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題 名 | 留存萌蘗枝數對銀合歡萌芽更新林分生物量和木材比重的影響=The Effects of Coppice Thinning on Biomass and Specific Gravity of Leucaena Leucocephala |
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作 者 | 潘富俊; | 書刊名 | 中華林學季刊 |
卷 期 | 31:3=122 1998.09[民87.09] |
頁 次 | 頁227-237 |
分類號 | 436.27 |
關鍵詞 | 銀合歡; 萌芽更新; 生物量; 木材比重; 木材含水率; 萌蘗疏伐; 林分結構; Leucaena leucocephala; Coppice; Biomass; Specific gravity; Moisture content of wood; Shoot thinning; Stand structure; |
語 文 | 中文(Chinese) |
中文摘要 | 南澳地區之 5 年生銀合歡造林木,砍伐後進行萌芽更新試驗,萌蘗於砍伐後一年 ,分成 4 種除蘗處理:不除蘗、留存 1 枝、2 枝、3 枝。觀察不同處理林分之生長,比較 6 年生林分不去蘗處理和其他各種去蘗處理之生物量和木材比重之表現,以確定不去蘗處理 是否為銀合歡萌芽更新中最合適和值得採行的經營方法。結果顯示,不去蘗處理林分之胸高 胸面積合計比 3 種去蘗處理為高, 其大小順序為:不去蘗>留存 3 枝>留存 1 枝>留存 2 枝。各種處理之生物量隨著萌蘗直徑增加而呈曲線上升,大徑木的生物量遠大於小徑木。 6 年生萌芽更新林分,不去蘗處理者之每公頃地上部鮮重可達 147.9ton,大於留存 3 枝之 132.1ton,留存 1 枝之 124.8ton 和留存 2 枝之 110ton; 地上部乾重不去蘗者亦大於去 蘗者, 不去蘗、留存 3 枝、留存 1 枝和留存 2 枝者分別為每為 68ton、60ton、60.8ton 和 50.6ton。每公頃可利用幹部的鮮重和乾重,未去蘗者亦高於去蘗處理者,前者的高低順 序為: 未去蘗( 97.8ton )>留存 3 枝( 88.9ton )>留存 1 枝( 50ton )>留存 2 枝( 72.8ton ); 後者順序為未去蘗( 55.8ton )>留存 1 枝( 50ton )未留存 3 枝 ( 49.4ton )>留存 2 枝( 41.4ton )。 銀合歡的林木比重隨樹幹部位不同而變化,底 部比重高,頂端樹幹中段的比重可代表全珠的平均值。6 年生林木含水率,4 種處理差異不 顯著,分別為未去蘗者 47.2 %, 留存 1 枝者 44.9 %, 留存 2 枝者 45.9 %,留存 3 枝者 46.9 %,林分平均比重未去蘗者 0.46, 留存 1 枝者 0.49,留存 2 枝者 0.46,留 存 3 枝者 0.47,4 者之值差異不大。綜合林分材積生長、各種生物量和木材比重等表現, 未去蘗處理均比去蘗處理為佳,或不遜色,如以生產紙漿用材或燃料材為目的,銀合歡的萌 芽更新以不去蘗(疏伐)為宜。 |
英文摘要 | Thinning trial of coppice regrowth had been conducted after the harvesting of 5-year leucaena stands (K8) at Nan-Au of northeastern Taiwan. Thinning experiment was initiated during one-year old stage of the regrowth. Biomass and specific gravity of the wood of the regrowth stand were measured on the purpose of assessing the performance of each treatment. The results indicated that the unthinned stands had highest sum basal area among the four treatments. Regardless of the treatments, all biomass components increased positively with shoot diameter. The 6-year regrowth stands of the unthinned produced 147.9 ton/ha of total fresh weight, higher than 132.1 ton/ha of 3-shooted treatment, 124.8 ton/ha of 1-shooted and 110 ton/ha of 2-shooted. The unthinned treatment also had more total dry weight than others, estimated 68 ton/ha compared with 60 ton/ha, 60.8 ton/ha and 50.6 ton/ha of 3-shooted, 1-shooted and 2-shooted, respectively. Both fresh and dry weight of useful wood in unthinned stands was higher than the thinned ones. The value of the specific gravity in middle portion of trunk was taken to represent the averaged specific gravity of each tree. The mean specific gravity of wood in the unthinned, and thinned stands was from 0.46 to 0.49. There was apparently no significant difference among the treatments. The four treatments had similar mean moisture content of the wood in the 6-year stand, with 47.2% in unthinned, 44.9% 1-shooted, 45.9% 2-shooted and 46.9% 3-shooted. Judging from volum yield, biomass production and wood specific gravity, no thinning is recommented as a means of the coppie management for Leucaena leucocephala designated for pulpwood or fuel wood production. |
本系統中英文摘要資訊取自各篇刊載內容。