The hillside bogs, sandstone glades, and woodlands of the Kisatchie Sandstone Hills in Louisiana are potential homes to a number of rare and endangered animals such as the red-cockaded woodpecker and the Louisiana pine snake. However, in much of the Kisatchie Hills, the open woodlands these animals need have vanished amid a dense midstory of shrubs and small trees.
“Restoration of the Kisatchie Hills requires reintroduction of fire,” says U.S. Forest Service scientist Andy Scott. “Past fires, though, have resulted in high erosion rates and soil loss.” Scott is a research soil scientist at the Forest Service Southern Research Station (SRS) Southern Pine Ecology unit, and author of a paper about erosion and prescribed fire on a study area established in the Kisatchie Hills. The paper was recently published in the Southeastern Naturalist.
The Kisatchie Hills are part of the Kisatchie National Forest in west-central Louisiana and feature a number of fire-dependent ecosystems. Historically, the area was logged and open to cattle for grazing, but now it’s been about 65 years since the 4,000-acre study area was logged, and the last burn or cattle grazing was more than 20 years ago. Kisatchie Ranger District personnel conducted two prescribed burns – one in the growing season and one in the dormant season – on half the study area and compared vegetation, fuels, and erosion potential in similar areas of the burned and unburned sites.
After the fires, many of the shrubs and small trees in the midstory were top-killed, while grasses and wildflowers began to sprout and spread. Scott and his colleagues found that in the burned areas, 40 percent of the forest floor was covered with grasses and wildflowers, while only 7 percent of forest floor in unburned areas had herbaceous vegetation cover. Both red-cockaded woodpeckers and Louisiana pine snakes need a healthy herbaceous understory.
“Red-cockaded woodpeckers require old, widely spaced canopy pines for roosting and nesting, and open pine habitat for foraging,” says Scott. “Louisiana pine snakes prey on animals such as Baird’s pocket gophers, which in turn eat the roots of herbaceous plants. The presence of herbaceous vegetation is of prime importance for both red-cockaded woodpeckers and Louisiana pine snakes.”
Attempting to restore the Kisatchie Hills with prescribed fire is challenging because of the soil and geology of the area. “Soils on the study site are quite infertile,” says Scott. “They are also highly susceptible to erosion.” Much of the topsoil has already washed away, and the soil underneath it is very finely textured and prone to runoff. The prescribed fires reduced the thickness and density of the protective forest-floor layer, and elevated the erosion risk in the burned sites. However, the increased erosion risk may have been countered by the protective effects of a shorter midstory, and the recovery of the herbaceous community.
“Future management should consider erosion prevention,” says Scott. “The timing and intensity of additional burns should also be used to maximize plant cover on the forest floor and to improve the habitat by converting the woody understory to an herbaceous understory.”
For more information, email Andy Scott at firstname.lastname@example.org