In the early 20th century, steam-powered logging equipment arrived in the longleaf pine forests of the southern U.S. Coastal Plain, and the “golden age of lumbering” began. When the sawdust settled, millions of acres in the region – especially along the Western Gulf Coast – were barren.
“In many areas, the harvest was so complete that no seed source remained,” says U.S. Forest Service Southern Research Station (SRS) emeritus scientist James Barnett. Barnett is part of the SRS Southern Pine Ecology unit, and the author of an SRS general technical report on the history and status of direct seeding southern pines.
Millions of acres of forest land clearcut in the early 1900s remained desolate and unproductive for decades. In 1930, Philip Wakeley, a pioneering Forest Service researcher, estimated that at the then-current rate of planting, it would take 900 to 1,000 years to reforest the denuded land.
The scale and urgency of the problem led the Southern Forest Experiment Station (precursor of the Southern Research Station) to establish the Alexandria Research Center in 1946 to develop regeneration techniques for efficiently restoring the vast acreage affected.
A number of challenges stood in the way. At the time, growing pine seedlings in nurseries was difficult and time-consuming, while direct seeding, which had been used since the 1920s, was only marginally successful. One of the most common problems with direct seeding was that birds and mice were always hungry for pine seeds. In fact, eastern meadowlarks and field sparrows alone could eat 90 percent or more of seeds sown.
Predation was so severe that people with shotguns would patrol recently seeded tracts for eight hours a day through the entire five-week period between planting and germination. “Even this expensive measure was not always effective,” says Barnett. “Developing chemical repellants in the 1950s to protect the seeds from birds and rodents was critical for successful reseeding.”
Once repellants were developed, foresters realized that there were not enough seeds available, and that quality seeds were difficult to obtain, especially for longleaf pine.
“Landowners soon began collecting cones, but there were no collection or processing guidelines,” says Barnett, who in 1961 began assisting Forest Service researcher Bobbie “Mac” McLemore in the seed research program. The program eventually led to techniques for estimating the amount of seeds per cone for longleaf, slash, and loblolly pine, as well as guidelines on processing and storing seeds, stratifying, and testing viability. “Longleaf pine seeds are the most difficult of the southern pines to collect, process, store, and treat successfully,” says Barnett.
Although many foresters and landowners wanted to replant longleaf, lack of seed availability limited its use, and many areas were seeded with loblolly and slash pine.
“Direct seeding was never meant to replace planting as a regeneration tool, but it was used over a 25-year period to aggressively reforest almost 2 million acres of land in the South,” says Barnett. “Although infrequently used today, direct seeding helped reforest vast acreages of cutover forests that remained without the seed sources needed for natural regeneration.”
For more information, email James Barnett at firstname.lastname@example.org.