Estimation of culm volume for bamboo, Phyllostachys bambusoides, by two-way volume equation

We determined a two-way volume equation for estimating the apparent culm volume for Phyllostachys bambusoides Sieb. et Zucc. The culm form analysis indicated that the normal form-factors at 0.6 and 0.9 in relative height were steady at 0.736 and 0.543, respectively. Substituting these normal form-factors and their relative heights into a generalized volume equation from the literature, the coefficients of the volume equation for P. bambusoides were determined. The applicability of the determined volume equation was evaluated using the test data collected from four different districts. The volume equation worked as a good model for estimating apparent culm volume for P. bambusoides, although it provided an underestimation of the culm volume when the site productivity was low. The result also demonstrated that there was a need for distinguishing the volume equation among bamboo species, because of the variability in the culm form. In conclusion, the volume equation presented here is one of the most effective models for evaluating the culm volume or stock for P. bambusoides.