Abstract
We examined the relationships between actual stem profiles and relative stem profile equations (RSPE) based on Behre’s equation derived using the methods of Inoue and Kurokawa in planted forests of Cryptomeria japonica (61∼67 years old) and Chamaecyparis obtusa (50∼61 years old) located in the Hida district, Gifu Prefecture, central Japan. RSPE derived on the basis of Forestry Agency stem volume equations underestimated the actual stem profiles by 2 cm for C. japonica and by 1 cm for C. obtusa. This was due mainly to the fact that the Forestry Agency equations had underestimated actual stem volumes by 10%. A theoretical stem volume equation had a smaller error compared to the Forestry Agency equations. RSPE derived using the equation was in accord well with the actual stem profiles and the cubic RSPE made by Gifu Prefecture, indicating a wide applicability of the method proposed by Inoue and Kurokawa.
