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Fire, Fuel and Smoke

Science Spotlights

A reddish plume of smoke from a wildfire above hills and agricultural fields.
We evaluated current scientific literature, datasets, and models to assess the state of the science on wildland fire emissions. The assessment evaluates current knowledge regarding the composition, intensity, and drivers of emissions and discusses the crucial gaps in our understanding of emissions.
A multi-panel image showing a target exploding and igniting straw bales.
Exploding targets composed of ammonium nitrate and aluminum powder are sold for recreational target shooting and sometimes ignite nearby vegetation. This study involved a series of tests that attempt to identify some of the principal factors affecting ignitions that might result after intended use of exploding target products.
A map of the United States showing firefighter entrapments with circles, where the size of the circle indicates number of personnel entrapped and the color of the circle indicates whether or not fatalities occurred.
A literature and data review were conducted to advance our understanding of the causes of firefighter entrapments. We identified several research needs related to a lack of knowledge, inadequate tools, and improved methods for data collection and storage. Prioritizing these needs will be difficult since they all have the potential improve firefighter safety, either directly or indirectly.
A map of the Deschutes National Forest, with the wildland-urban interface marked in red and various treatment areas marked in shades of blue.
We integrated the widely used Forest Vegetation Simulator with FSim, a large wildfire simulator, to study how management policies affect future wildfire regimes. The model leverages decades of research and development on the respective forest growth and wildfire simulation models, and their integration creates a strategic forest landscape model that can be used to examine forest fire and management policy issues on National Forests in the...
An eight-panel image of forest plots. Columns are 2005 and 2015; rows are control, burn-only, thin-only, and thin and burn.
Fuel treatments are important to restore vegetation structure and composition in dry forests, imbuing ecological resistance to future wildfire. But ecosystem benefits may change after treatment as forests regrow, especially if disturbances such as mountain pine beetle outbreak intervene. We found post-treatment growth plus beetle-caused mortality in thinning-only or burning-only strategies erased comparative benefits, and only combined thinning...
Prescribed crown fire at Manning Creek, Fishlake National Forest. Photo credit: Roger Ottmar. Photo taken: June 2019
The broad consensus among fire and fuel scientists and managers is that we need to reduce hazardous fuel accumulations on many more acres to mitigate the risk and severity of wildfires. But mechanical fuel treatments are expensive! Prescribed fire is a more cost effective tool to reduce fuel loads and to restore and maintain fuel conditions to something closer to the historical norm.
Figure 1 urban_interface_mulching
Recently, several large fires have burned through masticated sites – including in Colorado (Brewer et al. 2013), Washington, and New Mexico. Burning under extreme weather conditions with strong winds, these fires have challenged the benefits of using mastication, even though mastication can provide many positive environmental effects, such as soil moisture retention and cool, moist environments for soil microbes. However, informing managers when...
Pioneer Fire in Idaho, night time photo of active fire running up hill
The USDA Forest Service Rocky Mountain Research Station recently released a new General Technical Report, GTR-392, Cross-boundary Wildfire and Community Exposure: A Framework and Application in the Western US. The publication describes the development and application of a framework to assess cross-boundary wildfire exposure for the Western U.S. with the purpose of mapping potential fire transmission among public and private lands, and...
stand-level thinning
Large, old trees, often called legacy trees, serve a foundational role in old-growth forests. Restoration efforts to improve vigor of legacy trees and decrease risk to high-intensity wildland fire and drought-mediated insect mortality often include reductions in stand density. However, sometimes regulatory and social constraints limit stand-level thinning options by requiring maintenance of closed canopies.
During and after fire
Each year wildland fires kill and injure trees on millions of forested hectares globally, causing both positive and negative impacts to plant and animal biodiversity, carbon storage, hydrologic processes, and ecosystem services. Understanding the underlying mechanisms of fire-caused tree mortality is important to accurately predict mortality, estimate fire-driven feedbacks to the global carbon cycle, extrapolate to novel future conditions, and...