Artificial regeneration in the Southern Appalachians
|Authors:||S.L. Clark, S.E. Schlarbaum|
|Type:||General Technical Report|
|Station:||Southern Research Station|
|Source:||e-Gen Tech. Rep. SRS-237, Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station|
Reforestation of upland oak species on productive forest sites in the Southern Appalachian region will require different prescriptions than in other regions where yellow-poplar (Liriodendron tulipifera L.) is not a primary competitor. We present results from three studies on highly productive sites [site index, base age 50, for northern red oak (Quercus rubra) ranged from 78 to 98 feet] that represented a broad range of residual basal areas and competition control methods. In all studies, we used seedlings produced using the most advanced bare-root nursery protocols currently available (averaging 1.6 to 3.6 feet in height). Seven to 10 years after harvest, approximately 15 percent of planted seedlings were in canopy positions where recruitment into the overstory was probable, and recruitment capabilities were similar at all three study sites despite differences in site conditions and silvicultural prescriptions. Assuming a planting density of 300 trees per acre, a recruitment density of approximately 50 trees per acre would be expected. After 10 years, trees were capable of attaining 20 to 26 feet in height and averaged 9 to 10 feet for the two oldest plantings. The study that received the most targeted competition control treatment and the largest seedlings had a significant positive relationship between seedling height at the time of planting and recruitment density. Variability in silvicultural treatments, genetics, and site conditions probably masked this relationship for the other studies. We recommend planting high-quality seedlings from a diverse genetic mixture and targeted herbicide competition control to improve recruitment success rates of planted oak seedlings.