Earthworm invasion
Thursday, September 12, 2013 - 06:30
in Earth & Climate
Beavers reshape landscapes with their dams. Wolves control elk populations. Sea otters protect kelp forests by eating sea urchins. These are what ecologists call "keystone" species: critters that control an ecosystem and have a disproportionate impact on other species. And in Vermont forests, what are the keystone species?