U.S. Joint Fire Science Program


Date of this Version


Document Type



Fire Science Brief, Issue 125, January 2011


US government work.


Although complete fire exclusion is a thing of the past in the Sierra Nevada, fire and fuel managers must still contend with dense forests and higher fuel loads that have built up over time. Controlled fire is a helpful fuel reduction method, but it can be tricky to manage, especially in an area with excessive fuels, or in plantations with trees having smaller diameters and lower crowns, which are more susceptible to heat damage. Mastication can also be a useful fuel treatment and has become a popular alternative, but includes its own set of drawbacks and uncertainties. Since little research has been done to measure the fire behavior and effects of masticated fuel beds, researchers conducted a study on mastication and combined mastication/prescribed burning fuel treatments in the Red Mountain region of California’s Sequoia National Forest. Specifi cally, researchers hoped to get concrete answers to key questions, including: will mastication result in undesirably high surface fuels? How will mastication change fire behavior and effects? Will treatments involving mastication and prescribed fire lead to a healthier stand density and wildfire resiliency? And, will there be higher tree mortality when masticated sites burn in a wildfire? With this study, researchers also hoped to provide managers with the data for custom fuel models needed to effectively estimate masticated fuel loads, to predict how hot and fast they will burn, and to fine-tune fuel treatment planning efforts.