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.
Ecological systems theory
Ecological systems theory, also called development in context or human ecology theory, identifies five environmental systems with which an individual interacts. The theory offers a framework through which community psychologists examine individuals' relationships within communities and the wider society. Ecological systems theory was developed by Urie Bronfenbrenner. The theory is also commonly referred to as the ecological/systems framework.The person's own biology may be considered part of the microsystem; thus the theory has recently sometimes been called Bioecological model.