A Volume and Taper Prediction System for Bald Cypress

Abstract

A volume and taper prediction system based on d₁₀ and consisting of a total volume equation, two volume ratio equations (one for diameter limits, the other for height limits), and a taper equation was developed for bald cypress using sample tree data collected in Louisiana. Normal diameter (d_n), a subjective variable-height measure applied to bald cypress (Taxodium distichum (L.) Rich.) in place of diameter at breast height (dbh), was found to be inferior to five different fixed-height diameter measurement points in terms of predicting total volume. Diameter measured at 10 ft (3.0 m) above the ground, termed d₁₀ is recommended as a better diameter measurement point for bald cypress. A number of "goodness-of-fit" statistics were employed to evaluate alternative functions for predicting volume and taper. Two statistics, bias and sum of squared relative residuals, provided the best discrimination between functions.

Citation

Parresol, Bernard R.; Hotvedt, James E.; Cao, Quang V. 1987. A Volume and Taper Prediction System for Bald Cypress. Can. J. For. Res. 17: 250-259