AP Bio

Biological Community

All organisms living close enough together in an area for potential interaction

Interspecific interaction

relationships between individuals of different species in a community, categorized as postitive (+), negative (-), or neutral (0)

Interspecific competition

A (-/-) interaction where species compete for a limiting resource

Competitive exclusion

The local elimination of a competing inferior species when two species vie for the exact same limited resources

Ecological niche

The total sum of biotic and abiotic resources a species uses in its environment

Resource partitioning

The division of environmental resources that allows similar species to coexist

Character displacement

The tendency of characteristics to diverge more in sympatric (overlapping) populations than in allopatric (separate) populations

Predation

A (+/-) interaction where one species (predator) kills and eats the other (prey)

Herbivory

A (+/-) interaction where an organism eats parts of a plant or alga

Symbiosis

A close, direct ecological relationship between organisms of two different species; includes parasitism

Parasitism

A (+/-) symbiotic interaction where a parasite derives nourishment from a host

Mutualism

A (+/+) symbiotic interaction that benefits both interacting species

Commensalism

A (+/0) symbiotic interaction that benefits one species while leaving the other unaffected

Species diversity

The variety of organisms that make up a community, including species richness and relative abundance

Keystone species

A species that exerts strong control on community structure not by sheer abundance, but by its pivotal ecological role

Ecological succession

The sequence of community and ecosystem changes after a disturbance