藤枝地區台灣杉人工林疏伐修枝效果之研究

Effects of Thinning and Pruning on Taiwania Plantations in the Tengchih Area

羅卓振南(Chen-Nan Locho) ； 邱志明(Chih-Ming Chiu) ； 陳燕章(Yen-Chang Chen)

《台灣林業科學》 15卷2期 (2000/06) Pp. 237-244

https://doi.org/10.7075/TJFS.200006.0237

摘要

本研究探討台灣衫疏伐及修枝之效應，以期提高木材質量生長。供試林分為屏東林區管理處荖濃事業區第73林班，本所原實施疏伐修枝試驗之26年生台灣杉人工林，繼續施行第二次疏伐及第三次修枝試驗。疏伐方式計分為每公頃保留600株；800株：1000株及未疏伐之對照區。修枝處理則分為修枝6m樹高：修枝8m樹高及未修枝之對照區。經處理6年後之研究結果顯示，第二次疏伐以每公頃保留600株和800株之處理效應較佳，可增進胸徑、樹高、胸高斷面積和材積之生長。而樹冠幅係隨疏伐強度之增大而增大，枝下高則隨疏伐強度之增大而減小。第三次修枝對林分生長無明顯差異，即使修枝至8m樹高亦然，修枝6年後傷口完全癒合者達95%，修枝確有助無節材之生產。

關鍵字

台灣杉 ； 疏伐 ； 修枝

並列摘要

In order to enhance the growth of wood quality and quantity, the effects of thinning and pruning on Taiwania plantations were studied. The tested 26-yr-old Taiwania plantations were located at compartment no. 73, Laonung Working Circle in the Pingtung Forest District. These plantations had been thinned once and pruned twice. The 2nd thinning and 3rd pruning were carried out for this study. Thinning treatments included retaining (A) 600, (B) 800, and (C) 1000 trees/ha after thinning, and (D) no thinning. Pruning treatments were pruning (A) 6 m and (B) 8m of tree heights, and (C) no pruning. The effects of retaining 600 and 800 trees/ha after thinning were most significant. The growth of DBH, tree height, basal area at breast height, and volume were enhanced. Crown width increased as thinning intensity increased, but the clean length of trunks decreased as thinning intensity increased. The 3rd pruning, even with pruning up to 8 m of tree height, had no significant effects on stand growth. The occlusion percentage of branches 6 yr after pruning was 95% and, hence, this proves that pruning can increase the production of clear logs.

並列關鍵字

Taiwania cryptomerioides ； thinning ； pruning