The whole-bole system: a conditioned dual-equation system for precise prediction of tree profiles

Abstract

A review is presented of the shortcomings of most existing taper equations which predict diameter along the stem as a function of tree height and diameter at breast height. A new computerized system is developed that has many desirable features for tree profile prediction. This new system consists of two mathematical functions, one describing the upper bole and the other describing the lower bole. The two functions are linked together at the inflection point and are continuous at that point. Tests of this model on 32 species age and locality groupings of British Columbia species show that although there is still a slight bias near ground level, the prediction of diameter inside bark is almost perfect over most of the length of the trees.