Keystone species

Definition

A keystone species is an organism that has a disproportionately large impact on its environment relative to its abundance. The removal of a keystone species can cause significant changes in the structure and diversity of an ecosystem.

5 Must Know Facts For Your Next Test

1. Keystone species maintain the structure and health of their ecosystems.
2. Their presence supports many other organisms in the community.
3. Examples include sea otters, wolves, and certain types of bees.
4. The concept was first introduced by ecologist Robert Paine.
5. Keystone species can be predators, prey, plants, or pathogens.

Review Questions

• What role does a keystone species play in an ecosystem?
• How can the removal of a keystone species affect biodiversity?
• Name two examples of keystone species and explain their impact.

Related terms

Indicator Species: An organism whose presence, absence, or abundance reflects specific environmental conditions.

Ecosystem Engineer: A species that creates or modifies habitats affecting other organisms.

Trophic Cascade: A series of ecological changes triggered by the addition or removal of top predators.