ABIOTIC AND BIOTIC FACTORS OF THE TUNDRA - BIOLOGY - 2024

Among the biotic and abiotic factors of the tundra, a temperature ranging from 12 to -27 ° C and plants that are characterized by shallow roots stand out. The term tundra is used to define a set of biotic areas characterized by the lack of trees, very low temperatures, a lot of wind and little rainfall.

The name seems to derive from several languages, such as the Russian тундра and the Finnish voice tunturia, which mean "plain without trees"; and from the term tūndâr, from the Kildin Sami language of the Kola Peninsula (Russia), meaning "infertile land."

Siberian tundra (Russia). Taken and edited from Dr. Andreas Hugentobler, from Wikimedia Commons

This biome is found in various regions of the planet, especially in the polar areas; these areas occupy about 20% of the planet's surface. In the northern hemisphere it is found in America in countries such as Canada (north), Denmark (Greenland) and the USA (Alaska).

In Europe it is along the entire Arctic coast, which includes Finland, Iceland, Norway and Sweden. In Asia it is located in the region of Siberia (eastern Russia) and in the southern hemisphere of America it extends into countries such as Argentina and Chile.

Other locations in the tundra are the islands that surround the Antarctic Circle, such as South Georgia and Kerguelen.

General characteristics

The tundra has a large number of biotic and abiotic factors that characterize it. In addition to these, there are also some peculiarities that define this biome in a general way. Some of these characteristics are the following:

- They are areas with extremely low temperature climates.

- Biological diversity is relatively low.

- Soils have limited drainage.

- The morphology and architecture of the plant community is simple.

- The reproductive seasons of the flora and fauna are brief.

- Nutrients and energy are available mainly in the form of decomposing or dead organic matter.

- There are winds above 20 km / h most of the year, and can exceed 60 km / h.

Types of tundra

Arctic

As its name implies, it is located in the polar zone of the Arctic, in the northern hemisphere. It circles the north pole and extends into the taiga.

The defining characteristic of this tundra is the underground layer of ice or frozen soil (permafrost) inches from the surface.

Antarctica

It is found in the southern hemisphere in Antarctica and in the subantarctic islands. This tundra is characterized by being an area mostly covered with ice, like most of the Antarctic continent.

However, there are some areas that are not covered with ice but with rocky soil, and it is in these that the tundra exists as such. Permafrost also occurs on this type of tundra on the subantarctic islands of South Georgia and the South Sandwich.

Alpine

It occurs in mountainous areas around the world, specifically in mountains that exceed 3500 m in height. This tundra is also devoid of shrubs and trees, and has better drainage than other tundras because there is no permafrost.

Alpine tundra, Copper Mountain, Colorado (USA). Taken and edited from John Holm from Leadville, CO, USA, via Wikimedia Commons.

Abiotic factors

The term abiotic means that it has no life; therefore, abiotic factors are those without life. Within this group are temperature, luminosity, salinity and nutrients, among many others. The abiotic factors that define the tundra are the following:

Altitude

The tundra can be found both a few meters above sea level and in some arctic, Antarctic and subantarctic islands.

For example, in the specific case of the alpine tundra, it is found in mountain areas that exceed approximately 3,500 m in altitude.

Temperature

This biotic area is known for its low temperatures, although these can still rise or fall depending on the time of year.

Low temperatures range from -34 to -27 ° C in winter and 3 to 10 ° C in summer. Even some arctic tundras report 12 ° C in summer.

Permafrost

It is the layer of the subsoil that is permanently frozen. The depth varies from place to place, but ranges from approximately 25 to 90 cm deep.

This layer is characteristic of the tundra and is present in almost all regions defined as tundra, except those in the alpine areas.

Light

In the tundras the availability of sunlight is quite limited throughout the year. Even in the summer (6 to 8 weeks) the availability of light is similar to a cloudy day.

This time of greatest amount of available light coincides with the reproductive season, which lasts between 50 and 60 days.

Rainfall

When it comes to rainfall, these areas are practically desert places. Precipitation is very low and usually occurs in the form of snow.

For example, in Arctic tundra rainfall can be as high as 25 to 35 cm (including snowmelt).

Biotic factors

In contrast to abiotic factors, biotics are represented by the set of living beings in an area. Examples of biotic elements are bacteria, fungi, plants and animals.

In the tundra the biodiversity is lower compared to other biomes. Even some tundras are more diverse than others and this is due in part to the abiotic factors that govern the different areas where they are found. Below we will detail the plant and animal biotic diversity according to the type of tundra:

-Artic

Vegetable

The presence of permafrost limits the development of deep roots and, in turn, restricts the shape and structure of the plants that can thrive in this and all types of tundra that possess it.

At least 1,700 species of plants have been described for the Arctic tundra, among which at least 400 varieties of flowering plants, grasses, shrubs, some liverworts, mosses and even lichens stand out.

Animal

With regard to fauna, the Arctic tundra is low in animal biodiversity but with relatively large populations of each species.

About 48 species of mammals have been reported, such as reindeer, oxen, wolves, polar bears, free arctic and arctic foxes, among others.

-Antarctica

Vegetable

A study carried out in 2004 indicated that the Antarctic flora is represented by more than 1200 species of plant organisms, among which are more than 300 types of lichens, a hundred mosses and 700 species of rock, aquatic and soil algae. There are very few species of flowering plants and grasses.

Animal

In this region, whose surface is mainly covered with ice, several species of mammals and birds have been described that alternate their life in the water and on the coast, such as the Weddel seal, the leopard seal and several species of penguins, such as the emperor. There are also small mammals introduced by man, such as rabbits and cats.

-Alpina

Vegetable

The alpine tundra presents a vegetation very similar to that of the other types of tundras (Arctic and Antarctic). More than 300 species of plants are known to exist, including grasses, shrubs, hedges, and some species of mosses and lichens.

Animal

In this type of tundra, a diverse group of insect species from the Orthoptera (grasshoppers) and Coleoptera (beetles) groups, among others, has been described.

Mammal species such as marmots, goats, elk, and sheep have also been documented. As for birds, the most diverse group belongs to the Tetraonidae family.

References

1. E. Barretto. Tundra Characteristics. Recovered from sciencing.com.
2. Tundra. Biopedia. Recovered from biopedia.com.
3. Plants - British Antarctic Survey (2004). Recovered from bas.ac.uk.
4. Tundra. New World Encyclopedia. Recovered from newworldencyclopedia.org
5. The fauna and flora of Polar Regions: Antarctic. Visual dictionary. Recovered from ikonet.com
6. Tundra. National Geographic. Recovered from nationalgeographic.com.
7. The tundra biome. University of California Museun of Paleontology. Recovered from ucmp.berkeley.edu.
8. Tundra. Wikipedia. Recovered from en.wikipedia.org.