Standards for evaluating taper estimating systems

Four taper-estimating systems were evaluated for coastal Douglas-fir to demonstrate statistical and practical considerations that should be used when selecting a taper-estimating system for forest inventory purposes. The four equations compared were: Max and Burkhart's (1976) segmented polynomial, Newnham's (1988) variable-form, Ormerod's (1986) diameter-point and Kozak's (1988) variable-exponent equation. Key words: Taper, segmented polynomial, variable-form, diameter-point, variable exponent, coastal Douglas-fir