http://eschooltoday.com/ecosystems/scales-of-an-ecosystem.html Ecosystems come in indefinite sizes. It can exist in a small area such as underneath a rock, a decaying tree-trunk, or a pond in your village, or it can…
http://www.botanicalgarden.ubc.ca/kids/ecosystem.php An ecosystem is a community of plants, animals and smaller organisms that live, feed, reproduce and interact in the same area or environment. Some ecosystems are very large. For example, many bird…
http://en.wikibooks.org/wiki/Ecology/Biological_community A community or biocoenosis is an assemblage of organisms (species populations) whose composition and aspect is determined by the properties of the environment and by the relations of the organisms to each other (modified from…