Question

What is a keystone species? How does the removal of a keystone species affect the number of species in a community? Why aren’t all species in a community considered keystone species?

Answer 1

Ans. Keystone species- A species which have a very high effect on an ecosystem irrespective of its abundance.

Removal of a keystone species affect the number of species in a community because it is important for the overall function and structure of the ecosystem and also influences other species present in that ecosystem. A keystone specie defines an entire ecosystem. In the absence of a keystone species, the ecosystem would not exist as it is or it would cease to exist. Keystone species have low functional redundancy i.e no other species can fill the ecological niche of a keystone specie if it is removed from the ecosystem. Example- If a keystone predator is removed from an ecosystem, the populations of their prey increases exponentially.

All species aren't keystone species because not all specie can have such effect on the ecosystem as the keystone species. Ecosystems do not cease to exist if any specie is removed from it. That is why, keystone species are considered very important species for an ecosystem. They help in determining the types and numbers of various other species in the community. Therefore, keystone species can be targeted for conservation practices to maintain diversity and for keeping the structure of the community intact.