Evaluating the impact of managed wildfires as a restoration tool in southwestern ponderosa pine forests

Abstract

Predating the 20th-century fires in the southwestern U.S., the ponderosa pine-dominated forests burned regularly and at low intensities. Yet these southwestern forests have become overgrown and dense as a result of fire exclusion and suppression policies. Only recently have managed wildfires been an active tool in an effort to return current forest stands within a historical range of natural variability. This study examines (1) the effects of recent wildfires managed for resource benefit use on stand structure in the Coconino National Forest, Arizona, (2) the prolonged impacts of simulated and repeated resource benefit fires of varying severity, and (3) what combination of management activities are necessary to return current stands to near historical reference conditions. Results show that managed wildfires may not be enough to return overstocked forests within historical conditions and mechanical treatments may be necessary to initiate a shift in composition and structure.