Some animals matter so much to their ecosystems that losing them is like removing the keystone from an arch—the entire ...

Visitors from the North -- Web of life. Patterns in an ecosystem ; Living in a landscape of fear : trophic cascades mechanisms ; Origins : aquatic cascades ; Why the earth is green : terrestrial ...

A keystone in an arch's crown secures the other stones in place. Keystone species play the same role in many ecological communities by maintaining the structure and integrity of the community. The ...