Pacific Northwest Research Station

Title: Fire treatment effects on vegetation structure, fuels, and potential fire severity in Western U.S. forests.

Author: Stephens, Scott; Moghaddas, Jason J.; Edminster, Carl; Fiedler, Carl E.; Hasse, Sally; Harrington, Michael; Keeley, Jon E.; Knapp, Eric E.; McIver, James D.; Metlen, Kerry; Skinner, Carl N.; Youngblood, Andrew

Date: 2009

Source: Ecological Applications. 9(2): 305-320

Description: 

In this paper, we report the effects of Fire and Fire Surrogate (FFS) forest stand treatments on fuel load profiles, potential fire behavior, and fire severity under three weather scenarios from six Western U.S. FFS sites. This replicated, multisite experiment provides a framework for drawing broad generalizations about the effectiveness of prescribed fire and mechanical treatments on surface fuel loads, forest structure, and potential fire severity. Mechanical treatments without fire resulted in combined 1-, 10-, and 100-hour surface fuel loads that were significantly greater than controls at three of five FFS sites. For the combined treatment of mechanical plus fire, all five FFS sites with this treatment had a substantially lower likelihood of passive crown fire as indicated by the very high torching indices. FFS sites that experienced significant increases in 1-, 10-, and l00-hour combined surface fuel loads utilized harvest systems that left all activity fuels within experimental units. When mechanical treatments were followed by prescribed burning or pile burning, they were the most effective treatment for reducing crown fire potential and predicted tree mortality because of low surface fuel loads and increased vertical and horizontal canopy separation. Results indicate that mechanical plus fire, fire-only, and mechanical-only treatments using whole-tree harvest systems were all effective at reducing potential fire severity under severe fire weather conditions. Retaining the largest trees within stands also increased fire resistance.

Keywords: fire hazard, fire policy, fire suppression, fire resistance, fuel management, fuel treatment, mixed conifer, ponderosa pine, wildfire.

View and Print this Publication (2.17 MB)

Publication Notes: 

• We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
• This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
• You may send email to pnw_pnwpubs@fs.fed.us to request a hard copy of this publication. (Please specify exactly which publication you are requesting and your mailing address.)

 Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

Citation

Stephens, Scott; Moghaddas, Jason J.; Edminster, Carl; Fiedler, Carl E.; Hasse, Sally; Harrington, Michael; Keeley, Jon E.; Knapp, Eric E.; McIver, James D.; Metlen, Kerry; Skinner, Carl N.; Youngblood, Andrew  2009.  Fire treatment effects on vegetation structure, fuels, and potential fire severity in Western U.S. forests..   Ecological Applications. 9(2): 305-320.