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8.3. Habitat and ecological niche

Habitat and ecological niche

There are other terms used in ecology that can confuse us and that we should know that they are not synonymous with biotope:

  • Habitat: it is very similar to a biotope, but while the biotope refers to the environment in which the organisms of the ecosystem live (biological community), the habitat refers only to the environment in which an organism or population lives.
  • Ecological niche: it does not refer to a physical space, but to the role or function that an organism plays in the community and its position according to environmental conditions (temperature, pH, humidity, etc.). It is often said that it is something similar to the "trade" of a species within the ecosystem. That is, how they feed, hunt, avoid being hunted, compete, etc., with other members of the ecosystem. Therefore, the ecological niche includes environmental conditions (abiotic factors) and the influence of other species in their life (biotic factors).

The ecological niche that each species occupies is the result of interspecific competition that displaces species to occupy different sites. An example can be seen when the exotic species that are introduced into an ecosystem displace the native species to more restricted niches.

For example: The field rat (Rattus rattus) has a wide niche, being able to live in a wide range of environmental factors (biotic and abiotic). In the 18th century, the sewer rat ( Rattus novergicus ) was introduced, with a more specific niche, specialized to live in a more humid environment and with less light, thus displacing the field rat from the sewers.

If a species has a small ecological niche width, it is a highly specialized species under these conditions and can displace other less specialized species to occupy other niches.

Comparación entre la rata de campo y la rata de alcantarilla

By Vergleich_Hausratte_Wanderratte_DE.svg: Sponk (talk), based on a work by Karim-Pierre Maalejtranslated by: Sponk (Vergleich_Hausratte_Wanderratte_DE.svg) [CC BY-SA 3.0 or CC BY-SA 3.0], via Wikimedia Commons