Within Trunk Variation of the Strength Property of Wood from Formosan Alder, Long Glans Oak and Formosan Michelia in Taiwan

台灣產赤楊、錐果櫟及烏心石樹幹內木材強度性質變異

詹讓雷(Jung-Lei Tang)

《林業試驗所研究報告季刊》 10卷1期 (1995/03) Pp. 83-91

https://doi.org/10.7075/BTFRI.199503.0083

摘要

木材係一生物材料，由不同大小及形狀細胞組成，這些以及由其隨伴發生之顯微構造差異，為木材性質變異之一主因，因此，隨生長方向、樹種、以及同樹種之單株內而有變異，同時影響其加工利用。本研究就赤楊、錐果櫟及烏心石三種重要本省固有樹種，進行單株內強度性質變異分析，在試驗中，曾取得赤楊、錐果櫟及烏心石各一株，每株均外觀生長優良、不含不正常木質者。結果發現破壞係數以烏心石優於錐果櫟，而赤楊材最弱，但靜力抗壓強度則以錐果鑠材優於烏心石，三樹種中，錐果櫟材比重最大，烏心石材次之赤楊材最低，綜合各強度性質而言，錐果櫟及烏心石有隨樹高而強度漸減之趨勢，然而赤楊材則隨樹高而漸增，各強度在樹幹之東南西北方位間，並無明顯或一致之變異趨向，由樹心沿年輪至樹皮方向則均顯現增加材料之強度，似拋物線形曲線，惟其間因不同強度性質及樹種而稍有不同，一般而言，赤楊材生長較為迅速，因而其強度性質之變異性亦大於另二種試驗之樹材。

關鍵字

木材性質變異性 ； 強度性質 ； 台灣省產木材 ； 闊葉樹材 ； 赤楊 ； 錐果櫟 ； 烏心石

並列摘要

Wood is a biological material and composed of cells of various shapes and sizes. These and the associated changes in the anatomical structure of wood play a major role in the property variations, such as between and within species, growth directions, etc., which have a great effect on the wood utilization. The main purpose of this study is to examine the within trunk variation in the wood strength properties of three important hardwood species native to Taiwan. They are Alnus formosana or Formosan Alder (FA), Cyclobalanopsis longinux or Long Glans Oak (LGO), and Michelia formosana or Formosan Michelia (FM). One tree with straight truck and no signs of abnormal wood for each species was chose. The measured DBH values were 60.5, 44.0, and 78.0 cm for FA, LGO, and FM, respectively. Small, clear and streight grained specimen was made from the wood taken from three different heights of each smaple tree truck. It was found that the MOR of FM wood was stronger than that of LOG. The MOR of FA wood was the weakest among the three. For specific gravity and compression strength, they were shown in decreasing order as LGO, FM, and FA. No consistent variation patterns were found for various strength properties when comparing the results obtained from the different locations, i.e., north, south, east, and west aspect, of the cross section areas at the selected heights of a trunk. The wood strength for FM and LGO showed a decreasing trend with increasing in the trunk height. The reverse was true, however, for EA. From pith toward sapwood, a gradual increase in the strength properties was noted. In general, FA showed a faster rate of growth and larger variation than those of the other two hardwood species tested.

並列關鍵字

Wood variation ； mechanical property ； native wood in Taiwan ； hardwood ； Formosa Alder ； long Glans Oak ； Formosan Michelia