Growth Patterns Appearing in Annual Ring Width at Different Heights in Picea abies KARST. and Effects of Defoliation by Cephalcia isshikii TAKEUCHI

Norway spruce (Picea abies KARST.) caused damage by sawfly (Cephalcia isshikii TAKEUCHI) was examined, following the method proposed to analyze Pinus resinosa Ait. in Canada by DUFF & NOLAN in 1953. The method analyses radial growth of the stem in three different directions, namely oblique, horizontal and vertical sequence. Patterns appeared in these three sequences in Norway spruce were almost the same as described for Pinus resinosa Ait. by DUFF & NOLAN. The effects of the insect appeared most clearly in the oblique sequence, showing the progress of the growth reduction, stagnation caused by the insect and recovery from that, and indicated tendencies to be obscured by the trend of decrease in the horizontal sequence and by random fluctuations in the vertical sequence. The growth reduction by the insect appeared more clearly in the volume increment than in the height increment. The period of the damage was about 10 years and total loss was about 20 percent of normal volume increment.DUFF & NOLANが，レジノーサマツの生長を解析した手法を，オオアカズヒラタハバチの食葉被害をうけたドイツトウヒに適用した。この方法は，樹木の肥大生長を三方向から解析するものであるが，生長のパターンについては，彼らとほぼ同様の結果を得た。被害の影響は，斜め方向の系列に最も鮮明に現われ，被害が現われ，回復していく過程をよく示していた。水平方向の系列については，変動しながら減少していく系列の性質により，垂直方向の系列については，ランダムな変動により，害虫の影響による生長の減退は不明瞭であった。害虫の影響は，樹高生長よりも材積生長に鮮明に現われ，被害の期間は約10年間であり，総損失量は正常の生長量の約20％であった

ドイツトウヒの高さ別年輪幅に現われる生長のパターンとオオアカズヒラタハバチの食葉の影響

Norway spruce (Picea abies KARST.) caused damage by sawfly (Cephalcia isshikii TAKEUCHI) was examined, following the method proposed to analyze Pinus resinosa Ait. in Canada by DUFF & NOLAN in 1953. The method analyses radial growth of the stem in three different directions, namely oblique, horizontal and vertical sequence. Patterns appeared in these three sequences in Norway spruce were almost the same as described for Pinus resinosa Ait. by DUFF & NOLAN. The effects of the insect appeared most clearly in the oblique sequence, showing the progress of the growth reduction, stagnation caused by the insect and recovery from that, and indicated tendencies to be obscured by the trend of decrease in the horizontal sequence and by random fluctuations in the vertical sequence. The growth reduction by the insect appeared more clearly in the volume increment than in the height increment. The period of the damage was about 10 years and total loss was about 20 percent of normal volume increment.DUFF & NOLANが，レジノーサマツの生長を解析した手法を，オオアカズヒラタハバチの食葉被害をうけたドイツトウヒに適用した。この方法は，樹木の肥大生長を三方向から解析するものであるが，生長のパターンについては，彼らとほぼ同様の結果を得た。被害の影響は，斜め方向の系列に最も鮮明に現われ，被害が現われ，回復していく過程をよく示していた。水平方向の系列については，変動しながら減少していく系列の性質により，垂直方向の系列については，ランダムな変動により，害虫の影響による生長の減退は不明瞭であった。害虫の影響は，樹高生長よりも材積生長に鮮明に現われ，被害の期間は約10年間であり，総損失量は正常の生長量の約20％であった