An ecosystem is a natural unit consisting of all plants, animals and micro-organisms (biotic factors) in an area functioning together with all of the non-living physical (abiotic) factors of the environment. An ecosystem is a completely independent unit of interdependent organisms which share the same habitat. Ecosystems usually form a number of food webs which show the interdependence of the organisms within the ecosystem.

The term ecosystem was coined in 1930 by Roy Clapham to denote the combined physical and biological components of an environment. British ecologist Arthur Tansley later refined the term, describing it as “The whole system,… including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment.”  Tansley regarded ecosystems not simply as natural units, but as “mental isolates.”  Tansley later defined the spatial extent of ecosystems using the term “ecotope.”

Central to the ecosystem concept is the idea that living organisms interact with every other element in their local environment. Eugene Odum, a founder of ecology, stated: “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.” The human ecosystem concept is then grounded in the deconstruction of the human/nature dichotomy and the premise that all species are ecologically integrated with each other, as well as with the abiotic constituents of their biotope.