Report: Completed Fuels Treatments in Angora Creek Worked as Designed

From YubaNet.com

Regional
Report: Completed Fuels Treatments in Angora Creek Worked as Designed
Author: John Heil, Public Affairs, U.S. Forest Service
Published on Jun 30, 2009 - 2:37:30 PM

VALLEJO, Calif., Jun. 30, 2009 - The U.S. Forest Service Pacific Southwest Region has just released a report statistically detailing the effects of pre-fire forest fuel treatments on fire severity in the wildland-urban interface areas burned by the Angora Fire in 2007. The report: "Effects of fuel treatments on fire severity in an area of wildland-urban interface, Angora Fire, Lake Tahoe Basin, California" was published online by the journal Forest Ecology and Management last week.

The study (by the U.S. Forest Service's Dr. Hugh D. Safford and David A. Schmidt and Chris H. Carlson) found that with a few exceptions, the fuel treatments completed in the Angora Creek drainage performed as designed and significantly moderated fire behavior and fire effects to the forest. A previous Forest Service report (Murphy et al. 2007) detailed how these treatments aided fire suppression efforts in and around the housing tracts that were burned. The current study focused on a statistical assessment of the effects of the fire on the forest resource itself, in areas where fuel thinning projects had occurred and in neighboring untreated forest.

In most of the treatments examined, crown fire behavior changed to surface fire within 150 feet of encountering a fuel treatment. One year after fire, tree mortality in the sampled untreated forest was about 80 percent vs. about 20 percent in the treated stands. Due to fire, the density and basal area (a surrogate for biomass) of living trees declined drastically in the sampled untreated stands but did not decline significantly where fuel thinning treatments had been completed. This empirically supports recent modeling work (e.g., Hurteau et al. 2008, Hurteau and North 2009) which has suggested that forest fuel thinning can help to maintain carbon stocks in high fire-risk landscapes like the Sierra Nevada.

The report also noted that attack rates on trees by red turpentine beetles, which typically follow fires and often precede pine beetle attack, were also much lower in the treated forest, suggesting that long-term mortality in the untreated forest will rise above current levels.