Properties of Branch Wood; Especially on Specific Gravity, Tracheid Length, and Appearance of Compression Wood

The authors investigated the differences in wood properties between stems and branches. AKAMATSU (Pinus densiflora Sieb. et Zucc.) was used as the material for experiments, and studies were made with the specific gravity, the fibre length and the appearances of the compression wood in branches in this investigation. The results obtained in this study are presented in the tables, and the following conclusions are obtained. 1) Specific gravity a) The wood from branches is heavier than that from the stem. b) In a stem, there is no marked difference in the specific g ravity by directions and heights above the ground. c) In a transverse section of branches, the wood from the lower part is heavier than that from the upper part. 2) Fibre length a) Tracheids in the stem wood are longer than those in the branch wood. b) In a disk from the stem, tracheids on the north side of the disk are longer than those on the south side. Tracheid lengths increase upward and outward in a stem. c) Tracheids from the upper part in a transverse section of branches are longer than those from the lower part. 3) In a transverse section of branches, the compression wood is generally found in the lower part