Thursday, October 18, 2012

The Arctic Tundra

The Tundra is located in the northern regions of North America, Europe, Asia, as well as a few regions of Antarctica. The Tundra is the second largest vegetation zone in Canada. It can be divided clearly into three different sections: the High Arctic Tundra, the Low Arctic Tundra and the Alpine Tundra. The latter Alpine Tundra occurs in higher altitudes such as mountains whereas the first two are mainly based in plains and lowlands of some kind. The Low Arctic Tundra is the transmission point to the north. It is located above Canada's Boreal forests and is followed by the High Arctic Tundra. The High Arctic Tundra is located farther north and encompasses the Arctic circle as well as most of the western Northwest Territories. Generally though since climate more or less corresponds to vegetation zones, the Tundra is located in Arctic climate areas.

The Tundra suffers a very harsh climate. Because of this fact most of the area remains barren save for a few shrubs and lichens. It's winters last from 8-10 months and the summers are cool and short. Also due to the fact that much of it's territory is located within the northern pole a lot of the Tundra receives alternating 6 month periods of light and dark. This is also the reason why the Tundra receives cold weather; at it's degree of latitude the suns rays end up hitting the region obliquely, thus causing less solar heat. Here are the temperatures of the Tundra in general:
Average January temperature: -32.1 degrees Celsius
Average July temperature: +4.1 degrees Celsius
Temperature range: 36.2 degrees Celsius
Average annual temperature: -17 degrees Celsius
Lowest temperature recorded: -52.5 degrees Celsius
Highest temperature recorded: +18.3 degrees Celsius
After seeing these temperatures you can see the reason why barely anyone lives up there and why there is rather little natural vegetation.

Seasons And Moisture Content
The main seasons of the Tundra are summer and winter. The winter will last 8 to 10 months followed by the short and much less cold summer. During the summer some lower areas of the Tundra will defrost at which point most of the flora and fauna will start to creep out of hiding. The few summer months are used by many animals such as the polar bear, to mate and to prepare for the once again oncoming winter. During the winter months most everything remains frozen. Many of the animals migrate south for the winter whereas some stay behind or even group together for ritual group suicide (lemmings).
There is little precipitation all year long in the Tundra. The average yearly total is 136 mm, out of which 83.3 mm is snow. This low amount is due to the fact that there is very little evaporation. Since the average temperature is below freezing, it give little or no time for any of the snow and/or ice to melt. This is the reason that the Tundra is often referred to as a polar desert.

The Tundra's fertility is very low. It has An average growing season of about 60 days (1.5 to 3.5 months) which is not really enough time to allow anything to grow. This is also compounded with the fact that the soil is mainly thin and rocky. But, the main problem is that most of the ground in the Tundra region is permafrost (soil which stays frozen perennially). These 3 aspects of Tundra fertility make the Tundra all but useless for use to grow anything of value.
Forest Floor
The Tundra forest floor really depends on where you are. The further north that you go the less there is anything but snow, ice, and rocks. In the more temperate Tundra where there is plant life one could find more interesting floors. They contain once again mainly rocky soil which is most likely permafrost. Also there are many different kinds of mosses and lichens scattered along the ground or on bigger rocks along with possibly some short grasses.

Diversity of Plants
There are not very many species of plant life in the Arctic Tundra, nor is their growth rate giant or are they abundant but somehow they do survive. Most of the plant life occurs in the lower areas of the Tundra although there are sometimes a few "pockets" of vegetation as you move further north. There is also a bit more vegetation in the Alpine Tundra. During the few short summer months, the vegetation is able to grow, as opposed to winter where only a few cold resistant trees can survive the harsh climate and temperatures. The plants reproduce by division and by budding rather than by pollination since there is little time and little other plants.
The Vegetation is often divided into two distinct regions. The change from one to another is quite surprising. They are:
The low arctic Tundra which supports a nearly complete plant coverage. There are many low and dwarf shrubs which include willow, birch, and Heath. There is a large quantity of mosses and lichens in this area.
The high arctic Tundra is a place where it is obviously much more difficult to locate as many plants. Once again mosses and lichens are found but in smaller proportions. Scattered "patches" of willow and sedge occur as well.
Diversity of Animals
Even though the arctic Tundra is not seeping with wildlife, there are more than a few different kinds of animals. The arctic Tundra wildlife is closely related all around the world, but the variety is limited because of the difficult environment that they have to adjust to. There are of course the large herbivores, which include such species as the caribou, the musk-ox , and the reindeer. These eat the mosses and dwarf shrubs which they may come across as they cross the arctic. As for predators, they include the wolf and the arctic fox. These play a most crucial role in the Tundra by killing and eating several herbivores. Without this service the herbivores would eat all the plants and end up starving to death. There are also many birds which nest in the tundra during the summer months and then migrate south for the winter. Polar bears as well as brown bears are not uncommon to the arctic Tundra as well. Many other animals include: the snowy owl, the lemming, jaegers, the weasel, and the arctic hare to name a few. But perhaps the most annoying of all is the mosquitoes and blackflies which roam around in huge groups.

Symbiotic Relationship
The relationship of the Tundra is a delicate one; any slight faltering could result in massive repercussions. To survive, the herbivores need to eat what little dwarf shrubs and mosses that they can find and in turn the meat eaters need to eat them. Eventually when the animals die, they become the little earth that will perhaps allow some plant to grow. Without this earth the plants will not grow and all will die.
Structure Adaptations
Since the Arctic Tundra has such a harsh climate everything has had to adapt or be wiped out. The most common adaptation among animals is rather thick and white fur or feathers. Many animals such as the snowy owl have grown to use this to camouflage themselves to escape predators or as a predator themselves to catch their prey. Among Plants there are many changes. Many plants have adapted to contain most of their biomass in their roots so as to protect themselves from the winds. Also another common plant adaptation has been to develop a more aerodynamic and stronger frame to withstand the winds. Among insects the mosquitoes and blackflies have evolved into darker black colors so as to capture and save most of the days heat.

Other facts
When a vehicle passes in the Tundra area, the tracks cause deep ditches that can last not for days but for years. Also what could happen is that if a piece of the Tundra's permafrost is melted, it will cave in a large area. The Tundra is very fragile and we must take care not to destroy it for it is very frail.

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