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 [ change | change source ]

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]

Related pages [ change | change source ]

• Prey-predator equations

References [ change | change source ]