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| | Ecosystem |
 | | On a large scale, ecosystems have been defined on the basis of geographical extent alone (eg, arctic, tall-grass prairie or hardwood forest). |
 | | Etymologically the word ecosystem derives from the Greek oikos, meaning "home," and systema, or "system." Nineteenth- and early 20th-century ecologists, who were well aware of the complex interdependence of living and nonliving matter, coined several terms, such as biocoenosis, microcosm, holocoen, biosystem and geobiocoenosis. |
 | | The ecosystem has usually been given the form of a triangle or a pyramid where the base represents the lowest level on the food chain and the peak the highest level. |
| www.thecanadianencyclopedia.com /index.cfm?PgNm=TCE&Params=A1ARTA0002519 (637 words) |
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