Ant Community Structure and Related Environmental Factors After Line Thinning in Japanese Cedar (cryptomeria Japonica) Plantations

27 Mar Ant Community Structure and Related Environmental Factors After Line Thinning in Japanese Cedar (cryptomeria Japonica) Plantations

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Abstract

列状間伐による生物相への影響を明らかにするため, 間伐強度および間伐後の経過年数が異なる二つの列状間伐林分においてアリ群集構造を調査し, 隣接する対照林分と比較した。強度の列状間伐後11年経過した林分では対照林分よりも森林性種が少なく, 広域生息種が多く出現する傾向がみられた。一方で, 弱度の列状間伐後4年経過した林分では, 逆の傾向がみられた。また, 環境条件がアリ類の種構成に与える影響は明瞭ではなかったが, 林冠からの入射光量や下層植生のバイオマス量との関係が示唆された。アリ類は様々な生態的特長を有するため, アリ群集構造を人工林における森林施業の撹乱強度やその後の生物相の回復過程を表す指標として用いるためには更なる検討が必要であると考えられる。

English Abstract

In order to understand the effects of line thinning on forest biota, we compared ant community structure between the line thinned and an adjacent control stand in two Japanese cedar plantations in Hyogo Prefecture. The stand, which was heavily thinned 11 years ago, tended to have more woodland specialists and less habitat generalists compared with the control plot. In the stand, which was lightly thinned four years ago, the opposite trend was observed. The effect of environmental factors on ant species composition was not clear, but there were some effects of the amount of incident light to the forest floor and the biomass of understory vegetation. Our results indicate that more investigation is needed in order to use ant species composition as an indicator of the degree of disturbance and subsequent recovery of forest biota after forest ma gement practices.