Abstract
Shortleaf pine (Pinus echinata)–hardwood mixtures were once a common forest type on upland sites throughout the southeastern United States. These forest types have declined throughout much of shortleaf pine’s native range. Information on restoring shortleaf pine–hardwood types when a shortleaf pine seed source is not present is lacking. The objectives of this study were to investigate the effects of four site-preparation and release treatments (control, burn, herbicide, and herbicide and burn) on the development of even-aged mixtures of planted shortleaf pine and natural hardwoods located on the Highland Rim physiographic province of Tennessee, USA. Three years after study establishment, statistical differences among treatments occurred for shortleaf pine survival and basal diameter. Survival was greatest in the herbicide-only treatment. Height and basal diameter growth were greatest in the herbicide and burn treatment. Stem densities were greater in treatments that did not include a herbicide release than those where herbicide was used alone or combined with prescribed burning. The herbicide and burn treatment had the greatest potential after 3 years for developing into a balanced, mixed shortleaf pine–hardwood stand, whereas most treatments had an influx of exotic, invasive species such as Chinese privet (Ligustrum sinense) and callery pear (Pyrus calleryana).