頁籤選單縮合
題名 | 臺灣栽植柳杉之栽植距離對其密度與數種強度性質之影響= |
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作者 | 王松永; 林法勤; |
期刊 | 國立臺灣大學農學院研究報告 |
出版日期 | 19940600 |
卷期 | 34:2 1994.06[民83.06] |
頁次 | 頁124-152 |
分類號 | 436.257 |
語文 | chi |
關鍵詞 | 柳杉; 栽植距離; 靜曲性質; 動彈性係數; 壓縮性質; 剪斷強度; 衝擊彎曲性質; Japanese cedar; Plantation spacing; Bending strength; Dynamic modulus of elasticity; Compression strength; Shear strength; Impact bending strength; |
中文摘要 | 本研究係探討栽植距離對柳杉之密度及各種強度性質之影響。本實驗所 採用之五種不同栽植距離及其每公頃林木之株數如次:1 m X 1 m(Type A:10,000株 /公頃,2 m X 2 m (Tpye B:2,500株/公頃),3 m X 3 m (Type C:1,110株/公頃)4 m X 4 m (Type D:630株/公頃),及 5 m X 5 m (Type E:400株/公頃)。得到次述結果。 (1)柳杉之靜曲強度,動彈性係數,壓縮強度及衝擊性質在徑向變異性,其係由 髓心向外側先增後減,但剪斷強度之徑向變異性較不規則。 (2)栽植距離較小之Type A及Type B之柳杉的密度,靜曲強度,動彈性係數及壓縮 強度均會顯著(0.05 level)的大於栽植距離大的Type D及Type E。而剪斷強度及衝擊 性質雖Type A及Type B會較Type D及Type E大許多,但統計上並無顯著性差異。 (3)柳杉之密度,靜曲強度,壓縮強度,動彈性係數與栽植距離間均可以負直線迴 歸式表示。而適當的栽植距離與各種強度間關係可以非線性迴歸式表示,其具有 最大值及最小值。 (4)本實驗若單就力學性質考慮時,以1 m X 1 m 栽植距離為佳。 |
英文摘要 | The purpose of this study was to investigate the variation ofdensity and various mechanical properties in the radial direction of40-year old Japanese cedar (Cryptomeria japonica D. Don) trees withvarious plantation spacing sites. Five types of plantation spacing andthe number of trees per hectare used in this experiment were lmX1m (Type A : IO.OOOtrees/ha) , 2mX2m (Type B : 2,500trees/ha) , 3mX3m (Type C: l,100trees/ha) , 4mX4m (Type D: 630trees/ha) , and5mX 5m ( Type E : 400trees/ha ) . (1) In the radial direction, minimum values of bending strength,dynamic modulus of elasticity, compression strength and impactbending strength occurred near the pith and increased outward, andthen decreased toward the barks. However, the values of shearstrength showed an irregular variation along the radial direction. (2) The density, bending strength, dynamic modulus of elasticity,and compression strength of Japanese cedar from smaller plantationspacing sites of Type A and Type B were significantly (0.05 level)greater than those from larger plantation spacing sites of Type Dand Type E. Athough the shear strength and impact bendingstrength of Type A and Type B were more than those of Type Dand Type E, however, Significant difference is not existed bystatistic analysis. (3) The relationships among the density, bending strength,compression strength, dynamic modulus of elasticity of Japanesecedar and plantation spacings could be represented by negative linearregression formulas. However, suitable relationships between variousmechanical strength and plantation spacings could be expressed bynon-linear regression formulas, and they had a maximum value orminimum value. (4) The plantation spacing of lmX 1m (Type A) was a better site for Japanese cdear when mechanical strength was considered as theonly factor. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。