ecosystem

ecosystem Interacting community of organisms and their physical environment. It includes all organic life in a given area along with the soil, water and other inorganic components of their habitat, and all the ecological interactions that take place within and between the organic and inorganic. It is a complete ecosystem only if it can incorporate energy into organic compounds and pass it from organism to organism, and if it recycles elements for re-use. Examples of ecosystems include meadows, woodland and ponds.

ecosystem A biological community and the physical environment associated with it. Nutrients pass between the different organisms in an ecosystem in definite pathways; for example, nutrients in the soil are taken up by plants, which are then eaten by herbivores, which in turn may be eaten by carnivores (see food chain). Organisms are classified on the basis of their position in an ecosystem into various trophic levels. Nutrients and energy move round ecosystems in loops or cycles (in the case above, for example, nutrients are returned to the soil via animal wastes and decomposition). See carbon cycle; nitrogen cycle.