New Form-class Equations Improve Volume Estimates

Abstract

Three form-class volume equations involving the upper stem diameter at 19.5 ft (5.94 m) above ground level and three standard volume equations based on d.b.h. and height were tested for accuracy in estimating both tree and stand volume in different stands of red pine (Pinusresinosa Ait.). All three form-class equations met the required 10% accuracy in estimating individual tree volumes; the three standard volume equations failed to meet this accuracy. All three form-class equations also met the required 5% accuracy in estimating stand volume, but none of the standard equations did.