Research Database
Displaying 1 - 20 of 108
Reliability of satellite-based vegetation maps for planning wildfire-fuel treatments in shrub steppe: Inferences from two contrasting national parks
Year: 2025
Protecting habitat threatened by increasing wildfire size and frequency requires identifying the spatial intersection of wildfire behavior and ecological conditions that favor positive management outcomes. In the perennial sagebrush steppe of Western North America, invasions by fire-prone annual grasses are a key concern, and management of them requires reliable maps of vegetation cover, fuels, and wildfire behavior. We compared commonly used, publicly available vegetation cover and fuels maps, specifically the Rangeland Analysis Platform (RAP) and LANDFIRE, with field-based assessments at…
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
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
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
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
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
Temporal and spatial pattern analysis of escaped prescribed fires in California from 1991 to 2020
Year: 2025
Background: Prescribed fires play a critical role in reducing the intensity and severity of future wildfires by systematically and widely consuming accumulated vegetation fuel. While the current probability of prescribed fire escape in the United States stands very low, their consequential impact, particularly the large wildfires they cause, raises substantial concerns. The most direct way of understanding this trade-off between wildfire risk reduction and prescribed fire escapes is to explore patterns in the historical prescribed fire records. This study investigates the spatiotemporal…
Publication Type: Journal Article
Understanding household experiences with flooding in post-fire environments: risk perceptions, perceived drivers, and mitigation actions
Year: 2025
Flood events in post-fire environments produce cascading social and ecological consequences that are challenging to anticipate, mitigate, and manage. Engaging private property owners in mitigation is complex, and the drivers that motivate action or inaction are not yet well defined. We analyse household survey data collected after multiple rainfall events that triggered flooding on and adjacent to the 2019 Museum Fire burn scar in Flagstaff, AZ, USA, to explore relationships between risk perceptions, drivers of flood risk, and mitigation actions in post-fire environments. We received 623…
Publication Type: Journal Article
Influence of Time‐Averaging of Climate Data on Estimates of Atmospheric Vapor Pressure Deficit and Inferred Relationships With Wildfire Area in the Western United States
Year: 2025
Vapor pressure deficit (VPD) is a driver of evaporative demand and correlates strongly with wildfire extent in the western United States (WUS). Vapor pressure deficit is the difference between saturation vapor pressure (es) and actual vapor pressure (ea). Because es increases nonlinearly with temperature, calculations of time‐averaged VPD vary depending on the frequency of temperature measurements and how ea is calculated, potentially limiting our understanding of fire‐climate relationships. We calculate eight versions of monthly VPD across the WUS and assess their differences. Monthly VPDs…
Publication Type: Journal Article
Methods to assess fire-induced tree mortality: review of fire behaviour proxy and real fire experiments
Year: 2025
Background: The increased interest in why and how trees die from fire has led to several syntheses of the potential mechanisms of fire-induced tree mortality. However, these generally neglect to consider experimental methods used to simulate fire behaviour conditions.Aims: To describe, evaluate the appropriateness of and provide a historical timeline of the different approaches that have been used to simulate fire behaviour in fire-induced tree mortality studies.Methods: We conducted a historical review of the different actual and fire proxy methods that have been used to…
Publication Type: Journal Article
Perspectives: Six opportunities to improve understanding of fuel treatment longevity in historically frequent-fire forests
Year: 2025
Fuel-reduction and restoration treatments (“treatments”) are conducted extensively in dry and historically frequent-fire forests of interior western North America (“dry forests”) to reduce potential for uncharacteristically severe wildfire. However, limited understanding of treatment longevity and long-term treatment effects creates potential for inefficient treatment maintenance and inaccurate forecasting of wildfire behavior. In this perspectives paper, we briefly summarize current understanding of long-term effects of three common treatment types (burn-only, thin-only, and thin-plus-burn)…
Publication Type: Journal Article
Do natural hazard events and disasters trigger political and legislative change? A systematic scoping review of the impacts on commodity production.
