View source for Antarctic realm

{{Short description|One of Earth's eight biogeographic realms}}
{{See also|Antarctic microorganism|Wildlife of Antarctica}}
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[[Image:LocationAntarctica.png|thumb|320px|The Antarctic realm (in green)]]

The '''Antarctic realm''' is one of eight terrestrial [[biogeographic realm]]s. The ecosystem includes [[Antarctica]] and several island groups in the southern [[Atlantic Ocean|Atlantic]] and [[Indian Ocean|Indian]] oceans. The continent of Antarctica is so cold that it has supported only 2 vascular plants for millions of years, and its flora presently consists of around 250 [[lichen]]s, 100 [[moss]]es, 25–30 [[Marchantiophyta|liverworts]], and around 700 terrestrial and aquatic [[alga]]l species, which live on the areas of exposed rock and soil around the shore of the continent. Antarctica's two flowering plant species, the Antarctic hair grass (''[[Deschampsia antarctica]]'') and Antarctic pearlwort (''[[Colobanthus quitensis]]''), are found on the northern and western parts of the [[Antarctic Peninsula]]. Antarctica is also home to a diversity of animal life, including [[penguin]]s, [[pinniped|seals]], and [[whale]]s.

Several Antarctic and sub-Antarctic island groups are considered part of the Antarctic realm, including [[Bouvet Island]], the [[Crozet Islands]], [[Heard Island and McDonald Islands#Geography|Heard Island]], the [[Kerguelen Islands]], the [[McDonald Islands (Australia)|McDonald Islands]], the [[Prince Edward Islands]], the [[South Georgia and the South Sandwich Islands#South Georgia Group|South Georgia Group]], the [[South Orkney Islands]], the [[South Georgia and the South Sandwich Islands#South Sandwich Islands|South Sandwich Islands]], and the [[South Shetland Islands]]. These islands have a somewhat milder climate than Antarctica proper, and support a greater diversity of [[tundra]] plants, although they are all too windy and cold to support trees.

[[Antarctic krill]] is the [[keystone species]] of the ecosystem of the [[Southern Ocean]], and is an important food organism for [[whale]]s, [[seal (mammal)|seals]], [[leopard seal]]s, [[fur seal]]s, [[crabeater seal]]s, [[squid]], [[Notothenioidei|icefish]], [[penguin]]s, [[albatross]]es and many other [[bird]]s. The ocean there is so full of [[phytoplankton]] because water rises from the depths to the light-flooded surface, bringing [[nutrient]]s from all oceans back to the [[photic zone]].

On August 20, 2014, scientists confirmed the existence of [[microorganism]]s living {{convert|800|m|ft|abbr=off}} below the ice of [[Antarctica]].<ref name="NAT-20140820">{{cite journal |last=Fox |first=Douglas |title=Lakes under the ice: Antarctica's secret garden |date=August 20, 2014 |journal=[[Nature (journal)|Nature]] |volume=512 |issue=7514 |pages=244–246 |doi=10.1038/512244a |bibcode=2014Natur.512..244F |pmid=25143097|doi-access=free }}</ref><ref name="FRB-20140820">{{cite web |last=Mack |first=Eric |title=Life Confirmed Under Antarctic Ice; Is Space Next? |url=https://www.forbes.com/sites/ericmack/2014/08/20/life-confirmed-under-antarctic-ice-is-space-next/ |date=August 20, 2014 |work=[[Forbes]] |access-date=August 21, 2014 }}</ref>

== History ==
Millions of years ago, Antarctica was warmer and wetter, and supported the [[Antarctic flora]], including forests of [[Podocarpaceae|podocarps]] and [[southern beech]]. Antarctica was also part of the ancient supercontinent of [[Gondwana]]land, which gradually broke up by [[continental drift]] starting 110 million years ago. The separation of [[South America]] from Antarctica 30–35 million years ago allowed the [[Antarctic Circumpolar Current]] to form, which isolated Antarctica climatically and caused it to become much colder. The Antarctic flora subsequently died out in Antarctica, but is still an important component of the flora of southern [[Neotropical realm|Neotropical]] ([[Latin America and the Caribbean]]) and [[Australasian realm]]s, which were also former parts of Gondwana.

Some botanists recognize an [[Antarctic Floristic Kingdom]] that includes Antarctica, [[New Zealand]], and parts of Temperate South America where the Antarctic Flora is still a major component.

== Ecoregions ==
The Antarctic realm is divided into 17 [[tundra]] [[ecoregion]]s:<ref>Eric Dinerstein, David Olson et al. (2017). An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 2017, Pages 534–545, https://doi.org/10.1093/biosci/bix014</ref>

{{Antarctica tundra}}

== References ==
{{reflist}}

==Bibliography==
{{Wikivoyage|Wildlife of the Southern Ocean}}
* {{cite journal | last1 = Terauds | first1 = A | last2 = Chown | first2 = SL | last3 = Morgan | first3 = F | last4 = Peat | first4 = HJ | last5 = Watts | first5 = D | display-authors = et al | year = 2012 | title = Conservation biogeography of the Antarctic | journal = Diversity and Distributions | volume = 18 | issue = 7| pages = 726–741 | doi = 10.1111/j.1472-4642.2012.00925.x | doi-access = free | hdl = 10019.1/120035 | hdl-access = free }}
* [[Life in the Freezer]], a [[BBC]] [[television]] series on life on and around Antarctica
* [https://web.archive.org/web/20060208123258/http://www.planetavivo.org/english/ResearchPrograms/Antarctica/SlideShows/ArdleyIsland/ArdleyIsland1.html Biodiversity at Ardley Island, South Shetland archipelago, Antarctica]
* [http://www.foraminifera.eu/weddell.html Deep Sea Foraminifera] – Deep Sea Foraminifera from 4400m depth, Weddell Sea – an image gallery of hundreds of specimens and description
* [http://www.sciencenews.org/view/feature/id/340017/title/Aliens_in_Antarctica Aliens in Antarctica; Visitors carry unwelcome species into a once pristine environment] {{Webarchive|url=https://web.archive.org/web/20120510181813/http://www.sciencenews.org/view/feature/id/340017/title/Aliens_in_Antarctica |date=2012-05-10 }} May 5, 2012 ''[[Science News]]''

{{Antarctica|state=uncollapsed}}
{{Biomes}}

[[Category:Antarctic realm| ]]
[[Category:Biogeographic realms]]
[[Category:Biogeography]]
[[Category:Phytogeography]]