- Eugene Odum, often considered the father of modern ecology, particularly ecosystem ecology, emphasized the study of structure and function of ecosystems. - His definition of ecology as "the study of the structure and function of nature" appeared in his seminal work "Fundamentals of Ecology", first published in 1953, with later editions in 1959 and 1971. The phrasing "structure and function of ecosystem" is closely associated with his ecosystem-centric approach. - While other ecologists like Krebs have made significant contributions and written textbooks, Odum is most strongly linked to this specific definition and the development of the ecosystem concept.