Year: 2025
Food and fibre commodity production is fundamental to global food security and economic development. However, these commodities are vulnerable to different natural hazards. In this systematic scoping review, we assess the natural hazards literature to determine if and how specific natural hazard events that impact food and fibre commodity production have triggered political or legislative change. Bibliometric and thematic analysis methods were used to identify recurrent patterns and themes in the dataset. Bibliometric analysis confirmed robust international cooperation on hazards and…
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
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
Branching out: species-specific canopy architecture limits live crown fuel consumption in Intermountain West USA conifers
Year: 2024
Accurate estimates of available live crown fuel loads are critical for understanding potential wildland fire behavior. Existing crown fire behavior models assume that available crown fuels are limited to all tree foliage and half of the fine branches less than 6 mm in diameter (1 h fuel). They also assume that this relationship is independent of the branchwood moisture content. Despite their widespread use, these assumptions have never been tested, and our understanding of the physiochemical properties that govern live crown flammability and consumption remains limited. To test these…
Publication Type: Journal Article
Forest structural complexity and ignition pattern influence simulated prescribed fire effects
Year: 2024
Forest structural characteristics, the burning environment, and the choice of ignition pattern each influence prescribed fire behaviors and resulting fire effects; however, few studies examine the influences and interactions of these factors. Understanding how interactions among these drivers can influence prescribed fire behavior and effects is crucial for executing prescribed fires that can safely and effectively meet management objectives. To analyze the interactions between the fuels complex and ignition patterns, we used FIRETEC, a three-dimensional computational fluid dynamics fire…
Publication Type: Journal Article
Generating fuel consumption maps on prescribed fire experiments from airborne laser scanning
Year: 2024
Background. Characterisation of fuel consumption provides critical insights into fire behaviour, effects, and emissions. Stand-replacing prescribed fire experiments in central Utah offered an opportunity to generate consumption estimates in coordination with other research efforts. Aims. We sought to generate fuel consumption maps using pre- and post-fire airborne laser scanning (ALS) and ground measurements and to test the spatial transferability of the ALSderived fuel models. Methods. Using random forest (RF), we empirically modelled fuel load and estimated consumption from pre-…
Publication Type: Journal Article
Pixels to pyrometrics: UAS-derived infrared imagery to evaluate and monitor prescribed fire behaviour and effects
Year: 2024
Background: Prescribed fire is vital for fuel reduction and ecological restoration, but the effectiveness and fine-scale interactions are poorly understood. Aims: We developed methods for processing uncrewed aircraft systems (UAS) imagery into spatially explicit pyrometrics, including measurements of fuel consumption, rate of spread, and residence time to quantitatively measure three prescribed fires. Methods: We collected infrared (IR) imagery continuously (0.2 Hz) over prescribed burns and one experimental calibration burn, capturing…
Publication Type: Journal Article
Fire suppression makes wildfires more severe and accentuates impacts of climate change and fuel accumulation
Year: 2024
Fire suppression is the primary management response to wildfires in many areas globally. By removing less-extreme wildfires, this approach ensures that remaining wildfires burn under more extreme conditions. Here, we term this the “suppression bias” and use a simulation model to highlight how this bias fundamentally impacts wildfire activity, independent of fuel accumulation and climate change. We illustrate how attempting to suppress all wildfires necessarily means that fires will burn with more severe and less diverse ecological impacts, with burned area increasing at faster rates than…
Publication Type: Journal Article
Variability in weather and site properties affect fuel and fire behavior following fuel treatments in semiarid sagebrush-steppe
Year: 2024
Fuel-treatments targeting shrubs and fire-prone exotic annual grasses (EAGs) are increasingly used to mitigate increased wildfire risks in arid and semiarid environments, and understanding their response to natural factors is needed for effective landscape management. Using field-data collected over four years from fuel-break treatments in semiarid sagebrush-steppe, we asked 1) how the outcomes of EAG and sagebrush fuel treatments varied with site biophysical properties, climate, and weather, and 2) how predictions of fire behavior using the Fuel Characteristic Classification System fire…
Publication Type: Journal Article