• 作者： 洪良斌
• 作者服務機構： 臺灣省林業試驗所
• 中文摘要： 本試驗所得結果，約有下列數點： (一)可收改良紅檜林木之品質生長： 觀察及分析其經過修枝之林分，修枝傷口極大部份已經癒合，優勢木增加甚多，且每木均現出圓滿通直而光滑無癤之樹幹，可以促進其在今後木材品質之生長，對照區則否。 (二)可增進紅檜林木之材積生長量： 凡經過修枝撫育之林分，特別是(b)和(c)兩種處理林分，樹高生長較快，樹幹較為豐滿，所以其胸高形數較對照區增大甚多，因之其在單位面積上之材積生長量較不修枝之對照區林木增加甚多。 (三)提高林業者之純牧益數額： 各修枝處理及對照區在五年期間，詳細分析其每公頃每年之純收益數額，結果發現經過修枝撫育之林分，均大於不修枝之對照區，證明紅檜幼林實施修枝撫育，確可提高林業者之純收益數額。所以在林業經營上言之，紅檜造林成林後，不應任其畸形生長，而應及時實施修枝撫實，方為合算。
• 英文摘要： Red cypress (Chamaecyparis formosensisMatsum.) is one of the most importanteconomic tree species in Taiwan forestry.It distributes originally on all high centralmountain areas throughout this island. Now-adays, most of the old growth on all naturalstands of this species disappeared graduallyowing to carrying out the clearcutting on alarge scale. Fortunately, many new plantations ofthis species will be established by artificialreproduction on the cut-over lands. Thereis a young forest of this species, establish-ed by artificial planting in the year of 1957,owned by Lu-kuei Branch of T.F.R.I.. Itgrows very rapidly. But most of trees ofthis young stand had already sprouted outmany branches from the trunks near ground,especially those abnormal upward large bran-ches, like stems, affecting the main stemto grow. And the lateral branches of treesof this young forest could not wither downnaturally after the crown canopy was inclosure. For improving the growth condi-tion of this young forest, an experiment ofpruning was carried out in the winter of1967. The design of this experiment is includ-ing four kinds of treatment. i.e., (a) treat-ment:-pruning up to 1/3 tree height; (b)treatment:-pruning up to 1/2 tree height;(c) treatment:-pruning up to 2/3 tree height,(Q) treatment:-the check etc. Each treat-ment was replicated six times. Field ar-rangment of the plots was according to therandomized design. The size of each plotis 0.06 ha., rectangular in form. 5 yearslater, the increments of all trees withineach plot were remeasured. All of theseresults obtained may be summarized as fol-lows: (1) The number of the good trees in (b)or (c) treatment stands had been increasedgreatly through carrying out the operationof pruning. It means that the quality ofthe trees’trunks pruned had been improvedgreatly. But this phenomenon could not takeplace in the check or in (a) treatment standafter 5 years investigation. (2) The incre-ments in volume per ha. per year from (b)or (c) treatment stands are larger than thatfrom (o) the check stand, about threetimes. (c) The expenses paid for carryingout the operation of pruning as (b) or (c)treatments were not so much. But the netrevenues from the pruned stands as (b) or(c) treatments were larger than that fromthe check stand.
• 中文關鍵字： --
• 英文關鍵字： --