Four Site-Preparation Techniques for Regenerating Pine-Hardwood Mixtures in the Piedmont

Four variations of the fell-and-burn technique, a system developed to produce mixed pine- hardwood stands in the Southern Appalachian Mountains, were compared in the Piedmont region. All variations of this technique successfully improved the commercial value of low-quality hardwood stands by introducing a pine component. After six growing seasons, loblolly pine (Pinus taeda L.) occupied the dominant crown position and oaks the codominant position in fell-and-burn treated stands on poor to medium quality sites. The precise timing offelling residual stems, as prescribed by thefell-and-burn technique, may be,flexible because winter and spring,felling produced similar results. Although summer site preparation burns reduced hardwood height growth by reducing the length of thefirst growing season, they did not improve pine survival or growth. Pines were as tall as hardwoods withinfour growing seasons in burnedplots and within sixgrowing seasons in unburned plots. Additional research is needed to determine the level or intensity of site preparation needed to establish pine-hardwood mixtures over a range of site conditions. South. J. Appl. For. 21(3):116-122. Improving productivity on nonindustrial private forest (NIPF) lands in the Southeast is a major goal for meeting future timber demands. In the Piedmont and Mountain regions, over 68% of the commercial forestland (26.9 million ac) is occu- pied by hardwood or mixed pine-hardwood stands, and 7 1% of this land is owned by NIPF landowners (Bechtold and Ruark 1988). Because hardwood growth is vigorous in these regions, conversion of stands to pure pine requires extensive site preparation to control competition. Rather than spend the $150 to $250 per acre required for conversion to pure pine, most NIPF landowners choose to leave their forests unmanaged. These unmanaged forests are responsible for a large acreage of poorly stocked stands of low-quality hard- woods in the Southeast. Although timber production may not be the primary inter- est of many NIPF landowners, they may be attracted to enhancing income if their forestlands can provide other benefits such as aesthetics or wildlife habitat. Establishment of pine-hardwood mixtures is a method of providing mul- tiple benefits while improving productivity and minimizing investment (Phillips and Abercrombie 1987). However, guide-