TUNDRA: CHARACTERISTICS, TYPES, RELIEF, FLORA, FAUNA - GEOGRAPHY - 2025

The tundra is a biome characterized by sparse vegetation where the dominant elements are mosses, lichens, grasses and low shrubs. It is mainly distributed in the northern hemisphere towards the coasts of the Arctic Ocean and in the southern hemisphere in Antarctica and Antarctic islands.

The word tundra comes from the Finnish word tunturi, which means "ungrove plain." However, the term has been expanded to refer to any area of ​​low vegetation in a cold zone, for example the alpine tundra.

Tundra in Svalbard (Norway). Source: Sphinx (Sphinx 00:21, 12 August 2007 (UTC))

There is arctic tundra in North America (Alaska and Canada), Greenland and Eurasia (Scandinavia and Russia) and Antarctica in Chile, Argentina, the Antarctic coast and islands such as the Falklands, Kerguelen and South Georgia. For its part, the alpine tundra develops in the high mountains of the cold and temperate zones.

The World Wildlife Foundation or World Wildlife Fund (WWF) identifies up to 36 ecoregions belonging to the tundra biome. This biome has an extreme climate, with short and cold summers, long and very cold winters, low solar radiation and albedo or high.

The main characteristic of the soil is the presence of permafrost or frozen underground layer. The landscape is a mosaic of flooded areas, alternated with peatlands and patches of low vegetation dominated by mosses, lichens, grasses and small shrubs.

Among the terrestrial fauna are polar bears, wolves, musk oxen, polar foxes, reindeer and lemmings, among other animals. While in the marine fauna there are the killer whale, seals and sea lions, among many other species.

Among the economic activities that take place in the tundra, mining, oil and natural gas stand out. For their part, the traditional ethnic groups that inhabit it have always practiced subsistence fishing and hunting. In the case of the Sami, transhumant reindeer herding has been traditional, following it in its migration from the taiga to the tundra.

General characteristics

- Location and extension

The Arctic tundra is located around the 70th parallel in the Arctic Circle, covering a strip of 13,752 km in length and variable width. Its widest section is located in Taymyr reaching 600 to 700 km from south to north.

In the northern hemisphere it includes Siberia, Alaska, northern Canada, southern Greenland, and the Arctic coast of Europe. Whereas the alpine tundra is found in the high tropical and subtropical mountains of Eurasia and North America.

The Antarctic tundra stretches across the southern tip of America into Chile and Argentina. Also in subantarctic islands such as Las Malvinas, Kerguelen and South Georgia, and small areas of the coast of Antarctica.

- Soil and permafrost

The tundra is characterized by having a predominantly gley-type soil, characterized by developing in flooded plains. The subsoil is subjected to freezing all year round, forming the permafrost that waterproofs the ground, which is why puddles, lagoons and swamps are created.

Gley

This gley soil has a high content of ferrous iron, which gives it a gray-green hue. Its characteristic structure in the tundra is polygons, water-filled crevices, and mounds of peat. This is configured as a result of cryogenic processes (erosive effects of ice).

Permafrost

It consists of the layer of soil that is kept permanently frozen, although not necessarily covered with snow. It generally consists of a deep, permanently frozen layer (pergelisol) and a superficial layer that can periodically thaw (mollisol).

Permafrost. Source: Brocken Inaglory

A relevant characteristic of permafrost is that it is an important carbon sink, thus posing a serious threat to global warming. This is because as global temperature increases, permafrost thaws and releases methane (CH4) and CO2 into the atmosphere.

This in turn represents a chain reaction, since methane is one of the most important greenhouse gases. The carbon retained in permafrost for more than 15,000 years is estimated to be 1.85 trillion metric tons.

Peat

It is a light and spongy charcoal that is formed by the decomposition of organic plant remains in flooded soils. In the tundra there are extensive areas of peat forming part of the mosaic of marshy areas of this region.

- Wildlife reproduction period

A relevant biological characteristic is the short period that living beings have to reproduce in the tundra. Due to its extreme environmental conditions, this period only extends for a few weeks to a maximum of two months in some areas.

