Research Database
Displaying 1 - 20 of 143
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
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
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
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
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
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
A fire deficit persists across diverse North American forests despite recent increases in area burned
Year: 2025
Rapid increases in wildfire area burned across North American forests pose novel challenges for managers and society. Increasing area burned raises questions about whether, and to what degree, contemporary fire regimes (1984–2022) are still departed from historical fire regimes (pre-1880). We use the North American tree-ring fire-scar network (NAFSN), a multi-century record comprising >1800 fire-scar sites spanning diverse forest types, and contemporary fire perimeters to ask whether there is a contemporary fire surplus or fire deficit, and whether recent fire years are unprecedented…
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
Evidence for strong bottom-up controls on fire severity during extreme events
Year: 2025
BackgroundRecord fire years in recent decades have challenged post-fire forest recovery in the western United States and beyond. To improve management responses, it is critical that we understand the conditions under which management can mitigate severe wildfire impacts, and when it cannot. Here, we evaluated the influence of top-down and bottom-up fire severity forcings on 17 wildfires occurring during two consecutive record-setting years in the eastern Cascade Mountains of Washington State. Despite much of the area having been burned after an extended period of fire…
Fire Effects and Fire Ecology, Fire History, Fuels and Fuel Treatments, Restoration and Hazardous Fuel Reduction
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
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
Estimating the influence of field inventory sampling intensity on forest landscape model performance for determining high-severity wildfire risk
Year: 2024
Historically, fire has been essential in Southwestern US forests. However, a century of fire-exclusion and changing climate created forests which are more susceptible to uncharacteristically severe wildfires. Forest managers use a combination of thinning and prescribed burning to reduce forest density to help mitigate the risk of high-severity fires. These treatments are laborious and expensive, therefore optimizing their impact is crucial. Landscape simulation models can be useful in identifying high risk areas and assessing treatment effects, but uncertainties in these models can limit…
Publication Type: Journal Article
Assessing Conservation Readiness: The Where, Who, and How of Strategic Conservation in the Sagebrush Biome
Year: 2024
The sagebrush biome is rapidly deteriorating largely due to the ecosystem threats of conifer expansion, more frequent and larger wildfires, and proliferation of invasive annual grasses. Reversing the impacts of these threats is a formidable challenge. The Sagebrush Conservation Design (SCD) emphasized that limited conservation resources should first be used to maintain Core Sagebrush Areas (CSA), and then to grow such areas where possible. The SCD heightens the ecological importance of maintaining and strategically growing CSAs. However, the fact that these areas have been identified does not…
Publication Type: Journal Article
Trees have similar growth responses to first-entry fires and reburns following long-term fire exclusion
Year: 2024
Managing fire ignitions for resource benefit decreases fuel loads and reduces the risk of high-severity fire in fire-suppressed dry conifer forests. However, the reintroduction of low-severity wildfire can injure trees, which may decrease their growth after fire. Post-fire growth responses could change from first-entry fires to reburns, as first-entry fires reduce fuel loads and the vulnerability among trees to fire effects, which may result in trees sustaining less damage during reburns. To determine whether trees had growth responses that varied from first-entry fires to reburns, we cored…
Publication Type: Journal Article
Ladder fuels rather than canopy volumes consistently predict wildfire severity even in extreme topographic-weather conditions
Year: 2024
Drivers of forest wildfire severity include fuels, topography and weather. However, because only fuels can be actively managed, quantifying their effects on severity has become an urgent research priority. Here we employed GEDI spaceborne lidar to consistently assess how pre-fire forest fuel structure affected wildfire severity across 42 California wildfires between 2019–2021. Using a spatial-hierarchical modeling framework, we found a positive concave-down relationship between GEDI-derived fuel structure and wildfire severity, marked by increasing severity with greater fuel loads until a…
Publication Type: Journal Article
Climate limits vegetation green-up more than slope, soil erodibility, and immediate precipitation following high-severity wildfire
Year: 2024
BackgroundIn the southwestern United States, post-fire vegetation recovery is increasingly variable in forest burned at high severity. Many factors, including temperature, drought, and erosion, can reduce post-fire vegetation recovery rates. Here, we examined how year-of-fire precipitation variability, topography, and soils influenced post-fire vegetation recovery in the southwestern United States as measured by greenness to determine whether erosion-related factors would have persistent effects in the longer post-fire period. We modeled relationships between post-fire vegetation and these…
Publication Type: Journal Article
Stream chemical response is mediated by hydrologic connectivity and fire severity in a Pacific Northwest forest
Year: 2024
Large-scale wildfires are becoming increasingly common in the wet forests of the Pacific Northwest (USA), with predicted increases in fire prevalence under future climate scenarios. Wildfires can alter streamflow response to precipitation and mobilize water quality constituents, which pose a risk to aquatic ecosystems and downstream drinking water treatment. Research often focuses on the impacts of high-severity wildfires, with stream biogeochemical responses to low- and mixed-severity fires often understudied, particularly during seasonal shifts in hydrologic connectivity between hillslopes…
Publication Type: Journal Article
Model analysis of post-fire management and potential reburn fire behavior
Year: 2024
Recent trends in wildfire area burned have been characterized by large patches with high densities of standing dead trees, well outside of historical range of variability in many areas and presenting forest managers with difficult decisions regarding post-fire management. Post-fire tree harvesting, commonly called salvage logging, is a controversial management tactic that is often undertaken to recoup economic loss and, more recently, also to reduce future fuel hazard, especially when coupled with surface fuel reduction. It is unclear, however, whether the reductions in future fuels translate…
Publication Type: Journal Article
How bureaucracies interact with Indigenous Fire Stewardship (IFS): a conceptual framework
Year: 2024
BackgroundIndigenous Fire Stewardship (IFS) is contested within settler-colonial contexts, where its development is shaped by complex and dynamic socio-cultural, legal, and political factors. This manuscript draws from the policy sciences to sketch out a “zone of interaction” between IFS and the state’s wildfire policy system. Drawing from the strategies of bureaucracies, our goal is to illustrate the patterns in this “zone of interaction,” and to identify the implications for IFS, as well as for Indigenous Peoples and landscapes.ResultsDrawing insights from the Australian and Canadian…
Publication Type: Journal Article
Fire intensity effects on serotinous seed survival
Year: 2024
BackgroundIn fire-prone environments, some species store their seeds in canopy cones (serotiny), which provides seeds protection from the passage of fire before stimulating seed release. However, the capacity of serotinous cones to protect seeds under high intensity fire is uncertain. Beyond simply “high” versus “low” fire intensity or severity, we must understand the influence of the specific characteristics of fire intensity—heat flux, exposure duration, and their dynamics—on serotinous seed survival. In this study, we tested serotinous seed survival under transient levels of…
Publication Type: Journal Article