In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mountain tract". There are three regions and associated types of tundra: Arctic tundra,

alpine tundra Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated alpine climate, harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alp ...

, and Antarctic tundra. Tundra vegetation is composed of dwarf shrubs, sedges, grasses,

moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...

es, and

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. The tundra soil is rich in nitrogen and phosphorus. The soil also contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide in the

permafrost Permafrost is ground that continuously remains below 0 °C (32 °F) for two or more years, located on land or under the ocean. Most common in the Northern Hemisphere, around 15% of the Northern Hemisphere or 11% of the global surface ...

, making the tundra soil a carbon sink. As global warming heats the ecosystem and causes soil thawing, the permafrost carbon cycle accelerates and releases much of these soil-contained greenhouse gases into the atmosphere, creating a feedback cycle that increases climate change.

Arctic

Arctic tundra occurs in the far

Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...

, north of the taiga belt. The word "tundra" usually refers only to the areas where the subsoil is

, or permanently frozen soil. (It may also refer to the treeless plain in general so that northern Sápmi would be included.) Permafrost tundra includes vast areas of northern Russia and Canada. 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 Sami in Sápmi). Tundra in Siberia

Arctic tundra contains areas of stark landscape and is frozen for much of the year. The soil there is frozen from down, making it impossible for trees to grow. Instead, bare and sometimes rocky land can only support certain kinds of

Arctic vegetation About 1,702 species of plants live on the Arctic tundra, including flowering plants, short shrubs, herbs, grasses, mosses. These plants are adapted to short, cold growing seasons. They have the ability to withstand extremely cold temperatures in ...

, low-growing plants such as moss, heath ( Ericaceae varieties such as

crowberry ''Empetrum nigrum'', crowberry, black crowberry, or, in western Alaska, blackberry, is a flowering plant species in the heather family Ericaceae with a near circumboreal distribution in the Northern Hemisphere. It is usually dioecious, but there ...

and black bearberry), and

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.habitat conservation programs. In Canada and Russia, many of these areas are protected through a national Biodiversity Action Plan. Vontut National Park

Tundra tends to be windy, with winds often blowing upwards of . However, it is desert-like, with only about 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. Muskox and Geese

The biodiversity of tundra is low: 1,700 species of vascular plants and only 48 species of land mammals can be found, although millions of birds migrate there each year for the marshes. There are also a few fish species. There are few species with large populations. Notable plants in the Arctic tundra include blueberry ('' Vaccinium uliginosum''), crowberry ('' Empetrum nigrum''), reindeer lichen ('' Cladonia rangiferina''), lingonberry ('' Vaccinium vitis-idaea''), and Labrador tea ('' Rhododendron groenlandicum''). Notable animals include reindeer (caribou), musk ox, Arctic hare, Arctic fox, snowy owl, ptarmigan, northern red-backed voles, lemmings, the mosquito, and even

polar bear The polar bear (''Ursus maritimus'') is a hypercarnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the largest extant bear specie ...

s near the ocean. Tundra is largely devoid of poikilotherms 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 petroleum, natural gas, and uranium. In recent times this has begun to change in 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 global warming

A severe threat to tundra is global warming, which causes

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. It also represents a significant risk to infrastructure built on top of permafrost, such as roads and pipelines. In locations where dead vegetation and peat have accumulated, there is a risk of wildfire, such as the of tundra which burned in 2007 on the north slope of the Brooks Range in Alaska. Such events may both result from and contribute to global warming.

Greenhouse gas emissions

Antarctic

Antarctic tundra occurs on Antarctica and on several Antarctic and subantarctic islands, including South Georgia and the South Sandwich Islands and the

Kerguelen Islands The Kerguelen Islands ( or ; in French commonly ' but officially ', ), also known as the Desolation Islands (' in French), are a group of islands in the sub-Antarctic constituting one of the two exposed parts of the Kerguelen Plateau, a large ...

. Most of Antarctica is too cold and dry to support vegetation, and most of the continent is covered by ice fields. However, some portions of the continent, particularly the

Antarctic Peninsula The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martín in Argentina, and originally as Graham Land in the United Kingdom and the Palmer Peninsula in the United States, is the northernmost part of mainland Antarctic ...

, have areas of rocky soil that support plant life. The flora presently consists of around 300–400 species of lichens, 100 mosses, 25

liverworts The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of ge ...

