This document defines and provides examples of keystone species. It introduces the concept of the keystone species, which was established in 1969 by Robert T. Paine, and provides starfish and mussels as the original keystone predator and prey. Keystone species have a disproportionate impact on their environment relative to their abundance and play a critical role in maintaining ecosystem structure. The document then provides examples of different types of keystone species, including herbivores like elephants in African savannas, mutualists like hummingbirds and plants in Patagonia, and predators like starfish that control mussel and barnacle populations. It concludes by stating keystone species are integral to ecosystems and their conservation is essential for ecosystem maintenance and restoration.

1. PRESENTED BY:
BIBIN MATHEW,
2ND M. Sc. ENVIRONMENTAL SCIENCE,
CENTRAL UNIVERSITY OF KERALA.

2.  The concept of the keystone species was introduced in
1969 by Robert T Paine.
 Starfish – keystone predator and
 Mussels – keystone prey

3. KEYSTONE SPECIES
 Keystone species is a species that has a
disproportionately large effect on its natural
environment relative to its abundance.
 Plays a critical role in maintaining the structure of
an ecological community.
 Helps to determine the types and numbers of various other
species in the community.
 Without keystone species, the ecosystem will be different
 It can be any organism.
 Commonly it’s a predator.

4.  In general keystone species is a predator that prevents
a particular herbivorous species from eliminating
dominant plant species.

5. Types of keystone species
 1) Herbivores
 2) Mutualist
 3) Predators

6. HERBIVORES
 Their consumption of plants helps control the physical
and biological aspects of an ecosystem.
 In African savannas, Elephants are the keystone
species. Elephants eat shrubs and small trees, such as
acacia.
 Even if an acacia tree grows to a height of a meter or
more, elephants are able to knock it over and uproot it.
 This feeding behavior keeps the savanna a grassland
and not a forest or woodland.

8. MUTUALISTS
 Two or more species that engage in mutually beneficial
interactions.
 A change in one species would impact the other, and
change the entire ecosystem.
 In the woody grasslands of Patagonia, hummingbird
and indigenous plants act together as keystone
mutualists.
 Humming bird pollinates the plant.
 These plants provide the sugary nectar that makes up
most of the hummingbird’s diet.

10. PREDATOR: (CARNIVORES)
It can control the distribution and population of large
number of species.
 STARFISH-Predator
Mussels and Barnacles -Prey

11.  YELLOW STONE NATIONAL PARK
 Elk, Bison, Rabbit- PREY
 GREY WOLF- PREDATOR

12. YELLOW STONE NATIONAL PARK

13. CONCLUSION
 Integral part of ecosystem.
 Conservation and restoration of keystone species is
essential for maintaining and re establishing the
ecosystem.

14. REFERENCES
 https://biologydictionary.net/keystone-species/
 https://en.wikipedia.org/wiki/Robert_T._Paine_(zoologist)
 https://cals.arizona.edu/research/redsquirrel/res_pdf/Hale
Koprowski2018RestEcolKeystoneSppReintroductions.pdf
 https://en.wikipedia.org/wiki/Keystone_species
 https://greentumble.com/12-examples-of-keystone-
species/
 https://www.nationalgeographic.org/encyclopedia/keyston
e-species/

15. Thank you