Stem Volume Estimation of Sendan (Melia azedarach Linn.) Stand Subjected to Bud Pruning

Abstract

To obtain straight, tall (＞4 m) stems of Melia azedarach Linn. for timber production, bud pruning is performed. To estimate the effect of bud pruning on biomass distribution, we applied the stratified clip method to the aboveground parts of a 16-year-old M. azedarach stand and determined the allometric relationships among stems, branches, and leaves. Trees with relatively long straight stems and high clear lengths had smaller diameter at breast height (DBH) values. However, in even lower clear-length trees, the secondary branches died, such that leaves were distributed mainly in the upper layer of the crown. This effect may be a factor in the stem diameter growth suppression observed after the 10^th year. For M. azedarach, however, we used the standing-tree volume table for type-1 hardwoods in Western Japan, which includes the curved part of the stem. Therefore, we derived one allometric equation to estimate the total volume of straight stems and another to estimate the volume of knot-free stems with pruned buds at 0.2-4.2 m in height, which are useful for efficient timber production. These allometric equations will allow practical calculations of stem volume in bud-pruned M. azedarach for forestry applications.