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AP® Environmental Science

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Yellowstone Wolves

APES-PEF4LC

The reintroduction of the wolf to Yellowstone National Park caused the bison and elk populations to decrease, which caused the willow tree stands to grow.

With more willow trees, beaver populations grew, which resulted in more habitat for waterfowl and amphibians.

This complex series of events demonstrates how important the wolves were to this ecosystem.

Therefore, the wolves represent what type of species for this ecosystem?

A

Invasive species.

B

Keystone species.

C

Specialist species.

D

Non-native species.

E

Indicator species.