour Characteristics in Forests and Shrublands: Recent Progress
Year: 2025
Purpose of ReviewThe behaviour of wildland fires, namely their free spreading nature, destructive energy fluxes and hazardous environment, make it a phenomenon difficult to study. Field experimental studies and occasional wildfire observations underpin our understanding of fire behaviour. We aim to present a global synthesis of field-based studies in forest and shrublands fuel types published since 2003 with a focus on the most commonly measured fire behaviour attributes, namely rate of fire spread, ignition and spread sustainability, flame characteristics, fuel consumption…
Publication Type: Journal Article
High fire hazard Wildland Urban Interface (WUI) residences in California lack voluntary and mandated wildfire risk mitigation compliance in Home Ignition Zones
Year: 2025
Wildfire structure losses are increasing globally and particularly in California, USA. Losses can be mitigated in part by changes to the Home Ignition Zone (HIZ), including both home hardening and defensible space. In the United States, there are local, nation-wide, and industry-based home mitigation standards that are enforced or recommended. We explore the standards implementation (California code and two voluntary standards) at 176 participating residences in three Santa Cruz Mountains and two Sierra Nevada Mountains sites. Overall most residences had little compulsory or recommended…
Publication Type: Journal Article
Can ‘‘Fire Safe’’ Cigarettes (FSCs) Start Wildfires?
Year: 2025
Over the last 20 years, all states within the US have required all cigarettes sold to be ‘‘fire safe’’ or ‘‘fire standards compliant’’ meaning that they must pass ASTM standard E2187. Though these cigarettes are designed to self-extinguish, there have been recent studies suggesting that these ‘‘fire safe’’ cigarettes (FSCs) can still ignite mattresses and other furnishings, but there has been no guidance for fire investigators whether FSCs can ignite natural fuels, such as duff and needles, that can be the source of a wildland fire. This work sets out to investigate whether FSCs can indeed be…
Publication Type: Journal Article
Lightning ignition efficiency in Canadian forests
Year: 2025
Background: Lightning-caused fires have a driving influence on Canadian forests, being responsible for approximately half of all wildfires and 90% of the area burned. We created a climatology (2000–2020) of daily lightning efficiency (i.e., the ratio of cloud-to-ground lightning flashes to lightning-caused wildfires that occurred) over the meteorological summer for four ecozones and a subset of British Columbia (BC) ecoprovinces. We estimated lightning efficiency using data from the Canadian Lightning Detection Network and the Canadian National Fire Database. We used the ERA5…
Publication Type: Journal Article
Patterns and trends of heat and wildfire smoke indicators across rural–urban and social vulnerability gradients in Idaho
Year: 2025
Climate change poses a grave threat to human health with disparate impacts across society. While populations with high social vulnerability generally bear a larger burden of exposure to and impact from environmental hazards; such patterns and trends are less explored at the confluence of social vulnerability and rural–urban gradients. We show that in rural regions in Idaho, low vulnerability populations had both the highest long-term average and the highest increase rate of exposure to heatwaves from 2002–2020, coincident with a higher population density in low—as compared to high—…
Publication Type: Journal Article
Increasing Hydroclimatic Whiplash Can Amplify Wildfire Risk in a Warming Climate
Year: 2025
On January 7 and 8, 2025, a series of wind-driven wildfires occurred in Los Angeles County in Southern California. Two of these fires ignited in dense woody chaparral shrubland and immediately burned into adjacent populated areas–the Palisades Fire on the coastal slopes of the Santa Monica Mountains and the Eaton fire in the foothills of the San Gabriel Mountains. Both fires ultimately eclipsed the traditionally-defined “wildland-urban interface” boundaries by burning structure-to-structure as an urban conflagration. The scope of the devastation is staggering; at the time of writing, the…
Publication Type: Report
Review of thermal behaviour of firebrands and their role in fuel bed and structure ignition
Year: 2025
Firebrands or embers are a crucial phenomenon in wildfire behaviour. Firebrands – small, burning or smouldering pieces of wood or other flammable materials – can be carried by wind considerable distances, leading to ignition of new fires ahead of the main fire front. This process, called spotting, significantly contributes to the rapid spread of fires, particularly in wildland–urban interface (WUI) areas. Spot fires pose a severe threat to people and properties. Better understanding the thermal behaviour of firebrands and their ability to ignite various natural fuel beds and structural…
Publication Type: Journal Article
Future enhanced threshold effects of wildfire drivers could increase burned areas in northern mid- and high latitudes
Year: 2025
Wildfires exhibit extensive nonlinear characteristics and threshold effects in response to environmental changes. However, how threshold effects affect wildfire responses and their future changes remains unclear. Here we identified thresholds where wildfire-driver relationships shift and estimated the impact of threshold effects on wildfire dynamics in the 21st century in northern mid- and high latitudes (>30°N). Wildfire-driver thresholds, coregulated by gradient differences in heat and moisture conditions, vegetation productivity, and human activities, effectively explain the spatial…
Publication Type: Journal Article
Canadian forests are more conducive to high-severity fires in recent decades
Year: 2025
Canada has experienced more-intense and longer fire seasons with more-frequent uncontrollable wildfires over the past decades. However, the effect of these changes remains unknown. This study identifies driving forces of burn severity and estimates its spatiotemporal variations in Canadian forests. Our results show that fuel aridity was the most influential driver of burn severity, summer months were more prone to severe burning, and the northern areas were most influenced by the changing climate. About 6% (0.54 to 14.64%) of the modeled areas show significant increases in the number of days…
Publication Type: Journal Article
Trajectories of community fire adaptation: Social diversity, social fragmentation and the temporal evolution of wildfire action
Year: 2025
