The Regeneration of oak (Quercus spp.) on highly productive sites of the east Gulf Coastal Plain, Tennessee : a post-harvest approach

Oak (Quercus spp.) regeneration success historically can be described as highly variable, especially within highly productive systems. Research has shown that establishing large advance oak reproduction, prior to overstory removal, is necessary to maintain oak populations in future stands. However, experience indicates that forest landowners are typically unwilling to wait the necessary time to develop natural advance oak regeneration, instead allowing short-term economics to dictate harvest times. The use of artificial oak reproduction is one alternative to maintain oak as an important component of future stands. However, to date the success of artificial oak regeneration has also been highly variable. In developing an improved understanding and enhanced methods of artificial oak regeneration we examined the growth of outplanted high-quality, genetically improved, 1-0 northern red oak (Quercus rubra L.) seedlings and the effects of competing herbaceous vegetation after four overstory treatments (no-cut, high-grade, commercial clear-cut, two-age) on the Ames Plantation in west Tennessee. Sixty seedlings from two known and proven genetic families were outplanted within each of twelve, two-acre treatment units, resulting in three replicates of the four treatments. Initial height, root-collar diameter (RCD) and number of first-order lateral roots (FOLR) were recorded for each seedling. Outplantings were monitored monthly during the growing season and after all seedlings entered dormancy. The greatest first-year height growth (8.80 cm) was recorded for the no-cut treatment. However, all new growth was etiolated and high levels (33 percent) of mortality were recorded. Height growth among the 3 overstory harvest treatments was similar, but less than the no-cut (control) treatment. However, mortality was much less (5 percent). No mortality was observed within the commercial clearcut treatment. White-tail deer (Odocoileus virginianus) herbivory occurred in the early growing season only and significantly influenced first-year seedling growth. Results from logistic regression analysis indicated that the initial height of the seedling at time of planting was related to herbivory of the terminal shoot. Linear regression results suggested that competition from an exotic-invasive grass, Microstegium vimineum, was also impeding seedling growth. This study indicates that light availability, seedling quality, herbaceous competition along with browse pressure are important factors contributing to first-year seedling development. While results from this study appear positive, only first year growth has been observed and reported. As seedling development continues, further examination and research will prove informative. Differences between treatments, genetic stock and seedling quality may become more apparent as development continues.