The Efficacy of Using Inventory Data to Develop Optimal Diameter Increment Models

—Most optimal tree diameter growth models have arisen through either the conceptualization of physiological processes or the adaptation of empirical increment models. However, surprisingly little effort has been invested in the melding of these approaches even though it is possible to develop theoretically sound, computationally efficient optimal tree growth models using inventory data. The Potential Relative Increment (PRI) methodology is a good example of a flexible potential growth modeling system developed under these auspices. I present a series of suggestions for ecological consistency, variable and parameter assumptions, statistical properties, data quality, and model flexibility that should be considered when developing optimal increment models, exemplified with white oak (Quercus alba L.) equations from the Midsouth region. The increased utilization of ecological simulators has led to a proliferation of models designed to forecast tree growth. Several general types can be distinguished, ranging from empirical regression models to process-based theoretical constructs or other mathematical designs. The increment model of the Forest Vegetation Simulator (FVS) (Wykoff and others 1982) is a classic example of an empirical design: