Vocabulary Vocabulary ReviewReview

Ch 20Ch 20

Community Community EcologyEcology

A relationship between two

species in which one species, the

predator, feeds on the other species,

the preyPredation

A relationship between two species in which both species compete for limited resources

such that both species are negatively affected

by the relationship

Interspecific competition

A relationship in which two different

organisms live in close association with each other

Symbiosis

A relationship between two species

in which one species, the

parasite, benefits from the other

species, the host, which is harmed

Parasitism

A relationship between two

species in which both species

benefit

Mutualism

A relationship between two organisms in

which one organism benefits and the other is

unaffectedCommensalism

The number of different species

in an area or community

Species richness

A measure of the relative

abundance of each species in an

ecological community

Species evenness

A pattern in which the number of

species in an area increases as the area increases

Species-area effect

In ecology, an event that changes a community by removing or destroying

organisms or altering resource

availabiltyDisturbance

The tendency of a community to

maintain a relatively constant

structure

Stability

A gradual process of change and

replacement in a community

Ecological succession

Succession that begins in an area

that previously did not support life

Primary succession

The process by which one

community replaces another community

that has been partially or totally

destroyed

Secondary succession

A species that colonizes an

uninhabited area and that starts an ecological cycle in which many other species become

establishedPioneer species

A community that, after a process of

ecological succession, has

reached a generally stable

state

Climax community