In recent decades, many landscapes across the western United States have experienced substantial fire activity. These fires consume fuels and alter vegetation structure, which may be able to serve as a natural fuel treatment in the same manner as mechanical treatments or prescribed fire. Knowing that fire occurrence, size, and severity are limited by recent wildfires should provide greater flexibility and confidence in managing fire incidents and managing for resource benefit. Specifically, fire managers can use the findings from this study to help predict whether a previous fire will act as a fuel treatment based on fire age, forest type, and expected weather.
A portion of the Bob Marshall Wilderness, part of the Crown of the Continent Ecosystem, burned in the 2003 Little Salmon Creek fire. Photo by Sean Parks
Every year, wildland fires affect much more acreage in the United States compared to controlled burns. Like controlled burns, wildland fire can help promote biological diversity and healthy ecosystems, but despite these facts, wildland fire is not often considered as a fuel treatment in the United States.
Wildland fire is part of a self-regulating cycle that temporarily reduces landscape-level vegetation and fuel – a natural process that can reduce the size, spread, severity and even the occurrence of future fires. Wildland fires can reduce live and dead vegetation, while the ashes that remain can release nutrients that have been locked in older vegetation, which benefits surviving or regenerating trees and other vegetation. Wildland fires can also improve forest health by reducing the density of trees, which reduces competition for necessary resources such as light and water.
RMRS Scientists have evaluated more than 40 years of satellite imagery to determine what happens when a fire burns into a previously burned area. Results from this research are helping land managers to assess whether a previous wildland fire will act as a fuel treatment based on the length of time since the previous fire occurred, along with local conditions such as ecosystem type, topography and fire weather conditions. By factoring in the ecological benefits of fire, land managers are able to manage fire in a way that fosters landscapes that are more resilient.
Wildland fire acts as a fuel treatment by limiting the occurrence, size, and severity of subsequent fires.
The ability of wildland fire to act as a fuel treatment diminishes with time and this time varied by study area.
Under extreme weather conditions, the ability of wildland fire to act as a fuel treatment is reduced.
Parks S.A. (2015). The Ability of Wildfire to Act as a Fuel Treatment (webinar).
Parks, Sean, A; Gucker, Corey L. 2016. Effectiveness and longevity of wildland fire as a fuel treatment. Northern Rockies Fire Science Network Research Brief No. 1.