What are the causes and effects of forest fire? What can be done to prevent the forest fire? Information on forest fires.
Effects Of Forest Fires and Preventions; A large, raging forest fire is one of the most awesome and feared of natural phenomena. Forest fires have occurred on most of the temperate forest areas of the earth and on more tropic and subarctic areas than is commonly recognized. Large fires have taken many lives, destroyed immeasurable amounts of timber, and—along with insects and diseases—have brought about changes in tree and other forest populations over vast areas. Fires also have played and continue to play a role in forest evolution.
A forest fire is unenclosed and freely spreading combustion that burns the natural fuels of a forest. These fuels are all of about the same chemical composition, primarily cellulose. Fortunately, most fires in forests are small and can be controlled. A controlled fire can be a useful servant, functioning to perform important tasks in land clearing and forest management.
There are three kinds of forest fires. Surface fires, by far the most common, burn the leaves, debris, and small vegetation on the forest floor. All forest fires start as surface fires. Crown fires spread from treetop to treetop more or less independentiy of surface fires. Ground fires burn the organic material beneath the surface debris on the forest floor.
The origin, size, and the course followed by a forest fire depend on factors such as climate, local topography, and the kinds of trees and other vegetation present. The causes, however, are simply described: most forest fires are the result of man’s carelessness.
Effects of Forest Fires: Because of their varying effects on different trees, wildfires of the past have formed and perpetuated many particular associations of trees in forests. Thus the Douglas fir dominates the great forests of northwestern United States because the tree seeds well in the open areas caused by fires. The young firs are hardy, grow vigorously, and gain ascendancy over competing species. The longleaf pine of the southern United States is particularly resistant to the surface fires characteristic of the region, both as a young and as a mature tree.
The aspen of the Great Lakes region illustrates another method of thriving despite forest fires. It has low resistance to fire and it seeds only rarely, but it sends out long lateral roots that sprout profusely after a fire. These roots multiply into extensive stands of aspen,.
Trees of all species may be damaged even by small fires, because the fires cause wounds that provide prime breeding access to damaging insects and rot-causing fungi.
Prevention: A fire prevented causes no damage and never has to be put out. The first need is to get at causes and see that the forest fire does not get started in the first place. One important aspect of this effort has been to make the public more aware of the problems involved. Fire prevention programs, such as the “Smokey the Bear” campaign in the United States, helped make people increasingly careful about fire hazards in forests during dry seasons.
A second aspect of fire prevention is to reduce the fuels—that is, to dispose of the flammable materials that make it possible for wildfires to become damaging. Reduction may be accomplished by burning or removing such materials, by piling or bunching the forest debris that results from timber harvesting, and by cutting down dead trees that otherwise help to spread fires.
In some areas, controlled burning is carried out to remove—under safe burning conditions and with minimal damage to the forest—the flammable surface fuels that can support damaging fires under dry weather conditions.
Fire prevention techniques also include the construction of strategic firebreaks. These are strips of land of varying width that have been cleared of flammable fuels by use of controlled fires, or by mechanical or chemical means. Firebreaks help to contain fires once they get started, although mere is much controversy about their real efficacy.
Detection: For successful suppression action, fires must be promptly found when they are still small. Such rapid location of fires is not easy in forested areas.
Fire control organizations maintain large detection systems. The most common systems consist of a network of lookout towers located where they can command a good view of the countryside and spaced so that as much of the total area as possible can be seen. The towers are manned by lookouts during dry periods of “fire weather.” The lookouts have fire-locating equipment and radios or telephones for reporting fires to a reporting center, which dispatches fire-control crews to the fires.
Small airplanes are being used in ever-increasing numbers to supplement and sometimes to replace lookouts. The aircraft also are used to scout the fires reported, check their location, appraise the fuels present and the burning conditions, and report the best routes of access to the fires.
Fires may also be reported by local residents or by commercial and other aircraft passing by the area concerned. While these reports are useful, they cannot be relied upon for prompt discovery of small fires.