View source for Earth:Tundra

In [[Earth:Physical geography|physical geography]], a '''tundra''' ({{IPAc-en|ˈ|t|ʌ|n|d|r|ə|,_|ˈ|t|ʊ|n|-}}) is a type of [[Biology:Biome|biome]] where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: Arctic,<ref name="berkeley">{{cite web |title=The Tundra Biome |url=http://www.ucmp.berkeley.edu/glossary/gloss5/biome/tundra.html |access-date=5 March 2006 |work=The World's Biomes |publisher=[[Organization:University of California, Berkeley|University of California, Berkeley]]|archive-url=https://web.archive.org/web/20230722054716/https://ucmp.berkeley.edu/exhibits/biomes/tundra.php |archive-date=22 July 2023}}</ref> [[Earth:Alpine tundra|Alpine]],<ref name="berkeley" /> and Antarctic.<ref name="wwf">{{cite web |title=Terrestrial Ecoregions: Antarctica |url=http://www.nationalgeographic.com/wildworld/profiles/terrestrial_an.html |url-status=dead |archive-url=https://web.archive.org/web/20110805095438/http://www.nationalgeographic.com/wildworld/profiles/terrestrial_an.html |archive-date=5 August 2011 |access-date=2 November 2009 |work=Wild World |publisher=[[Organization:National Geographic Society|National Geographic Society]]}}</ref>

Tundra vegetation is composed of dwarf [[Biology:Shrub|shrub]]s, [[Biology:Cyperaceae|sedges]], [[Biology:Poaceae|grasses]], [[Biology:Moss|moss]]es, and [[Biology:Lichen|lichen]]s. Scattered trees grow in some tundra regions. The [[Earth:Ecotone|ecotone]] (or ecological boundary region) between the tundra and the forest is known as the [[Earth:Tree line|tree line]] or timberline. The tundra soil is rich in [[Chemistry:Nitrogen|nitrogen]] and [[Chemistry:Phosphorus|phosphorus]].<ref name="berkeley" /> The soil also contains large amounts of biomass and decomposed biomass that has been stored as [[Chemistry:Methane|methane]] and [[Chemistry:Carbon dioxide|carbon dioxide]] in the [[Earth:Permafrost|permafrost]], making the tundra soil a [[Physics:Carbon sink|carbon sink]]. As global warming heats the ecosystem and causes soil thawing, the [[Earth:Permafrost carbon cycle|permafrost carbon cycle]] accelerates and releases much of these soil-contained greenhouse gases into the atmosphere, creating [[Earth:Climate change feedbacks|a feedback cycle]] that contributes to [[Earth:Climate change|climate change]].

== Etymology ==
The word comes from the Russian "ту́ндра" (''tundra''). The first use of tundra in English was in 1824, spelled "toundra", possibly indicating borrowing from French.<ref name=wwwords>{{cite web|url=https://www.worldwidewords.org/qa-tun1.html|title=Tundra|publisher=World Wide Words|date=29 Oct 2011|first=Michael|last=Quinion}}</ref> The origin of the Russian word is uncertain: it may be a borrowing of the word "тундар" (''tundar'') the [[Social:Sámi languages|Sámi language family]] word for "[[Earth:Fell|fell]]", "elevated wasteland" or "marshy plain", from the 16th century.<ref name=wwwords/><ref>{{cite OED|Tundra|2408626084}}</ref><ref>{{cite web|url=https://www.etymonline.com/word/tundra|title=Tundra|work=Etymology}}</ref>
Some sources attribute the origin to Finnish<ref name="wwwords" /><ref name="NASA" />.

== Arctic == <!-- This section is linked from [[Biology:Reindeer|Reindeer]] -->
{{anchor|Arctic tundra}}
Arctic tundra occurs in the far [[Earth:Northern Hemisphere|Northern Hemisphere]] ([[Company:Arctic|Arctic]]), north of the taiga belt. The word "tundra" usually refers only to the areas where the subsoil is [[Earth:Permafrost|permafrost]], or permanently frozen soil. (It may also refer to the treeless plain in general so that northern [[Place:Sápmi|Sápmi]] would be included.) Permafrost tundra includes vast areas of northern Russia and Canada.<ref name="berkeley"/> The polar tundra is home to several peoples who are mostly nomadic reindeer herders, such as the Nganasan and Nenets in the permafrost area (and the [[Place:Sámi people|Sámi]] in Sápmi).

