牛樟樹造林木及天然木之樹輪特徵研究

Tree Ring Characteristics of Plantation and Natural Stout Camphor Tree (Cinnamomum kanehirai Hay.)

林振榮(Cheng-Jung Lin) ； 鍾智昕(Chih-Hsin Chung) ； 林謙佑(Qian-You Lin) ； 黃國雄(Gwo-Shyong Hwang) ； 張東柱(Tun-Tschu Chang) ； 何政坤(Cheng-Kuen Ho)

《林產工業》 32卷1期 (2013/03) Pp. 1-12

https://doi.org/10.6561/FPI.2013.32(1).1

摘要

本研究探討牛樟樹造林木及天然木的樹輪特徵值，牛樟樹輪特徵值在四個不同生育地之間具有顯著性的差異。牛樟天然木的第1-20樹輪平均寬度顯著小於牛樟造林木；天然木的樹輪密度（484.58 kg m^(-3)）顯著低於造林木（511.2~550.6 kg m^(-3)）；生長相對緩慢的牛樟樹有較高的晚材率。採穗作業會影響樹木徑向生長，建議採穗作業應該採取影響樹木生長較低的時機施行。牛樟造林木在第1-20個樹輪內，樹輪寬度由髓心往樹皮方向，逐漸降低到樹皮側；樹輪密度在橫向由髓心往樹皮方向的變異，大致是隨著樹輪數目的增加而緩慢的增加。天然木的樹輪寬度在髓心1-40個樹輪呈現起伏，之後，樹輪寬度維持一定範圍的不規則波動，逐漸變小到樹皮側；天然木樹輪密度是隨著樹輪數目的增加而緩慢的上升，同樣在生長初期呈現較大起伏，最後樹輪密度大致維持一定常數的波動降低到樹皮側。樹輪寬度與樹輪密度之間，在20個樹輪的範圍內牛樟造林木兩者之間是具有極顯著的負相關，而牛樟天然木兩者之間沒有顯著性關係存在。

關鍵字

牛樟 ； 樹輪特徵 ； 造林木 ； 天然木

並列摘要

The purpose of this study was to investigate the tree ring characteristics of plantayion and natural camphor (Cinnamomum kanehirai) trees. Significant differences in average ring characteristics occurred among four sites. The average annual diameter growth of natural camphor trees was slower than that of plantation trees. Latewood percentage of slower growth trees was higher than that of faster growth trees. In natural trees, narrower tree rings and higher ring density occurred from 1^(st) outward to 20^(th) ring from pith, while wider tree rings and lower ring density happened from 20^(th) ring outward to bark. From 1^(st) outward to 20^(th) ring from pith, ring width in the radial direction increased from pith outward to about the 3^(rd) ring and then gradually decreased toward the bark or to the 20^(th) ring. Moreover, Ring density in the radial direction increased slowly from the pith outward to the bark. In natural trees, ring width in the radial direction increased from pith outward to about the 3^(rd) ring and then gradually decreased to the 20^(th) ring. Finally, they gradually decreased toward the bark. Moreover, ring density in the radial direction increased from pith outward to about the 20^(th) ring and then gradually decreased to the 40^(th) ring, and then increased to the 80^(th) ring. Finally, they remained almost constant toward the bark. From 1^(st) outward to 20^(th) ring from pith, there were significantly negative high (r=0.92, p＜0.01) or weak (r=0.23-0.37, p＜0.01) relationships between ring width and density in plantation trees; furthermore, there was no significant relationship between ring width and density in natural trees.

並列關鍵字

Stout camphor tree (Cinnamomum kanehirai) ； Tree ring characteristics ； Plantation tree ； Natural tree