Like the word ecology, ecosystem was applied to a concept with a long history. It also had a number of competing synonyms when it was coined, suggesting that the time was ripe for its appearance, and there was a lag period between its coinage and its widespread incorporation into ecological science. The British plant ecologist Tansley (1935) introduced ecosystem in the context of a discussion of the superorganism concept of the plant community and succession which was developed around 1905 by F. E. Clements and was still being strongly advocated in the 1930s by the South African botanist John Phillips. Tansley commented that Phillips's articles “remind one irresistably of the exposition of a creed – of a closed system of religious or philosophical dogma,” a flavor not entirely missing from some later expositions of “systems ecology,” facetiously called “theological ecology” (Van Dyne 1980).

Godwin (1977) noted that Tansley, like many biologists of his era, was “remarkably unspecialized” and a man “of wide culture and familiarity with many sciences,” just what the ecosystem concept called for. Tansley was also well read in philosophy and psychology, having studied with Freud, which, perhaps, influenced his ecological thought. He defined ecosystem as