, and around 700 terrestrial and aquatic 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 ''Deschampsia antarctica'', the Antarctic hair grass, is one of two flowering plants native to Antarctica, the other being '' Colobanthus quitensis'' (Antarctic pearlwort). They mainly occur on the South Orkney Islands, the South Shetland Island ...

(''Deschampsia antarctica'') and

Antarctic pearlwort ''Colobanthus quitensis'', the Antarctic pearlwort, is one of two native flowering plants found in the Antarctic region. It has yellow flowers and grows about 5 cm (two inches) tall, with a cushion-like growth habit that gives it a moss-like appe ...

(''Colobanthus quitensis''), are found on the northern and western parts of the Antarctic Peninsula. In contrast with the Arctic tundra, the Antarctic tundra lacks a large mammal fauna, mostly due to its physical isolation from the other continents. Sea mammals and sea birds, 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 ecoregion includes the

Bounty Islands The Bounty Islands ( mi, Moutere Hauriri; "Island of angry wind") are a small group of 13 uninhabited granite islets and numerous rocks, with a combined area of , in the South Pacific Ocean. Territorially part of New Zealand, they lie about e ...

, Auckland Islands, Antipodes Islands, the Campbell Island group, and Macquarie Island. Species endemic to this ecoregion include '' Corybas dienemus'' and '' Corybas sulcatus'', the only subantarctic orchids; the

royal penguin The royal penguin (''Eudyptes schlegeli'') is a species of penguin, which can be found on the sub-Antarctic Macquarie Island and adjacent islands. The International Union for Conservation of Nature (IUCN) classifies the royal penguin as near th ...

; and the

Antipodean albatross The Antipodean albatross (''Diomedea antipodensis'') is a large seabird in the albatross family. Antipodean albatrosses are smaller than wandering albatrosses, and breed in predominantly brown plumage, but are otherwise difficult to distinguish f ...

. There is some ambiguity on whether

Magellanic moorland 250px, Magellanic moorland at Herschel Island, Cabo de Hornos National Park. The Magellanic moorland or Magellanic tundra ( es, Tundra magallánica) is an ecoregion on the Patagonian archipelagos south of latitude 48° S. It is characterized by h ...

, on the west coast of Patagonia, should be considered tundra or not.

Phytogeographer Phytogeography (from Greek φυτόν, ''phytón'' = "plant" and γεωγραφία, ''geographía'' = "geography" meaning also distribution) or botanical geography is the branch of biogeography that is concerned with the geographic distribution o ...

Edmundo Pisano called it tundra ( es, tundra Magallánica) since he considered the low temperatures key to restrict plant growth. The flora and fauna of Antarctica and the Antarctic Islands (south of 60° south latitude) are protected by the Antarctic Treaty.

Alpine

Alpine tundra does not contain trees because the climate and soils at high altitude block tree growth. The cold climate of the alpine tundra is caused by the low air temperatures, and is similar to

polar climate The polar climate regions are characterized by a lack of warm summers but with varying winters. Every month in a polar climate has an average temperature of less than . Regions with polar climate cover more than 20% of the Earth's area. Most of ...

. Alpine tundra is generally better drained than arctic soils. Alpine tundra transitions to subalpine forests below the tree line; stunted forests occurring at the forest-tundra ecotone (the treeline) are known as '' Krummholz''. Alpine tundra occurs in mountains worldwide. The flora of the alpine tundra is characterized by plants that grow close to the ground, including perennial grasses, sedges, forbs, cushion plants,

es, and

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship. The flora is adapted to the harsh conditions of the alpine environment, which include low temperatures, dryness, ultraviolet radiation, and a short growing season.

Climatic classification

Tundra climates ordinarily fit the Köppen climate classification ''ET'', signifying a local climate in which at least one month has an average temperature high enough to melt snow (), but no month with an average temperature in excess of . The cold limit generally meets the ''EF'' climates of permanent ice and snows; the warm-summer limit generally corresponds with the poleward or altitudinal limit of trees, where they grade into the

subarctic climate The subarctic climate (also called subpolar climate, or boreal climate) is a climate with long, cold (often very cold) winters, and short, warm to cool summers. It is found on large landmasses, often away from the moderating effects of an ocean, ge ...

s designated ''Dfd'', ''Dwd'' and ''Dsd'' (extreme winters as in parts of Siberia), ''Dfc'' typical in Alaska, Canada, mountain areas of Scandinavia,

European Russia European Russia (russian: Европейская Россия, russian: европейская часть России, label=none) is the western and most populated part of Russia. It is geographically situated in Europe, as opposed to the cou ...

