U.S. Joint Fire Science Program


Date of this Version


Document Type



Fire Science Brief, Issue 4, January 2008


US government work.


In late September 2002, an accidental fire ignited on Blacks Mountain in the dry pine forest of the Cascade Range of northeastern California. The fire burned through the Blacks Mountain Experimental Forest where a large-scale, long-term study was already underway to test ecological responses to two different stand structures the scientists had created using various treatments: high diversity, with and without prescribed fire, and low diversity, with and without prescribed fire. The study was not originally designed to test the effects of severe wildfires. The Cone Fire created an opportunity to evaluate the effects of different treatments on tree survival in the presence of wildfire. Fire severity, as observed through tree death, was high in the untreated areas adjacent to treated stands. Stands with ladder fuels reduced by thinning and a follow-up surface fuel treatment by prescribed fire had the best survival and lowest occurrence of damage to boles (trunks) and crowns. Stands in which ladder fuels were thinned, without follow-up treatment of surface fuels by prescribed fires, were intermediate between the other two. However, even the stands with thinning only brought the fire mostly to the surface with no more than occasional torching.