Community Ecology

community

group of populations of different species living close enough to interact

ecological niche

sum total of an organism’s use of abiotic / biotic resources in the environment

fundamental niche

niche potentially occupied by the species

realised niche

portion of fundamental niche the species actually occupies

interspecific competition ( - / - )

two or more organisms compete for a resource that is in short supply

competitive exclusion principle

two species cannot coexist in a community if their niches are identical

resource partitioning

differences in niches that enable similar species to coexist

herbivory ( + / - )

a herbivore eats part of a plant of algae

predation ( + / - )

biological interaction where one organism, predator, kills and eats another organism, prey

cryptic coloration

camouflaged by coloring

warning coloration

bright color of poisonous animals

batesian mimicry

harmless species mimic color of harmful species

mullerian mimicry

when two or more unpalatable species evolve to resemble each other, reinforcing avoidance by predators.

herivory

plants avoid by chemical toxins, spines, and thorns

mutualism ( + / + )

symbiotic relationship in which both species benefit from the relationship

commensalism ( + / 0 )

symbiotic relationship in which one member of the association benefits and the other is neither helped nor harmed

parasitism ( + / - )

a symbiotic relationship in which one organism benefits at the expense of the other.

dominant species in food chain

has highest biomass or is the most abundant in the community

keystone species in food chain

exert control on community structure by their important ecological niches

disturbances

changes a community by removing organisms or changing resource availability

primary succession

plants & animals invade where soil has not yet formed (ex. colonization of volcanic island or glacier)

secondary succession

occurs when existing community is cleared by a disturbance that leaves soil intact (ex. forest fire, abandoned farm)

biogeographic islands

natural labs for studying species diversity