Modern Biology, Ch. 20

predation

the relationship between two species in which the predator species feeds on the other species, the prey

interspecific competition

a type of interaction in which two or more species use teh same limited resource

symbiosis

a close, long-term relationship between two organisms.

parasitism

a relationship in which one individual is harmed while the other individual benefits

mutualism

a relationship in which both organisms dervie some benefit.

commensalism

one organism benefits, but the other organism is neither helped nor harmed.

species richness

the number of species in a community

species evenness

the relative abundance of each species

species-area effect

a pattern in which the number of species in an area increases as the area increase

disturbances

events that change communities, remove or destroy organisms from communities, or alter resource availability

stability

the tendency of a community to maintain relatively constant conditions

ecological succession

the gradual sequential regrowth of a community of species in an area

primary succession

the development of community in an area that has not supported life previously, such as bare rock, a sand dune, or an island formed by a volcanic eruption

secondary succession

the equential replacement of species that follows disruption of an existing community

pioneer species

the species of organisms that predominate early in succession - tend to be small, reproduce quickly, and grow quickly.

climax community

a community that, after a process of ecological sucession, has reached a generally stable state.