Keystone species
A keystone species is a species, usually of wildlife, that has a disproportionate effect on its environment. In our region, the classic example of this is the beaver.
Beavers dam and flood fields and forests, essentially creating, or driving, their own natural disturbance events. Besides making great habitat for themselves, they support a whole ecosystem, home to many reptiles, amphibians, birds, mammals, plants and more.