A Simple, Variable Form Volume Estimation System

A volume estimation system giving the stem profile (upper stem diameter outside bark), total tree volume, and merchantable volume to a height or diameter limit is developed based on a simple, variable form stem taper curve. The stem taper curve is defined by coefficient values indicating conic and parabolic tree forms. For a given height, small diameter trees are assigned parabolic forms and large diameter trees are assigned conic forms. A tree's position in the tree form continuum is defined by its total height to diameter at breast height ratio. Performance of the volume estimation system is evaluated using stem analysis information on red pine, jack pine, and white spruce from the upper Great Lakes Region. Key words: Pinus resinosa Ait., Pinus banksiana Lamb., Picea glauca (Moench) Voss, taper curve, merchantable volume, volume ratio, total tree volume.