Evaluation of standing tree quality of Japanese cedar grown with differentspacing using stress-wave and ultrasonic-wave methods

Citation
St. Chuang et Sy. Wang, Evaluation of standing tree quality of Japanese cedar grown with differentspacing using stress-wave and ultrasonic-wave methods, J WOOD SCI, 47(4), 2001, pp. 245-253
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Material Science & Engineering
Journal title
JOURNAL OF WOOD SCIENCE
ISSN journal
1435-0211 → ACNP
Volume
47
Issue
4
Year of publication
2001
Pages
245 - 253
Database
ISI
SICI code
1435-0211(2001)47:4<245:EOSTQO>2.0.ZU;2-F
Abstract
The quality of wood in 47-year-old standing trees of Japanese cedar grown i n five plantation sites with different spacing (A, 1 x 1 m; B, 2 x 2m; C, 3 x 3 in; D, 4 x 4 m; E, 5 x 5 m) was evaluated using stress-wave and ultras onic-wave propagation methods. The magnitude of the velocities of these wav es and the calculated dynamic modulus of elasticity (MOE) were used as inde xes for assessing wood quality in standing trees. Results indicated that pl antation spacings had moderate influence on the stress-wave and ultrasonic- wave velocities, and the degree of influence varied with the wave-propagati ng direction. Regardless of the testing method used, the velocities of wave s propagated parallel to the grain in the standing trees with medium and po or growth conditions were significantly greater than those with superior gr owth conditions. The dynamic MOE of the trunk of standing trees of Japanese cedar was calculated by adjusting the effective mobility of free water and effective density in the trunk at various moisture contents. Results indic ated that the dynamic MOE of wood in the standing trees of Japanese cedar w as affected somewhat by the testing methods used. Furthermore, the dynamic MOE of the wood in the standing trees varied with the growth conditions imp osed.