頁籤選單縮合
題 名 | 疏伐與修枝對臺灣杉人工林生長之影響 |
---|---|
作 者 | 羅卓振南; | 書刊名 | 林業試驗所研究報告季刊 |
卷 期 | 6:2 1991.06[民80.06] |
頁 次 | 頁155-168 |
分類號 | 436.254 |
關鍵詞 | 人工林; 生長; 修枝; 疏伐; 臺灣杉; |
語 文 | 中文(Chinese) |
中文摘要 | 臺灣杉人工林應以長伐期為經營導向,並以生產高品質之大徑木為經 營之目標,因此,中間撫育之施行,需以用途為導向。本研究乃就屏東林區管理 處荖濃事業區第73林班,本所原實施修枝試驗之臺灣杉人工林,繼續進行疏伐 試驗。試驗所擇之疏伐度係以每公頃胸高斷面積保留量為準,計分為四種:(A) 弱度疏伐:保留量為51㎡/ha;(B)中度疏伐:保留量為46㎡/ha;(C)強度疏伐: 保留量為41㎡/ha;對照區。疏伐木之選定,依照下層疏伐法的原則進行,於民 國73年1月間(17年生)進行疏伐處理,並經過連續六年調查分析,其結果如下: 1.本研究結果顯示,中度疏伐和強度疏伐處理,可增進臺灣杉單株林木之胸徑和 樹高生長,並提高林分斷面積和材積之生長量。此種效應於疏伐後第3年最為顯 著,至第6年時,斷面積和材積的生長潛能,亦仍維持緩和上升之趨勢。 2.臺灣杉若於11年生時修枝,對林木之胸徑、樹高、斷面積及材積生長均無顯 著之影響,即使修枝高度達4.5m處亦然。 3.鬱閉林分經疏伐後,其樹冠幅和側枝節徑隨疏伐度之增加而增大,惟側枝節徑 增幅不高,對林木品質之負面影響不大。 4.本試驗林分樹幹分叉之林木甚多,採用強度及中度之下層疏伐,可伐除此類幹 形不良之樹木,並增加大徑木所佔的百分比,而有助於提高林分之經濟價值。 5.根據樹幹解析資料顯示,若臺灣杉人工林每公頃林分密度維持在1,600 株左右 時,則以14∼18年生為實施疏伐撫育最適之林齡。 |
英文摘要 | The present study was carried out in a 17-year-old Taiwain (Taiwania cryptomerioides Hayata) plantation located in Southern Taiwan. Four thinning treatments, based on the absolute basal area (BA) per hectare left after thinning namely: (A)light thinning with 51m^2/ha of BA retained, (B) intermediate thinning with 46m^2/ha of BA retained, (C)heavy thinning with 41m^2/ha of BA retained, and (D)no thinning. (i.e. the control were applied). After six years' continuous investigation and anlysis, the result can be summarized as follows: 1.Intermediate and heavy thinning significantly increased the D.B.H. and height growth of individual trees as well as the BA and volume growth of the plantations. These observed thinning effects were particularly evident during the third years after thinning. 2.Pruning, even up to 4.5m of the tree height, did not effect the increase of D.B.H., height, basbl aera and volume of 11-year-old Taiwania plantation. 3.Although the diameter of nodes and the width of crown increased with the intensity of thinning pure effects, however, did not result in lowering the wood quality. 4.The removal of all deformed and over topped trees in intermediate and heavy thinning resulted in an increase of the percentage of large diameter trees, and, thus, increase the economic values of the plantation. 5.Results of stem analyses showed that, at stand density of 1,600 trees perhectare, the best time for thinning of Taiwania plantation would be at the age of 14-18 years old. |
本系統中英文摘要資訊取自各篇刊載內容。