ecosystem

noun

(eco[logy] + system) A community of organisms within a particular physical environment which is linked by a flow of materials through the non-living (abiotic) as well as the living (biotic) sections of the system. Thus, ecosystems can range in size from the whole earth to a drop of water, although in practice, the term is generally used for units below the size of biomes (e.g. sand dunes, oak woodland).