[[File:Tundra in Siberia.jpg|thumb|Tundra in Siberia]]

Arctic tundra contains areas of stark landscape and is frozen for much of the year.<ref>{{Cite web |title=Tundra Biome |url=https://education.nationalgeographic.org/resource/tundra-biome |access-date=2024-04-04 |publisher=National Geographic}}</ref> The soil there is frozen from {{cvt|25|to|90|cm|0}} down, making it impossible for trees to grow there. Instead, bare and sometimes rocky land can only support certain kinds of Arctic vegetation, low-growing plants such as moss, heath ([[Biology:Ericaceae|Ericaceae]] varieties such as [[Biology:Empetrum nigrum|crowberry]] and [[Biology:Arctous alpina|black bearberry]]), and [[Biology:Lichen|lichen]].<ref name=NASA/><ref name=":0" />

There are two main seasons, winter and summer, in the polar tundra areas. During the winter it is very cold, dark, and windy with the average temperature around {{cvt|-28|C}}, sometimes dipping as low as {{cvt|-50|C}}. However, extreme cold temperatures on the tundra generally do not drop as low as those experienced in taiga areas further south (for example, Russia's, Canada's, and Alaska's lowest temperatures were recorded in locations south of the tree line). During the summer, temperatures rise somewhat, and the top layer of seasonally-frozen soil melts, leaving the ground very soggy. The tundra is covered in marshes, lakes, bogs, and streams during the warm months. Generally daytime temperatures during the summer rise to about {{cvt|12|C}} but can often drop to {{cvt|3|C}} or even below freezing. Arctic tundras are sometimes the subject of [[Biology:Habitat conservation|habitat conservation]] programs. In Canada and Russia, many of these areas are protected through a national [[Biology:Biodiversity action plan|biodiversity action plan]].

[[File:Vontut National Park.jpg|thumb|left|[[Vuntut National Park]] in Canada]]
Arctic tundra tends to be windy, with winds often blowing upwards of {{cvt|50|-|100|kph}}. It is also a [[Earth:Polar desert|polar desert]], with only about {{cvt|150|-|250|mm|0}} of precipitation falling per year (the summer is typically the season of maximum precipitation). Although precipitation is light, evaporation is also relatively minimal. During the summer, the permafrost thaws just enough to let plants grow and reproduce, but because the ground below this is frozen, the water cannot sink any lower, so the water forms the lakes and marshes found during the summer months. There is a natural pattern of accumulation of fuel and wildfire which varies depending on the nature of vegetation and terrain. Research in Alaska has shown fire-event return intervals (FRIs) that typically vary from 150 to 200 years, with dryer lowland areas burning more frequently than wetter highland areas.<ref>{{cite journal |first2=Melissa L. |last2=Chipman |first3=Jennifer L. |last3=Barnes |first4=Michael A. |last4=Urban |first5=Feng Sheng |last5=Hu |name-list-style=amp |title=Variability of tundra fire regimes in Arctic Alaska: millennial-scale patterns and ecological implications |journal=Ecological Applications |date=December 2011 |volume=21 |issue=8 |pages=3211–3226 |doi=10.1890/11-0387.1 |issn=1051-0761 |display-authors=4 |last1=Higuera |first1=Philip E.|bibcode=2011EcoAp..21.3211H }}</ref>

[[File:CAKR muskox lazily graze in the Kakagrak Hills. (34900059504).jpg|thumb|A small herd of [[muskox]]en in the Kakagrak Hills, Alaska]]

