ScienceDaily (Mar. 21, 2009) — Scientists compared the effectiveness of fire fuel reduction methods under the U.S. National Fire and Fire Surrogate Study. Four articles examine the effects of prescribed burns, mechanical treatment (usually thinning of the smallest trees) and a combination of both with control plots at 12 study sites in forests across the United States.

Many U.S. forests once experienced frequent natural fires that removed many of the low-lying plants, including downed woody plants, shrubs and grasses that fueled these burns. But human activities, such as livestock grazing, preferential logging of large trees and outright fire suppression or exclusion have led to changes in forest structure. Increases in tree density, smaller tree size and increased fuel load place as many as 10 million hectares of U.S. forest at high risk of hazardous fires, the authors write.

Under extreme weather conditions, the authors found that prescribed fire alone, a combination of prescribed fire and mechanical fuel removal, and fuel removal alone were all effective at reducing fire severity. More specifically, they report that to quickly restore forests with few, large-diameter trees, a combination of prescribed burns and mechanical fuel removal achieved the best results.

The authors note, however, that this combination treatment also favored nonnative species invasions at some sites. In addition, a combination of prescribed burns and mechanical thinning increased the incidence of tree death from bark beetles and wood borers. Still, the authors emphasize that a no-treatment option is not sustainable in these fire-prone environments. They recommend caution and case-by-case assessments of best management practices for different forest types.

Journal reference:

1. McIver et al. The national fire and fire surrogate study: Ecological consequences of alternative fuel reduction methods in seasonally dry forests. Forest Ecology and Management, 2008; 255 (8-9): 3075 DOI: 10.1016/j.foreco.2008.01.035

Related Stories

Biscuit Fire Tests Effectiveness Of Forest Thinning And Prescribed Burning Practices (Mar. 15, 2006) — Fuel reduction treatments should simultaneously take place in the overstory, understory, and on the ground to adequately reduce fire ...  > read more

Salvage Logging, Replanting Increased Biscuit Fire Severity (June 12, 2007) — The Biscuit Fire of 2002 burned more severely in areas that had been salvage logged and replanted, compared to similar areas that were also burned in a 1987 fire but had been left to regenerate ...  > read more

Wildfires And Logging: Are Severe Reburns Likely With Or Without Logging? (Apr. 12, 2007) — A new study on the effects of timber harvest following wildfire shows that the potential for a recently burned forest to reburn can be high with or without logging. This study demonstrates that the ...  > read more

Forest Fire Prevention Efforts Could Lessen Carbon Sequestration, Add To Greenhouse Warming (July 12, 2009) — Widely sought efforts to reduce fuels that increase catastrophic fire in Pacific Northwest forests will be counterproductive to another important societal goal of sequestering carbon to help offset ...  > read more

Search ScienceDaily

Fire Stopper