Difference between juvenile wood and mature wood in compressive and shear strength of 55-year-old sugi (Cryptomeria japonica D. Don) trees originated from seedlings
2009
Ishiguri, F.(Utsunomiya Univ. (Japan). Faculty of Agriculture) | Terazawa, E. | Matsumoto, K. | Sanpe, H. | Ishido, M. | Ohno, H. | Iizuka, K. | Yokota, S. | Yoshizawa, N.
Sugi (Cryptomeria japonica D. Don) is one of the main tree species which are extensively planted in Japan. Recently, the rotation period of sugi plantation has been prolonged. For effective utilization of sugi wood resources in the future, therefore, it is very important to understand the properties of wood derived from aged-sugi trees. In the present study, radial variation of wood properties (microfibril angle, MFA; air-dried density, rho) and mechanical properties (compressive strength parallel to grain, sigma; shear strength, tau) were investigated for 55-year-old sugi trees originated from seedlings. Based on the obtained results, differences in wood and mechanical properties between juvenile wood (JW) and mature wood (MW) were discussed. Significant differences between JW and MW were found in tau, but not in sigma. Relatively highly correlation coefficients were recognized between rho and sigma in both JW and MW. By multiple regression analysis, MFA and rho may also influence on the sigma in JW. On the other hand, significant positive correlation between tau and rho was found in JW, but not in MW. In addition, tau was not strongly affecting by the MFA. These results suggest that wood property influencing the mechanical property was different between JW and MW.
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