森林立地学会誌 森林立地36(1), 1994, pp. 28〜35

 

論 文

 

南アルプス亜高山帯針葉樹林の齢構造と更新過程

 

山 中 典 和・安 藤  信・玉 井 重 信

 

  1982年の台風10号により,南アルプス仙丈ヶ岳の北東斜面に成立したシラビソ,オオシラビソが優占する極相状態の亜高山帯針葉樹林が壊滅的被害をうけた。被害は本数割合で95.6%の林木が枯死した。枯死木の54.0%は幹折れであり,残りは根返り木であった。枯死木について年輪解析を行い,林分の更新過程を調べた。齢分布は,90年以下,90年から180年,180年以上の3つの齢グループに分かれた。最高齢はトウヒの286年であった。また年輪データの解析から,同調的に生じる顕著な直径生長の増加が幾度もみられ,本林分は幾度も小規模の攪乱を受けていたものと考えられた。これらの攪乱のなかで約200年前と約100年前に生じた攪乱に関係して,多くの椎樹が更新したものと考えられた。

 

Norikazu YAMANAKA, Makoto ANDO, and Sigenobu TAMAI : Age structure and regeneration process of a subalpine couiferous forest in the south Japanese Alps, Central Japan.

On early August, 1982, a climax subalpine coniferous forest in the South Japanese Alps, dominated by Abies mariesii and A. veitchii, was severely damaged by the Typhoon No.10. Among trees more than 4.0cm in DBH, 95.6% were damaged. The stem broken trees made up 54.0% of damaged trees and the rest were uprooted trees. The regeneration process of the forest were studied on the basis of annual ring data of damaged trees. The age class distribution was discontinuous and three age groups, less than 90 years, between 90 and 180 years, and more than 180 years were distinguished. The oldest trees were 286 years old for Picea jezoensis Var. hondoensis. The results of annual ring analysis showed that synchronous and rapid increase in diameter growth occurred several times. This indicate that small scale disturbances occurred several times in the forest. It seemed that many trees established in relation to disturbances occurred about 200 and 100 years ago.


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