肖楠人工林中小徑木強度性質變異性探討

Strength Properties of Taiwan Incense-cedar Plantation Wood

周群(Chun Chou) ； 李銘鐘(Ming-Chung Lee) ； 黃清吟(Chin-Yin Hwang)

《台灣林業科學》 17卷4期 (2002/12) Pp. 463-469

https://doi.org/10.7075/TJFS.200212.0463

摘要

本研究針對35年生肖楠造林木，探討修枝、樹高、及離髓心距對其強度性質之影響。在基本性質方面，修枝對樹高及胸徑無顯著影響；林木尖削度在1/2樹高以下較小，可得較佳之製材率；心材直徑、年輪寬、及心材年輪寬均隨樹高增加而減少，但邊材長度及邊材年輪寬則不受樹高影響。在強度方面，修枝對試材靜曲強度無顯著影響，但壓縮及剪斷強度則顯著增加；除剪斷強度外，試材各項強度，隨樹高增加而降低，彈性係數降低之程度較靜曲及壓縮強度爲大；離髓心愈遠，各項強度愈高，但剪斷強度則反之。

關鍵字

肖楠 ； 修枝 ； 樹高 ； 離髓心距 ； 強度

並列摘要

The strength properties of 35-year-old Taiwan incense-cedar wood were studied to investigate the effects of pruning, tree height, and distance from the pith. Results show that pruning had no significant effect on tree height or diameter at breast height. Tapery below 1/2 of tree height was smaller than that above and would result in a better lumberutilization rate of logs. Diameter of heart wood, annual ring width, and annual ring width of heart wood decreased with increasing tree height. The length and annual ring width of sapwood, however, were not affected by tree height. No significant pruning effect on the bending strength of the wood was detected. Pruning, however, increased the compression and shear strength of wood. The strength properties, except for shear strength, decreased with in creasing tree height and with increasing distance from the pith.

並列關鍵字

Taiwan incense-cedar ； pruning ； tree height ； distance frompith ； strength