A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. Such species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community.
The role that a keystone species plays in its ecosystem is analogous to the role of a keystone in an arch. While the keystone is under the least pressure of any of the stones in an arch, the arch still collapses without it. Similarly, an ecosystem may experience a dramatic shift if a keystone species is removed, even though that species was a small part of the ecosystem by measures of biomass or productivity. It has become a very popular concept in conservation biology.
Famous quotes containing the word species:
“The French manner of hunting is gentlemanlike; ours is only for bumpkins and bodies. The poor beasts here are pursued and run down by much greater beasts than themselves; and the true British fox-hunter is most undoubtedly a species appropriated and peculiar to this country, which no other part of the globe produces.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)