Harrison Experimental Forest

The Harrison Experimental Forest is on the DeSoto National Forest, 25 miles north of Gulfport, MS. The Agency chose the site because its soils and appearance mirrored the South’s 31 million acres of coastal forest land. By the 1930’s, loggers had almost completely clearcut these vast stretches of southern pine. In some areas, residual trees produced seed for natural regeneration. Much more often, however, few seed trees remained to start the regeneration process. The seedlings that did sprout soon succumbed to cattle, feral hogs, palmetto competition, fire, or pest infestations.

Some of the earliest studies on the Harrison involved fire behavior and wood preservation. Scientists on the Harrison introduced water spray as a preprocessing preservative. This technique is still in use at sawmills today. Early trials of fence posts treated with various preservatives have been revisited every year since 1939. The problems with planting and growing trees and reestablishing forests soon became the primary focus for research at the Harrison. One important effort the southern pine seed-source study got underway to match regeneration sites with seed sources and to determine how far seeds could be moved without jeopardizing regeneration.

Long after the seed-source study results were reported, the plantings for this study continued to be useful for new research, such as efforts to determine the genetic basis of pest resistance, variation in wood quality, and effects of climate on pine growth. Most recently, Harrison’s scientists have begun evaluating the original genetic variation of the plantings with a vision toward long-term gene preservation.

Since 1956, the Harrison has been home to the Southern Institute of Forest Genetics (SIFG). The institute’s research on the inheritance of growth, form, and pest resistance of forest trees has guided tree improvement programs across the South. Some of its most recent research on DNA markers is being used to help incorporate resistance into the American chestnut needed to reestablish a species that has been obliterated from the forests of the East by the chestnut blight.

While planting trees and reestablishing forests were needed early in the century, sustainability is now the collective vision for southern forests. The South needs new knowledge and guidance on how to manage biological and ecological systems within a social and economic context. The SIFG scientists are working to discover the principles of heredity that operate in southern forests and to show how those principles may be applied in sustaining forest quality and productivity.