ecosystem ec·o·sys·tem (ěk'ō-sĭs'təm, ē'kō-)
n.
An ecological community together with its environment, functioning as a unit.
A collection of living things and the environment in which they live. For example, a prairie ecosystem includes coyotes, the rabbits on which they feed, and the grasses that feed the rabbits.
Note: Chemical substances move through ecosystems on the Earth in cycles (see carbon cycle).
Note: The source of energy for almost every ecosystem on Earth is the sun.