Botanik online 1996-2004. Die Seiten werden nicht mehr bearbeitet, sie bleiben als historisches Dokument der botanischen Wissenschaft online erhalten!
The different groups of organisms are labelled as follows: P: producers, K: consumers (of the first, second, and third order). The wood as an example of an intact ecosystem. Despite the heavy decrease of biomass from one trophic level to the next higher one, each level consists of numerous species. Grassland is an example for a partially cultivated ecosystem. The number of species is strongly reduced, but the number of individuals remains high. The corn field is an example of a complete use of the biomass by the human (according to G. M. WOODWELL, 1970).