U.S. Joint Fire Science Program


Date of this Version


Document Type



Fire Science Brief, Issue 114, June 2010


US government work.


In the mixed conifer forests of the Sierra Nevada, it appears that fire dynamics have changed from predominantly low and moderate intensity surface fires to a greater proportion of larger, stand-replacing fires. To help reduce fuels and speed the restoration process, the Forest Service harvests dead trees and uses herbicides to control early stages of shrubs. But there are concerns about these post-burn restoration treatments and their infl uence on emerging fine fuels. Some of these treatments have been linked to an increase in annual grass invasions, specifi cally non-native grasses, which have the potential to significantly alter fuel characteristics, promote repeat fires, and hinder forest regeneration efforts. For that reason, the U.S. Geological Survey ecologists and the University of California, Berkeley foresters—with the support of the Forest Service—conducted a scientific study to determine how logging fi re-killed trees and using herbicides affect plant community composition, fuel load, fuel structure, and potential fire behavior in four major fire areas of the Sierra Nevada. By using existing treatments on national forests that have detailed site histories, researchers were able to quantify the effects of restoration treatments on fine fuels over time and to provide the scientific input needed to fine-tune future restoration plans.