AskDefine | Define biosphere

Dictionary Definition

biosphere n : the regions of the surface and atmosphere of the Earth (or other planet) where living organisms exist

User Contributed Dictionary

English

Noun

  1. the part of the earth and its atmosphere capable of supporting life
  2. the totality of living organisms and their environment

Translations

Related terms

Extensive Definition

The biosphere is the part of the Earth, including air, land, surface rocks, and water, within which life occurs, and which biotic processes in turn alter or transform. From the broadest biophysiological 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, hydrosphere, and atmosphere. This biosphere is postulated to have evolved, beginning through a process of biogenesis or biopoesis, at least some 3.5 billion years ago.
Biomass accounts for about 3.7 kg carbon per square meter of the earth's surface averaged over land and sea, making a total of about 1900 gigatonnes of carbon.

Origin and use of the term

The term "biosphere" was coined by geologist Eduard Suess in 1875, which he defined as:
The place on earth's surface where life dwells.
While this concept has a geological origin, it is an indication of the impact of both Darwin and Maury 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. It is an interdisciplinary concept for integrating astronomy, geophysics, meteorology, biogeography, evolution, geology, geochemistry, hydrology and, generally speaking, all life and earth sciences.

Narrow definition

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 narrow 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. Others may include the creation of artificial non-Earth biospheres — for example, human-centered biospheres or a native Martian biosphere — in the field of biospherics.

Gaia's biosphere

The concept that the biosphere is itself a living organism, either actually or metaphorically, is known as the Gaia hypothesis.
James Lovelock, an atmospheric scientist from the United Kingdom, proposed the Gaia hypothesis to explain how biotic and abiotic factors interact in the biosphere. This hypothesis considers Earth itself a kind of living organism. Its atmosphere, geosphere, and hydrosphere are cooperating systems that yield a biosphere full of life. in the early 1970s, Lynn Margulis, a microbiologist from the United States, added to the hypothesis specifically noting the ties between the biosphere and other Earth systems. For example, when carbon dioxide levels increase in the atmosphere, plants grow more quickly. As their growth continue, they remove more and more carbon dioxide from the atmosphere.
Many scientists are now devoting their careers to organizing new fields of study, such as geobiology and geomicrobiology, to examine these intriguing relationships .

Extent of Earth's biosphere

Nearly every part of the planet, from the polar ice caps to the Equator, supports life of some kind. 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 actual thickness of the biosphere on earth is hard to measure. Birds typically fly at altitudes of 650 to 2000 meters, and fish that live deep underwater can be found down to -8,372 meters in the Puerto Rico Trench.
There are more extreme examples for life on the planet: Rüppell's Vulture has been found at altitudes of 11,300 meters; Bar-headed Geese migrate at altitudes of at least 8,300 meters (over Mount Everest); Yaks live at elevations between 3,200 to 5,400 meters above sea level; mountain goats live up to 3,050 meters. Herbivorous animals at these elevations depend on lichens, grasses, and herbs but the biggest tree is the Tine palm or mountain coconut found 3,400 meters above sea level.
Microscopic organisms live at such extremes that, taking them into consideration puts the thickness of the biosphere much greater, but at minimum it extends from 5,400 meters above sea level to at least 9,000 meters below sea level.
Our 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 populous 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.

Specific biospheres

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.
  • BIOS-3 was a closed ecosystem at the Institute of Biophysics in Krasnoyarsk, Siberia, in what was then the Soviet Union.
  • Biosphere J - An experiment in Japan.

Hyperbaric biosphere

In 1999, Carl Baugh patented a small "hyperbaric biosphere" chamber, designed to emulate the conditions thought by him to exist on the early earth, providing double atmospheric pressure, enhanced oxygen, and protection from ultraviolet radiation, while magnetic coils attempt to make up for earth's reduced magnetic field; a much larger hyperbaric biosphere is currently under construction in the same location.

See also

References

External links

  • GLOBIO.info, an ongoing programme to map the past, current and future impacts of human activities on the biosphere
  • Paul Crutzen Interview Freeview video of Paul Crutzen Nobel Laureate for his work on decomposition of ozone talking to Harry Kroto Nobel Laureate by the Vega Science Trust.
biosphere in Afrikaans: Biosfeer
biosphere in Arabic: الغلاف الحيوي
biosphere in Bengali: জীবমণ্ডল
biosphere in Banyumasan: Biosfer
biosphere in Bosnian: Biosfera
biosphere in Breton: Biosferenn
biosphere in Bulgarian: Биосфера
biosphere in Catalan: Biosfera
biosphere in Czech: Biosféra
biosphere in Danish: Biosfære
biosphere in German: Biosphäre
biosphere in Estonian: Biosfäär
biosphere in Modern Greek (1453-): Βιόσφαιρα
biosphere in Spanish: Biosfera
biosphere in French: Biosphère
biosphere in Galician: Biosfera
biosphere in Hindi: जैवमण्डल
biosphere in Indonesian: Biosfer
biosphere in Italian: Biosfera
biosphere in Hebrew: אקולוגיה#.D7.94.D7.91.D7.99.D7.95.D7.A1.D7.A4.D7.A8.D7.94
biosphere in Javanese: Biosfer
biosphere in Lithuanian: Biosfera
biosphere in Hungarian: Bioszféra
biosphere in Macedonian: Биосфера
biosphere in Dutch: Biosfeer
biosphere in Japanese: 生物圏
biosphere in Norwegian: Biosfære
biosphere in Occitan (post 1500): Biosfèra
biosphere in Polish: Biosfera
biosphere in Portuguese: Biosfera
biosphere in Romanian: Biosferă
biosphere in Quechua: Kawsay pacha
biosphere in Russian: Биосфера
biosphere in Simple English: Biosphere
biosphere in Slovak: Biosféra
biosphere in Slovenian: Biosfera
biosphere in Serbian: Биосфера
biosphere in Finnish: Biosfääri
biosphere in Swedish: Biosfär
biosphere in Vietnamese: Sinh quyển
biosphere in Ukrainian: Біосфера
biosphere in Chinese: 生物圈

Synonyms, Antonyms and Related Words

Earth, Gaea, Ge, Tellus, Terra, aerosphere, all that lives, atmosphere, biochore, biocycle, biota, biotope, brawn, ecosphere, fiber, flesh, flora and fauna, gaseous envelope, geography, geosphere, globe, lift, living matter, living nature, mother earth, noosphere, organic matter, organic nature, organized matter, plasm, terra, terrestrial globe, the blue planet, this pendent world, tissue, vale, vale of tears, welkin, whole wide world, world
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