The [[Biology:Biodiversity|biodiversity]] of tundras is low: 1,700 species of [[Biology:Vascular plant|vascular plant]]s and only 48 species of land mammals can be found, although millions of birds migrate there each year for the marshes.<ref>{{cite web |url=http://www.ibacanada.com/site.jsp?siteID=NU078&seedet=N |title=Great Plain of the Koukdjuak |publisher=Ibacanada.com |access-date=16 February 2011}}</ref> There are also a few fish species. There are few species with large populations. Notable plants in the Arctic tundra include blueberry (''[[Biology:Vaccinium uliginosum|Vaccinium uliginosum]]''), crowberry (''[[Biology:Empetrum nigrum|Empetrum nigrum]]''), reindeer lichen (''[[Biology:Cladonia rangiferina|Cladonia rangiferina]]''), lingonberry (''[[Biology:Vaccinium vitis-idaea|Vaccinium vitis-idaea]]''), and Labrador tea (''[[Biology:Rhododendron groenlandicum|Rhododendron groenlandicum]]'').<ref name=LakeClark/> Notable animals include [[Biology:Reindeer|reindeer]] (caribou), musk ox, [[Biology:Arctic hare|Arctic hare]], [[Biology:Arctic fox|Arctic fox]], snowy owl, [[Biology:Lagopus|ptarmigan]], [[Biology:Northern red-backed vole|northern red-backed vole]]s, [[Biology:Lemming|lemming]]s, the [[Biology:Ochlerotatus|mosquito]],<ref>{{cite web |url=https://www.esa.org/blog/2020/08/04/where-are-arctic-mosquitoes-most-abundant-in-greenland-and-why |publisher=Ecological Society of America |date=4 August 2020 |title=Where Are Arctic Mosquitoes Most Abundant in Greenland and Why?}}</ref> and even [[Biology:Polar bear|polar bear]]s near the ocean.<ref name=LakeClark>{{cite web |title=Tundra |work=Lake Clark National Park & Preserve |publisher=NPS |url=https://www.nps.gov/lacl/learn/nature/tundra.htm |access-date=18 October 2021}}</ref><ref>{{cite web |title=Tundra |work=Blue Planet Biomes |url=http://www.blueplanetbiomes.org/tundra.htm |access-date=5 March 2006}}</ref> The tundra is largely devoid of [[Biology:Poikilotherm|poikilotherm]]s such as frogs or lizards.

Due to the harsh climate of Arctic tundra, regions of this kind have seen little human activity, even though they are sometimes rich in natural resources such as [[Chemistry:Petroleum|petroleum]], [[Chemistry:Natural gas|natural gas]], and [[Chemistry:Uranium|uranium]]. In recent times this has begun to change in [[Earth:Alaska|Alaska]], Russia, and some other parts of the world: for example, the Yamalo-Nenets Autonomous Okrug produces 90% of Russia's natural gas. 

=== Relationship to climate change ===
[[File:Permafrost in Herschel Island 014.jpg|thumb|right|Permafrost thawing can cause slumping in the landscape]]
A severe threat to tundra is [[Earth:Climate change|climate change]], which causes [[Earth:Permafrost|permafrost]] to thaw. The thawing of the permafrost in a given area on human time scales (decades or centuries) could radically change which species can survive there.<ref>{{cite web |title=Tundra Threats |work=National Geographic |url=http://environment.nationalgeographic.com/environment/habitats/tundra-threats.html |archive-url=https://web.archive.org/web/20081207072624/http://environment.nationalgeographic.com/environment/habitats/tundra-threats.html |url-status=dead |archive-date=7 December 2008 |access-date=3 April 2008}}</ref> It also represents a significant risk to infrastructure built on top of permafrost, such as roads and pipelines. 

In locations where dead vegetation and [[Earth:Peat|peat]] have accumulated, there is a risk of wildfire, such as the {{cvt|1039|km2}} of tundra which burned in 2007 on the north slope of the Brooks Range in Alaska.<ref name="NYT Thaw">{{cite news |title=As Permafrost Thaws, Scientists Study the Risks |url=https://www.nytimes.com/2011/12/17/science/earth/warming-arctic-permafrost-fuels-climate-change-worries.html |access-date=17 December 2011 |newspaper=The New York Times |date=16 December 2011 |first=Justin |last=Gillis}}</ref> Such events may both result from and contribute to global warming.<ref name=Nature2011>{{cite journal |first1=Michelle C. |last1=Mack |first2=M. Syndonia |last2=Bret-Harte |first3=Teresa N. |last3=Hollingsworth |first4=Randi R. |last4=Jandt |first5=Edward A. G. |last5=Schuur |first6=Gaius R. |last6=Shaver |first7=David L. |last7=Verbyla |display-authors=4 |title=Carbon loss from an unprecedented Arctic tundra wildfire |journal=Nature |date=28 July 2011 |volume=475 |issue=7357 |pages=489–492 |doi=10.1038/nature10283 |pmid=21796209 |url=http://www.environmentportal.in/files/file/wildfires.pdf |access-date=20 July 2012 |bibcode=2011Natur.475..489M |s2cid=4371811 |archive-date=14 November 2012 |archive-url=https://web.archive.org/web/20121114001622/http://www.environmentportal.in/files/file/wildfires.pdf |url-status=dead}}</ref>