Types

- The arctic tundra

This is the tundra proper and it extends mainly in the subarctic zone around the parallel 70º north latitude. Within this zone four areas are distinguished from north to south, in line with the worsening of climatic conditions towards the north.

Tundra in Alaska. Source: US Fish and Wildlife Service

By lowering the temperature and decreasing solar radiation, conditions become harsher for the survival of flowering plants. In these conditions, mosses and lichens predominate.

Northern tundra or arctic tundra

It is bordered to the north by the Arctic polar desert and the environmental conditions are more extreme, detecting the lowest temperatures and the lowest annual insolation. The vegetation is scattered, composed almost exclusively of mosses and lichens, while the grasses appear as small pads almost at ground level.

Central or typical tundra

It is the semi-desert plain area with typical tundra vegetation dominated by mosses, lichens, grasses and low shrubs.

Southern tundra

In this area located further south, taller shrubs develop, in addition to the characteristic tundra vegetation. Permafrost develops deeper, sometimes more than a meter.

Tundra-Taiga Ecotone

This is the transition zone between the tundra and the boreal forest or taiga composed of trees from the gymnosperm group. In this area there is a greater development of bushy vegetation alternated with patches of mosses, grasses and fragments of the forest.

- The alpine or montane tundra

This is the name given to the high mountain area of ​​cold and temperate areas above the tree line. Here, similar to the arctic tundra, grasses, mosses and lichens predominate, as well as small shrubs.

Alpine tundra in Venezuela. Source: Adolfo

However, the diversity of angiosperms is much greater and they predominate over mosses and lichens. It also differs from the arctic tundra in that the soils here are generally well drained.

Permafrost does not form in alpine tundra, but it is common for the surface of the soil to freeze overnight.

- The Antarctic tundra

It is the unspoiled area on a rocky substrate covered with mosses, lichens and algae, in restricted areas of the coast and islands. Also, some species of grasses are found, but the plant diversity is much lower than in the Arctic tundra.

Relief

- Arctic tundra

The fundamental relief of the Arctic tundra is a great plain geologically originated by the decrease in sea level. This plain acquired a polygonal structure, modeled by the flow cycle of water, its freezing and thawing.

All this in combination with its particular vegetation dominated by mosses, lichens, grasses and small shrubs, give it its particular physiognomy.

Water as a modeler of the landscape

Water is abundant in the tundra, precipitating in both liquid and snow forms and subject to freezing and thawing processes. Therefore, this element is an important factor in the modeling of the relief and the landscape in general.

From the air, the tundra shows an almost continuous appearance of countless lakes and ponds. These are formed as a result of the melting of permafrost and underground ice.

- Antarctic tundra

These are rocky coasts, with abundant pebbles and undulating coastal plains.

- Alpine tundra

In the case of the alpine tundra, these are high mountain areas that include plateaus, slopes and high intramontane valleys.

Weather

The tundra develops in an arctic climate characterized by minimum temperatures of down to -50 ° C and maximums that can be relatively high. In the north of the tundra they can reach 20-29ºC in July, while in the south they can reach 25ºC.

However, in other areas of the tundra the July maximum does not exceed 6ºC. This is because, although it is a coastal area, the Arctic Ocean does not moderate the temperature because it is covered with ice.

Summers in the Antarctic tundra are much colder than in the Arctic tundra, reaching temperatures of 0-3 ºC.

Precipitation and humidity

In terms of precipitation, the tundra is an arid zone, with rainfall varying from 150 mm to 350 mm per year. However, in this biome there is a high degree of humidity due to the low evaporation rate as a consequence of the low solar radiation.

On the other hand, the accumulation of frost on the surface of the snow is another source of environmental humidity. This occurs especially when the region is subjected to temperate drafts.

Solar radiation

Total solar radiation is relatively low in the tundra compared to the taiga and steppe. While in the tundra solar radiation reaches 67 Kcal / cm2, in the taiga it exceeds 70 and in the steppe it reaches 119 Kcal / cm2.

