The term was coined by the geologist Eduard Suess in 1875. The concept of biosphere is thus from geological origin and is an indication of the impact of Darwin on Earth sciences. The ecological concept of the biosphere comes from the 1920s (see Vladimir I. Vernadsky), preceding the 1935 introduction of the term ecosystem by Arthur Transley. The biosphere is an important concept in astronomy, geophysics, meteorology, biogeography, evolution, geology, geochemistry, and generally speaking all life and earth sciences.
Biosphere is often used with more restricted meanings. For example, geochemists also give define the biosphere as being the total sum of living organisms (usually named biomass or biota by biologists and ecologists). In this sense, the biosphere is one of the four components of the geochemical model, the others being the lithosphere, hydrosphere, and atmosphere).
Some consider that the semantic and conceptual confusion surrounding the term biosphere is reflected in the current debates related to biodiversity, or sustainable development. The meaning used by geochemists is one of the consequences of the specialization of modern science.
Many appear to prefer the word ecosphere, coined in the 1960s-'70s. Others, however, claim this word is sullied by association with the idea of ecological crisis.
Vernadsky defined ecology (originally intended as the "economy of nature") as the science of the biosphere.
The Second International Conference on Closed Life Systems defined biospherics as the science and technology of analogs and models of Earth's biosphere, ie. 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.
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2 Earth's Biosphere 3 See Also |
When the word Biosphere is followed by a number, it is usually referring to a specific biosystem.
Biosphere 1, Biosphere 2, Biosphere 3
See also: biome, cryosphere, Biosphere Reserve, noosphere, geosphere, eco-evolution, homeostasis, life support (environment)
Earth's Biosphere
Earth is the only place where life is proven to exist. The planet's lifeforms are sometimes said to form a "biosphere". This biosphere is generally believed to have evolved ~3.5B years ago.The 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.
Some theorists therefore believe that the Earth is poorly suited to life. However, every part of the planet supports life, from the polar ice caps to the Equator. Recent advances in microbiology have proven that microscopic life lives inside rocks under the Earth's surface, and that the total mass of microbial life in so-called "uninhabitable zones" may, in terms of sheer biomass, outweigh all animal and plant life combined on the surface of the Earth.
Oceans mediate the cold and distribute nutrients. The Antarctic krill, Euphausia superba, for example, is generally considered to be the most successful animal of the planet, with a biomass probably over 500 million tonnes (c.f. human biomass of about 250 million tonnes).