Use of dummy variables to harmonize tree biomass tables

Abstract

When constructing biomass tables for various tree components, it is often necessary to force their regression functions to be similar in shape and consistent in spacing. A procedure using dummy variables is presented for the harmonization of the regression functions of the biomass of the tree bole up to various top diameters. The procedure allows one to calculate several regressions simultaneously to test their similarity, control their spacing, and compare statistically various regression models.