What are Keystone species? Different types of keystone Species with examples

Definition of Keystone species: Any species whose removal or reduction from an ecosystem adversely affect the overall diversity, stability and trophic structure of an ecosystem

The term keystone species was coined by Robert Paine, famous American ecologist during his studies in rocky intertidal ecosystem. He used the term keystone species to indicate the importance of star fish in that ecosystem.

Watch this video for better understanding.

How Keystone species affects an Ecosystem?

Removal of keystone species causes

• Reduction in prey population
• Reduction at producer level causing complete imbalance of an ecosystem.
• Reduces the overall species diversity of an ecosystem
• Trophic cascade

Different Types of Keystone species

• Most often predators:  Tiger, Starfish, Shark, Sea otter, Wolf, Prairie dogs  in northern grasslands, Grizzly bears,
• Prey: Antarctic krill (food of Blue whale, Dolphins etc), Snowshoe hare in North America
• Ecosystem engineers: Species that keeps that ecosystem as such.
• Beaver (making dam, creating an ecosystem), African elephants in African Savanna, (overgraze the grassland preventing the growth of tall plants thus maintaining it as a grass land)
• Mutualist: Humming birds, bees (pollinating many plant species)
• Food and nesting source: Saguaro Cactus (Carnegiea gigantea) food and nesting source for many bird and insect species in Desert Ecosystem),Fig (Ficus) in rain forests (as a food source for all species throughout the year)

This are the reasons we are spending lot of money to conserve this species. They are the keystone in the sustenance of that ecosystem. Thank you