2. The realm or sphere or life in which the total biological process takes place.
The earth's surface and the top layer of the hydrosphere (water layer) have the greatest density of living organisms.
The geosphere, or nonliving world, is made up of the lithosphere (solid earth or stone), hydrosphere, and atmosphere.3. In Arizona, USA, an enclosed, supposedly self-contained experimental eco-system designed to provide environmental insights.
The initial two-year test, started in 1991, was called "Biosphere 1"; the second one was called "Biosphere 2", and was started in 1994.
Ranging from submicroscopic viruses to giant sequoia trees, this horde of organisms has adapted to almost every kind of environment, from hot springs to glacial ice.
Such habitats involve the interactions of plants and animals with various parts of the earth and are involved in many important earth processes.
Coal and petroleum have been formed from the remains of prehistoric organisms.
Bacteria played an essential role in the development of certain types of iron ore.
Finally, the study of fossils has provided a great deal of information about earth's history and the development of life.
Also see "The Development and Explanations of Life and Its Characteristics for additional information related to this subject.
Under a sealed glass and metal dome, different habitats were recreated, with representatives of nearly 4,000 species, to test the effects that various environmental factors have on ecosystems.
Simulated ecosystems, or "mesocosms", include savanna, desert, rain forest, marsh, and Caribbean reef.
The response of such systems to elevated atmospheric concentrations of carbon dioxide gas are among the priorities of Biosphere 2 researchers.
As of June 5, 2007, the property of Biosphere 2, including surrounding land, totaling 1,650 acres (6.7 km2), sold to a residential home developer for US $50 million.
A development including homes and a resort hotel was planned for a portion of the land. The Biosphere itself remains open for tours.
On June 26, 2007, the University of Arizona announced it would take over research at Biosphere 2. The announcement ended immediate fears that the famous glass vivarium would be demolished.
University officials said private gifts and grants enabled them to cover research and operating costs for three years with the possibility of extending that funding for 10 years.