The Living World: Ecosystem Structure: Keystone Species
Keystone species - A species, often a predator, that exerts a profound influence on a community in excess of that expected by its relative abundance.
Species richness - The number of species in a community.
Ecotone - A transitional zone where two or more communities meet.
Species richness - The number of species in a community.
Ecotone - A transitional zone where two or more communities meet.
Example of an ecotone between two ecosystems.
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