Eugene Odum and the Homeostatic Ecosystem

Although the ecosystem is an important ecological concept, it has been highly contested. The idea originated from a dispute over the nature of biological communities. ¹ During the early twentieth century, the prominent American ecologist Frederic Clements claimed that plant communities could be thought of as “complex organisms” that underwent a predictable pattern of development (ecological succession) leading to a mature, climax community in harmony with its physical environment. The idea that communities of living organisms are themselves organisms was controversial, and in 1935 the British ecologist Arthur Tansley proposed the ecosystem as a more philosophically acceptable concept. ² Inspired by developments in the physical sciences, as well as his deep interests in philosophy and Freudian psychology, Tansley claimed that biotic communities and abiotic environments formed interacting systems. ³ Because these systems overlap and are always parts of more encompassing systems, Tansley argued that ecosystems were mental constructs. Nonetheless, in many cases ecosystems corresponded closely to a physical reality. For example, ponds or lakes often have well-defined boundaries that partially separate them from surrounding areas. But even in cases where boundaries are less distinct (e.g. a forest intergrading into grassland) the ecologist could mentally construct a system of interacting physical and biological components, at least some of whose properties could be measured. After World War II, ecosystem ecology flourished as an important area of research. With the rise of environmental movements in the 1960s and ‘70s, the ecosystem concept also entered popular culture. ⁴