By Isabela Bruña, Jacobo Ocampo, Cristina Lucena, Lydia Herrera and Camilo Cañaveral Alzate.
The Arctic tundra circles the North Pole and is located in the northern hemisphere. The Arctic expands from Alaska, North Canada, Greenland and northern Europe.
Permafrost under the temporarily melted ground makes water drainage impossible, so there are many small lakes and puddles, and much of the ground is soggy.
Permafrost is perennially frozen ground that remains at or below zero degrees Celsius for two or more years and forms in regions where the mean annual temperature is colder than zero degrees Celsius.
Permafrost underlies about 20% of the land in the Northern Hemisphere and is well-known within the Arctic Ocean’s vast continental shelves and in parts of Antarctica.
Most of the world’s permafrost has been frozen for millennia and can be up to 5,000 feet thick.
It is most known for its cold, desert-like conditions with temperatures reaching as low as ?40 °C, the coldest recorded temperature is approximately ?68 °C, and up to 3-12oC in summer, enabling this biome to sustain life.
The average yearly rainfall varies in different regions of the arctic. Yearly precipitation, including snow, is 15 to 25cm.
As spring arrives, the days become longer at a rapidly increasing rate. The further north one goes the longer they get.
After the equinox fall, the days become shorter and for every extra hour of summer daylight, there is an extra hour in darkness during winter.
Due to the conditions animals and plants have to live throughout the years, they have adapted themselves to survive.
The location of the tundra affects the vegetation in such a way that vegetation is scarce, and is mostly moss because it doesn’t need as much water compared to other plants and any tree or flower that does grow here, is evergreen.
Animals usually, have thick skin and fur to insulate them during the winter and to allow them to swim through the freezing rivers and seas. Most animals usually hibernate until spring because food is scarce during winter.
Although the tundra seems like an inhabitable place for any sorts of species amazingly life flourishes every year during the summer bloom, temperatures rise and the snow melts, the sun’s rays penetrate to stimulate plant growth.
As the air warms, insects by the million emerge, and birds and mammals that have wintered over begin to fatten.
Soon the inhabitable terrain becomes feeding and breeding grounds for not only the native animals of the tundra, animals from as far as South America or Africa migrate there every year to breed and feed.
Native animals and plants of the tundra include:
Grizzly bears are big and are always hungry. They eat everything. During summer they snap up lemmings, ground squirrels, nesting birds’ eggs, or injured caribou. They sometimes eat grass, roots and berries. They hibernate during the winter.
Most bears are found in North America and Eurasia. They’re found on the Alaskan north-west Canadian tundra. They’re considered a subspecies of the brown bear. They’re mostly found in the north-west part of North America. Their habitat can include forests, mountains, meadows and valleys.
Grizzlies have amazing physical strength and considering their size they can run surprisingly fast over short distances.
They are aggressive and have no trouble driving away predators like wolves and mountain lions. They have a great sense of smell.
They are characterised for their heavy, Stout body, big head and short tail. It has a distinctive hump between its shoulder blades.
The tundra grizzly is often creamy tallow on the back with brownish legs. They can weigh up to 704 lbs., over 8 feet in length, and stand 3 ½ feet high at the shoulders.
They have a thick, shaggy coat of hair, layers of fat to insulate them. During winter they sleep in dens packed with leaves and sticks where they hibernate.
However it doesn’t go into full hibernation and will occasionally come out of its den. It doesn’t eat during this time but instead lives off stored body-fat until spring.
Scientists discovered that 75% of the bear population lives off plants alone. They will also eat insects, small rodents and honey. It is strong enough to kill a caribou and outrun a moose, but usually doesn’t hunt. It will eat abandoned kills made by other predators, by driving them away from their kill.
Females have cubs at around the age of five. She will give birth to 2-4 cubs, usually twins in January. Cubs weigh about 1lb at birth and will suckle until May. Their life span is around 25 years.
Caribou or reindeer, are the wild deer of Arctic North America, they’re the wild and domesticated herds of Europe and Asia. They migrate north during spring, south during autumn. Calves are born during the spring migration.
They’re found in countries such as Canada, Russia, Sweden, Finland, Norway, and Greenland. They can also be found in Alaska.
Their diet varies throughout the year. During summer, when vegetation is plentiful, Caribou will feed on a variety of plant including willow leaves. During winter, they use their hooves to dig through snow to get to the moss and other lichen that lie beneath the arctic surface.
They’re migratory animals and are known for mass migrations across the tundra in search of food. They’re well adapted to living in the tundra, with thick fur and skin that enables them to enter freezing rivers while migrating.
Female Caribou will weigh about 200 pounds, and can weigh as little as 180 pounds as adults.
Males weigh twice as much on average but can weigh up to as much as 600pounds. Both females and males have antlers and they will shed them at different times in the year, older males losing theirs after mating season and females losing theirs in the summer.
Mating season occurs in autumn and the calving season occurs in spring when females will usually give birth to one calf.
Known as willow ptarmigans because they feed almost entirely on leaves and buds of dwarf willows, these birds need year-round camouflage to protect them from predators.
Mottled brown in summer and white in winter, they simply disappear into their background. They’re found only in the colder regions of North America.
During winter they migrate further south than normal and can be seen in locations throughout Canada that they would not normally live in.
They can also be found in Britain, but it’s called the Red Grouse, however they do not turn white during winter.
The Arctic Fox is circumpolar and can be found throughout the Arctic region. This includes parts of Canada, Russia, Greenland, Iceland, Scandinavia, Svalbard and Alaska.
