A Guide for Prescribed Fire in Southern Forests
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The Objective of this To help resource managers plan and ■ Describing the various techniques execute prescribed burns in Southern of prescribed burning. Prescribed Burning forests by: ■ Giving general information pertain- G uide ing to prescribed burning. ■ Explaining the reasons for prescribed burning. ■ Emphasizing the environmental effects. ■ Explaining the importance of weather in prescribed burning. A GUIDE FOR PRESCRIBED FIRE IN SOUTHERN FORESTS Backing fire in young slash pine Postburn results Rewritten in 1988 by Dale D. Wade, Photo assistance was provided by the Appreciation is expressed to the Southeastern Forest Experiment Alabama Forestry Commission; Georgia various State and Federal agencies, Station; and James D. Lunsford, Fire Forestry Commission; North Carolina private industries and other organiza- Management, Southern Region, Forest Service; USD1 Fish and Wildlife tions for their helpful reviews and USDA Forest Service Service, Piedmont National Wildlife cooperation. Refuge; South Carolina Commission of Originally written in 1966 by Merlin J. Forestry; Southeastern Forest Experi- Dixon, Southern Region, USDA Forest ment Station, Southern Region, and Service. Southern Forest Experiment Station, USDA Forest Service; Tall Timbers 1973-1979 revisions, lead author Hugh Research Station; Union Camp Cor- E. Mobley, Southern Region, USDA poration; and Westvaco Corporation. Forest Service. This guide provides basic information needed to help you become technically proficient in the proper use of prescribed fire. A glossary toward the end of this manual will help you with unfamiliar terms. To learn more about the subject of prescribed fire, a list of suggested reading follows the glossary. Nearby State and Federal resource management agencies are also excellent sources of information. Many of these agencies provide periodic training in fire behavior and prescribed fire. Contents ii iii Palmetto-gallberry fuel type prior to prescribed burn Po stburn results iv introduction The Ecology of Fire point, change is biologically necessary southern range became a custom. This to maintain a healthy ecosystem. practice, plus destructive wildfires Fire has played a major role in Resource managers have learned to after logging left millions of acres of determining the distribution of plants manipulate fire-caused changes in forest land in the south devoid of trees. across the South. Some plant com- plant and animal communities to meet The increasing wildfire problem munities such as cypress swamps sur- their needs, and those of humankind in coupled with the need for a fire-free vive for centuries between prolonged general, while at the same time preser- interval of several years to allow the droughts that finally allow stand- ving underlying natural processes and pines to become reestablished led replacement fires to enter. Other com- functions. They do this by varying the many foresters to advocate the exclu- munities such as the once vast expanse timing, frequency, and intensity of fire. sion of all fire from the woods. Others, of longleaf pine burn every few years. however, pointed out that fire might In fact some ecosystems, for example have a place in the management of the longleaf pine-wiregrass associa- Prescribed Fire History longleaf pine. Fire has been used by tion, require periodic fire for their professional foresters to reduce hazar- very survival. The use of fire in the forests of the dous fuels since the turn of the century. A basic premise of fire ecology is United States has come full cycle. Ear- The misconceptions and controversy that wildland fire is neither innately ly settlers found Indians using fire in surrounding the deliberate use of fire destructive nor constructive: it simply virgin pine stands and adopted the to achieve resource management causes change. Whether these changes practice themselves to provide better objectives have slowly been replaced are viewed as desirable or not depends access, improve hunting, and to get rid by facts. As knowledge accumulated, upon their compatibility with one's ob- of brush and timber so they could the use of prescribed fire grew. jectives. Irrespective of man's view- farm. Annual burning to "freshen up" Depression-era photo of unproductive forest land Present Use This manual will be most useful in necessary to minimize any detrimental the lower Piedmont and Coastal Plain. effects to air quality. Potential off-site Today prescribed fire is applied to Prescribed burning in these areas has impacts such as downstream water roughly 8 million acres in the South been perfected by several generations quality should be carefully considered, each year — about half of which are of resource managers. Although the as should on-site impacts to soil and burned to achieve various forest potential of prescribed fire in the upper aesthetics. management objectives. Most of the Piedmont and mountains of the South Public opinion is another factor to remainder is for range and agricultural has been demonstrated, few