♻️ap environmental science review

10% Rule

Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 examWritten by the Fiveable Content Team • Last updated September 2025

Definition

The 10% rule is a principle in ecology that states that only about 10% of the energy available at one trophic level is transferred to the next trophic level. This means that as you move up the food chain, only a small fraction of the energy from the lower trophic levels is passed on.