Individual tree diameter, height, and volume functions for longleaf pine
Currently, little information is available to estimate individual tree attributes for longleaf pine (Pinus palustris Mill.), an important tree species of the southeastern United States. The majority of available models are local, relying on stem diameter outside bark at breast height (dbh, cm) and not including stand-level parameters. We developed a set of individual tree equations to predict tree height (H, m), stem diameter inside bark at 1.37 m height (dbhIB, cm), stem volume outside bark (VOB, m3), and stem volume inside bark (VIB, m3), as well as functions to determine merchantable stem volume ratio (both outside and inside bark) from the stump to any top diameter. Local and general models are presented for each tree attribute. General models included stand-level parameters such as age, site index, dominant height, basal area, and tree density. The user should decide which model type to use, depending on data availability and level of accuracy desired. To our knowledge, this is the first comprehensive individual tree-level set of equations reported for longleaf pine trees, including local and general models, which can be applied to longleaf pine trees over a large geographical area and across a wide range of ages and stand characteristics. The system presented here provides important new tools for supporting future longleaf pine management decisions.