Table of Content:
- Ecological Niche – Definition
- Habitat vs Niche
- Types of Ecological Niche
- Segregation of Ecological Niche
- Frequently Asked Questions
Ecological Niche – Definition
“Niche describes the role of an organism in its particular ecosystem”
The term ‘niche’ was first used by Joseph Grinnel in 1917. He stated niche as an ultimate distributional unit, within which each organism is held by its instinctive and structural limitations. He also stated that no two species can inhabit the same niche for a long time.
Elton, in 1927 referred to niche as a place of an animal in a biotic environment pertaining to its relation with food and predators.
Hutchinson, in 1957 defined the niche of a species as an n-dimensional hypervolume or hyperspace of environmental variables.
In other words, it can be loosely defined as the requirement of a species for existence in a given environment and its impacts on that environment.
Habitat vs Niche
Habitat is a single phrase that signifies an area in which an organism grows and lives along with its abiotic factors. Examples include marine habitats, forest habitats, coastal habitats, etc.
Microhabitat – Every habitat comprises several microhabitats that subtly differ with respect to temperature, light, humidity and other factors. For example, lichens that thrive on the northern side of the boulderstone differ from those that grow near the ground and on the southern side. The environmental variables pertaining to the microhabitat are known as the microenvironment.
Ecological Niche – The ecological niche is an inclusive term that involves not only the physical space occupied by an organism but also its functional role in the community. It describes an organism’s response to the distribution of food and competitors.
Also Check: Difference between Habitat and Niche
Types of Ecological Niche
The three vital aspects of an ecological niche are – physical level, function role and its position in the environmental gradient. Based on this, ecological niche can be classified into three types –
- Habitat or Spatial Niche
- Trophic Niche
- Hypervolume Niche
Habitat or Spatial Niche
This pertains to the physical space inhabited by an organism. For example, consider an invertebrate community (millipedes) underneath a fallen log in a forest. In the dynamic view of the entire forest, some logs can be very old while some are new; some are untouched while some are recently disturbed. This variability also determines the distribution of the millipede species in that particular habitat. Here, the habitat under consideration is the forest floor of maple-oak vegetation. One species of millipede is predominant at the centre of logs, while another is at the superficial wood of logs. Likewise, different species of millipedes are found under the log, beneath the bark, beneath the litter, etc.
Trophic Niche
In the case of trophic niche, two species occupy the same habitat but have different functional roles or trophic positions. This is because of their variations in food habits. Example – Aquatic birds Corixa and Notonecta live in the same pond but inhabit different trophic niches. Notonecta is an active predator that swims its way through to feed on other animals. Whereas Corixa feeds mostly on decaying vegetation. Another classic example would be Darwin’s finches or Galapagos finches that showed adaptive radiation. The beak shape and size of these passerine birds are adapted as per their food sources.
Multifactor or Hypervolume Niche
This concept is based on the various environmental factors to which organisms of a population are uniquely adapted. Hutchinson (1957) emphasised his view of the n-dimensional hypervolume as a metaphor for the niche. Here, n is the number of environmental factors (temperature, humidity, etc.) for a given organism in a particular space or hypervolume. Since there are a large number of environmental factors, it is represented as n-dimensional hypervolume.
Segregation of Ecological Niche
Segregation of niches is vital for the survival of an organism. This will reduce competition and will save a lot of time and energy. In general, niche favours species that are more adapted to the microenvironment than the other organisms. Thus, other species can inhabit elsewhere where there is no or less competition. Segregation also avoids conflict and confusion in activities between the organisms and paves the way for an orderly and efficient life cycle.
Explore: Genetic Diversity
Frequently Asked Questions
What is the difference between ecological niche and habitat?
Habitat and niche are slightly entangled concepts. Habitat describes a subset of a specie’s niche, referring to the physical and some biotic features of the environment, but not explicitly the interaction among the other species. Whereas niche describes the organism’s functional role along with its ecosystem. In simple words, if habitat is the ‘address’, then niche is more like the ‘profession’ of an organism.
Define ecology.
The term ecology is derived from two Greek words, oikos (house) and logos (discussion). Ecology literally discusses the organisms in their native environment. Generally, it is defined as the relationship of all organisms with respect to their organic and inorganic environments. An ecosystem is the functional and structural unit of ecology.
What is a biotic community?
All living organisms of an ecosystem form a single component called the biotic community or ecological community. The organisms of a biotic community share habitat and have a direct or indirect influence on the survival of each other. Also, it is a larger unit than the population. Species diversity, ecological dominance and trophic structures are some characteristic features of a biotic community.
What is a guild?
An ecological guild is a collection of species that make use of the same ecological resource. It also refers to a group of species that exploit different resources in a similar way. Thus they need not occupy the same ecological niche. Examples – planktons, grazers, saprophytes, etc.
Also Read: Ecology and Environment
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