History of the Ecosystem Concept

The word "ecosystem" was coined first by Roy Clapham in 1930. However, it was the ecologist Arthur Tansley that fully defined an ecosystem concept. In the classic article from 1935, Tansley defined an ecosystem as:
"The whole system,… including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment".

The ecosystem concept signalled a critical step in the study of ecology, as Tansely used the term specifically to replace the previous "superorganism" concept, which stated that communities of organisms comprised something like a higher-level and more complex organism - a mistaken conception which formed a theoretical barrier for ecological scientific research. Though Tansely with other ecologists used the ecosystem idea together with the now abandoned concept of an ecological "climax" (the "final“ or "equilibrium" type of ecosystem or community arising under some environmental conditions), the idea of ecosystem dynamics now replaces this. Eugene Odum, the major figure for advancing the study of ecology, made the ecosystem concept into a central part in the seminal textbook on ecology, by defining ecosystems as:
"Any unit that includes all of the organisms (ie: the "community") in a given area interacting with the physical environment so that a flow of energy leads to clearly defined trophic structure, biotic diversity, and material cycles (ie: exchange of materials between living and nonliving parts) within the system is an ecosystem."