Advanced Oak Seedling Development as Influenced by Shelterwood Treatments, Competition Control, Deer Fencing, and Prescribed Fire

Advanced northern red oak (Quercus rubra) seedlings in an 85-year-old forest located in north-central Pennsylvania were observed for 10 years after manipulation of available sunlight by shelterwood treatments, reduction of interfering plants by broadcast herbicides and/or a single prescribed fire, and reduction of deer damage by fencing. Twenty-four treatment combinations including untreated controls were studied on 72 permanent plots. The key to sustainable oak regeneration is to enhance both survival and growth of the advanced oak seedlings several years before a planned overstory harvest. In this study, survival and growth of 4,235 tagged oak seedlings were greatest in plots that received an overstory shelterwood harvest or midstory removal to increase sunlight, plus mist-blown herbicides to reduce interfering plants and fencing to reduce deer browsing. The overstory shelterwood harvest and midstory removal treatments reduced basal area by 30 and 12%, respectively. The prescribed fire treatment reduced survival because of the small size of the seedlings at the time of the burn. Published dominance probabilities were applied to the density and size of seedlings present after 10 years to compare the predicted number of codominant oaks resulting from the various treatments. Predicted success was greatest in fenced plots that received herbicide reduction of interfering plants and either the overstory shelterwood harvest or midstory removal treatments.