Editor's Column

Guest Columns

Forest Facts

By: Jim Petersen

When logging slash is not properly disposed of it can be a fire hazard. This is why piles of discarded limbs and treetops are burned when burning can be done safely.

Forest managers face an interesting challenge where slash disposal is concerned. Minimizing the risk of subsequent fire is very important, but limbs and treetops also help enrich the soil as they decay and they provide habitat for rodents, birds and insects.

When logging debris is properly disposed of the risk of post-logging wildfire is minimal. [Top photo] Trees too small to have commercial value are piled for burning at Fort Valley, west of Flagstaff. [Bottom] Finely ground woody debris from the Blue Ridge demonstration project near Lakeside. Biomass technology and marketing expertise is desperately needed in the Southwest.

Numerous scientific studies affirm the fact that when slash is properly treated it does not pose a serious fire threat. One such study, conducted in California’s Sierra Nevada range in 1996, drew this conclusion:

“Timber harvest, through its effects on forest structure, local microclimate and fuel accumulation, has increased fire severity more than any other recent human activity. If not accompanied by adequate reduction of fuels, logging (including slave of dead and dying trees) increases fire hazard by increasing surface dead fuels and changing the local microclimate. Fire intensity and expected fire spread rates thus increase locally and in areas adjacent to harvest. However, logging can serve as a tool to help reduce fire hazard when slash is adequately treated and treatments are maintained.” [Emphasis added]

There is also new evidence that past forest management activity, including logging, can help slow the pace of even large fires. Near Show Low, the Rodeo Chediski fire was finally stopped just inside the city limits—averting the possible loss of the entire town—when it entered an area that had been thinned. With less to burn, the fire slowed, giving firefighters an opportunity to contain it.

“The fire did the least amount of damage in areas that had been thinned, where logging slash had been treated and prescribed fire was later applied to reduce woody debris accumulations,” reported Jim Youtz, a Bureau of Indian Affairs silviculturist assigned to the White Mountain Apache tribe at Fort Apache. Mr. Youtz helped battle the conflagration, which started on tribal forestland.

“Areas where no management activity had occurred were devastated,” he explained. “Where logging or thinning had occurred but slash was not removed, there was more damage than in areas where slash had been treated and prescribed fire had been used to eliminate excess woody debris. We also noticed that old burns helped slow the pace of the fire, but small trees growing in old burns did not survive unless the area had been salvaged logged. But where salvage logging had occurred, trees that had been planted or sprouted naturally after the fire survived the new burn.”

Managing forests— thinning overly dense stands, removing diseased, dead and dying trees, treating logging slash and controlling woody debris accumulations—is expensive, but not nearly as costly or environmentally destructive as catastrophic wildfire. And as you will learn in this report, there are hopeful signs that these costs can be offset through development of new commercial markets for most forest residues.

"We must always consider the environment and people together, as though they are one, because the
human need to use natural resources is fundamental to our continued presence on earth."