Ecosystem

Most ecologists will not commit to defining what constitutes an ecosystem. Here is meant any community of a wide variety of plants and animals bonded together by a common geographic region and sharing the flow of energy that drives the system to equilibrium. Ecosystems are complex enough to allow the development and maintenance of stable food chains and food webs. This activity links all those life forms into interdependencies. Most of the energy cycles through the communities located within the confines of a given ecosystem unless that system becomes disturbed (e.g., encroachment, natural disasters, etc.).

Links
  http://www.ecostudies.org/