Keystone species
A) influence the communities in which they live more than expected on the basis of their abundance.
B) may influence the species richness of communities.
C) may influence the number of trophic levels in communities.
D) are not necessarily predators.
E) All of the above

Question

Quizplus · Accepted Answer

Keystone species are species that have a disproportionate effect on the structure and function of their ecosystem relative to their abundance. They may influence the species richness of communities by facilitating the growth and reproduction of certain species or reducing the populations of competitors or predators. They may also influence the number of trophic levels in communities, as they often occupy positions at critical points in food webs. Keystone species are not necessarily predators, though they often are.

Keystone Species