Keystone Species and Their Role in Ecosystem

Keystone species are those that are unique and essential to the functioning of an ecosystem. Keystone species research provides essential theory and evidence for conservation ecology, biodiversity, habitat management, and the dynamics and stability of the ecosystem. Their daily actions have a direct or indirect impact on a wide range of other species. Keystone species can also include herbivores. They contribute to the biological and physical regulation of an environment through their consumption of plants.

What are Keystone Species?

A keystone species is any species whose removal from an ecosystem hurts the overall variety and stability of the ecosystem. The concept of keystone species implies that an ecological community is more than just a collection of species. Typically, keystone species do not require huge habitats and hence remain limited to the ecosystem. Keystone species are usually non-migratory and have an impact on a specific environment or habitat.

Keystone species are the cohesive elements of a habitat; they might include plants, animals, or even microorganisms like bacteria and fungi. Keystone species are those whose importance to an ecosystem is such that their presence and function have a significant, sometimes disproportionate, impact on other creatures in the ecosystem that make up their habitat.

Where Did the Name ‘Keystone’ Come From?

This term originated in Robert Paine’s study in 1966 on a rocky shore community in California, where the entire species assemblage collapsed when the top predator (carnivorous starfish-pisasterochracceus) was removed. The concept of keystone species originated from the thought that the species diversity of an ecosystem was controlled by the predators in the food chains, and they affected many other creatures in the ecosystem.

Types of Keystone Species

The following are the types of keystone species:

Keystone Predators

Predators dominates the density and feed on a major consumer, perhaps driving other species out of the ecosystem through competition or predation. Furthermore, predators that control the abundance of other ecologically important prey species have been named keystone species.

Keystone Ecosystem Engineers/Modifiers

Ecosystem engineers shape the physical topography of their habitat, much like foundation species do. Habitats are created, altered, and maintained by ecosystem engineers. Some engineers alter their biology in order to alter their surroundings. We refer to these as autogenic engineers. The surroundings that allogenic engineers work in are physically altered.

Keystone Mutualists

Two or more species that collaborate effectively are known as keystone mutualists. A shift in one species would have an effect on the others and alter the ecosystem as a whole. These are frequently pollinators like bees.

Keystone Hosts

If mobile linkages, also known as keystone mutualists, rely on critically or ecologically significant host plants, then these hosts are also referred to as keystones. This group includes plants that support generalist pollinators as well as trait dispersers that are considered key mobility linkages.

Keystone Preys

Keystone prey are species that can sustain their numbers despite being preyed upon, hence controlling the density of a predator. A predator-prey species that can maintain its abundance in the face of predation might influence community structure by preserving predator density and thereby reducing the density of other prey.

Importance of Keystone Species

Keystone Species are important because of the following reasons:

• A keystone is the highest stone in an arch; it stabilises the other stones and prevents the arch from collapsing. A species that is essential to the survival of many other species in the environment is known as a keystone species.
• The other dependent species will also vanish if a keystone species is completely eradicated from a system.
• Keystone species include top predators that manage their prey, massive herbivores that shape the environment in which other species coexist, significant plants that sustain specific bug species that serve as food for birds, bats that spread plant seeds, and a plethora of other organisms.
• Variety of insects that serve as food for birds, bats that carry plant seeds, and a host of other creatures.
• Keystone species can be found at any stage of the ecosystem, ranging from plants and herbivores (feeders of plants) to carnivores (eating of meat) and detritivores (eaters of garbage).

Keystone Species Examples

The following are the examples of Keystone Species:

Categories of Key stone species	Example
Predators	Wolves – Apex Predators Movement and distribution of elk impacts aspen, cottonwood, and willow regeneration. Reduction in elk population size has reduced competition with bison, bison numbers have increased. Aspen and cottonwood trees are important for songbird habitat. Willow trees (along streambanks) stabilizes the soil- shelter for wildlife, food for moose and beavers.
Modifiers	American Alligator Control prey numbers depressions provide deeper water during dry seasons. Black-Tailed Prairie Dog Control plant growth and maintain plant diversity. Burrows: shelter for many animals.
Prey	Pacific Salmon Eaten by many predators Waste from grizzly bears adds nutrients to the soil for tree growth.
Mutualists	Ruby throated humming bird. Symbiotic relationship- pollinator: eats nectar and spreads pollen for seed production.
Hosts	Quaking Aspen Aspen stands are habitat for many insects. Insects are prey for many songbirds Nesting habitat for many birds.

Keystone Species Examples In India

The below are the examples of keystone species in India:

1. Fiddler crabs are detritivores, which means they eat dead organic stuff. The ecosystem cannot function without it. These crabs provide an important service by removing leaf litter and delivering nutrients to the soil.
2. Cullenia exarillata tree (local name Veipla) is native to India’s Western Ghats, is home to a diverse range of species. This life-giving stationery guardian attracts insects, birds, and mammals alike.
3. Sloth bears in the wild serve critical roles in the ecology they dwell in, excavating termite, mounds, and hills with their enormous claws and munching on the morsels buried within. These are keystone species because their food, which consists primarily of termites, fruits, and tubers, contributes to forest health. Ramdurga ecosystem protection in Karnataka has recovered to its former glory! Sloth bears, leopards, and the uncommon pangolin have all made a comeback.
4. Elephants are a keystone Engineers in the southern part of India including Karnataka, kerala and Tamil nadu. Elephants consume small trees and shrubs that thrive in the area. Elephants can topple and uproot the acacia tree, even if it reaches a height of a yard or more. Because of their grazing habits, the area remains a grassland instead of a forest.
5. The mutually beneficial relationships that bees have with plants make them an excellent example of keystone species of arch. They increase plant growth and fertilisation potential, for instance, when they gather nectar and pollen, which are their main food sources.

FAQs on Keystone Species

What is a Keystone Species and Examples?

Large mammalian predators are keystone species for large ecosystems. They consume a wide variety of species and thereby help in maintaining a balance in the ecosystem. For eg., Lions, tigers, jaguars are a few large mammalian predators.

What is the Difference Between a Species and a Keystone Species?

An indicator species is one that reflects the health of its ecosystem and can be studied to monitor environmental conditions and changes. A keystone species is one that has a disproportionately large impact on its surrounding communities.

Who Defined Keystone Species?

Ecologist Robert Paine, who coined the term “keystone species” in the 1960s, observed the importance of such species in a study of starfish along the rocky Pacific coastline in Washington state.

Are Humans a Keystone Species?

Human identified higher-order or ‘hyperkeystone’ species that drives complex interaction chains by affecting other keystone actors across different habitats.

What was the First Keystone Species?

The first keystone species ever identified was the predatory purple sea star (Pisaster ochraceus), found along the rocky coasts of Makah Bay in Washington State. In 1963, Paine noticed that these sea stars preyed extensively on mussels.

What is an Example of a Keystone Species being Removed?

The entire ecosystem will change or collapse. Possibly the most well known example of this was in Yellowstone National Park when the gray wolves were removed from the ecosystem in the 1920s.

Can a Producer be a Keystone Species?

Keystone species are species that are important for maintaining homeostasis in the ecosystem. They cannot be replaced by other species and often their removal causes a population crash in the ecosystem. Producers can be keystone species in a variety of ways.