U.S. Joint Fire Science Program


Date of this Version


Document Type



Fire Science Brief, Issue 24, December 2008


US government work.


The Malheur National Forest is located in the Blue Mountains on Oregon’s eastern side, the portion of the state that lies east of the Cascade Crest. In the mid 1990s, researchers and land managers conceived a suite of experiments to explore the effects of prescribed fi re on forest health. The studies were designed to coincide with prescribed burns conducted by the USDA Forest Service. The experiments took place in the Emigrant Creek Ranger District, a remote area dominated by ponderosa pine. One of the research projects aimed to assess soil health after different intervals of fire frequency and in two burn seasons, spring and fall. Overall, the study revealed that return interval and season of burn had few signifi cantly harmful effects on soil health. Fire can, however, affect the soil’s ability to retain moisture, the primary limiting factor in the ability of the tree to thrive.