Volume and biomass estimation in fia: National consistency vs. regional accuracy

Volume and biomass estimates are among the most widely used data produced by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service. This paper documents the various methods used by FIA in the Eastern U.S. and compares those methods for 67 species that cross regional boundaries. Four different methods currently being used by FIA to estimate the gross cubic foot volume, gross board foot volume (International 1/4-inch scale), and total gross biomass are examined. Overall, these four methods produce similar results, but large differences exist for specific species and diameters. I recommend that FIA develop a nationally consistent method for estimating volume and biomass, Users of FIA data are cautioned against making regional comparisons of volume or biomass information for small diameter trees.