樹木医学研究カラマツ生立木の非破壊腐朽診断-応力波測定法と打診法の比較-.

小林 元, 田代 直明, 山内 康平, 内海 泰弘, 古賀 信也, 大崎 繁, 鍜治 清弘, 岡野 哲郎

Research output: Contribution to journalArticlepeer-review

Abstract

九州大学北海道演習林と信州大学野辺山ステーションの50年生カラマツ林において,生立木の腐朽診断を応力波伝播速度測定装置を用いて行った.健全木の樹幹直径方向の応力波伝播速度のヒストグラムは正規分布型を示すが,腐朽木を含んだ林分の個体群全体の分布型は,腐朽木の応力波伝播速度が健全木よりも遅い側に偏って分布するため,左側に裾広がりのJ字型の分布型を示した.また,樹幹直径方向の腐朽率(%)と応力波伝播速度(km・s^<-1>)との直線回帰式の傾きは-0.011〜-0.015程度の値を示した.さらに,直線回帰式のy-切片は健全木の応力波伝播速度と一致した.本研究で得られたこれらの結果は,応力波伝播速度測定によるカラマツの生立木の腐朽診断を行う上で,有効な知見になると考えられる. Stress-wave velocity of the trunk in the transverse direction was investigated in 50-year old Larix kaempferi stands in the research forests of Kyushu and Shinshu Universities. The frequency distribution of stress-wave velocity classes of sound trees was normally distributed. However, because the stress-wave velocities of decayed trees were lower than those of sound trees, the stress-wave velocity classes exhibited a J-shaped frequency distribution in stands with decayed trees. The slope of the linear regression between the percentage of the decayed portion along the diameter of the trunk and stress-wave velocity (km・s^<-1>) ranged from -0.011 to -0.015. The y-intercept of the linear regression conformed to the average of the stress-wave velocity of sound trees. These findings provide effective information in diagnosing wood decay using stress-wave velocity measurements.
Original languageJapanese
Pages (from-to)119-124
Number of pages6
Journal樹木医学研究
Volume12
Issue number3
Publication statusPublished - Jul 30 2008

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