, and

Western Siberia Western Siberia or West Siberia (russian: Западная Сибирь, Zapadnaya Sibir'; kk, Батыс Сібір) is a part of the larger region of Siberia that is mostly located in the Russian Federation. It lies between the Ural region an ...

(cold winters with months of freezing). 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 vapor pressure of water in the chilly atmosphere, but as a rule 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. The amount of native tundra biomass depends more on the local temperature than the amount of precipitation.

Places featuring a tundra climate

;Alpine tundra * Gavia Pass, Italy *

Mount Fuji , or Fugaku, located on the island of Honshū, is the highest mountain in Japan, with a summit elevation of . It is the second-highest volcano located on an island in Asia (after Mount Kerinci on the island of Sumatra), and seventh-highest p ...

, Japan * Cerro de Pasco, Peru * Apartaderos, Venezuela *

Puno Puno (Aymara and qu, Punu) is a city in southeastern Peru, located on the shore of Lake Titicaca. It is the capital city of the Puno Region and the Puno Province with a population of approximately 140,839 (2015 estimate). The city was establish ...

, Peru *

Kasprowy Wierch Kasprowy Wierch (; Slovak; ''Kasprov vrch''; sometimes in ''Kasper Peak'') is a peak of a long crest (ridgeline) in the Western Tatras one of Poland's main winter ski areas. Its dominant southern crests, WSW and ESE, mark the border with Slovak ...

, Poland * High Tatras, Slovakia *

Murghob Murghob ( tg, Мурғоб) or Murghab (russian: Мургаб, from the Persian word ''margh-ab'', meaning 'prairie river') is the capital of Murghob District in the Pamir Mountains of Gorno-Badakhshan, Tajikistan. With a population of just u ...

, Tajikistan * Mount Wellington, Australia * Cairn Gorm, United Kingdom *

Putre Putre is a Chilean town and commune, capital of the Parinacota Province in the Arica-Parinacota Region. It is located east of Arica, at an altitude of . The town is backdropped by Taapaca volcanic complex. Putre is on the edge of the Lauca Nati ...

, Chile *

Coranzuli Coranzuli is a rural municipality and village in Jujuy Province in Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an ar ...

, Argentina * Yu Shan, Taiwan * Juf, Switzerland * Finse, Norway ;Polar tundra *

Longyearbyen Longyearbyen (, locally �lɔ̀ŋjɑrˌbyːən "The Longyear Town") is the world's northernmost settlement with a population greater than 1,000 and the largest inhabited area of Svalbard, Norway. It stretches along the foot of the left bank ...

Svalbard Svalbard ( , ), also known as Spitsbergen, or Spitzbergen, is a Norwegian archipelago in the Arctic Ocean. North of mainland Europe, it is about midway between the northern coast of Norway and the North Pole. The islands of the group range ...

, Norway * Yamal Peninsula, Russia * Iqaluit, Canada *

Utqiagvik Utqiagvik ( ik, Utqiaġvik; , , formerly known as Barrow ()) is the borough seat and largest city of the North Slope Borough in the U.S. state of Alaska. Located north of the Arctic Circle, it is one of the northernmost cities and towns in th ...

, United States * ''

, French Southern Lands (France)'' * '' Nuuk, Greenland (Denmark) '' * ''

Grytviken Grytviken ( ) is a settlement on South Georgia in the South Atlantic and formerly a whaling station and the largest settlement on the island. It is located at the head of King Edward Cove within the larger Cumberland East Bay, considered the b ...

South Georgia South Georgia ( es, Isla San Pedro) is an island in the South Atlantic Ocean that is part of the British Overseas Territory of South Georgia and the South Sandwich Islands. It lies around east of the Falkland Islands. Stretching in the east� ...

(United Kingdom) '' * Tiksi, Russia * '' Mykines, Faroe Islands (Denmark)'' * Campbell Island, New Zealand

References

External links

WWF Tundra Ecoregions

* ttps://web.archive.org/web/20051225213602/http://www.antarctica.ac.uk/About_Antarctica/Wildlife/Plants/ British Antarctica Surveybr>Antarctica: West of the Transantarctic Mountains
{{Authority control Terrestrial biomes Geography of the Arctic Environment of the Arctic Köppen climate types Nearctic realm Palearctic realm