Abstract
The notion of entorno is discussed and its mutual dependence upon the organism is emphasised. Both the etymology and meaning of ethos, oikos, entorno and ecotomo are discussed. The intimate relation between Ethology and Ecology is also shown. A reference background is given to explain how the commonly considered isolated components organism/society and entorno/nature articulate in the form of a relation. It is argued that the integrated concepts that originated the notion of ecosystem have been set aside. The term ecotomo is proposed, which refers to any territorial unit that, considered at a local, regional or global level, emerges from the society-nature relationship.