A simultaneous growth and yield model for loblolly pine
A model to project cubic-foot volume from initial age, site index, and basal area is developed for natural stands of loblolly pine. For a projection period of zero years, the model predicts current yield and is thus a simultaneous growth and yield model. Statistical procedures to obtain a single estimate of the parameters of this model, using data from remeasured plots, are considered under two assumptions about the error correlations of such data. Parameter estimates for each case are obtained and compared, using data from the Southeastern Forest Experiment Station's loblolly pine stand density study. Parameter estimates for a basal area projection model are also obtained. When taken together, these fitted models are a numerically consistent set of prediction equations for cubic-foot yield, cubic-foot volume projection, and basal area projection.