guidelines consider because the general public is purposes. Prescribed burning is a exist. If you are interested in the concerned about the deterioration of desirable and economically sound emerging use of fire in the mountains, the environment. Smoke from practice on most southern pine sites. In a good source of information and help prescribed fires, as well as from many cases, prescribed burning is the is your local State or Federal forestry wildfires, is highly visible. It is our job only practical choice. Few, if any, office. as resource managers to inform the alternative treatments have been public of the differences between developed that can compete with fire I mpact of Prescribed prescribed fire and wildfire—which often from the standpoint of effectiveness Burning look identical to the untrained eye. and cost. Chemical applications Prescribed fire is a complex tool generally cost more than 10 times as A single prescribed burn can and should be used only by those trained much per acre as prescribed fire. achieve multiple benefits. For example in its use. Proper diagnosis and detailed Mechanical treatments such as disk- a prescribed burn that consumes more planning are needed for every area ing, chopping, or raking are at least 20 dead fuel than it creates will reduce the where burning is contemplated. The times more expensive. Each of these fire hazard and, with few if any incomplete assessment of any factor three alternatives also has associated modifications, will also improve can pose serious liability questions environmental costs, such as destruc- wildlife habitat. Almost any prescribed should the fire escape or its smoke tion of habitat and soil erosion. Both burn improves access. cause damage. A prescribed fire that the probability of causing damage, and Prescribed fires aren't always does not accomplish it's intended ob- the magnitude of such damage, should beneficial, however. When conditions jective(s) is a loss of both time and it occur, need to be kept in mind. are wrong, prescribed fire can severely money, and it may be necessary to In this guide, prescribed burning is damage the very resource it was in- reburn as soon as sufficient fuel ac- defined as fire applied in a tended to benefit. Prescribed fire can cumulates. Keep in mind that some knowledgeable manner to forest fuels temporarily reduce air quality, but resource management objectives can on a specific land area under selected usually to a much lesser degree than be met with a single fire, some require weather conditions to accomplish wildfire. For every prescribed fire op- several fires in fairly quick succession, predetermined, well-defined manage- portunity, there are tradeoffs that and some can only be accomplished by ment objectives. should be recognized and carefully burning periodically throughout the weighed before a decision is reached. rotation. Proper planning and execution are 2 Reasons For Prescribed Fire In Forest Resource Management ■ Reduce hazardous fuels ■ Prepare sites for seeding and planting ■ Dispose of logging debris ■ Improve wildlife habitat ■ Manage competing vegetation ■ Control disease ■ Improve forage for grazing ■ Enhance appearance ■ Improve access ■ Perpetuate fire-dependent species ■ Cycle nutrients ■ Manage endangered species Reduce Hazardous control. The appropriate interval be- high in these vast contiguous stands. tween prescribed burns for fuel reduc- The initial hazard-reduction burn in a Fuels tion varies with several factors, young pine stand requires exacting Forest fuels accumulate rapidly in including the rate of fuel accumula- conditions of wind, humidity, and pine stands on the Coastal Plain. In 5 tion, past wildfire occurrence, values temperature. Higher wind velocities to 6 years, heavy "roughs" can build at risk, and the risk of a fire. The time and cooler temperatures minimize up, posing a serious threat from interval between fires can be as often scorch damage. Southern pine planta- wildfire to all forest resources. as every year although a 3- or 4-year tions averaging 10 to 12 feet in height Prescribed fire is the most practical cycle is usually adequate after the can be burned by experienced people way to reduce dangerous accumula- initial fuel-reduction burn. under the right conditions without tions of combustible fuels under The need to reduce hazardous fuel damage. Young plantations on in- southern pine stands. Wildfires that accumulations in the pine plantations dustrial lands arc often burned for the burn into areas where fuels have been of the South is increasing. Without fuel first time when they are 15 to 20 feet reduced by prescribed burning cause reduction, fire hazard is extremely tall using aerial ignition; close spacing less damage and are much easier to Winter backing fire in heavy rough Damaging wildfire in heavy rough 3 of ignition spots (e.g., 2 chains by 2 chains), and cool, damp conditions with some wind are a must to avoid crown damage. Subsequent fuel reduction burns need not cover the entire area. The ob- jective is to break up fuel continuity. Fuel reduction on 75 to 80 percent of the area is sufficient.