Research Database
Displaying 21 - 40 of 202
Fire gives avian populations a rapid and enduring boost in protected forests of California
Year: 2025
BackgroundFire can impact ecosystems and species over both short and long timeframes, resulting in pervasive impacts on the structure of avian communities. While recent research has highlighted the strong impact of fire on bird communities in the short term, there remains a need for understanding long-term population processes following fire, particularly in forested landscapes that are burning more frequently than in the past century. We analyzed avian response to fire using point-count data from 1999–2019 within national parks of the Sierra Nevada Inventory & Monitoring Network,…
Publication Type: Journal Article
Comparing modeled soil temperature and moisture dynamics during prescribed fires, slash-pile burns and wildfires
Year: 2025
Background: Wildfires, prescribed fires and slash-pile burns are disturbances that occur in many terrestrial ecosystems. Such fires produce variable surface heat fluxes causing a spectrum of effects on soil, such as seed mortality, nutrient loss, changes in microbial activity and water repellency. Accurately modeling soil heating is vital to predicting these second-order fire effects. The process-based Massman HMV (Heat–Moisture–Vapor) model incorporates soil water evaporation, heat transport and water vapor movement, and captures the observed rapid evaporation of soil moisture. Aims:…
Publication Type: Journal Article
The western North American forestland carbon sink: will our climate commitments go up in smoke?
Year: 2025
Pathways to achieving net-zero and net-negative greenhouse-gas (GHG) emission targets rely on land-based contributions to carbon (C) sequestration. However, projections of future contributions neglect to consider ecosystems, climate change, legacy impacts of continental-scale fire exclusion, forest accretion and densification, and a century or more of management. These influences predispose western North American forests (wNAFs) to severe drought impacts, large and chronic outbreaks of insect pests, and increasingly large and severe wildfires. To realistically assess contributions of future…
Publication Type: Journal Article
Drivers of fire severity in repeat fires: implications for mixed-conifer forests in the Sierra Nevada, California
Year: 2025
BackgroundWhile the reintroduction of recurring fire restores a key process in frequent-fire adapted forests, the ability to significantly shift the structure and composition of departed contemporary forests has not been clearly demonstrated. Our study utilized an extensive network of field plots across three short-interval successive fires occurring in the northern Sierra Nevada, California. We evaluated the influence of plot-level forest structure and composition, topography, and weather on fire severity in a third successive fire (i.e., second reburn). Additionally, we assessed the range…
Publication Type: Journal Article
Wildfire disturbance and ecological cascades: Teasing apart the direct and indirect effects of fire on tick populations
Year: 2025
- Wildfires are a significant ecological force in the western United States, reshaping landscapes and ecological communities. However, assessing wildfires' full impact is challenging due to the complexity of fire severity and its varied effects on ecological dynamics. Understanding species-specific responses to disturbances within their environmental context is essential for predicting cascading ecological impacts. Arthropods, including ticks, are particularly sensitive to both abiotic and biotic changes, making them especially vulnerable to the impacts of wildfire.
- In this…
Publication Type: Journal Article
Fire Intensity and spRead forecAst (FIRA): A Machine Learning Based Fire Spread Prediction Model for Air Quality Forecasting Application
Year: 2025
Fire activities introduce hazardous impacts on the environment and public health by emitting various chemical species into the atmosphere. Most operational air quality forecast (AQF) models estimate smoke emissions based on the latest available satellite fire products, which may not represent real-time fire behaviors without considering fire spread. Hence, a novel machine learning (ML) based fire spread forecast model, the Fire Intensity and spRead forecAst (FIRA), is developed for AQF model applications. FIRA aims to improve the performance of AQF models by providing realistic, dynamic fire…
Publication Type: Journal Article
Rapid Declines in Southern Sierra Nevada Fisher Habitat Driven by Drought and Wildfire
Year: 2025
Aim: Forest disturbances are a natural ecological process, but climate and land-use change are altering disturbance regimes at an unprecedented rate, posing significant threats to biological communities and the species of concern. Our aim was to develop an automated habitat monitoring system for the Southern Sierra Nevada Distinct Population Segment of fisher (Pekania pennanti) in California, USA, to investigate long-term habitat trends and the effects of a recent megadrought and numerous megafires on fisher habitat.Location: Southern Sierra Nevada, California, USA.Methods: We used…
Publication Type: Journal Article
Prescribed fire, managed burning, and previous wildfires reduce the severity of a southwestern US gigafire
Year: 2025
In many parts of the western United States, wildfires are becoming larger and more severe, threatening the persistence of forest ecosystems. Understanding the ways in which management activities such as prescribed fire and managed wildfire can mitigate fire severity is essential for developing effective forest conservation strategies. We evaluated the effects of previous fuels reduction treatments, including prescribed fire and wildfire managed for resource benefit, and other wildfires on the burn severity of the 2022 Black Fire in southwestern New Mexico, USA. The Black Fire burned over 131,…
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
Pre-fire structure drives variability in post-fire aboveground carbon and fuel profiles in wet temperate forests
Year: 2025
