Biosphere
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The biosphere is that part of a planet earth's outer shell—including air, land, and water—within which life occurs, and which biotic processes in turn alter or transform. From the broadest geophysiological point of view, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere (rocks), hydrosphere (water), and atmosphere (air). Earth is the only place where life is known to exist. This biosphere is generally believed to have evolved beginning at least some 3.5 billion years ago.
The term "biosphere" was coined by geologist Eduard Suess in 1875. The concept thus has a geological origin and is an indication of the impact of Darwin on the earth sciences. The biosphere's ecological context comes from the 1920s (see Vladimir I. Vernadsky), preceding the 1935 introduction of the term "ecosystem" by Sir Arthur Tansley (see ecology history). Vernadsky defined ecology as the science of the biosphere. The biosphere is an important concept in astronomy, geophysics, meteorology, biogeography, evolution, geology, geochemistry, and, generally speaking, all life and earth sciences.
Some life scientists and earth scientists use biosphere in a more limited sense. For example, geochemists define the biosphere as being the total sum of living organisms (the "biomass" or "biota" as referred to by biologists and ecologists). In this sense, the biosphere is but one of four separate components of the geochemical model, the other three being lithosphere, hydrosphere, and atmosphere. The meaning used by geochemists is one of the consequences of specialization in modern science. Some might prefer the word ecosphere, coined in the 1960s, as all encompassing of both biological and physical components of the planet.
The Second International Conference on Closed Life Systems defined biospherics as the science and technology of analogs and models of Earth's biosphere; i.e., artificial Earth-like biospheres. Some also include the creation of artificial non-Earth biospheres—for example, human-centered biospheres or a native Martian biosphere—in the field of biospherics.
Some theorists have postulated that the Earth is poorly suited to life, although nearly every part of the planet, from the polar ice caps to the Equator, supports life of some kind. Indeed, recent advances in microbiology have demonstrated that microbes live deep beneath the Earth's terrestrial surface, and that the total mass of microbial life in so-called "uninhabitable zones" may, in biomass, exceed all animal and plant life on the surface.
The concept that the biosphere is itself a living organism, either actually or metaphorically, is known as Gaia theory.
Biosphere 1, Biosphere 2, Biosphere 3
When the word Biosphere is followed by a number, it is usually referring to a specific system. Thus:
- Biosphere 1 - The planet Earth.
- Biosphere 2 - A laboratory in Arizona which contains 3.15 acres (13,000 m²) of closed ecosystem.
- Biosphere 3 - Experiment conducted by Russians in 1967-8. [1] (http://www.permanent.com/s-bios3.htm)[2] (http://www.biospherics.org/russia.html)[3] (http://www.biospheres.com/hisbios3fax.html)
--- See also: biome, cryosphere, Biosphere Reserve, noosphere, geosphere, eco-evolution, homeostasis, life support system
Biosphere 1
biosphere is divided into a number of biomes, inhabited by broadly similar flora and fauna. On land, biomes are separated primarily by latitude. Terrestrial biomes lying within the Arctic and Antarctic Circles are relatively barren of plant and animal life, while most of the more populus biomes lie near the Equator. Terrestrial organisms in temperate and arctic biomes have relatively small amounts of total biomass, smaller energy budgets, and display prominent adaptations to cold, including world-spanning migrations, social adaptations, homeothermy, estivation and multiple layers of insulation.
For important major components of Earth's biosphere, see: Ocean; Forest; Desert; Steppe; Lake; River.ca:Biosfera de:Biosphäre es:Biosfera fr:Biosphère id:Biosfer ja:生物圏 nl:Biosfeer pl:Biosfera pt:Biosfera ro:Biosferă ru:Биосфера sv:Biosfär