Masting characteristics of white oak: implications for management
Acorn production is variable from year to year and among species. Weather, insect damage, and genetics are primary causes for variation. Silvicultural techniques have been recommended to improve acorn production; however, those recommendations primarily address variation among red oaks (Quercus rubra). Variability among individual white oaks (Quercus alba) has not been well documented and is an important consideration for forest and wildlife managers. We measured acorn production among 200 white oaks on two sites—one in east Tennessee and one in western North Carolina, 2006–2008. Acorn production varied by site and year, and acorn yield was highly variable among individuals, as one-third of the trees produced approximately 75% of the acorns collected at both sites. Approximately one-half of the trees at both sites were poor producers and yielded only 10% of the acorns collected. Acorns per m2 was not influenced by diameter at breast height, crown area, or production frequency of individual trees. Thus, with no accurate predictor of acorn yield, acorn production surveys during late summer should be conducted for no fewer than three years to identify good producers. We encourage managers to evaluate mast production of white oaks prior to deciding which trees to retain during two-aged regeneration harvests or timber stand improvement. Our data suggest net white oak acorn production can be maintained in a stand, and over time potentially increase, with removal of up to 50% of the white oaks.