Earth’s Polar Regions First the Arctic--TundraBy Moira Whitehouse PhD
The Arctic tundra is in the northern hemispherearound the north pole. The arctic is known for itscold, desert-like conditions. The average wintertemperature is minus 30° F below zero. In thesummer it warms up to between 37-54° F so someplants can grow during this time.
Summer are short, cool and light most ofWinter are long the daycold, and dark
The tundra isvery, very cold,flat andtreeless. Theword tundracomes from aFinnish wordand means“treeless plain”.
In the tundra, except for about a meter of soilon top, the ground is permanently frozen. Thislayer of frozen soil is called permafrost.
This frozen soil under the melted snow stops thewater from soaking into the ground. As a resultin the spring puddles of water, big and small,form on top of the frozen ground (permafrost).
These bodies of water are perfect places formosquitoes, black flies and other insects tolay eggs. The eggs quickly hatch and growinto biting insects.
There are so manymosquitoes andblack flies in thetundra during thesummer months thatyou would have towear this kind of suitto protect themfrom biting you.
In the very short summers when it warms up,the top level of soil melts just long enough forplants to grow and reproduce. These plantsbecome dormant (hibernate) over winter. Buteven during the summer, the permafrostlayer never thaws. permafrost
In spite of the harsh conditions, there are manykinds of lichen and plants that grow in the Arctic.Lichens are the main living thing in the tundrathat carries out photosynthesis. Lichens arereally two living things– an alga and a fungus.Together they become a lichen. It is nearlyimpossible to identify the alga or the fungusonce they get together and become a lichen.Lichens can survive very cold temperatures andmany continue to live even when covered withsnow for up to three years.
The alga provides the food and the fungus providesthe water for the lichen. The alga uses light, water,and carbon dioxide (through photosynthesis), toproduce food (carbohydrates) for itself and thefungus. In return for its food, the fungus providesliquid water for itself and the alga. The fungus alsoattaches to the rocky surface. Two types of Arctic lichen.
Summer in the far north is very short—6-10 weeks. Plants must grow, flower and reproduce in this very short amount of time.Tundra plants have adapted to live in this environment. They have shallow roots for the thin layer of soil and grow low to the ground for protection from the cold and wind.
There are many low growing plants calledsedges and forbs that bloom beautifully for avery short time in the tundra.
Mosses, very simple plants without roots, areoften thick in the tundra where there is somesoil and water.Moss growing around a rock Moss growing around a rock with lichen
Many different species of animals that live inthe tundra-- some on land, some in the water. Some living on land are herbivorest hat eat the plants and lichen that grow there.
Musk Ox Caribou Dali Sheep Ptarmigan ArcticLemming Hare
Others are carnivores that eat the herbivores. wolverine ermine Arcticwolf Arcticfox
Polar bears live on the icesheets but usually catchtheir favorite food, seals,by grabbing them andpulling them through theseal’s breathing hole inthe ice.
Walruses climb out on the sea ice to restand to give birth. They congregatetogether in great numbers. However, theydive in the water to catch various kinds ofseafood.
Others like Beluga whales live all the time in the icy cold water of the Arctic Ocean .Animals that live in the Arctic have specialadaptations that allow them to survive theconditions there.
Some animals arewhite in the winterand brown insummer either forprotection (prey) orto help them hunt(predators).
Many grow thickfur, hair or feathersin the winter tokeep warm andlose it in spring.
Mammals living in the Arctic prepare for thewinter months by eating more food to put onextra body fat. Food is scarce in the winter andthey often need to live off stored body fat.
Some like this lemming burrow under the snow in winter to keep warm.Some like this Arcticground squirrel eat alot of food in the fallstoring it as fat andthen hibernate for thewinter living off thisstored fat.
Animals that live in the Arctic Ocean suchas seals, whales and walruses have an extralayer of fat called blubber which keepsthem warm in the cold.
Many birds haveadapted to the coldArctic throughmigration. In summer,thousands of birdsmigrate to the Arcticfrom Central and SouthAmerica to feed and toraise their young.
Antarctica is the coldest, driest, windiest place on Earth.Around the coasts of Antarctica, temperaturesare generally close to freezing in the summermonths. During winter, average monthlytemperatures are always well below freezing--between 14°F and −22°F.On the high plateau in the middle ofAntarctica temperatures are much colder.Here, summer temperatures struggle to getabove −4°F and monthly averages in thewinter fall below −76 °F.
These extreme conditions make Antarctica ahabitat in which only the hardiest can survive.
Only two percent ofthe continent ofAntarctica is ice freein summer, so veryfew producers livethere. Theproducers include30 mosses, twoflowering plants andsome algae.The most common life form is the lichen.
About one hundred and fifty to two hundred differentkinds of lichen live in the Antarctica. A lichen,remember, is an algae and a fungus growing together.They depend on one another for survival. OnAntarctica, the fungus provides the water while thealgae, a producer, makes food both of them.
Two kinds of lichen that grow in the Antarctica
Mosses are very small green plants that haveno roots. They have stems not much thickerthan a stand of your hair and are covered withtiny, tiny leaves. Many mosses grow togetheron rocks forming a thick green mass. Mosses growing in the Antarctica
On the Antarctic continent, some algae (verysmall producers) live in lakes and streams, onmoist soil and in snow banks. Algae also live inthe spaces between the sandstone rocks. Algae growing in the Antarctica Many, many algae live in the Antarctica Ocean and are the bottom of the ocean food chains.
Only two native flowering plants cansurvive in this cold climate, theAntarctica Hair Grass and the AntarcticaPearlwort. Both these plants toleratevery cold and dry conditions. They growin small clumps near the shore of thewest coast of Antarctic Peninsula. This isin marked contrast to the Arctic regionswhere nearly 100 flowering plants arefound.
Sincehardly any plants live on the continent, noland animals can actually call it home. Its justtoo cold and dry to support very many lifeforms!Penguins (Emperors and Adelies) are the onlybirds that actually inhabit this frozen landscape.They come on land only to breed and raise theiryoung. They must find their food in the oceanssurrounding Antarctica
Man does not live on Antarctica—a fewresearchers and tourists only visit for a fewmonths of the year. Antarctica, a place where it is too cold and dryfor humans to live, is indeed a fascinatingcontinent.
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