[[Earth:Greenhouse gas emissions|Carbon emissions]] from permafrost thaw contribute to the same warming which facilitates the thaw, making it a [[Positive feedback|positive climate change feedback]]. The warming also intensifies the Arctic [[Physics:Water cycle|water cycle]], and the increased amounts of warmer rain are another factor which increases permafrost thaw depths.<ref name="Douglas2020">{{Cite journal |last1=Douglas |first1=Thomas A. |last2=Turetsky |first2=Merritt R. |last3=Koven |first3=Charles D. |date=24 July 2020 |title=Increased rainfall stimulates permafrost thaw across a variety of Interior Alaskan boreal ecosystems |journal=npj Climate and Atmospheric Science |volume=3 |issue=1 |page=5626 |doi=10.1038/s41612-020-0130-4 |doi-access=free |bibcode=2020npCAS...3...28D }}</ref>

The [[Earth:IPCC Sixth Assessment Report|IPCC Sixth Assessment Report]] estimates that [[Chemistry:Carbon dioxide|carbon dioxide]] and [[Chemistry:Methane emissions|methane released]] from permafrost could amount to the equivalent of {{convert|14-175|e9t}} carbon dioxide per {{cvt|1|C-change}} of warming.<ref name="AR6">{{cite book|last1=Fox-Kemper|first1=B|display-authors=et al|year=2021|chapter-url=https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter09.pdf|chapter=Chapter 9: Ocean, Cryosphere and Sea Level Change|url=https://www.ipcc.ch/report/ar6/wg1/|title=Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change|publisher=Cambridge University Press|location=Cambridge|doi=10.1017/9781009157896.011|page=1237}}</ref>  For comparison, by 2019, ''annual'' anthropogenic emission of carbon dioxide alone stood around {{convert|40|e9t}}.<ref name="AR6" /> A 2018 perspectives article discussing [[Earth:Tipping points in the climate system|tipping points in the climate system]] activated around {{cvt|2|C-change}} of global warming suggested that at this threshold, permafrost thaw would add a further {{cvt|0.09|C-change|2}} to global temperatures by 2100, with a range of {{cvt|0.04-0.16|C-change|2}}<ref>{{Cite journal |last1=Schellnhuber |first1=Hans Joachim |display-authors=et al|date=2018 |title=Trajectories of the Earth System in the Anthropocene |journal=Proceedings of the National Academy of Sciences |volume=115 |issue=33 |pages=8252–8259 |bibcode=2018PNAS..115.8252S |doi=10.1073/pnas.1810141115 |issn=0027-8424 |pmc=6099852 |pmid=30082409 |doi-access=free}}</ref>

== Antarctic ==

{{anchor|Antarctic tundra}}
[[File:11 Le Mont Werth (908m) devant le Ross.jpg|thumb|right|Tundra on the Kerguelen Islands.]]

Antarctic tundra occurs on [[Earth:Antarctica|Antarctica]] and on several Antarctic and subantarctic islands, including South Georgia and the South Sandwich Islands and the Kerguelen Islands. Most of Antarctica is too cold and dry to support vegetation, and most of the continent is covered by [[Earth:Ice field|ice field]]s or [[Earth:Polar desert|cold deserts]]. However, some portions of the continent, particularly the Antarctic Peninsula, have areas of rocky soil that support plant life. The flora presently consists of around 300–400 species of lichens, 100 mosses, 25 [[Biology:Liverwort|liverwort]]s, and around 700 terrestrial and aquatic [[Biology:Algae|algae]] 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 (''[[Biology:Deschampsia antarctica|Deschampsia antarctica]]'') and Antarctic pearlwort (''[[Biology:Colobanthus quitensis|Colobanthus quitensis]]''), are found on the northern and western parts of the Antarctic Peninsula.<ref>{{cite web |title=Terrestrial Plants |work=British Antarctic Survey: About Antarctica |url=http://www.antarctica.ac.uk//about_antarctica/wildlife/plants/ |access-date=5 March 2006}}</ref>

