He tundra ecosystem is a region without trees that is in the Arctic and in the top of the mountains, where the climate is cold and with strong winds. In these ecosystems rainfall is scarce.
The tundra lands are covered with snow almost all year round, until in the summer a group of wildflowers is born. There are three types of tundra: alpine tundra, arctic tundra and Antarctic tundra.
In the tundra, the growth of vegetation is restricted by the low temperatures and the short seasons of the climate. Its name means"mountainous tract without trees".
To be classified as tundra, the climate of at least one month must have an average temperature high enough to melt the snow, but no month with an average temperature exceeding 10 degrees Celsius.
Tundra ecosystems are hostile to woody vegetation, even though winters are comparatively mild for polar standards.
Location
The tundra is located in the Arctic Circle and Antarctica, especially in the Northern Hemisphere. The tundra can be found in Siberia, Alaska, Iceland, southern Greenland, northern Canada, Russia, Scandinavia, and in the Antarctic sub islands between Chile and Argentina.
The overall extent of this ecosystem is considerable: it occupies almost 10% of the Earth's surface. The southern boundary of the Arctic tundra follows the northern edge of the coniferous forest belt.
The alpine tundra occupies about 3% of the Earth and is mainly found in the northern hemisphere.
Types of tundra
There are three types of tundra: Arctic, Alpine and Antarctic. The main characteristics are as follows:
Arctic tundra
It lies under the ice sheets of the northern hemisphere and extends into the coniferous forests. Mostly it is found in most of Alaska and almost in the middle of Canada.
Alpine tundra
It is located in the mountains of almost the whole world; mainly occupy so high heights where trees do not grow. They do not have permafrost (soil layer that is always frozen), unlike the Arctic tundra.
Antarctic tundra
It is the least common tundra. It can be found in some islands of southern Argentina.
Main Features
Weather
The climate of the tundra varies considerably. The most severe occurs in Arctic regions, where temperatures fluctuate from 4 to -32 ° C during the winter.
The alpine tundra has a more moderate climate: summers can be from 3 to 12 ° C, and winters have temperatures that rarely fall below -18 ° Celsius.
The annual precipitation of the Arctic tundra is less than 38 centimeters. The rest falls in an expanded form in the form of snow, which can accumulate from 64 to 191 centimeters. Annual precipitation in the alpine tundra is generally higher than in the Arctic.
Blinding snowstorms that darken the landscape are prevalent during the winter months; summer rains can be heavy.
Although the winds are not as strong in Arctic tundras as in Alpine tundras, their influence has a great climatic factor.
Floors
Permafrost is present in the Arctic tundra. The southern boundary of continuous permafrost occurs within the forested belt of North America and Eurasia. In the south of this zone, permafrost exists in fragments.
During the winter, water in the soil can freeze on ice, causing the soil on the ice to form a structure called pingo.
The alpine tundra is generally drier; the lack of continuous permafrost and the inclined topography generate a rapid drainage.
Flora
The vegetation of alpine and arctic tundra tends to be greenish-brown. The plants do not remain flowered for more than a few days or weeks, the buds are generally large in relation to the size of the plant and quite colorful.
The plant organisms of the tundra have a low diversity, but many also flower. Many lichens, molds and small shrubs bloom in the Arctic tundra.
The plants that live in the soil with continuous permafrost usually adapt to the climate, since they are short and grow grouped, to resist the winds and to protect themselves.
The tundra found in the coastal areas produces herbaceous landscapes. Algae and fungi are found on the rocky peaks. In the driest tundra, lichens develop.
Areas of arctic tundra are dominated by weeds and molds. At the highest sites, willows, legume family plants and sunflowers are common alongside the rivers.
But the vegetation is rather scarce on the higher ground, at the foot of the hills and in the Arctic mountains.
Fauna
The organisms in the northern alpine tundra probably evolved earlier than those in the Arctic tundra. However, few alpine animals contributed directly to the evolution of the species of the Arctic tundra; their physical barriers prevented the migration of species.
The animals of the Alpine and Arctic tundra specialized in their particular environments. Some animals migrated east and west, across the mountains to Europe and North America. Alpine tundras are quite limited in the number of animal species and diversity residing in them.
Most Arctic animals are circumpolar. These animals include the polar bear, arctic fox, arctic wolf, arctic hare, snow owl and various species of lemurs.
The Arctic tundra is home to large herbivores, such as the reindeer of Eurasia and North America, where they are known as caribou. The musk ox lives in Greenland and in some Arctic Canadian islands.
Large body size is an adaptive advantage: there is less surface area relative to volume, and therefore less opportunity for heat to dissipate from outside.
Exceptionally thick coat also helps them survive. The sharp hooves and reindeer bunches help them cut around the snow to forage lichens and plants.
The limited fauna of the alpine tundra is due to the fact that most of the animals are not adapted to alpine life all year round. Most follow a vertical migration; some vertically migrating animals are mountain sheep, many birds, ibex and many wild cats.
References
- Tundra. Retrieved from kids.nceas.ucsb.edu
- Tundra. Retrieved from wikipedia.org
- Tundra (2012). Retrieved from Wikipedia
- Tundra. Recovered from britannica.com
- Tundra. Retrieved from nationalgeographic.com