Record setting fires in Northwest forests in recent summers have made fire management a top priority of land managers.
Students can use the debate to learn about forest ecosystems and public policy.
by Valerie Vogrin
Fire has been an important ecological process for thousands of years in Northwest woodlands. Fire has been responsible for the species composition and structure of many of our forest types. Almost all of the Douglas fir old-growth forests west of the Cascades originated from historic fires. At present, however, forest fires pose numerous difficult problems for foresters and policy makers. According to The New York Times, by mid-August this year fires in the West have burned an area larger than Connecticut and Rhode Island combined.
Native American Use of Fire
Native Americans had a great respect for fire and made frequent use of it. They used smoke to flush bees from their hives and bears from their dens and to temporarily chase away mosquitoes and other pests. They often used fire to encourage the growth of plants that were eaten by animals they hunted. Controlled burns kept grasslands fertile so buffalo would be attracted to the area.
The impact of a fire on a forest ecosystem depends on its intensity. Hotter, longer lasting fires have more extensive impacts than cooler, brief fires. In low to moderate fires, seeds and roots will take hold soon after, sending up new shoots. Plant nutrients in the form of ash are put back into the soil, resulting in rich new plant growth. Grasses and sedges quickly sprout. Hotter fires heat the ground so much that all plant life is destroyed. Soil and plant recovery takes years because roots die in the fire. New growth depends on unburned seeds buried in the organic layer of soil, or on seeds brought in from other areas by animals or wind. Eventually most of the same pants will return to the burned area but in a different growth pattern. Some animal species will thrive in the open conditions and others will lose their habitats through fire.
Fire has many natural benefits. Frequent low-intensity fires help prevent the build-up of materials that can cause a large fire. Some trees, such as the lodgepole pine, giant sequoia, longleaf pine, ponderosa pine and Douglas fir need sunlight to grow and are therefore helped by ground fires which clear out dense forest growth. The lodgepole pine needs the heat from a fire to open its cones and release its seeds. As forests burn, fire releases minerals from wood and grasses, breaking them down and returning them to the soil so plant roots can absorb them and grow more rapidly.
Fire sets in motion a fairly predictable process of forest redevelopment with clear, identifiable stages. Forest succession proceeds from the Forbs stage (the first five years) – when small plants and mosses germinate and shrubs and seedlings begin to establish – through the shrub stage, the young forest stage, and finally to the mature forest stage (51-150 years), in which a few large evergreen species dominate the ecosystem.
Accompanying these stages are changes in the wildlife populations. In the Forbs stage insects, small rodents, and songbirds are the primary residents. As the ecosystem grows more complex, a greater variety of animals make their home in the forest, including large mammals such as beavers and deer and the even larger animals that eat them, such as cougar and bear. Some forests eventually develop into a climax forest (50-300 years). In a climax forest fewer big trees take up more area so there are fewer trees per acre. Dead trees provide additional nesting sites and the ecosystem becomes even more diverse.
Historically, fires in Westside Douglas-fir forests were infrequent, with fire intervals averaging 100 to 400 years. These fires were intense and large, replacing entire forest stands. In contrast, fire was a frequent source of disturbance in the ponderosa pine and mixed-conifer forests east of the Cascades. In any given stand, they occurred regularly in intervals ranging from 3 to 25 or more years.
Consequences of Fire Management
At the beginning of the twentieth century, the conventional wisdom was that fire was bad (or even evil) – something to be wiped out. Gifford Pinchot, the first head of the U.S. Forest Service, said “There is no doubt that forest fires encourage a spirit of lawlessness and a disregard for property rights.” This kind of thinking led to a half-century of aggressive fire suppression and prevention.
After World War II, efficient and expensive fire-fighting technologies were devised, including bombers being refit as water bombers. Campaigns were developed that taught people about fire prevention. In 1942 Smokey the Bear became the symbol of forest prevention. These campaigns reinforced the idea in the public mind that all forest fires were bad.
Meanwhile, the fire policies of the first half of the century were having severe, unintended results. Forest suppression measures have increased both fire hazard and fire risk on a monumental scale. As fires were prevented and suppressed, shade-tolerant tree species regenerated under the pine, and dead wood and needles began to accumulate. The forests became denser, a more continuous ladder of fuels was formed, and the large mature Pines became more stressed and susceptible to insects and disease due to competition with other vegetation for water.
When fires did occur, they were often large and more intense than the historic norm because the grass ignited low shrubs, which in turn spread flames to the understory trees. Because of their thin bark, the understory trees were less fire-resistant, and when they burned, their flames were much more likely to reach the crowns of the large pines, destroying them as well. Fire ecologists view much of the Northwest’s forestland – particularly on the dry east side of the Cascades, in the high Cascades and in the southwest Coast Range – as having moved dangerously away from its natural condition.
