a general term to describe any close, long-term relationship between two different species

a symbiotic relationship where one organism benefits while the other is harmed

a symbiotic relationship where one organism benefits while the other is unaffected

a symbiotic relationship where both organisms benefit

the non-living parts of the environment, such as sunlight, water, and temperature

an interaction where two organisms fight over the same resource, such as food, shelter, or a mate

the process during which gradual changes take place in a biological community; can be primary or secondary

the first organisms to colonize or inhabit an area such as lichens, moss, or fern

Example: mistletoe feeds off a tree, sucking the water and nutrients away from the tree

Example: a bird drinks the nectar from a plant, but in doing so, pollinates the flowers for reproduction

Example: When grazing, cows stir up the grass and reveal the worms within the soil. Egret like to live near the cows to get their food more easily.