HOME    About this site    mypage    Japanese    library    university    Feedback

University of the Ryukyus Repository >
Faculty of Agriculture >
Bulletin >
The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus >
No.17 (1970/12) >

 
Title :移入実生スギ材の年輪巾, 晩材率, 気乾比重, 仮道管長について(沖縄産スギ材の材質(第 2 報))(林学科)
Title alternative :On the annual ring breadth, late wood percentage, specific gravity in air dry and length of tracheid of raised from & eed & introduced. (Studies on the quality of Sugi wood (Cryptomeria japonica D. Don) grown in Okinawa. II) (Department of Forestry)
Authors :仲宗根, 平男
Authors alternative :Nakasone, Hirao
Issue Date :1-Dec-1970
Abstract :沖縄本島北部に大正初期から吉野スギが移入植林されていた。わずかに現存しているスギ林分の戦前の植栽林から2本, 戦後植栽の九州産スギ林から1本を伐採して試料とした。それらの幹材の理学的性質を明らかにして造林樹種としての価値判定に役立てる目的でこの実験を行なった。なお, 比較のため日田産スギ材円板1枚も実験に加えた。この実験の結果, 沖縄産実生スギ材の材質について, つぎのことがあきらかになった。1)年輪巾 : 沖縄産実生スギ材は, 未成熟材と思われる10番目年輪までは2∿10mmと変動が大であるが, 成熟材部は4∿6mmと安定した値を示している。2)晩材率 : 沖縄産実生スギ材は, 平均50%で地スギ材より低い値を示したが, 九州産スギ材よりは20∿30%も高く, 沖縄産実生スギ材の特徴と考えられる。3)気乾比重 : 未成熟材, 成熟材の早材部において沖縄産0.3∿0.4,日田産0.2∿0.3と沖縄産が高く, 晩材部では一定の傾向は見られない。4)細胞膜厚 : 未成熟材の早材で沖縄産5∿8μ, 日田産2∿4μと沖縄産が厚く, 晩材部で差がない。成熟材では一定の傾向は見られない。5)細胞径 : 未成熟材の細胞径は, 早材で沖縄産20∿35μ, 日田産35∿45μと沖縄産が小さく, 晩材部では差がない。成熟材では早晩材とも一定の傾向は見られない。6)細胞径に対する細胞膜厚割合 : 未成熟材の早材においては沖縄産20∿30%, 日田産5∿15%と沖縄産が大きく, 晩材部では両者には差がない。成熟材では早晩材とも一定の傾向は見られない。7)仮道管長 : 未成熟材部は髄から10番目年輪程度までで, 成熟期に達する期間は地スギ材と大差がなく, 仮道管長は日田産スギ材より短い傾向にある。8)材質特徴 : 未成熟材の早材部は, 細胞膜厚やや厚く, 細胞径が小さく, 細胞径に対する細胞膜厚の割合も大である。他の部分においては日田産と大差がないが, 未成熟材, 成熟材とも晩材率が50%を示して, 本土産スギより20∿30%高い値となっている。
Yoshino-sugi (Cryptomeria japonica D. Don) which was imported seed from Japan had been planted since 1920 in northern part of Okinawa. Afterward, it was imported from Kyushu and was shown a remarkable growth. In this paper, the Okinawan materials were collected three wood of seedling sugi of prewar planting and Japanese material was harvested a piece of wood of seedling sugi in Hita area. The structural character of each wood for experiment on valuable determination as planting species was investigated. The results obtained are summarized as follows. 1) Annual ring breath : The seedling-sugi shown a great variation (2∿10mm) from pith to 10th annual ring and afterward, it stabilized (4∿6mm). 2) Late wood percentage : proportion of the seedling-sugi was shown lower value (average 50%) than the ji-sugi. But the value was 20-30% higher than Japanese sugi. I guess character of the seedling sugi of Okinawa. 3) Specific gravity in air dry : Early wood in part of juvenile wood shown higher value (0.3∿0.4) than Japanese sugi. But others were not shown a stable tendency. 4) Thickness of double cell woll : Early wood in part of juvenile wood shown higher value (5∿8μ) than Japanese sugi (2∿4μ). But late wood was not shown a stable tendency. 5) Cell diameter : Early wood in part of juvenile wood shown lower value (20∿35μ). But others were not shown a stable tendency. 6) Rate of wall thickness against cell diameter : : Early wood in part of juvenile wood shown higher value (20∿30%) than Japanese sugi (5∿15%). But others were not shown a stable tendency. 7) Length of tracheid : Juvenile wood of the seedling-sugi were from pith to 10th annual ring and period got to mature age was the same as the ji-sugi. But length of tracheid was shorter than Japanese sugi. 8) Character of the seedling sugi : On early wood in part of juvenile wood, membranous thickness was thick and cell diameter was small and specific gravity in air dry was great. But others were not shown stable tendency. Late wood panecntge was shorter value (50%) than the ji-sugi. But the value is character of the seedling sugi in Okinawa. On the detailed wood character, the experiment, have been proceeding.
Type Local :紀要論文
ISSN :0370-4246
Publisher :琉球大学農学部
URI :http://hdl.handle.net/20.500.12000/4515
Citation :琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus no.17 p.203 -212
Appears in Collections:No.17 (1970/12)

Files in This Item:

File Description SizeFormat
KJ00000162337.pdf974KbAdobe PDFView/Open