๐Ÿงฌap biology review

Keystone organism

Written by the Fiveable Content Team โ€ข Last updated August 2025
Verified for the 2027 exam
Verified for the 2027 examโ€ขWritten by the Fiveable Content Team โ€ข Last updated August 2025

Definition

An organism whose presence has a disproportionately large effect on ecosystem structure and function relative to its abundance, such that its removal would significantly destabilize the ecosystem.

AP course connection

Topic 8.5: 8.5 Community Ecology

Unit 8

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