concept

Foundation species

An abundant, usually large species whose body constitutes the habitat its whole community lives in — the shade, the humidity, the surfaces, the shelter. Unlike a keystone species, which is rare and acts by eating, a foundation species acts through its sheer mass, and the mass is the point. Paul Dayton named it in 1972 from work on the Antarctic seafloor. Giant kelp, eastern hemlock, a three-hundred-metre tree: lose one and you have not lost a strand of the food web, you have lost the premises.