There is increasing acknowledgement that the unique characteristics (i.e., social contexts) of human communities influence variable means for adapting to the growing risks posed by wildland fire. However, there has been less work documenting how community social contexts evolve over time, and the ways they might influence collective mitigations pursued in partnership with professionals when addressing wildfire planning. We conducted 73 semi-structured interviews with 112 residents, emergency management professionals, government officials and members of community organizations in two Nevada…
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
Multifactor Change in Western U.S. Nighttime Fire Weather
Year: 2025
Reports from western U.S. firefighters that nighttime fire activity has been increasing during the spans of many of their careers have recently been confirmed by satellite measurements over the 2003–20 period. The hypothesis that increasing nighttime fire activity has been caused by increased nighttime vapor pressure deficit (VPD) is consistent with recent documentation of positive, 40-yr trends in nighttime VPD over the western United States. However, other meteorological conditions such as near-surface wind speed and planetary boundary layer depth also impact fire behavior and exhibit…
Publication Type: Journal Article
Spatiotemporal Synchrony of Climate and Fire Occurrence Across North American Forests (1750–1880)
Year: 2025
Aim: Increasing aridity has driven widespread synchronous fire occurrence in recent decades across North America. The lack of historical (pre-1880) fire records limits our ability to understand long-term continental fire-climate dynamics. The goal of this study is to use tree-ring reconstructions to determine the relationships between spatiotemporal patterns in historical climate and widespread fire occurrence in North American forests, and whether they are stable through time. This information will address a major knowledge gap required to inform projections of future fire.Location: North…
Publication Type: Journal Article
Compounding effects of climate change and WUI expansion quadruple the likelihood of extreme-impact wildfires in California
Year: 2025
Previous research has examined individual factors contributing to wildfire risk, but the compounding effects of these factors remain underexplored. Here, we introduce the “Integrated Human-centric Wildfire Risk Index (IHWRI)” to quantify the compounding effects of fire-weather intensification and anthropogenic factors—including ignitions and human settlement into wildland—on wildfire risk. While climatic trends increased the frequency of high-risk fire-weather by 2.5-fold, the combination of this trend with wildland-urban interface expansion led to a 4.1-fold increase in the frequency of…
Publication Type: Journal Article
Integrating fire-smart fuels management with bioenergy benefits remote and Indigenous communities in Canada
Year: 2025
The global urgency of more damaging wildfires calls for proactive solutions. Integrating fire-smart fuels management with bioenergy could reduce wildfire risk while providing feedstock for bioenergy. We explore this strategy in off-grid communities in Canada who are heavily dependent on diesel for their energy needs, many of which are home to Indigenous peoples. Combining national remote sensing data and community-based information, we identify 33 diesel-dependent communities at high wildfire risk due to a large accumulation of undisturbed flammable forest. We demonstrate that 30 of these 33…
Publication Type: Journal Article
Compounding effects of climate change and WUI expansion quadruple the likelihood of extreme-impact wildfires in California
Year: 2025
Previous research has examined individual factors contributing to wildfire risk, but the compounding effects of these factors remain underexplored. Here, we introduce the “Integrated Human-centric Wildfire Risk Index (IHWRI)” to quantify the compounding effects of fire-weather intensification and anthropogenic factors—including ignitions and human settlement into wildland—on wildfire risk. While climatic trends increased the frequency of high-risk fire-weather by 2.5-fold, the combination of this trend with wildland-urban interface expansion led to a 4.1-fold increase in the frequency of…
Publication Type: Journal Article
Burning from the ground up: the structure and impact of Prescribed Burn Associations in the United States
Year: 2025
Background: To combat losses and threats from fire exclusion and extreme wildfire events, communities in the United States are increasingly self-organizing through locally led Prescribed Burn Associations (PBAs) to plan and implement prescribed burns on private lands.Aim: Our study aimed to document the expansion of PBAs and provide insight into their structure, function, and impacts.Methods: Leaders from 135 known PBAs across the United States were invited to participate in an online survey.Key results: Survey results demonstrate a widespread emergence of PBAs in the United States,…
Publication Type: Journal Article
Wildland fire entrainment: The missing link between wildland fire and its environment
Year: 2025
Wildfires are growing in destructive power, and accurately predicting the spread and intensity of wildland fire is essential for managing ecological and societal impacts. No current operational models used for fire behavior prediction resolve critical fire-atmospheric coupling or nonlocal influences of the fire environment, rendering them inadequate in accounting for the range of wildland fire behavior scenarios under increasingly novel fuel and climate conditions. Here, we present a new perspective on a dominant fire-atmospheric feedback mechanism, which we term wildland fire entrainment (…
Publication Type: Journal Article
Role of Forensic Anthropology in the Search and Recovery of Fatal Wildland Fire Victims
Year: 2025
The search and recovery process of fatal fire victims is one of the greatest challenges in forensic anthropology, especially in large-scale wildland fire disasters. Burned human remains can exhibit significant variation in their degree of preservation depending on the temperature of the fire, the length of exposure to the heat source, and intrinsic characteristics of the victim (e.g., body size, age, and bone density). Wildland fire victims typically exhibit characteristics of the final stages of burning (i.e., nearly complete to complete calcination). The search for burned human remains is…
Publication Type: Journal Article
Evaluating a simulation-based wildfire burn probability map for the conterminous US
Year: 2025
Background: Wildfire simulation models are used to derive maps of burn probability (BP) based on fuels, weather, topography and ignition locations, and BP maps are key components of wildfire risk assessments.Aims: Few studies have compared BP maps with real-world fires to evaluate their suitability for near-future risk assessment. Here, we evaluated a BP map for the conterminous US based on the large fire simulation model FSim.Methods: We compared BP with observed wildfires from 2016 to 2022 across 128 regions representing similar fire regimes (‘pyromes’). We…
Publication Type: Journal Article