Additionally, the combination of more human-caused fires (twice as many as lightning-caused) and a strict policy of suppression have interrupted the natural process of forest succession. With fires occurring of uncharacteristic scope and intensity, forest habitats are more drastically altered. By disturbing the natural fire process humans have inadvertently changed the nature and composition of the forest.
The Role of Logging
Though timber companies have a strong interest in wanting to limit the damage caused by forest fires, logging practices contribute to the problem. Commercial logging often removes only the most marketable portion, the tree trunks, leaving slash behind. This highly flammable debris — saplings and piles of twigs, limbs, and needles — is additional fire fuel. Soon more prime fuel is on the way, as weeds and bushes invade the cleared land. When loggers remove the largest trees, the overstory canopy is reduced, exposing the forest floor to increased wind and sun. Surface temperatures increase and relative humidity decreases, with the end result being hotter, drier fuels.
Even logging roads have to take some of the blame. In 1999 the U.S. Forest Service (USFS) estimated that there were over 93,000 miles of logging roads on forest service land alone in the Pacific Northwest. Land cleared for roads is vulnerable to invasive weeds and brush and if the roads aren’t adequately maintained more debris and weeds accumulate.
A report submitted to Congress in 1996 by the Sierra Nevada Ecosystem Project (SNEP) and the USFS indicated that “timber harvest, through its effects on forest structure, local microclimate, and fuel accumulation, has increased fire severity more than any other recent human activity.”
Forest Fires in the New Millennium
Large, severe, summer wildfires seem to be a recurring pattern. Two of the last three summers have been among the worst fires years on record. In recent years. The 1998 wildfires in Yellowstone National Park, which lasted for months and burned nearly a million acres, started a national dialogue on fire. Controversy over those fires persists and questions remain about the place of fire in managing lands. How much should we let nature take its course? Can prescribed fires serve the same purpose as natural fires? What do we do about lands in urban settings where liability concerns often prevent managers from letting fires burn?
Following the severe fires of 2000, President Clinton requested a report whose findings led to the adoption of a National Fire Plan. The plan recommended active management in the form of mechanical thinning and prescribed fires to return forests on federal lands to historic levels of density and species composition. The plan noted, however, that reversing the effects of a century of aggressive fire suppression would be a long, slow process – some experts estimate 50 to 100 years.
There is much disagreement regarding the interpretation of the plan. The Bush administration is focusing on thinning as a solution, to the extent that the president has asked Congress to relax environmental laws to enable the timber industry to increase logging of national forest land. President Bush has asked that provisions of the National Environmental Policy Act be waived to hasten approval of thinning operations. Many environmentalists are fighting this move, claiming that it is politically motivated, and that selective thinning might actually increase the risk of forest fire.
There is no consensus on the plan. Some environmentalists believe the safest course is to stop interfering with nature altogether, to the extent that we shouldn’t attempt to control wildfires. Many land managers and environmentalists (including the Sierra Club) promote the return of controlled burns, arguing that controlled burns reduce the chance of larger, more destructive fires. They also open up an area to sunlight and help to control insects and tree diseases, restoring the natural role of fire. While controlled burning might be a sound solution, there is no financial motivation for it to be used.
Others note that the repeated use of fire many endanger watersheds through erosion and could harm soils, reduce the natural beauty of the area, create air pollution, and decrease the timber supply. Prescribed burns also have immediate risks which must be weighed against the risk of high-intensity wildfires. In 1993, what was planned as a two-acre controlled burn near Meadow Creek near Lake Wenatchee seared 350 acres. Putting it out required bulldozers, aircraft and hundreds of firefighters. The effort cost $500,000.
Prescribed burning also runs into legal barriers. Laws and policies also collide with fire management efforts. The huge amount of forestland in need of prescribed burning is in conflict with the federal Clean Air Act (1970). Prescriptive burning can also run up against the Endangered Species Act (1973). The places where spotted owls are doing best are also the places that are most susceptible to fire.
This isn’t a controversy that can be ignored. Fire ecologists estimate that in Oregon and Washington combined there are 10 to 12 million acres of Condition Class 3 forestland (the highest risk of fire, and when fires occur they will be intense, with a high probability that they will reach the crowns of the larger trees and kill them). Meanwhile, fuel loads continue to increase as underbrush grows while mature trees continue to weaken. Whether the cause is lightning striking or a careless person throwing a lighted cigarette out a car window, forest fires are inevitable.
Valerie Vogrin is the Environmental Education Program Coordinator for the Washington Forest Protection Association in Olympia, Washington.