The longleaf pine (Pinus palustris Mill.) ecosystem has been reduced to isolated fragments scattered across the southeastern United States, where millions of hectares once existed. Associated with threatened and endangered species habitat, high value forest products, and possibly carbon storage, longleaf pine ecosystems provide a viable option for public lands and private landowners interested in managing a tree species over longer rotations. Ongoing efforts to restore longleaf pine forests are building momentum with plans to more than double the current acreage of the species. The focus is often on planting new stands, while sustaining natural stands is often overlooked. The success of these efforts beyond one rotation is dependent on sustainable restoration and conservation practices that promote natural regeneration and prescribed fire in existing stands and for future plantations. Spatial examples of natural stands, plantations, and data from a nearly 5-decade old study examining longleaf pine stand dynamics were evaluated to assess the sustainability of current practices.
In 1964, the U.S. Forest Service established the Regional Longleaf Pine Growth Study (RLGS) to study longleaf pine stand dynamics. Data from the RLGS cover a range of age classes, basal area classes, and site indices across the southern United States. The RLGS dataset provides over 40 years of measurements with the 45th measurement already underway. The maintained basal area classes mimic stand densities from stand replacement regeneration cuts to single tree selections and high density stands left to grow. Data from the RLGS and spatial examples of natural stands and plantations were used to evaluate the potential for successful natural regeneration under different thinning regimes and planting densities. Through the use of GIS technology, results show potential problems with low densities from thinning or plantings which can cause potential problems when trying to use natural regeneration and prescribed fire. Results from these efforts are being used to produce educational guidelines to assist management techniques that ensure the sustainability of longleaf pine ecosystems across its range.