Prescribed Fire: Using Fire Wisely
Wildfire is fire at the wrong time, the wrong place, and frequently the wrong intensity and severity. Wildfire - fire that is uncontrolled by definition, costs the Florida taxpayers many millions of dollars each year.
What is Prescribed Fire?
Prescribed burning is the controlled application of fire to existing naturally occurring fuels under specified environmental conditions, following appropriate precautionary measures, which allows the fire to be confined to a predetermined area and accomplishes the planned land management objectives.
PHOTO: Professionals tending a prescribed burn.
Why is fire in a woodland setting considered good at one time and bad at another? The answer can be found in almost all facets of nature. Most people will agree that rain is good. Without rain, the forest would not be able to grow. The same can be said for sunshine. However, excessive amounts of either of these two elements can be ruinous. The same formula applies to fire. The appropriate amount of fire, applied at just the right time and in just the right amount is as necessary to the forest and the animals that live there, as rain and sunshine.
Protecting people and forests from wildfire is a definite necessity. But this protection often produces heavy accumulations of underbrush and ground cover. During extended dry periods, this underbrush becomes vulnerable to wildfire. If a wildfire should occur under these circumstances, you would naturally expect great losses to both the trees and the animals.
The use of prescribed fire can reduce the threat of wildfire. Careful use of prescribed fire can benefit Florida's woodlands. However, there are many factors that must be carefully considered. These include the social, economic, legal and ecological effects a burn may have in a particular area.
What Are the Benefits of Prescribed Fire?
In order to discuss the benefits of prescribed burning, its objectives are divided into six categories. They are:
- Fuel Reduction
- Site Preparation
- Disease Control
- Wildlife Management
- Range Management
- Biological Community Restoration and Maintenance
1. FUEL REDUCTION
One of the most important reasons for prescribed burning is to reduce naturally occurring fuels within forest areas, particularly those forests in close proximity to urbanizing areas. Reduction of forest fuels reduces the risk of major life-threatening wildfire and reduces the threat of substantial economic losses of timber. It is one of the most effective elements of any fire prevention program. The U.S. Forest Service surveyed wildfire statistics on federal land in the South for the 1985 fire season and found that the difference between areas that had been burned as opposed to areas that had not been burned with respect to the number of fires is not especially significant. The fires that occurred in the areas that had not been burned accounted for 77% of the total acreage destroyed during the 1985 fire season. Only 17% of the wildfires that were larger than 300 acres occurred in prescribed burned areas. An overall comparison of costs was made to determine the economic benefits of prescribed burning in terms of suppression and damage. For each dollar spent in fuels management, $2.14 in suppression and damage costs was saved. This does not include the indirect benefits to wildlife and other resources.
2. SITE PREPARATION
Prescribed fire is the most environmentally sound and least expensive method of preparing areas for the seeding or planting process. Materials such as brush or slash which remain following any type of harvest can inhibit mechanical replanting and retain nutrients which could be used by the young trees to be planted or seeded. The return of nutrients to the soil through the natural decay process is extremely time consuming, but may be hastened in a clean and efficient manner through burning.
While mechanical removal is an alternative to prescribed burning in site preparation, its use is considerably more expensive, destructive, and fails to return valuable nutrients to the soil.
3. DISEASE CONTROL
Certain pathogens that reduce growth in pines and other species, can be controlled or eliminated by the use of prescribed burning. A classic example of this is brown spot needle blight in longleaf pine. This is a fire tolerant species which has adapted to allow fire to be utilized at an early stage of its life. Once the diseased needles on young pine trees have been consumed by fire, the blight is controlled, and the seedlings can continue to store carbohydrates in their roots. This can accelerate the growth response of long leaf pine by 10 or 12 years.
4. WILDLIFE MANAGEMENT
Fire and wildlife have had a long and intimate association both in and out of a forest environment. Unlike wildfire, prescribed fire is rarely lethal to most forms of wildlife. However, it does have profound effects on them. Fire is an efficient and economical tool for improving habitat for certain wildlife species. Prescribed burning alone is the only alternative in most cases to increasing and maintaining healthy wildlife populations.
