WEBVTT

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（ダイナミックな音楽）

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オリジナルキーストーンとは

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石のアーチの頂上にあるくさび形の
石板を指します

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キーストーンを外すと
すべてが転倒する危険があります

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一部の生態系は同じように機能し
1つのキーストーン種に依存しています

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生物学では
キーストーン種は

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彼らの生息地に不釣り合いに大きな影響を与え

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それらのサイズまたは個体数に鑑みると

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それらの日常の活動は他のあらゆる種類の種に
影響を及ぼします

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直接的または間接的に

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そしてそれらの数の変化は栄養カスケードを
引き起こす可能性があります

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影響が生態系全体に波及する場所

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多くの場合驚くべき方法で

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ワイオミング州のイエローストーン国立公園の
灰色のオオカミをとりあげましょう

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その数は1930年代初頭頃にゼロに落ちました

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