In contrast with the Arctic tundra, the Antarctic tundra lacks a large mammal fauna, mostly due to its physical isolation from the other continents. [[Biology:Marine mammal|Sea mammals]] and seabirds, including seals and penguins, inhabit areas near the shore, and some small mammals, like rabbits and cats, have been introduced by humans to some of the subantarctic islands. The Antipodes Subantarctic Islands tundra, an [[Earth:Ecoregion|ecoregion]] that includes the Bounty Islands, [[Earth:Auckland Islands|Auckland Islands]], [[Earth:Antipodes Islands|Antipodes Islands]], the [[Biology:Campbell Islands|Campbell Islands]], and [[Biology:Macquarie Island|Macquarie Island]].<ref name="wwf2">{{WWF ecoregion|id=aa1101 |name=Antipodes Subantarctic Islands tundra |access-date=2 November 2009}}</ref> Species endemic to this ecoregion include the windswept helmet-orchid (''[[Biology:Corybas dienemus|Corybas dienemus]]'') and the grooved helmet-orchid (''[[Biology:Corybas sulcatus|Corybas sulcatus]]''), the only subantarctic [[Biology:Orchid|orchid]]s; the [[Biology:Royal penguin|royal penguin]]; and the [[Biology:Antipodean albatross|Antipodean albatross]].<ref name="wwf2"/>

There is some ambiguity on whether Magellanic moorland, on the west coast of [[Place:Patagonia|Patagonia]], should be considered tundra or not.<ref name=Longton1988>{{cite book|last=Longton|first=R.E. |date=1988 |title=Biology of Polar Bryophytes and Lichen |publisher=Cambridge University Press |page=20 |isbn=978-0-521-25015-3 |series=Studies in Polar Research}}</ref> Edmundo Pisano, a Chilean [[Biology:Phytogeography|Phytogeographer]], called it tundra ({{langx|es|tundra Magallánica}}) since he considered the low temperatures key to restrict plant growth.<ref name=Longton1988/> More recent approaches have since recognized it as a temperate grassland, restricting southern tundra to coastal Antarctica and its islands.<ref>{{cite journal|last=Olson|first=David M.|title = Terrestrial Ecoregions of the World: A New Map of Life on Earth |journal = BioScience |year = 2011 |volume = 51 |issue = 11 |pages = 933–938 |doi = 10.1641/0006-3568(2001)051[0933:TEOTWA]2.0.CO;2 |doi-access = free|display-authors=0}}</ref><ref>{{cite journal|last=Dinerstein|first=Eric|display-authors=0|year=2017|title=An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm|journal=BioScience|volume=67|issue=6|pages=534–545|doi=10.1093/biosci/bix014|doi-access=free|pmid=28608869 |pmc=5451287}}</ref><ref>{{Cite web|url=https://www.oneearth.org/bioregions/patagonia-steppe-low-mountains-nt2/|title=Patagonia Steppe & Low Mountains Bioregion|website=One Earth}}</ref>

The flora and fauna of Antarctica and the Antarctic Islands (south of 60° south latitude) are protected by the Antarctic Treaty System.<ref>{{cite web |title=Protocol on Environmental Protection to the Antarctic Treaty |work=British Antarctic Survey: About Antarctica |url=http://www.antarctica.ac.uk//about_antarctica/geopolitical/treaty/ |access-date=5 March 2006}}</ref>

== Alpine ==
{{anchor|Alpine tundra}}
{{main|Earth:Alpine tundra}}

[[File:Sahale Peak.jpg|thumb|upright=1.67|Alpine tundra in the [[North Cascades]] of Washington, United States]]
Alpine tundra does not contain trees because the climate and soils at high altitude block tree growth.<ref>{{cite book |first=D.L. |last=Elliott-Fisk |chapter=The Taiga and Boreal Forest |editor1-first=M.G. |editor1-last=Barbour |editor2-first=M.D. |editor2-last=Billings |edition=2nd |publisher=Cambridge University Press |year=2000 |isbn=978-0-521-55986-7 |title=North American Terrestrial Vegetation}}</ref>{{rp|51}} The cold climate of the alpine tundra is caused by the low air temperatures, and is similar to [[Earth:Polar climate|polar climate]]. Alpine tundra is generally better drained than arctic soils.<ref name=":0">{{cite web |url=https://ucmp.berkeley.edu/exhibits/biomes/tundra.php |title=The tundra biome |publisher=University of California Museum of Paleontology |access-date=11 September 2020}}</ref> Alpine tundra transitions to [[Earth:Montane ecosystem#Subalpine zone|subalpine forests]] below the [[Earth:Tree line|tree line]]; stunted forests occurring within the [[Earth:Forest-tundra|forest-tundra]] ecotone  are known as ''[[Earth:Krummholz|Krummholz]]''. Alpine tundra can be affected by [[Earth:Woody plant encroachment|woody plant encroachment]].<ref>{{Cite journal |last1=Marsman |first1=Floor |last2=Nystuen |first2=Kristin O. |last3=Opedal |first3=Øystein H. |last4=Foest |first4=Jessie J. |last5=Sørensen |first5=Mia Vedel |last6=De Frenne |first6=Pieter |last7=Graae |first7=Bente Jessen |last8=Limpens |first8=Juul |date=January 2021 |editor-last=Pugnaire |editor-first=Francisco |title=Determinants of tree seedling establishment in alpine tundra |url=https://onlinelibrary.wiley.com/doi/10.1111/jvs.12948 |journal=Journal of Vegetation Science |language=en |volume=32 |issue=1 |doi=10.1111/jvs.12948 |bibcode=2021JVegS..32E2948M |issn=1100-9233|hdl=11250/2733966 |hdl-access=free }}</ref>

