Gray wolves were reintroduced into Yellowstone National Park in 1995, resulting in a trophic cascade through the entire ecosystem. After the wolves were driven extinct in the region nearly 100 years ago, scientists began to fully understand their role in the food web as a keystone species.

Noun

management of a natural resource to prevent exploitation, destruction, or neglect.

Noun

branch of biology that studies the relationship between living organisms and their environment.

Noun

all related food chains in an ecosystem. Also called a food cycle.

reintroduce
Verb

to return members of a species to their historical range.

Yellowstone National Park
Noun

large national park in the U.S. states of Wyoming, Idaho, and Montana.