FIA Volume Calculations

Tree-level attributes are variables associated with individual trees tallied on FIA ground plots. Various expressions of tree volume and weight are among the most basic statistics reported by FIA. Tree volumes and weights are not directly measured in the field, but computed from other variables that are measured (e.g, species and DBH). The functions used to compute these values are typically regression or mathematical models that have been developed by state or region. Commonly reported volume and weight statistics are defined below: VOLCFGRS (Gross cubic-foot volume). The total volume inside bark of the central stem of a tree 5.0 inches diameter or larger from a 1-foot stump to a minimum 4-inch top d.o.b. or to where the central stem breaks into limbs all of which are less than 4.0 inches d.o.b. Includes rotten/missing and form cull. VOLCFSND (Sound cubic-foot volume). The volume of sound wood in the central stem of a tree 5.0 inches diameter or larger from a 1-foot stump to a minimum 4-inch top d.o.b., or to where the central stem breaks into limbs al