熱帯雨林の食物網における明らかな競争の実験的証拠
Rebecca J Morris1, Owen T Lewis, H Charles J Godfray
1NERC Centre for Population Biology, Imperial College London, Silwood Park Campus, Ascot, Berkshire SL5 7PY, UK. r.j.morris@imperial.ac.uk
Nature
|March 19, 2004
まとめ
種が共有する自然敵を通じて相互作用する明らかな競争は,熱帯雨林で調査されました. 葉を採掘する昆虫を除去すると,寄生虫が減少し,他の種の個体数が増加し,多様な昆虫コミュニティの構造化におけるその重要性を示唆しました.
科学分野:
- エコロジー エコロジー エコロジー
- トロピカル生物学 トロピカル生物学
- 昆虫の生態学 昆虫の生態学とは
背景:
- 熱帯雨林は,非常に多様な草食昆虫のコミュニティを宿し,その構造と組織原理を識別することは困難です.
- 直接的な種間競争は宿主植物特異性によって制限されているが,共有された自然敵による明らかな競争は,代替の相互作用メカニズムを提供する.
- 明らかな競争は理論的に議論されているが,特に多種多様な熱帯の生態系内で,経験的証拠が欠けている.
研究 の 目的:
- 熱帯昆虫のコミュニティの構造化における明らかな競争の役割を実験的に調査する.
- 特定の草食動物種の絶滅が寄生虫の発生率や,自然敵を共有する他の種の集団密度に影響するかどうかを判断する.
主な方法:
- 熱帯雨林の昆虫コミュニティから2種の草食動物 (ジプテランとコレオプテランの葉鉱夫) の実験的除去.
- 処理場と制御場の両方で,寄生虫の発生率と他の昆虫種の集団密度の監視.
- 移された草食動物種を含む場所と存在しない場所の間の生態学的パラメータを比較する.
主要な成果:
- 両方の除去症例では,対照群と比較して,治療部位で寄生虫の発生率が著しく低いことが観察されました.
- ディプテランの葉鉱夫の除去の後,1年後に関連する昆虫種の豊富さの有意な増加が記録されました.
- コレオプテリアの除去も,統計的に有意ではないが,増加傾向を示した.
結論:
- この発見は,熱帯雨林内の昆虫のコミュニティの構造化において,明らかな競争が果たす重要な役割を実証的に裏付けている.
- 共通の自然敵は,多種多様な熱帯の生態系における人口動態とコミュニティ構成に相当な影響を及ぼします.
- この研究は,熱帯の草食動物コミュニティの組織を形作る重要なプロセスとしての明らかな競争を強調しています.
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