<P> A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance . Such species are described as playing 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 . A keystone species is a plant or animal that plays a unique and crucial role in the way an ecosystem functions . Without keystone species , the ecosystem would be dramatically different or cease to exist altogether . </P>
<P> A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance . Such species are described as playing 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 . A keystone species is a plant or animal that plays a unique and crucial role in the way an ecosystem functions . Without keystone species , the ecosystem would be dramatically different or cease to exist altogether . </P>
a species that has an essential role in maintaining ecosystem structure is called a
a species that has an essential role in maintaining ecosystem structure is called a
A keystone species
A keystone species