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Encyclopedia > Oligotrophic

Oligotrophic refers to any environment that offers little to sustain life. This term is usually used to describe bodies of water or soils with very low nutrient levels. For other uses, see Life (disambiguation). ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... Loess field in Germany Surface-water-gley developed in glacial till, Northern Ireland Technically, soil forms the pedosphere: the interface between the lithosphere (rocky part of the planet) and the biosphere, atmosphere, and hydrosphere. ... A nutrient is either a chemical element or compound used in an organisms metabolism or physiology. ...


Greek etymology: Oligo : small, little, few; and trophe: nutrients, food. Not to be confused with Entomology, the study of insects. ...


Oligotrophic environments are of special interest for the alternative energy sources and survival strategies life could rely upon.

Contents

Examples of oligotrophic environments

An example of such a lake is Lake Vostok, a liquid freshwater lake which has been isolated from the world beneath 4 km of Antarctic ice for approximately 500,000 years.[1] Lake Vostoks location within Antarctica (NASA) Lake Vostok is the largest of more than 70 subglacial lakes in Antarctica. ... Greek ἀνταρκτικός, opposite the arctic) is a continent surrounding the Earths South Pole. ...


An example of oligotrophic soils are those on white-sands, with soil pH lower than 5.0, on the Rio Negro basin on northern Amazonia that house very low-diversity, extremely fragile forests and savannahs drained by blackwater rivers. These owe this colour to the high concentration of tannins, humic acids and other organic compounds derived from the very slow decomposition of plant matter.[2] Similar forests are found in the oligotrophic waters of the Patía River delta on the Pacific side of the Andes.[3] This does not adequately cite its references or sources. ... The Negro (Spanish: black) River, the great northern tributary of the Amazon River and the largest blackwater river in the world, has its sources along the watershed between the Orinoco and the Amazon basins, and also connects with the Orinoco by way of the Casiquiare canal. ... // “Amazonian” redirects here. ... Blackwater rivers are rivers with waters colored like black tea to coffee. ... Tannins are astringent, bitter-tasting plant polyphenols that bind and precipitate proteins. ... Humic acid is one of the major components of humic substances which are dark brown and major constituents of soil organic matter humus that contributes to soil chemical and physical quality and are also precursors of some fossil fuels. ...


Other oligotrophic environments include the sandplains and lateritic soils of southern Western Australia, where an extremely thick craton has precluded any geological activity since the Cambrian and there has been no glaciation to renew soils since the Carboniferous. Thus, soils are extremely nutrient-poor and most vegetation must use stregies such as proteoid roots to gain even the smallest quantities of such nutrients as phosphorus and sulfur. Cutting of laterite brickstones, Angadipuram, India Laterite is a surface formation in tropical areas which is enriched in iron and aluminium and develops by intensive and long lasting weathering of the underlying parent rock. ... Capital Perth Government Constitutional monarchy Governor Ken Michael Premier Alan Carpenter (ALP) Federal representation  - House seats 15  - Senate seats 12 Gross State Product (2004-05)  - Product ($m)  $100,900 (4th)  - Product per capita  $50,355/person (3rd) Population (December 2006)  - Population  2,050,900 (4th)  - Density  0. ... World geologic provinces. ... The Cambrian is a major division of the geologic timescale that begins about 542 ± 1. ... A glaciation (a created composite term meaning Glacial Period, referring to the Period or Era of, as well as the process of High Glacial Activity), often called an ice age, is a geological phenomenon in which massive ice sheets form in the Arctic and Antarctic and advance toward the equator. ... The Carboniferous is a major division of the geologic timescale that extends from the end of the Devonian period, about 359. ... Proteoid roots of Leucospermum cordifolium Proteoid roots, also known as cluster roots, are plant roots that form clusters of closely spaced short lateral rootlets. ... General Name, Symbol, Number phosphorus, P, 15 Chemical series nonmetals Group, Period, Block 15, 3, p Appearance waxy white/ red/ black/ colorless Standard atomic weight 30. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Standard atomic weight 32. ...


The vegetation in these regions, however, is remarkable for its biodiversity, which in places is as great as that of a tropical rainforest and produces some of the most spectacular wildflowers in the world. It is however, severely threatened by climate change which has moved the winter rain belt south, and also by clearing for agriculture through use of fertilisers, which is highly economic due to low land costs. Rainforests are among the most biodiverse ecosystems on earth Biodiversity is the variation of taxonomic life forms within a given ecosystem, biome or for the entire Earth. ... Amazon river rain forest in Brazil Tropical rainforests are rainforests generally found near the equator. ... Variations in CO2, temperature and dust from the Vostok ice core over the last 400,000 years For current global climate change, see Global warming. ... Fertilizers are chemicals given to plants with the intention of promoting growth; they are usually applied either via the soil or by foliar spraying. ...


References

  1. ^ Priscu, JP, Adams, EE, Pearl, HW, Fritsen, CH, Dore, JE, Lisle, JT, Wolf, CF, Mikucki, JA. (2002) "Perennial Antarctic Lake Ice: A refuge for Cyanobacteria in an extreme environment" In Life in Ancient Ice (eds. Rogers, S and J Castello), Princeton Press;
  2. ^ German, Laura A. (December 2004) "Ecological praxis and blackwater ecosystems: a case study from the Brazilian Amazon" Human Ecology: An Interdisciplinary Journal 32(6): pp. 653-683;
  3. ^ Del Valle-Arango, Jorge Ignacio (August 2003) "Cantidad, calidad y nutrientes reciclados por la hojarasca fina en bosques pantanosos del Pacífico sur colombiano." Interciencia 28(8): pp. 443-452 (in Spanish);

See also

An oligotroph is an organisn that can live in a very low carbon concentration, one part per million! ...

External Links

  • Special Issue about Lake oligotrophication published in Freshwater Biology

  Results from FactBites:
 
Oligotroph at AllExperts (184 words)
An oligotroph is an organism that can live in a very low carbon concentration, less than one part per million.
Oligotrophs are characterized by slow growth, low rates of metabolism, and generally low population density.
Low-carbon environments are ubiquitous; oligotrophs may be found a wide range of environments including in deep oceanic sediments, caves, glacial and polar ice, deep subsurface soil, aquifers, and ocean water.
Oligotrophic Summary (304 words)
The term oligotrophic is derived from the Greek term meaning "poorly nourished" and refers to an aquatic system that has low overall levels of primary production, principally because of low concentrations of the nutrients that plants require.
Oligotrophic environments are of special interest for the alternative energy sources and survival strategies life could rely upon.
An example of oligotrophic soils are those on white-sands, with soil pH lower than 5.0, on the Rio Negro basin on northern Amazonia that house very low-diversity, extremely fragile forests and savannahs drained by flwater rivers.
  More results at FactBites »

 
 

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