Acorn Production Characteristics of Southern Appalachian Oaks: A Simple Method to Predict Within-Year Crop Size
We examined acorn production from 1993-97 by black oak (Quercus velutina Lam.), northern red oak (Q. rubra L.), scarlet oak (Q. coccinea Muenchh.), chestnut oak (Q. prinus L.), and white oak (Q. alba L.) in the Southern Appalichians to determine how frequency of acorn production, levels of intraspecific synchrony, and acorn density per tree influence crop size. We then developed a linear regression model for each species to quantitatively estimate acorn crop size within years using the proportion of trees bearing acorns as the independent variable. We also developed acorn yield tables for each species. Using these equations, land managers can quantitatively estimate within-year crop size per species if they know the proportion of fruiting trees as estimated by simple visual surveys (presence or absence of acorns or both). By applying the estimate (in units of number per square meter basal area) for each species to a basal area inventory of oaks in their area, managers can tail within-year crop size estimates to specific land management units. Alternatively, acorn yield tables can be applied to oak basal area inventories to tailor estimates of acorn production (the sum of each species) on an average annual basis to any area. Yield tables also can be used to test how acorn production will be affected on an average annual basis using different basal area apportionment scenarios among oak species.