Earth’s Polar Regions

First the Arctic--Tundra

By Moira Whitehouse PhD

The Arctic tundra is in the northern hemisphere around the north pole. The arctic is known for its cold, desert-like conditions. The average winter temperature is minus 30° F below zero. In the summer it warms up to between 37-54° F so some plants can grow during this time.

Winter are long cold, and dark

Summer are short, cool and light most of the day

The tundra is very, very cold, flat and treeless. The word tundra comes from a Finnish word and means “treeless plain”.

In the tundra, except for about a meter of soil on top, the ground is permanently frozen. This layer of frozen soil is called permafrost.

This frozen soil under the melted snow stops the water from soaking into the ground. As a result in the spring puddles of water, big and small, form on top of the frozen ground (permafrost).

These bodies of water are perfect places for mosquitoes, black flies and other insects to lay eggs. The eggs quickly hatch and grow into biting insects.

There are so many mosquitoes and black flies in the tundra during the summer months that you would have to wear this kind of suit to protect them from biting you.

In the very short summers when it warms up, the top level of soil melts just long enough for plants to grow and reproduce. These plants become dormant (hibernate) over winter. But even during the summer, the permafrost layer never thaws.

permafrost

Lichens are the main living thing in the tundra that carries out photosynthesis. Lichens are really two living things– an alga and a fungus. Together they become a lichen. It is nearly impossible to identify the alga or the fungus once they get together and become a lichen.

Lichens can survive very cold temperatures and many continue to live even when covered with snow for up to three years.

In spite of the harsh conditions, there are many kinds of lichen and plants that grow in the Arctic.

The alga provides the food and the fungus provides the water for the lichen. The alga uses light, water, and carbon dioxide (through photosynthesis), to produce food (carbohydrates) for itself and the fungus. In return for its food, the fungus provides liquid water for itself and the alga. The fungus also attaches 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.

They have shallow roots for the thin layer of soil and grow low to the ground for protection from the cold and wind.

Tundra plants have adapted to live in this environment.

There are many low growing plants called sedges and forbs that bloom beautifully for a very short time in the tundra.

Mosses, very simple plants without roots, are often thick in the tundra where there is some soil and water.

Moss growing around a rock Moss growing around a rock with lichen

Many different species of animals that live in the tundra-- some on land, some in the water.

Some living on land are herbivoresthat eat the plants and lichen that grow there.

Musk Ox Caribou

Dali Sheep

LemmingArctic Hare

Ptarmigan

Others are carnivores that eat the herbivores.

ermine

Arcticfox

wolverine

Arcticwolf

Polar bears live on the ice sheets but usually catch their favorite food, seals, by grabbing them and pulling them through the seal’s breathing hole in the ice.

Walruses climb out on the sea ice to rest and to give birth. They congregate together in great numbers. However, they dive in the water to catch various kinds of seafood.

Others like Beluga whales live all the time in the icy cold water of the Arctic Ocean .

Animals that live in the Arctic have special adaptations that allow them to survive the conditions there.

Some animals are white in the winter and brown in summer either for protection (prey) or to help them hunt (predators).

Many grow thick fur, hair or feathers in the winter to keep warm and lose it in spring.

Mammals living in the Arctic prepare for the winter months by eating more food to put on extra body fat. Food is scarce in the winter and they often need to live off stored body fat.

Some like this Arctic ground squirrel eat a lot of food in the fall storing it as fat and then hibernate for the winter living off this stored fat.

Some like this lemming burrow under the snow in winter to keep warm.

Animals that live in the Arctic Ocean such as seals, whales and walruses have an extra layer of fat called blubber which keeps them warm in the cold.

Many birds have adapted to the cold Arctic through migration. In summer, thousands of birds migrate to the Arctic from Central and South America to feed and to raise their young.

Some of the birds in North America that migrate.

Now Antarctica—the other polar region

Antarctica is a continent near the south pole.

View of Antarctica from above—the frozen continent

Interior of Antarctica

Coast of Antarctica

Around the coasts of Antarctica, temperatures are generally close to freezing in the summer months. During winter, average monthly temperatures are always well below freezing--between 14°F and −22°F.

On the high plateau in the middle of Antarctica temperatures are much colder. Here, summer temperatures struggle to get above −4°F and monthly averages in the winter fall below −76 °F.

Antarctica is the coldest, driest, windiest place on Earth.

These extreme conditions make Antarctica a habitat in which only the hardiest can survive.

Only two percent of the continent of Antarctica is ice free in summer, so very few producers live there. The producers include 30 mosses, two flowering plants and some algae.

The most common life form is the lichen.

About one hundred and fifty to two hundred different kinds of lichen live in the Antarctica. A lichen, remember, is an algae and a fungus growing together. They depend on one another for survival. On Antarctica, the fungus provides the water while the algae, a producer, makes food both of them.

Two kinds of lichen that grow in the Antarctica

Mosses growing in the Antarctica

Mosses are very small green plants that have no roots. They have stems not much thicker than a stand of your hair and are covered with tiny, tiny leaves. Many mosses grow together on rocks forming a thick green mass.

On the Antarctic continent, some algae (very small producers) live in lakes and streams, on moist soil and in snow banks. Algae also live in the spaces between the sandstone rocks.

Many, many algae live in the Antarctica Ocean and are the bottom of the ocean food chains.

Algae growing in the Antarctica

Only two native flowering plants can survive in this cold climate, the Antarctica Hair Grass and the Antarctica Pearlwort. Both these plants tolerate very cold and dry conditions. They grow in small clumps near the shore of the west coast of Antarctic Peninsula. This is in marked contrast to the Arctic regions where nearly 100 flowering plants are found.

Antarctic Pearlwort

Antarctic Hair Grass

Sincehardly any plants live on the continent, no land animals can actually call it home. It's just too cold and dry to support very many life forms!

Penguins (Emperors and Adelies) are the only birds that actually inhabit this frozen landscape. They come on land only to breed and raise their young. They must find their food in the oceans surrounding Antarctica

Emperor penguin with baby

Adelie penguin with baby

Emperor penguin carrying baby on his feet to keep it warm (yes, his feet, Mom has gone to find food)

Emperor penguin on the ice sheet .

Emperor penguins diving in water to get food.

Emperor penguins huddling together to keep warm.

The ocean surrounding the continent of Antarctica is home to many, many animals.

Weddell Seal

Orcas

Antarctic Fur Seal

Leopard Seal

Blue Whale

Crabeater Seal

Chinstrap Penguin Antarctic Shag

Rockhopper Penguins

Black-bowed Albatross

Antarctica, a place where it is too cold and dry for humans to live, is indeed a fascinating continent.

Man does not live on Antarctica—a few researchers and tourists only visit for a few months of the year.