On the other hand, the albedo (radiation reflected by the light tonality of the surface), is higher in the tundra. In this area it is close to 50%, while in the taiga it is less than 40% and in the steppe it does not exceed 30%.

Arctic night

It is necessary to bear in mind that in this part of the world, during the months of November to February, the so-called Arctic night occurs. In this period, the duration of the day is zero or close to zero, so that solar radiation is also almost zero.

Flora

The vegetation consists mainly of mosses and lichens, while the angiosperms present are mostly grasses and some low shrubs. Many species have dark red leaves to maximize heat absorption.

Similarly, cushion, rosette and clump shapes predominate to protect against the cold.

- Mosses

There are more than 100 species of mosses, being abundant those of the genus Sphagnum, which are peat mosses. Mosses are very important in the ecology of water and energy flows.

Submerged chestnut moss (Scorpidium scorpioides) also plays an important ecological role by oxidizing methane, thus reducing its emissions.

- Lichens

Lichens are symbiotic associations of mosses, fungi and bacteria, and in the tundra they are one of the most abundant elements. Only in the Russian Arctic there are about 1,000 species of lichens.

- Angiosperms

Sedges

Among these, species of the genus Carex predominate, such as Carex bigelowii and Carex aquatilis. Similarly, various species of the genus Eriophorum (E. vaginatum, E. angustifolium) are common.

Subshrubs and shrubs

Among the bushes there are ericaceae, such as those of the genus Vaccinium (V. vitis-idaea, V. Uliginosum) and Ledum palustre known as Labrador tea. There are also bushes of Salix (salicaceae), Betula and Alnus (betulaceae), among other families and subshrubs such as Papaver radicatum and Ranunculus nivalis.

Grasses

Deschampsia antarctica and Poa pratensis are common in the Antarctic tundra.

Antarctic dicots

Crucifers are found such as Pringlea antiscorbutica, with a high content of vitamin C, and rosaceae such as different species of the genus Acaena.

- Variations in flora

Global warming is causing subarctic species to invade the tundra. For example, in Alaska the dominant sedge Eriophorum vaginatum is being displaced by the deciduous shrub Betula nana.

Fauna

- Terrestrial fauna

Given the extreme conditions of the tundra and its sparse vegetation, the terrestrial fauna that exists there is not very diverse. However, there are characteristic species such as the polar bear or the ptarmigan, as well as other migratory species that form large herds such as the reindeer.

On the other hand, there are various microorganisms and invertebrates that inhabit the soil and permafrost.

Reno (

Reindeer form herds of thousands of animals that migrate from the taiga to the tundra in summer to feed on grasses and mosses.

Wolf (

Wolves also form packs and hunt in groups, following reindeer migrations.

Musk ox (

This enormous animal that inhabits sub-arctic areas including the tundra, although morphologically similar to cattle, is related to goats and sheep.

Polar Bear (

It is one of the largest terrestrial carnivores that exist, its favorite prey being the seals. It is an animal adapted to arctic conditions, being a good swimmer that resists low temperatures thanks to a thick layer of subcutaneous fat.

Polar bear (Ursus maritimus). Source: Alan Wilson

In addition, their skin is black to better absorb solar radiation, but it is covered with translucent hairs. These hairs reflect sunlight giving the sensation of whiteness and in this way it is heated at the same time as it is camouflaged.

Ptarmigan (

It is a galliform bird that inhabits both the Arctic tundra and various areas of alpine tundra in Eurasia and North America. It is characterized by having seasonal homochromia, that is, in winter it has white plumage that later changes to dark and variegated tones.

Arctic fox (

This small canid inhabits caves dug into the ground and camouflages itself to hunt with its snow-white fur. Its main prey is the lemmings, although it also hunts other small mammals and birds.

Lemmings (Lemmini tribe)

These small rodents are capable of reproducing even during the harsh arctic tundra winter. It feeds on herbs, roots and fruits and inhabits caves dug into the ground.

