BIOSPHERE

In its broadest sense, the entire planetary ecosystem including all living organisms and those parts of the earth and its atmosphere in which living organisms exist or that are capable of supporting life, to include, in addition to the plant and animal species: (1) Atmosphere: the gaseous layer covering the earth; (2) Lithosphere: the solid portion of the earth's crust and mantle; (3) Hydrosphere: that portion of the earth composed of liquid water; and Also referred to as the Ecosphere. In a more restrictive sense, may also refer to only the living organisms on earth and not to their physical and chemical environments.