U.S. Joint Fire Science Program


Date of this Version


Document Type



Fire Science Brief, Issue 5, February 2008


US government work.


With a history of management choices that have suppressed fire in the West, ecosystems in which fire would play a vital role have developed tremendous fuel loads. As a result, conditions are prime for fires to grow large, escape attack measures, and become catastrophic conflagrations that damage watersheds, forest resources, and homes. With a quiver of treatment options, land managers have successfully used prescribed burning and thinning to modify landscapes at the stand level. But planning treatments to modify fuel build up on a patch of forest is vastly different than planning treatments that could modify fire’s spread over larger landscapes. Using information specific to a site, such as fuels, topography, and weather, simulations are run to identify the pathways fire would likely follow, the elements that would cause a fire to grow from moderate to severe, and the treatment options that would best modify the fuel load present. The simulations identify the best placement of treatment units and number of units on a landscape. Little is known about how long treatments will last, but studies suggest the benefits are limited to 10 to 15 years. To achieve desired effects in tempering fire’s behavior, land managers must apply optimally placed treatments at a rate of 1% to 2% per year.