Some of the effects of prescribed burning include:
- Increased yield of herbs and legumes
- Increase in browse and browse quality
- Opening for feeding and travel
Moreover, species diversity maintenance can be accomplished with the proper use of prescribed fire. Certain species such as scrub jays and quail require specific cover types for nesting that can only be brought about through a fairly frequent prescribed burning program, while others such as deer and turkey can be maintained in areas receiving less frequent prescribed burning.
5. RANGE MANAGEMENT
In Florida, more acres are being burned for grazing purposes than for all other uses of fire combined. Both forest and non-forest land use types are involved. An eight year study of the effects of grazing and burning on a coastal plain pine-wood area near Alapaha, Georgia by Halls, Southwell, and Knox in 1952, gave the following results in terms of forage production and cattle weight gains:
The effect of winter burning on forage quality was pronounced, but primarily limited to the spring months. Cattle gains were much greater on burned range than on unburned range during the spring, and 2 to 3 times higher for the entire season. Also, the cattle showed a strong preference in the spring for recently burned areas when available.
6. BIOLOGICAL COMMUNITY RESTORATION & MAINTENANCE
Most of Florida's natural systems are dependent upon periodic fire for maintenance of their biological integrity. Plant species which occupy biological communities such as pine flatwoods, sandhills and sand pine scrub, demonstrate the recurring historical presence of fire through their developed "fire tolerant" characteristics. For most such species, fire is required for regeneration and growth, thus demonstrating the essential role of fire in their continued existence. Without fire, shade tolerant species will surpass the pines and fire tolerant species resulting in a far less diverse plant community. Additionally, many species on federal and state threatened and endangered lists rely on fire for their survival, e.g., red-cockaded woodpecker. If fire were totally excluded from the systems where these species exist, tremendous habitat loss and population declines would be almost certain. The use of prescribed burning is an irreplaceable process in maintaining biological diversity and balance.
In some cases, areas which have been altered or manipulated for Silvicultural or agricultural purposes are targeted for restoration to a natural condition. In these cases, the planting of typical species which may have occurred naturally is not adequate for restoring the grasses and forbs which constitute the critical under story. Similarly, soil-borne microorganisms, insects and smaller animals will not return until a long-term regimen of periodic fire is undertaken. Prescribed burning is critical to natural systems restoration.
A process of such enormous capabilities can, if used incorrectly, have negative ramifications. The negative aspects fall into two categories:
Unfortunately when using fire, there will be certain emissions into the surrounding air. These emissions can affect the local environment. In addition to temporarily reducing air quality, prescribed burning can also decrease visibility. This is a primary concern with respect to road rights-of-way.
There are proven methods of avoiding the above problems, if the person responsible for the fire follows certain guidelines. Should these guidelines be ignored, or prescribed burning be used by the inexperienced, the results can be less then desired.
Even the most experienced burners can find themselves in very uncomfortable situations. The most important tool of all prescribed burners is not their torch, or the tractors used to create the fire breaks, but rather forecasted weather information. If this information is incorrect, or conditions unexpectedly become dangerous, the burn must be discontinued, and all attempts made on the part of those responsible to inform local authorities (DOT or Highway Patrol) that a problem exists.
2. PROPERTY DAMAGE
The possibility of property damage and the threat to personal safety from prescribed fire is greatest if the fire escapes the area where the prescription boundaries have been set. In this situation, the resulting wildfire is very dangerous, and should be brought under control as quickly, and safely as possible. The negative effects to the environment, e.g., timber, local ecosystems, air quality, wildlife, watershed and others by wildfire are as many as the positive effects of prescribed fire. All persons who use prescribed burning should also be fully aware of what procedures to follow should the fire escape.
It should be emphasized that if all appropriate precautions have been taken on the part of those responsible for the prescribed burn, the possibility of the fire escaping is minimal. This is not to say that a perfectly executed site preparation burn may not find vertical vortices (fire whirl) forming inside the burn that will throw sparks and embers outside the fire line, resulting in an escape. However, we do know when these types of phenomenon are most likely to occur, and the experienced burner will avoid burning under those conditions.
Where to Go For Help
The dangers of careless prescribed burning approach those of wildfire. The Florida Forest Service offers its help in any woodland problem, and endorses the practice of wisely-used prescribed burning. Foresters will be glad to inspect your woodlands, and provide additional services.
Training programs are now offered for both beginning and seasoned burners. Write or phone your local Florida Forest Service Field Unit for more information. They can assist you, but the final decision rests entirely with the land manager.