Current forests in many fire-dependent ecosystems of the United States are denser and more spatially uniform, have many more small trees and fewer large trees, and have greater quantities of forest fuels than did their presettlement counterparts. Fire suppression policy, past livestock grazing and timber harvests, and changes in climate have contributed to these conditions. These practices have resulted in a general deterioration in forest ecosystem integrity and an increased probability of large, high-severity wildfires. Such conditions are prevalent especially in forests with historically short-interval, low- to moderate-severity fire regimes.

The report of the Sierra Nevada Ecosystem Project highlighted these problems and explained the need for large-scale and strategically-located thinning (especially of small trees), fuel treatment, and use of prescribed fire. Modeling studies have indicated that some fuel and silvicultural treatments can be effective in limiting the size and intensity of wildfires, but these predictions need to be validated with field experiments. Furthermore, the extent to which alternative fuel and stand treatments restore ecosystem structure and function is largely unknown.

A team of scientists and land managers has designed an integrated national network of 11 long-term research sites to address this need, with support from the USDA/USDI Joint Fire Science Program. The steering committee and other participants in this national Fire/Fire Surrogate (FFS) study represent a number of federal and state agencies, universities, and private entities, as well as a wide range of disciplines and geographic regions. The study will use a common experimental design to facilitate broad applicability of results. The primary focus is on the ecosystem impacts of the fire hazard reduction treatments. As part of the FFS study, USGS researchers at the Western Ecological Research Center will assess fuel-reducing treatments in a 5-year study at Sequoia and Kings Canyon National Parks to determine the ecosystem impacts of different fire regimes used to reduce fire hazard.