Definition of Keystone Species
Keystone species is such an organism that is responsible for holding the environment together as it is considered to be the vital most part of the ecosystem. Due to the disappearance of the keystone stone, the ecosystems would not get adapted to the changes that take place in an environment.
Under such circumstances, either the ecosystem would end or an invasive species would attack and resultantly the whole ecosystem would be shifted in a different direction. The concept of keystone species tells us that how one species becomes so important and crucial for the survival of other species. Predators, ecosystem engineers, and mutualists are known to be the types of such species.