Research Database
Displaying 41 - 60 of 256
A fire-use decision model to improve the United States’ wildfire management and support climate change adaptation
Year: 2024
The US faces multiple challenges in facilitating the safe, effective, and proactive use of fire as a landscape management tool. This intentional fire use exposes deeply ingrained communication challenges and distinct but overlapping strategies of prescribed fire, cultural burning, and managed wildfire. We argue for a new conceptual model that is organized around ecological conditions, capacity to act, and motivation to use fire and can integrate and expand intentional fire use as a tool. This result emerges from more considered collaboration and communication of values and needs to address…
Publication Type: Journal Article
Human driven climate change increased the likelihood of the 2023 record area burned in Canada
Year: 2024
In 2023, wildfires burned 15 million hectares in Canada, more than doubling the previous record. These wildfires caused a record number of evacuations, unprecedented air quality impacts across Canada and the northeastern United States, and substantial strain on fire management resources. Using climate models, we show that human-induced climate change significantly increased the likelihood of area burned at least as large as in 2023 across most of Canada, with more than two-fold increases in the east and southwest. The long fire season was more than five times as likely and the large areas…
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
Tamm review: A meta-analysis of thinning, prescribed fire, and wildfire effects on subsequent wildfire severity in conifer dominated forests of the Western US
Year: 2024
Increased understanding of how mechanical thinning, prescribed burning, and wildfire affect subsequent wildfire severity is urgently needed as people and forests face a growing wildfire crisis. In response, we reviewed scientific literature for the US West and completed a meta-analysis that answered three questions: (1) How much do treatments reduce wildfire severity within treated areas? (2) How do the effects vary with treatment type, treatment age, and forest type? (3) How does fire weather moderate the effects of treatments? We found overwhelming evidence that mechanical thinning with…
Publication Type: Journal Article
Using focus groups for knowledge sharing: Tracking emerging pandemic impacts on USFS wildland fire operations
Year: 2024
In early 2020 the US Forest Service (USFS) recognized the need to gather real-time information from its wildland fire management personnel about their challenges and adaptations during the unfolding COVID-19 pandemic. The USFS conducted 194 virtual focus groups to address these concerns, over 32 weeks from March 2020 to October 2020. This management effort provided an opportunity for an innovative practice-based research study. Here, we outline a novel methodological approach (weekly, iterative focus groups, with two-way communication between USFS staff and leadership), which culminated in a…
Publication Type: Journal Article
Predicting daily firefighting personnel deployment trends in the western United States
Year: 2024
Projected increases in wildfire frequency, size, and severity may further stress already scarce firefighting resources in the western United States that are in high demand. Machine learning is a promising field with the ability to model firefighting resource usage without compromising dataset size or complexity. In this study, the Categorical Boosting (CatBoost) model was used with historical (2012-2020) wildfire data to train three models that calculate predicted daily counts of 1) total assigned personnel (total personnel), 2) assigned personnel that are at the fire (ground personnel), and…
Publication Type: Journal Article
Expanding our understanding of nitrogen dynamics after fire: how severe fire and aridity reduce ecosystem nitrogen retention
Year: 2024
Fires release large pulses of nitrogen (N), which can be taken up by recovering plants and microbes or exported to streams where it can threaten water quality. The amount of N exported depends on the balance between N mineralisation and rates of N uptake after fire. Burn severity and soil moisture interact to drive these rates, but their effects can be difficult to predict. To understand how soil moisture and burn severity influence post-fire N cycling and retention in a dryland watershed, we quantified changes in plant biomass, plant N content, soil microbial biomass, inorganic N pools, and…
Publication Type: Journal Article
Prescribed fire placement matters more than increasing frequency and extent in a simulated Pacific Northwest landscape
Year: 2024
Prescribed fire has been increasingly promoted to reduce wildfire risk and restore fire-adapted ecosystems. Yet, the complexities of forest ecosystem dynamics in response to disturbances, climate change, and drought stress, combined with myriad social and policy barriers, have inhibited widespread implementation. Using the forest succession model LANDIS-II, we investigated the likely impacts of increasing prescribed fire frequency and extent on wildfire severity and forest carbon storage at local and landscape scales. Specifically, we ask how much prescribed fire is required to maintain…
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
Restoring frequent fire to dry conifer forests delays the decline of subalpine forests in the southwest United States under projected climate
Year: 2024
- In southwestern US forests, the combined impact of climate change and increased fuel loads due to more than a century of human-caused fire exclusion is leading to larger and more severe wildfires. Restoring frequent fire to dry conifer forests can mitigate high-severity fire risk, but the effects of these treatments on the vegetation composition and structure under projected climate change remain uncertain.