The Arctic Fox’s diet consists of small mammals including voles, lemmings, birds and their eggs. They’re opportunistic and will sometimes scavenge on dead carcasses of animals and are often seen following polar bears to feed on their leftovers.
Arctic foxes will also eat some vegetation such as berries.
Like many foxes, the Arctic fox builds a den. It can sometimes be in a hillside or river bank, and will usually have multiple entrances and exits.
It can be found either in the arctic or alpine tundra.
It measures 3-3.5 feet in length from head to tail. Their weight ranges from 6-9 pounds, with females being smaller than males.
They have special adaptation to help them survive in this extremely cold weather.
These adaptations include fur on its paws to help keep them warm, a thick dense coat of fur around its body, short ears, a small body, and a large, bushy tail that it uses to curl around its body.
Their mating season occurs in the spring and after a gestation period of 7-8 weeks a female fox will give birth to an average litter size of 6-8 kits.
As summer approaches they malt their fur and it turns from white to brown with white.
They live around the Arctic Ocean and neighbouring seas. Males weigh up to 600 kg; females are lighter, 250 kg. They live mainly on seals.
As year-round residents in the Arctic they have to survive sub-zero temperatures. Their dense white fur, up to 30cm thick, it protects them from the worst polar weather. The fur is waterproof too, so bears can swim for hours in icy seas. In autumn they fatten on fish, particularly salmon, which they scoop from freshwater.
They live where food is rarely plentiful; polar bears usually walk on their own. Two or three together are most likely to be a mother with cubs. When lone males meet, they growl, roar, and even wrestle until one is driven away.
Despite their weight and bulk, polar bears are agile. They leap from iceberg to iceberg and wander many miles every day in search of food. The ability to leave land and travel over sea ice gives them access to breeding seals-their main food in early spring.
They’re lone animals that live by their wits; they’re strong enough to break into houses and food shops. Even though they’re hunted in small numbers they’re still protected by international agreement throughout the Arctic.
When young, cubs stay with their mother for up to two years, until almost fully grown.
Polar bears mate in summer. In autumn the pregnant females dig dens for themselves in snow banks, where they sleep throughout winter.
FLORA IN THE ARCTIC
Hello, my name is Camilo and I am going to introduce you into this topic, flora in the Arctic. I will be explaining the main features of the plants and then the main biome in the Arctic, the Tundra and its two principal species, the moss and the Lichen.
The Arctic region embraces parts of Canada, Russia, Greenland, United States, Norway, Sweden, Finland, and Iceland. Temperatures normally reach the ?28 °C. That is pretty cold…
Due to these conditions the soil is frozen and there are very strong winds so trees can’t grow here. The few plants that do grow here are adapted to strong winds, low temperatures and lack of soil. They are very low and are usually found in groups to stay warm. In fact, some types are so adapted that they can grow under snow!
Do you know why certain plants have red leaves? No? Well, this characteristic allows them to absorb more heat from the sun that they would if they had ordinary leaves.
Did you know that the Arctic is the least affected area of the planet by human activity? It has many virgin areas (zones that have never been touched by humans)
The main biome in the Arctic is the:
The word Tundra comes from Russia and means uplands.
There are three types of Tundra: Arctic, Alpine and Antarctic.
The region between the tundra and the forest is known as timberland
I will be concentrating in the:
The Arctic Tundra has very few species and they grow slowly because their growing season is extremely brief. They photosynthesise in short periods of daylight.
There are only two seasons: winter and summer.
Winter is cold and dark and temperatures can drop to -50°C!! In summer temperatures rise up to 12°C so the top layer of the permafrost melts, leaving the ground soggy. If you walked during the warm months you would probably find marshes , lakes, bogs and streams.
The Arctic Tundra has oil and Uranium.
The principal vegetation here is mosses and lichens.
Mosses are tiny and soft plants. They measure typically from 1 to 10cm tall. They grow close to each other in dark or damp areas. They do not have seeds or flowers. They absorb nutrients and water through their leaves. They only have roots to anchor them.
You want to see mosses in a city? That is easy. Mosses grow on rocks so you can find them anywhere. On the cracks between paving stones, on the walls, on the ceiling… They can even grow on trees!
Lichens are very complex dual organisms and I really don’t understand them. To ‘get’ them you have to know about botany.
Here is an explanation by British Lichens:
Lichens are ‘dual’ organisms. They consist of two (or more) different life-forms living together symbiotically in a more-or-less well defined body or thallus.
The main partner is the fungus or mycobiont. The other partner is a green alga or a cyanobacterium (the photobiont). Many cyanobacteria are able to fix nitrogen which is an essential nutrient. In 10% of lichens (e.g. Collema and Leptogium) the photobiont is a cyanobacterium. The nutritional benefits of having a nitrogen fixing capability is why some lichens, where the primary photobiont is a green alga, have evolved separate structures called cephalodia which contain cyanobacteria (the secondary photobiont). So for these lichens there are three partners in the symbiosis.
Lichens are named after the fungal partner.
If you want more information you can go to: http://www.britishlichens.co.uk/whatarelichens.html
Other vegetation found in Tundras is shrubs (bushes), sedges and grasses.
Throughout the years Global Warming has become an increasing problem especially in the Arctic, what scientists originally thought about the Arctic in concern to global warming has now changed. Scientists have discovered that the effect global warming has on the Arctic has accelerated significantly in the past 30 years.
The snow cover in May and June has decreased by close to 20 per cent. The winter season has also become almost two weeks shorter — in just a few decades. In addition, the temperature in the permafrost has increased by between half a degree and two degrees.
Areas of both permanent and annually-renewed Arctic sea ice grow smaller year by year and have lost 38% of their area over the past 30 years.