Community (ecology)
In ecology, a community is the living things in a place. It may mean a group of living things that are not dependent on other communities. It may mean a small group, such as the living things in a piece of dead wood.[1] Populations of many species make up a community. A community with its physical and chemical environment makes an ecosystem. Each population may have an effect on other populations in the community in different ways (called symbiosis).[2]
Relations between species
In consumption, one living thing eats another. Three kinds of consumption are predation, herbivory, and parasitism. In predation, one animal, the predator, kills and eats another animal, the prey. In herbivory, an animal called an herbivore eats a plant, either in part or in whole. In parasitism, a parasite lives on another living thing, the host. The parasite eats small parts of tissue or nutrients from the host, but usually does not kill it.
In competition, two living things, from the same or different species, both need the same resources. If one species is better at getting the resources, the population of the other species may die out. Competition may have a negative effect on both species. In mutualism, two species both help each other, so they have a positive effect on each other. In commensalism, one species is helped, but it has no effect on the other species.[3]
Community (ecology) Media
A bear with a salmon. Interspecific interactions such as predation are a key aspect of community ecology.
a) A trophic pyramid showing the different trophic levels in a community. b) A food web of the same community
A simple trophic cascade diagram. On the right shows when wolves are absent, showing an increase in elks and reduction in vegetation growth. The left one shows when wolves are present and controlling the elk population.
Table visualising size-symmetric competition, using fish as consumers and crabs as resources.
A generalised graph of a predator-prey population density cycle
A red-chested cuckoo chick being feed by a significantly smaller Cape robin-chat adult
Related pages
References
- ↑ "Community". Biology Dictionary. 2016-12-29. Archived from the original on 2020-11-27. Retrieved 2021-03-12.
- ↑ Starr, Cecie (2006). Biology : Concepts and Applications. Christine A. Evers, Lisa Starr (6th ed.). Belmont, CA: Thomson, Brooks/Cole. p. 706. ISBN 0-534-46223-5. OCLC 57966041.
- ↑ Freeman, Scott (2011). Biological Science (4th ed.). San Francisco, CA: Pearson Education, Inc. pp. 1058–1070. ISBN 978-0-321-59796-0. OCLC 472790415.