Alpine tundra occurs in mountains worldwide. The flora of the alpine tundra is characterized by plants that grow close to the ground, including [[Biology:Perennial|perennial]] grasses, [[Biology:Cyperaceae|sedges]], [[Earth:Forb|forb]]s, [[Biology:Cushion plant|cushion plant]]s, [[Biology:Moss|moss]]es, and [[Biology:Lichen|lichen]]s.<ref name="functional">{{Cite book |first=Christian |last=Körner |title=Alpine Plant Life: Functional Plant Ecology of High Mountain Ecosystems |place=Berlin |publisher=Springer |year=2003 |isbn=978-3-540-00347-2}}</ref> The flora is adapted to the harsh conditions of the alpine environment, which include low temperatures, dryness, [[Physics:Ultraviolet|ultraviolet]] radiation, and a short growing season.

== Climatic classification ==

[[File:Kongsfjorden from Blomstrandhalvoja.jpg|thumb|right|Tundra region with fjords, glaciers and mountains. Kongsfjorden, [[Spitsbergen]].]]
Tundra climates ordinarily fit the [[Earth:Köppen climate classification|Köppen climate classification]] ''ET'', signifying a local climate in which at least one month has an average temperature high enough to melt snow ({{cvt|0|C}}), but no month with an average temperature in excess of {{cvt|10|C}}.<ref>{{cite journal |last1=Kottek |first1=Markus |last2=Grieser |first2=Jürgen |last3=Beck |first3=Christoph |last4=Rudolf |first4=Bruno |last5=Rubel |first5=Franz |year=2006 |title=World Map of the Köppen-Geiger Climate Classification Updated |journal=Meteorol. Z. |volume=15 |issue=3 |pages=259–263 |doi=10.1127/0941-2948/2006/0130 |bibcode=2006MetZe..15..259K |url=https://nbn-resolving.org/urn:nbn:de:bvb:384-opus4-400838}}</ref> The cold limit generally meets the ''EF'' climates of [[Earth:Ice cap|permanent ice and snow]]s; the warm-summer limit generally corresponds with the poleward or altitudinal limit of trees,<ref>{{cite web |url=https://geodiode.com/climate/tundra |title=Tundra |website=geodiode.com|date=September 2011 }}</ref> where they grade into the [[Earth:Subarctic climate|subarctic climate]]s designated ''Dfd'', ''Dwd'' and ''Dsd'' (extreme winters as in parts of Siberia), ''Dfc'' typical in Alaska, Canada, mountain areas of [[Place:Scandinavia|Scandinavia]], European Russia, and Western Siberia (cold winters with months of freezing).<ref>{{cite journal |last1=Peel |first1=M.C. |last2=Finlayson |first2=B.L. |last3=McMahon |first3=T.A. |year=2007 |title=Updated world map of the Köppen-Geiger climate classification |journal=Hydrol. Earth Syst. Sci. |volume=11 |issue=5 |pages=1633–1644 |doi=10.5194/hess-11-1633-2007 |bibcode=2007HESS...11.1633P |s2cid=9654551|doi-access=free }}</ref>

