Wood Properties of Rare Natural Cedar (Cryptomeria japonica) “Aoyajiro” in Akita Prefecture

Abstract

Diameter at breast height (DBH) and stress-wave velocity (Vs) of stem were investigated in “Aoyajiro”, a mutant of natural Japanese cedar (Cryptomeria japonica D. Don), and compared with data from plus trees (PLT) and snow-resistant trees (SRT). Vs of “Aoyajiro” trees was similar to that of SRT but significantly faster than that of PLT. A negative correlation was observed between Vs and DBH in “Aoyajiro”. These results suggested “Aoyajiro” trees have sufficient snow-resistance based on high dynamic Young's modulus and its elasticity value decreasing with aging. Moisture content, crude ash and volatile components of heartwood obtained by the use of increment borer in “Aoyajiro” were analyzed and compared with those of PLT. There were no significant differences among these components, although “Aoyajiro” tended to contain higher crude ash content than PLT. Cubebol or δ-cadinene were detected by GC (Gas Chromatography) analysis as the major volatile components in “Aoyajiro”. Cubebol has the potential to change antimicrobial substances, such as cubenol, epicubenol and δ-cadinene, affecting specific lactobacilli that rot Sake. We propose that cubebol and δ-cadinene contents be used as indices to evaluate the superiority of “Aoyajiro”.