Shortleaf pine tree with immature cones. Photo by Frank Bonner, courtesy of Bugwood.org.
On June 14th, at the annual meeting of the Southern Group of State Foresters, Arkansas State Forester Joe Fox and U.S. Forest Service Southern Region Deputy Regional Forester Ken Arney announced the release of a long-awaited five-year plan developed by the Shortleaf Pine Initiative to stem the rapid decline of regional shortleaf pine forests.
Shortleaf pine forests once covered an estimated 70 to 80 million acres across a range that stretched from New Jersey down to Florida then west to eastern Oklahoma and Texas. Over the last 30 years alone, this extensive shortleaf pine ecosystem has lost over 50 percent of its former acres, with most of the significant decline taking place east of the Mississippi River.
Shortleaf pine has been displaced by oak and other hardwoods as a result of extensive timber harvesting, land clearing, insect outbreaks, and wildfire followed by decades of fire exclusion.
Since its start as a working group in 2010, the Shortleaf Pine Initiative has held numerous workshops in states across the former and current shortleaf pine range. Feedback from workshops held in the Southern Appalachian region showed an increasing interest in restoring shortleaf pine, especially to mixed hardwood stands. Discussions about restoration techniques often included references to the fell-and-burn method developed over 30 years ago by U.S. Forest Service researchers and national forest collaborators.
The fell-and-burn regeneration technique was developed as a low-cost method to establish planted pines among hardwood sprouts and involves clearcutting a hardwood stand, felling the remaining hardwood stems in the spring, and then burning the site in the summer to support hardwood regeneration. Burning is followed by planting pine seedlings at a wide spacing (10 by 10 feet).
In the early to mid-1980s, Forest Service researchers and silviculturists applied the fell-and-burn technique to stands in the Sumter National Forest Andrew Pickens Ranger District, which is located in the mountainous western edge of South Carolina. To help guide new restoration efforts, the Forest Service Southern Research Station (SRS) recently published an e-Research Paper that documents the long-term success of the fell-and-burn method on the sites on the Andrew Pickens.
Though there are studies that evaluated the long-term establishment of loblolly pine stands using the fell-and-burn method, none have existed for shortleaf pine. Tom Waldrop, SRS Station team leader and research forester who collaborated on the fell-and-burn studies in the 1980s and later, and Lauren S. Pile, then a postdoctoral research fellow at Clemson University, set out to evaluate the success of the regeneration method for shortleaf by revisiting plots on study sites in the Andrew Pickens where it was used 34 years ago to establish mixed shortleaf pine-hardwood forests on stands formerly dominated by hardwoods.
“Each step was designed to reduce competition from hardwood sprouts and allow pines the opportunity to establish and grow,” said Waldrop, who founded the Consortium of Appalachian Fire Managers and Scientists (CAFMS) to promote communication about fire ecology and management in the Appalachian region. “These mixed-species stands increase economic incentives, promote forest resiliency by supporting greater species diversity, and add other ecological benefits such as wildlife habitat.”
The researchers measured the trees on the original sites using the same plot arrangement, although exact plot locations could no longer be found. They found shortleaf pine basal area (the amount of a given area occupied by a cross-section of trees and stems measured at their base) ranged between 32 and 54 percent. Shortleaf pine densities ranged from 241 to 253 trees per acre, representing a survival of 53 to 56 percent of the pines planted 34 years earlier.
“Our study indicated that the fell-and-burn technique was effective for establishing shortleaf pine on sites with moderate levels of soil fertility and moisture, where fast-growing hardwood sprouts were competitive and present at high densities,” said Waldrop. “On the sites we studied, shortleaf pine had an advantage over the hardwoods after 34 years. They were taller, with larger diameters, and occupied a considerable proportion of the total stand even with large densities of hardwoods.”
Read the full text of the SRS e-Research Paper.
For more information, email Tom Waldrop at twaldrop@fs.fed.us.