Ecosystem – Environment of life Ecosystem Introduction: Ecology is the branch of biology that deals with the interactions among organisms in an environment. The term ‘ecology’ was first introduced by German zoologist Ernst Haeckel (1869). Eugene P. Odum is considered to be the father of modern ecology. Ecology has certain types, which are as follows: Individual ecology - Study of the life history of an individual (i.e., species) & its response to its environment. Population ecology - Study of the abundance, distribution, & dynamics of a group of individuals of the same species. Community ecology / synecology - Study of the interactions between species in communities on many spatial and temporal scales, including the distribution, structure, abundance, demography, and interactions between coexisting populations . Ecosystem ecology - Study of interactions among organisms and their physical environment as an integrated system. In ecology, the term ecosystem refers to the environment of life. Ecosystems are specific areas of environment that develop as a result of interaction between the earth’s four spheres.  Lithosphere - the rigid outer part of the earth, consisting of the crust and upper mantle.  Hydrosphere - discontinuous layer of water at or near Earth’s surface.  Atmosphere - is a layer or a set of layers of gases surrounding a planet or other material body that is held in place by the gravity of that body.  Biosphere - also known as the ecosphere. It is the worldwide sum of all ecosystems. The ecosystem first appeared in publication by the British ecologist Arthur Tansleyin 1935 although the concept of such an ecological system is found in the writings of Karl Mobius in 1877, wherein he has mentioned the term biocoenosis. In America S.A Forbes in 1877 used the word microcosms a synonym to biocoenosis. The Russian ecologists have used the term biocoenosis and geo-biocoenosis meaning the same as ecosystem. Ecosystem is a self-sustaining, structural and functional unit of biosphere. The biotic and abiotic components in a habitat constitute an interacting environmental system in which inorganic constituents are synthesized into organic structure and through energy exchange processes life of various forms exists in the system. 1