Despite the potential diversity of climates in the ''ET'' category involving precipitation, extreme temperatures, and relative wet and dry seasons, this category is rarely subdivided. Rainfall and snowfall are generally slight due to the low [[Physics:Vapor pressure|vapor pressure]] of water in the chilly atmosphere, but as a rule [[Earth:Potential evapotranspiration|potential evapotranspiration]] is extremely low, allowing soggy terrain of swamps and bogs even in places that get precipitation typical of deserts of lower and middle latitudes.<ref name=NASA>{{cite web |url=https://earthobservatory.nasa.gov/biome/biotundra.php |title=Tundra |work=Earth Observatory |publisher=[[Organization:NASA|NASA]] |accessdate=11 September 2022}}</ref> The amount of native tundra [[Earth:Biomass (ecology)|biomass]] depends more on the local temperature than the amount of precipitation.<ref>{{cite journal |last1=Keuper |first1=F. |last2=Parmentier |first2=F.J. |last3=Blok |first3=D. |last4=van Bodegom |first4=P.M. |last5=Dorrepaal |first5=E. |last6=van Hal |first6=J.R. |last7=van Logtestijn |first7=R.S. |last8=Aerts |first8=R. |title=Tundra in the rain: differential vegetation responses to three years of experimentally doubled summer precipitation in Siberian shrub and Swedish bog tundra |journal=Ambio |year=2012 |volume=41 Suppl 3(Suppl 3) |issue=Suppl 3 |pages=269–80 |doi=10.1007/s13280-012-0305-2 |pmid=22864700 |pmc=3535056|bibcode=2012Ambio..41S.269K }}</ref>

== See also ==
* Alas
* [[Earth:Fellfield|Fellfield]]
* List of tundra ecoregions from the [[Organization:World Wide Fund for Nature|World Wide Fund for Nature]]
* [[Earth:Mammoth steppe|Mammoth steppe]]
* Park Tundra
* Tundra of North America
* [[Earth:International Tundra Experiment|International Tundra Experiment]]

== References ==
{{reflist}}

== Further reading ==
{{refbegin}}
* {{Cite book |last1=Allaby |first1=Michael |last2=Moore |first2=Peter D. |last3=Day |first3=Trevor |last4=Garratt |first4=Richard |date=2008 |title=Tundra |url=https://archive.org/details/tundra0000moor |url-access=registration |quote=Tundra. |publisher=Facts on File |isbn=978-0-8160-5934-8}}
* {{Cite book |last=Bliss |first=L. C |author2=O. W. Heal |author3=J. J. Moore |date=1981 |title=Tundra Ecosystems: A Comparative Analysis |url=https://books.google.com/books?id=mK48AAAAIAAJ&q=Tundra&pg=PP1 |publisher=International Biological Programme Synthesis Series (No. 25) |isbn=978-0-521-22776-6}}
* {{Cite book |last=Warhol |first=Tom |date=2007 |title=Tundra |url=https://books.google.com/books?id=oYUc7o43cuAC&q=Tundra&pg=PP1 |publisher=Marshall Cavendish Benchmark |isbn=978-0-7614-2193-1}}
* {{Cite book |last=Yu I |first=Chernov |date=1998 |title=The Living Tundra;Studies in Polar Research |url=https://books.google.com/books?id=agc5AAAAIAAJ&q=Tundra&pg=PP1 |publisher=Cambridge University Press |isbn=978-0-521-35754-8}}
{{refend}}

==External links==
*[http://www.panda.org/about_our_earth/ecoregions/about/habitat_types/selecting_terrestrial_ecoregions/habitat11.cfm WWF Tundra Ecoregions] {{Webarchive|url=https://web.archive.org/web/20100223091305/http://www.panda.org/about_our_earth/ecoregions/about/habitat_types/selecting_terrestrial_ecoregions/habitat11.cfm |date=23 February 2010 }}
*[https://web.archive.org/web/20011004081203/http://www.cotf.edu/ete/modules/msese/earthsysflr/tundra.html The Arctic biome at Classroom of the Future]
*[https://web.archive.org/web/20110720194120/http://kaares.ulapland.fi/home/arktinen/tundra/tundra.htm Arctic Feedbacks to Global Warming: Tundra Degradation in the Russian Arctic]
*[https://web.archive.org/web/20051225213602/http://www.antarctica.ac.uk/About_Antarctica/Wildlife/Plants/ British Antarctica Survey]
*[http://www.worldwildlife.org/ecoregions/an1101 Antarctica: West of the Transantarctic Mountains]
*[https://databayou.com/world/tundra.html World Map of Tundra]

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{{Biomes}}
{{Earth's landforms}}
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{{Periglacial environment}}
{{Arctic topics}}
{{Antarctica}}
{{Biodiversity of South Africa|ecoreg}}
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[[Category:Environment of the Arctic]]

{{Sourceattribution|Tundra}}