Keystone Species

Definition

A keystone species is an organism that plays a critical role in maintaining the structure of an ecological community, affecting many other organisms in the ecosystem and helping to determine the types and numbers of various other species in the community.

Related terms

Predator Keystone Species: This is a type of keystone species that controls population sizes and diversity by preying on other animals. For example, wolves are predator keystones because they control populations of deer and elk, which in turn affects vegetation growth.

Mutualist Keystone Species: These are organisms that engage in mutually beneficial interactions with other species, which significantly impact ecosystem function. An example would be bees who pollinate flowers while gathering nectar for food.

Engineer Keystone Species:

These are organisms that create, modify or maintain physical habitat for themselves and other species. Beavers are an example as they build dams that alter water flow and create new habitats for different kinds of wildlife.