Using Prescribed Fire in the Silviculture of Longleaf Pine

The natural range of longleaf pine (Pinus palustris Mill.) includes most of the Atlantic and Gulf Coastal Plains from southeastern Virginia, south to central Florida and west to eastern Texas, with extensions into the Piedmont, Ridge Valley, and Mountain Provinces of Alabama and northwest Georgia.

The longleaf pine forest is considered a fire subclimax type that has developed and maintained itself in close association with periodic fires. The species is the most fire-tolerant of the southern pines. It is also very sensitive to competition, especially as seedlings. This has restricted longleaf largely to sites that have been periodically burned and to poor sites supporting only a sparse cover of competing vegetation. Longleaf pine is a pioneer species that, given an adequate seed source, can invade abandoned fields or areas cleared by a catastrophic event such as blowdown or severe wildfires.

Once established, longleaf pine tends to perpetuate itself in areas where fires occur frequently. Needle litter from overstory pines helps to support hot surface fires. These fires slow or prevent the encroachment of hardwoods and other pines; they also provide a favorable seedbed by removing accumulated litter and exposing mineral soil. Grass-stage longleaf seedlings are highly resistant to fire and can even tolerate growing season fires in the open or under a light pine overstory. But under a medium to heavy pine overstory, most seedlings cannot survive the combination of slow growth resulting from overstory competition plus hot fires fueled by abundant needle litter. Therefore, longleaf pine usually originates in openings or under a light overstory where less intense fires still suppress hardwoods but do little harm to vigorous longleaf seedlings.

Longleaf pine can tolerate prescribed fire at all ages, except for young seedlings less than about 0.3 inch in root-collar diameter. Therefore, this species is better adapted to uneven-aged management than any other southern pine, as regular burning can be used to control hardwood competition. Although this type of management may best suit the goals of some landowners, especially those with a limited acreage, even-age management is, and will continue to be, a predominant form of management for longleaf pine.

Since fire is such an integral part of longleaf pine management, the management unit, where an even-age stand is established and maintained, should also be a convenient burning unit, bounded by roads and streams, to minimize the length of maintained firebreaks.

For additional information on the use of prescribed fire in the silviculture of longleaf pine, see:

• Managing Longleaf Pine, from the manual Silvicultural Systems for the Major Forest Types of the United States (Burns 1983), provides additional information on how prescribed fire can be used in combination with different silvicultural systems to manage longleaf pine.
• Silvics of Longleaf Pine, from the on-line Silvics of North America (Burns and Honkala 1990), provides information on longleaf pines habitat (range, climate, soils, topography, associations), life history (reproduction and early growth, sapling and pole stages to maturity); special uses; and genetics.
• Fire Ecology and Management of Longleaf Pine Savannas, from the Fire Ecology section of this encyclopedia, provides a review of historical fire regimes in the longleaf pine range, fire effects, and the use of fire for ecological restoration and maintenance.
• Pinus palustris, from the on-line Fire Effects Information System, provides a review of the fire ecology, fire effects and management considerations of longleaf pine.