同齡級林分柳杉立木材質之非破壞性檢測

Nondestructive Test on the Properties of Japanese Cedar Standing Tree Growing in the Even-Age Stand

陳勁豪(Jin-Hau Chen) ； 邱志明(Chih-Ming Chiu) ； 林振榮(Cheng-Jung Lin) ； 楊德新(Te-Hsin Yang) ； 王松永(Song-Yung Wang)

《林產工業》 29卷4期 (2010/12) Pp. 217-226

摘要

本報告係對於柳杉生長在同齡級林分內，因生長狀態之不同，其立木材質差異，藉由非破壞性技術檢測，強度試驗進行探討。結果可歸納於次：栽植密度較大林分（樣區2）之立木的各項性質，如立木之密度（D），超音波速（V），動彈性模數（DMOE），微破壞抗壓強度（Fcf）等均會大於栽植密度較小之林分（樣區1），但立木表面刺入深度（P）則相反。其差異均具有統計上之顯著性相關。在同齡級林分之立木，優勢木之V，Fcf值會顯著的小於劣勢木，但P值則相反。中勢木之V，Fcf與P值係居於優勢木與劣勢木之間。

關鍵字

同齡級 ； 柳杉 ； 非破壞性檢測 ； 立木材質

並列摘要

This report discusses the diversities of material properties of even-aged Japanese cedar standing trees caused by different growth conditions. Material properties were tested by nondestructive technique detection and strength examination. The results are the followings. Density (D), ultrasonic wave velocity (V), dynamic modulus of elasticity (DMOE) and compressive strength (Fcf) of the standing trees grown in the higher planting density parcel (Site 2) are all significantly greater than those in the lower planting density parcel (Site 1), but the value of pilodyn (P) is opposite. The V and Fcf of dominant standing trees are obviously smaller than suppressed standing trees in the even-aged stand, but the P is on the contrary. The V, Fcf and P of middle standing trees are between those of dominant standing trees and suppressed standing trees.

並列關鍵字

Even-aged stands ； Japanese cedar (Cryptomeria japonica) ； Nondestructive test ； Material quality of standing wood