Ecosystem
The term ecosystem was first used in 1935 in a publication by British ecologist Arthur Tansley. Tansley devised the concept to draw attention to the importance of transfers of materials between organisms and their environment. He 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.
Arthur Tansley
William S. Cooper considered Tansley's most influential publications synthesised individual studies into a whole. In 1935 Tansley published "The use and abuse of vegetational terms and concepts" in which he introduced the ecosystem concept. In the 1930s ecological thinking was dominated by the work of Clements, who thought of ecological communities as organisms, and associations as superorganisms. Tansley devised the concept to draw attention to the importance of transfers of materials between organisms and their environment, regarding ecosystems as the basic units of nature.
Tansley's interest in teaching led to the production of the "Elements of Plant Ecology" in 1922, which was followed by "Practical Plant Ecology" in 1923 and "Aims and methods in the study of vegetation" in 1926, coauthored with Thomas Ford Chipp. The last book, edited for the British Empire Vegetation Committee, was extremely influential not just in defining ecological methods but in highlighting the need for a complete inventory of the empire's "vegetational assets". With this information, it would be possible to efficiently manage the vast natural resources of the empire. Tansley's most comprehensive work, "The British Islands and Their Vegetation" was published in 1939. In recognition of this achievement, he was awarded the Linnean Medal in 1941.