Maintaining Southeastern Pine Woodlands: Is Mechanical Shearing a Surrogate for Prescribed Burning

摘要

Mechanical chipping (often referred to as mulching) is now in wide use in southeastern USA pinelands for a variety of objectives, including fuel hazard and smoke reduction, fire behavior modification and vegetation management. With respect to vegetation management, chipping is being used as an initial treatment to reinitiate pine savanna/woodland restoration (usually an initial chip treatment is followed up by resumption of prescribed fire) and, occasionally, as a surrogate for fire in locations where prescribed fire is no longer feasible. Despite the widespread use of chipping, this technique has not been comprehensively evaluated. To investigate these issues we set up demonstration plot experiments across the range of longleaf pine, from South Carolina to eastern Texas. Fire behavior and smoke issues were investigated in the main study site in Francis Marion NF, near Charleston, South Carolina. Vegetation management questions were investigated at FMNF and three peripheral sites: Sam Houston NF (near Huntsville, TX), Blackwater River State Forest (east of Pensacola, FL), and Savanna River Site (near Aiken, SC). At each site we set up a randomized block experiment intended for three experimental treatments: (1) chipping, (2) burning, (3) combination of chipping and burning. Treatments were randomly assigned and initial chip treatments were carried out at all sites. One set of burn treatments was carried out in FMNF. No burn treatments have taken place in BWRSF or SRS.