- Marine fauna

Sea lion (Otaria flavescens). Source: V. Laroulandie

The marine fauna is diverse, including a great diversity of fish and marine mammals such as the killer whale (Orcinus orca) and seals (Phocidae family). Sea lions (Otaria flavescens) are found in the Antarctic region.

Economic activities

- Mining

Mining is the most lucrative economic activity on the tundra, due to its extraordinary wealth in various strategic minerals. For example, in Taimyr (Siberia, Russia) there are important nickel mines and smelters while in Alaska the mining of gold, coal and copper is expanding.

- Oil and natural gas

Alaska

The Alaskan tundra is an area rich in oil and natural gas, the exploitation of which has impacted this ecoregion. In 1989, the Exxon Valdez oil tanker ran aground off the coast of Alaska, seriously affecting marine and coastal life.

Then in 2006 an oil pipeline broke, spreading more than 200 thousand liters of crude oil on the tundra.

Greenland

The tundra in Greenland is also an oil area and this activity represents one of the threats to this biome in the region.

Siberia

Oil is also produced in this region, although extraction costs are high due to the extreme environmental and soil conditions.

- Hunting and fishing

Native tribes in the tundra regions of Alaska, Canada, Greenland (Inuit), Scandinavia, and Siberia (Samis) traditionally hunt and fish for survival.

- Transhumant reindeer herding

The Sami in Scandinavia and Russia maintain the traditional reindeer herding, following them on their migrations from the taiga to the tundra in summer.

Examples of tundra in the world

- Central Siberian tundra on the Taimyr peninsula

Location

The Taimyr ecoregion is a peninsula located in north-central Russia that constitutes the northernmost part of the Asian continent. It is a region that covers 400 thousand km2 with coasts in the Kara and Laptev seas.

characteristics

In the Taimyr tundra the active period for the reproduction of fauna and flora does not exceed two months. There the musk ox inhabited in the wild that became extinct and fortunately was successfully reintroduced in 1975.

Tundra on the Taimyr Peninsula (Russia). Source: Dr. Andreas Hugentobler

Also, in this area the reindeer migration occurs in the summer, a time when the sun is still seen at midnight. In addition, other elements of the fauna are the polar bear and the seals.

- The Greenland tundra

Location

In the Kalaallit Nunaat ecoregion we find the high arctic tundra of northern Greenland. It constitutes part of the northernmost fraction of land on the planet.

characteristics

In winter for almost 4 months of the year this region is in total darkness and with temperatures below zero and during the summer the temperatures do not exceed 5 ºC.

Musk ox, arctic wolf, polar bear and seal populations were depleted by hunting, but are now recovering. In this sense, in 1974 the largest national park in the world with 1 million km2 was created in this region.

They also inhabit the arctic hare (Lepus arcticus), the arctic fox (Vulpes lagopus), the wolf (Canis lupus) and the caribou or reindeer (Rangifer tarandus). Likewise, it is possible to find the ermine (Mustela erminea), the collared lemming (Dicrostonyx torquatus) and the glutton (Gulo gulo).

- The alpine tundra of the Mackenzie Mountains

Location

This mountain range is located in Canada, forming part of the Yukon and reaching its maximum elevation at 2,972 meters (Keele Peak).

characteristics

Summers are short temperate to cold with average temperatures of 9ºC and winters long and cold, with few hours of sunshine. Average temperatures in winter vary between -19.5 ºC and -21.5 ºC; extreme temperatures of -50 ºC are not rare and precipitation ranges from 300 to 750 mm.

Here the alpine tundra at higher elevations consists of lichens, rosaceae (Dryas hookeriana), and intermediate to dwarf ericaceous shrubs (Ericaceae). Herbs include sedges of the genus Carex and cotton grass (Eriophorum spp.)

Among the fauna are the caribou or reindeer (Rangifer tarandus) and the ram or Dalli mouflon (Ovis dalli). Like the elk (Alces alces) and the beaver (Castor canadensis). While among the predators are the wolf (Canis lupus) and the red fox (Vulpes vulpes). As well as two species of bear that are the brown bear and the black bear (Ursus arctos and U. americanus).

References

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