- We used a forest landscape model to assess the impact of thinning and prescribed burns in dry conifer forests across an elevation gradient, encompassing low-elevation…
Fire Effects and Fire Ecology, Fire History, Mixed-Conifer Management, Prescribed Burning, Restoration and Hazardous Fuel Reduction
Publication Type: Journal Article
An optimization model to prioritize fuel treatments within a landscape fuel break network
Year: 2024
We present a mixed integer programming model for prioritizing fuel treatments within a landscape fuel break network to maximize protection against wildfires, measured by the total fire size reduction or the sum of Wildland Urban Interface areas avoided from burning. This model uses a large dataset of simulated wildfires in a large landscape to inform fuel break treatment decisions. Its mathematical formulation is concise and computationally efficient, allowing for customization and expansion to address more complex and challenging fuel break management problems in diverse landscapes. We…
Publication Type: Journal Article
When do contemporary wildfires restore forest structures in the Sierra Nevada?
Year: 2024
Background: Following a century of fire suppression in western North America, managers use forest restoration treatments to reduce fuel loads and reintroduce key processes like fire. However, annual area burned by wildfire frequently outpaces the application of restoration treatments. As this trend continues under climate change, it is essential that we understand the effects of contemporary wildfires on forest ecosystems and the extent to which post-fire structures are meeting common forest restoration objectives. In this study, we used airborne lidar to evaluate fire effects across yellow…
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
Wildfire probability estimated from recent climate and fine fuels across the big sagebrush region
Year: 2024
BackgroundWildfire is a major proximate cause of historical and ongoing losses of intact big sagebrush (Artemisia tridentata Nutt.) plant communities and declines in sagebrush obligate wildlife species. In recent decades, fire return intervals have shortened and area burned has increased in some areas, and habitat degradation is occurring where post-fire re-establishment of sagebrush is hindered by invasive annual grasses. In coming decades, the changing climate may accelerate these wildfire and invasive feedbacks, although projecting future wildfire dynamics requires a better…
Publication Type: Journal Article
A Wildfire Progression Simulation and Risk-Rating Methodology for Power Grid Infrastructure
Year: 2024
As the frequency and intensity of power line-induced wildfires increase due to climate-, human- , and infrastructure-related risk drivers, maintaining power system resilience and reducing environmental impacts become increasingly crucial. This paper presents a comprehensive methodology to assess the susceptibility, vulnerability, and risk of power line-induced wildfires for lines and nodes in an electric grid. The methodology integrates a well-established wildfire spread simulator into power flow analysis through a set of analytical steps. The proposed approach is applied to a case study…
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
Abiotic Factors Modify Ponderosa Pine Regeneration Outcomes After High-Severity Fire
Year: 2024
Large high-severity burn patches are increasingly common in southwestern US dry conifer forests. Seed-obligate conifers often fail to quickly regenerate large patches because their seeds rarely travel the distances required to reach core patch area. Abiotic factors may further alter the distance seeds can travel to regenerate a patch, which would change expected post-fire regeneration patterns. We used the presence and density of ponderosa pine regeneration as a proxy for seed dispersal to quantify the effect of abiotic factors on seed dispersal into high-severity patches. We established 45…
Publication Type: Journal Article
Future fire events are likely to be worse than climate projections indicate – these are some of the reasons why
Year: 2024
BackgroundClimate projections signal longer fire seasons and an increase in the number of dangerous fire weather days for much of the world including Australia.AimsHere we argue that heatwaves, dynamic fire–atmosphere interactions and increased fuel availability caused by drought will amplify potential fire behaviour well beyond projections based on calculations of afternoon forest fire danger derived from climate models.MethodsWe review meteorological dynamics contributing to enhanced fire behaviour during heatwaves, drawing on examples of…
Publication Type: Journal Article
Global rise in forest fire emissions linked to climate change in the extratropics
Year: 2024
Climate change increases fire-favorable weather in forests, but fire trends are also affected by multiple other controlling factors that are difficult to untangle. We use machine learning to systematically group forest ecoregions into 12 global forest pyromes, with each showing distinct sensitivities to climatic, human, and vegetation controls. This delineation revealed that rapidly increasing forest fire emissions in extratropical pyromes, linked to climate change, offset declining emissions in tropical pyromes during 2001 to 2023. Annual emissions tripled in one extratropical pyrome due to…
Publication Type: Journal Article
Contemporary fires are less frequent but more severe in dry conifer forests of the southwestern United States
Year: 2024
Wildfires in the southwestern United States are increasingly frequent and severe, but whether these trends exceed historical norms remains contested. Here we combine dendroecological records, satellite-derived burn severity, and field measured tree mortality to compare historical (1700-1880) and contemporary (1985-2020) fire regimes at tree-ring fire-scar sites in Arizona and New Mexico. We found that contemporary fire frequency, including recent, record fire years, is still <20% of historical levels. Since 1985, the fire return interval averages 58.8 years, compared to 11.4 years before…
Publication Type: Journal Article