(par 3. 2.1) Trophic levels and energy transfer
http://en.wikipedia.org/wiki/Trophic_level Trophic levels and Biomass The trophic level of an organism is the position it occupies on the food chain. The word trophic derives from the Greek τροφή (trophē) referring to food or feeding. A food chain represents a succession of organisms that eat another organism and are, in turn, eaten themselves. The number of […]
(par 3. 2.1) Food Chain: Detritus (wikipedia) Cycle
http://en.wikipedia.org/wiki/Detritus From Wikipedia, the free encyclopedia In biology, detritus (pronounced dee-try-tus) is non-living particulate organic material (as opposed todissolved organic material). It typically includes the bodies or fragments of dead organisms as well asfecal material. Detritus is typically colonized by communities of microorganisms which act to decompose(or remineralize) the material. In terrestrial ecosystems, it is encountered as leaf litter and other organic matter intermixed with soil, which is referred to as humus. […]