Tundra Biome – Characteristics, Flora, Fauna


Tundra Biome

The tundra biome is a cold, treeless region found in the Arctic, Antarctic, and high mountain tops. The term “tundra” comes from the Finnish word “tunturi,” meaning “treeless plain.” The word in Russian is “тундра” (túndra), which then entered English.

Main Characteristics of the Tundra

The main characteristics of the tundra are extremely cold temperatures, a short growing season, and a lack of trees. The environment is harsh, with strong winds, low precipitation, and poor soil nutrients. Despite these challenges, the tundra supports a variety of life forms uniquely adapted to survive in such conditions.

Where Is the Tundra Located?

Like other biomes, tundra occurs in regions according to either latitude or altitude. The tundra covers approximately 10% of Earth’s land surface.

Latitude

The tundra biome primarily occurs in the Arctic regions, between 60° to 70° North latitude. It spans the northern parts of North America, Europe, and Asia. Additionally, the Antarctic tundra is on the Antarctic Peninsula and several sub-Antarctic islands.

Altitude

Alpine tundra occurs on high mountain tops around the world above the tree line. The tree line varies mainly according to temperature, but generally ranges from about 2,400 meters (8,000 feet) in the tropics to 1,000 meters (3,300 feet) in higher latitudes.

Types of Tundra

Depending on who you ask, there are either two or three types of tundra. Some sources omit the Antarctic tundra.

Arctic Tundra

The Arctic tundra is the northernmost and coldest biome in the northern hemisphere. Arctic tundra features a layer of permanently frozen subsoil called permafrost. This biome covers northern Alaska and Canada, Greenland, Scandinavia, and Siberia.

Alpine Tundra

Found at high altitudes around the world, Alpine tundra lacks permafrost but shares the cold climate and low biodiversity of Arctic tundra. Examples of locations with alpine tundra include portions of the Alaska, Canada, the continental United States, Mexico, Finland, Norway, Japan, Mt. Kilimanjaro in Africa, and the Andes Mountains of South America.

Antarctic Tundra

Located on the Antarctic Peninsula and several sub-Antarctic islands, Antarctic tundra has a milder climate compared to the central Antarctic ice cap but still experiences cold temperatures and low biodiversity. The Antarctic tundra is the biome of the South Georgia, Kerguelen, and South Sandwich Islands. It also includes portions of northern and western Antarctica.

Biomes Bordering the Tundra

In the northern hemisphere, the tundra biome borders the taiga (boreal forest) biome to the south. In high mountain regions, it transitions into alpine meadows or forests. The polar ice caps border the Arctic and Antarctic tundra.

Difference Between Tundra and Taiga

The tundra and taiga are cold biomes that are easily confused, but also easily distinguished.

  • Trees: The most noticeable feature of the tundra is the absence of trees. In contrast, the taiga is a land of forests.
  • Permafrost: Except for alpine tundra, the ground of the tundra biome is typically frozen with a layer of permafrost. Usually, the frost layer melts in the taiga.
  • Animals: Some creatures live in both the taiga and the tundra, but the taiga mainly features forest animals, while animals of the tundra are exposed in the treeless land and often blend into the landscape;

Geography and Climate

Temperature

The tundra experiences bitterly cold winters, but the brief summers are warm enough for mosquitoes and flowers. The tundra experiences average temperatures ranging from -28°C to -34°C in winter and 3°C to 12°C in summer.

Growing Season

The growing season is very short, typically lasting only about 50 to 60 days.

Soil

Tundra soils are poor in nutrients, often waterlogged, and often contain permafrost, which limits root growth.

Precipitation

The tundra receives very little precipitation, usually less than 250 mm annually, mostly in the form of snow. In terms of precipitation, the tundra is similar to the desert.

Hours of Daylight

The polar tundra experiences extreme variations in daylight, with continuous daylight in summer (midnight sun) and continuous darkness in winter (polar night). The hours of daylight vary for alpine tundra.

Glaciation Status

Much of the tundra was glaciated during the last ice age, and glaciers still persist in some areas.

Relationship to Permafrost

Permafrost is a defining feature of the Arctic tundra. It is a layer of soil that remains frozen throughout the year, limiting water drainage and plant root growth. The active layer above the permafrost thaws during the short summer, allowing some plant and microbial activity.

Flora of the Tundra

Main Plant Species

The tundra supports mosses, lichens, grasses, sedges, and dwarf shrubs. Common plants include Arctic moss, bearberry, and Labrador tea.

Adaptations

  • Low growth form: Plants grow close to the ground to resist cold temperatures and wind.
  • Perennial growth: Many plants are perennials, conserving energy by surviving multiple years.
  • Dark pigmentation: Some plants have dark leaves to absorb more heat from the sun.
  • Rapid flowering and seed production: Plants have short life cycles to take advantage of the brief growing season.

Fauna of the Tundra

Main Animal Species

  • Mammals: Arctic fox, caribou, musk ox, lemming, and polar bear.
  • Birds: Snowy owl, Arctic tern, and ptarmigan. Migratory birds are abundant in summer.
  • Insects: Mosquitoes and other biting insects are abundant in summer.

Adaptations

  • Insulating fur or feathers: Thick fur or feathers help retain body heat.
  • Fat storage: Animals like bears and seals store fat to provide energy and insulation.
  • Behavioral adaptations: Migration (birds and caribou) and hibernation (bears) to survive harsh conditions.

Importance of the Tundra

The tundra plays a critical role in Earth’s climate system, acting as a carbon sink and influencing global weather patterns. It also supports unique biodiversity and provides habitat for migratory species.

Effects of Climate Change

Climate change alters the tundra and taiga biomes significantly:

  • Permafrost thawing: Releases stored carbon dioxide and methane, contributing to global warming.
  • Temperature rise: Alters species composition and threatens cold-adapted species.
  • Increased shrub growth: Changes the landscape and affects the albedo effect (surface reflectivity).

Human Impact and Conservation Efforts

Human activities such as oil and gas extraction, mining, and infrastructure development pose significant threats to the tundra. Conservation efforts protect these areas through international agreements, sustainable practices, and minimizing human disturbance. Pollution and habitat disruption are serious threats because the cold temperatures slow ecosystem growth and recovery.

References

  • Bliss, L. C; O. W. Heal; J. J. Moore (1981). Tundra Ecosystems: A Comparative Analysis. International Biological Programme Synthesis Series (No. 25). ISBN 978-0-521-22776-6.
  • Douglas, Thomas A.; Turetsky, Merritt R.; Koven, Charles D. (2020). “Increased rainfall stimulates permafrost thaw across a variety of Interior Alaskan boreal ecosystems”. npj Climate and Atmospheric Science. 3 (1): 5626. doi:10.1038/s41612-020-0130-4
  • Higuera, Philip E.; Chipman, Melissa L.; et al. (2011). “Variability of tundra fire regimes in Arctic Alaska: millennial-scale patterns and ecological implications”. Ecological Applications. 21 (8): 3211–3226. doi:10.1890/11-0387.1
  • Körner, Christian (2003). Alpine Plant Life: Functional Plant Ecology of High Mountain Ecosystems. Berlin: Springer. ISBN 978-3-540-00347-2.
  • Peel, M.C.; Finlayson, B.L.; McMahon, T.A. (2007). “Updated world map of the Köppen-Geiger climate classification”. Hydrol. Earth Syst. Sci. 11 (5): 1633–1644. doi:10.5194/hess-11-1633-2007