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Andy Kerr's Forest Fire Quotes Page Twentieth century forest management, for all its good intentions, has left a mess on the landscape. Jim Agee, Ph.D., 1994, University of Washington |
Compiled by Evan Frost As a by-product of clearcutting, thinning, and other tree-removal activities, activity fuels create both short- and long-term fire hazards to ecosystems...Even though these hazards [with logging slash] diminish, their influence on fire behavior can linger for up to 30 years in the dry forest ecosystems of eastern Washington and Oregon.
Timber harvest, through its effects on forest structure, local microclimate, and fuels accumulation, has increased fire severity more than any other recent human activity. If not accompanied by adequate reduction of fuels, logging (including salvage 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.
Clearcutting can change fire climate so that fires start more easily, spread faster, and burn hotter. The effect of these changes on the fire control problem is extremely important. For each man required to control a surface fire in a mature stand burning under average conditions, 20 men will be required if the area is clearcut.
We need to accept that in many areas throughout the region, past forest management may have set the stage for fires larger and more intense than have occurred in at least the last few hundred years.
Because salvage logging removes natural fire breaks, it homogenizes the landscape and increases susceptibility to catastrophic fires and insect outbreaks.
Intensive timber management contributes to additional fire hazards due to greater road access and associated increases in human-caused fires, operation of logging equipment, slash build-up following logging, and the associated decrease in moisture content of forest understories.
The original old-growth ponderosa pine were quite resistant to crown fires, because the frequent ground fires kept fuel levels from building too high. Excluding ground fires, coupled with forestry practices such as clearcutting that convert old-growth to younger stands, has increased the probability of a ground fire moving into crowns and gaining intensity as it spreads. There is no doubt that big, thick-barked trees are most resistant to fire, and foresters have noted since the early decades of the century that plantations were particularly vulnerable to fire. Susceptibility was reduced with the advent of slash disposal. However, even with slash disposal, densely stocked plantations are more vulnerable to fires than healthy old-growth.
Those small logging operations create tremendous fuel loading where traditional logging operations occur. We're going in and taking out the large trees, and we're leaving the thickets behind, or we're leaving slash, heavily intermingled with built-up areas. The logging slash is supposed to be treated, but that's been a serious problem.
More often than not, timber harvesting prescriptions have been 'high grades' -- take the biggest trees and leave the rest. And do a sloppy job in the process. Which means you end up with overstocked stands of small diameter trees.... You end up with a fuel problem.
The slash treatment backlog has led to tremendous wildfire risk on lands recently harvested for either green timber or salvage.
Sparks from the logging railroads set alight piles of slash and dead wood left after cutting, and the resultant fires burned so hot that what grew up afterward were often thickets...
It is after logging that the damage from fires is greatest, on account of the inflammable and unburned slash.
Where the cut has been heavy and the resulting debris correspondingly large, all the difficulties of fire fighting are proportionally increased. All kinds of waste material left in the woods supply food for the flames, but the leaving of large unlopped softwood tops on the ground adds enormously to the fury of a brush fire and greatly prolongs the length of time that slash remains a menace to its own and surrounding areas...Fires on cutover lands usually kill all standing timber left on the area burned, as well as all the young growth.
Within the last sixty years, however, fires have done little damage to the virgin timber, although prevalent on the cut-over areas...Fire on these areas is of the hottest character, and once started is extremely difficult and often impossible to check.
Fresh, dry slash of any species makes a high-intensity, unapproachable fire. A fire started in dry, fresh slash can become uncontrollable in seconds.... It appears significant that many large fires in western United States have burned almost exclusively in slash. Some of these fires have stopped when they reached uncut timber; none has come to attention that started in green timber and stopped when it reached a slash area.
Logging slash was generally left where it fell creating abnormal fuel loads in these dry forests. Thus, the potential for future epidemics of insects and disease and more destructive fires was becoming established. Extensive railroad logging throughout the [inland West] region created dangerous levels of dry logging slash resulting in extreme fire hazard. For example, in 1931 on the Boise National Forest, stand-destroying wildfire burned 62,000 acres of ponderosa pine/Douglas-fir forest that had previously experienced only surface fires for, at the least, 300 years. Observers attributed the intensity of this fire to the large volume of slash created by railroad logging in the late 1920s.
What is apparent to me now is that large salvage sale contracts are NOT a major part of addressing the large acreage and urban inter-mix needs. Planning and attempting to market several salvage sales, ranging from 100 to 7,000 acres, has shown that the value of salvageable material will not bear the cost of adequate treatment for fuels reduction and long-term forest health.
In large wildland fires on urban-interface lands, city and county fire departments cannot protect every home. What I am saying is that all of us concerned with wildfires and the loss of life and property must begin addressing basic, common sense, fire prevention and fuels reduction guidelines for these areas.
One are of increasing concern is the wildland/urban interface. Here, the forest health problems that lead to intense and inordinately hot wildfires are magnified by concerns for protection of buildings and human safety. In recent years, thousands upon thousands of homes have been built in natural settings where low-intensity fires once burned every 5 to 30 years.
There may be an indication that harvested land had a better chance to burn black [most intense] when compared to unharvested land.
Although salvage logging reduces fuel loading, the removal of overstory trees increases afternoon temperatures and windspeeds, and decreases relative humidity. This increases relative fire danger on the site.
As the loggers finished their work, they left behind a literal wasteland. Great piles of slash -- small timber, branches, and other debris that had little economic value -- remained on the ground, sometimes in piles ten to fifteen feet high. They accumulated over a vast area, turned brown in the summer heat, and waited for the dry season, when a spark might set them alight. Fires had long been common in the forests. Indeed, fires were an important reason why the pine was so abundant, for the tree was adapted to reproduce most effectively in newly burned-over lands. But the fires that followed in the wake of the loggers were not like earlier ones....
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