Biological legacies (i.e., materials that persist following disturbance; “legacies”) shape ecosystem functioning and feedbacks to future disturbances, yet how legacies are driven by pre-disturbance ecosystem state and disturbance severity is poorly understood—especially in ecosystems influenced by infrequent and severe disturbances. Focusing on wet temperate forests as an archetype of these ecosystems, we characterized live and dead aboveground biomass 2–5 years post-fire in western Washington and northwestern Oregon, USA, to ask: How do pre-fire stand age (i.e., pre-disturbance ecosystem…
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
Motivating parents to protect their children from wildfire smoke: the impact of air quality index infographics
Year: 2025
Background. Wildfire smoke events are increasing in frequency and intensity due to climate change. Children are especially vulnerable to health effects even at moderate smoke levels. However, it is unclear how parents respond to Air Quality Indices (AQIs) frequently used by agencies to communicate air pollution health risks. Methods. In an experiment (3 × 2 × 2 factorial design), 2,100 parents were randomly assigned to view one of twelve adapted AQI infographics that varied by visual (table, line, gauge), index type (AQI [0-500], AQHI [1-11+]), and risk…
Publication Type: Journal Article
Assessing fuel treatments and burn severity using global and local analyses
Year: 2025
BackgroundWildfires in western U.S. dry forest ecosystems have increased in size and severity during recent decades due primarily to more than a century of fire suppression, exclusion of Indigenous fire, and a rapidly warming climate. Fuel treatments have been employed to restore historical forest conditions and mitigate burn severity. However, their influence on burn severity in the context of other environmental variables and firefighting operations has not been extensively explored. The 2021 Bootleg Fire in south-central Oregon provided an opportunity to evaluate the effectiveness of…
Publication Type: Journal Article
Implications of recent wildfires for forest management on federal lands in the Pacific Northwest, USA
Year: 2025
Adoption of the Northwest Forest Plan (NWFP) in 1994 marked a pivotal moment in federal forest management in the Pacific Northwest, shifting focus away from intensive timber harvest toward an ecosystem management approach that emphasized late successional and old forest habitat with the creation of a reserve network across moist and dry forest zones. Thirty years after implementation, concerns over accelerating wildfire threats have prompted efforts to adapt the Plan to a warming climate, yet the actual effects of recent fires on NWFP forests are not well understood. In this study, we…
Publication Type: Journal Article
Montane springs provide regeneration refugia after high-severity wildfire
Year: 2024
In the mountainous regions of the Western United States, increasing wildfire activity and climate change are putting forests at risk of regeneration failure and conversion to non-forests. During periods with unfavorable climatic conditions, locations that are suitable for post-fire tree regeneration (regeneration refugia) may be essential for forest recovery. These refugia could provide scattered islands of recovering forest from which broader forest recovery may be facilitated. Spring ecosystems provide cool and wet microsites relative to the surrounding landscape and may act as regeneration…
Publication Type: Journal Article
A laboratory-scale simulation framework for analysing wildfire hydrologic and water quality effects
Year: 2024
Background: Wildfires can significantly impact water quality and supply. However logistical difficulties and high variability in in situ data collection have limited previous analyses.Aims: We simulated wildfire and rainfall effects at varying terrain slopes in a controlled setting to isolate driver-response relationships.Methods: Custom-designed laboratory-scale burn and rainfall simulators were applied to 154 soil samples, measuring subsequent runoff and constituent responses. Simulated conditions included low, moderate, and high burn intensities (~100–600°C); 10…
Publication Type: Journal Article
Few large or many small fires: Using spatial scaling of severe fire to quantify effects of fire-size distribution shifts
Year: 2024
As wildfire activity increases and fire-size distributions potentially shift in many forested regions worldwide, anticipating the spatial patterns of burn severity expected with future fire activity is critical for ecological understanding and informing management and policy. Because spatial patterns of burn severity are influenced by a complex mixture of drivers, they remain difficult to predict for any given burned landscape. At broader extents, however, spatial scaling relationships relating high-severity patch size and shape to overall fire size, when combined with scenarios regarding…
Publication Type: Journal Article
Before the fire: predicting burn severity and potential post-fire debris-flow hazards to conservation populations of the Colorado River Cutthroat Trout (Oncorhynchus clarkii pleuriticus)
Year: 2024
Background: Colorado River Cutthroat Trout (CRCT; Oncorhynchus clarkii pleuriticus) conservation populations may be at risk from wildfire and post-fire debris flows hazards. Aim: To predict burn severity and potential post-fire debris flow hazard classifications to CRCT conservation populations before wildfires occur. Methods: We used remote sensing, spatial analyses, and machine learning to model 28 wildfire incidents (2016–2020) and spatially predict burn severity from pre-wildfire environmental factors to evaluate the likelihood…
Publication Type: Journal Article
Fire severity drives understory community dynamics and the recovery of culturally significant plants
Year: 2024
Anthropogenic influences are altering fire regimes worldwide, resulting in an increase in the size and severity of wildfires. Simultaneously, throughout western North America, there is increasing recognition of the important role of Indigenous fire stewardship in shaping historical fire regimes and fire-adapted ecosystems. However, there is limited understanding of how ecosystems are affected by or recover from contemporary “megafires,” particularly in terms of understory plant communities that are critical to both biodiversity and Indigenous cultures. To address this gap, our collaborative…
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