Tundras (Biomes)

Introduction arth is home to millions of different organisms, all of which have specific survival needs, These organisms rely on their environment, or the place where they live, for their survival. All plants and animals have relationships with their environment. They interact with the environment itself, as well as the other plants and animals within the environment. This interaction creates an ecosystem. Different organisms have different needs. Not every animal can survive in extreme climates. Not all plants require the same amount of water. Earth is composed of many types of environments, each of which provides organisms with the living conditions they need to survive. Organisms with similar environmental needs form communities in areas that meet these needs. These areas are called biomes. A biome can have several ecosystems. Alaska is home to Denali National Park. Tbe tallest mountain peak in North America, Mount McKinley, towers above tbis frozen tundra zone.

Biomes are sometimes called "life zones " because they are divided according to the different kinds of plant and animal life that live within them. Elephant seals were huotiid for their hluhher and were on the verge of extinction. By the late ißOOs, the population was only 100. Today, the estimated population is 130,000. The Lapland longspun a common tundra bird, builds its nest under clumps of grass.

Tundras are regions in the coldest places on Earth. There are two types of tundra. Arctic tundra is found mainly in the far north of the northern hemisphere, such as the North Pole. Alpine tundra is found on high mountains all over the world, including the Swiss Alps. Tundras have low temperatures, little precipitation, and short growing seasons. Plants and animals have been forced to adapt to these difficult conditions in order to survive. Though tundras may seem lifeless, they are home to some of the most interesting plants and animals on Earth. Plants found in tundras include tundra poppies and lichens. Polar bears and caribou are just two types of animals found in the tundra.

Tundra Locations undra can be found in the most northern parts of the world, some parts of Antarctica, and on the tallest mountain peaks. In these areas, temperatures remain below freezing most of the year. The ground beneath the arctic tundra is always frozen. This permanently frozen ground is called permafrost. It is difficult for trees and plants to grow in these conditions. Tundra covers about 20 percent of Earth's surface. The largest area of tundra is the arctic tundra zone, which covers the most northern reaches of North America, Europe, and Asia. North America's tundra region stretches north of Alaska to the easternmost part of Greenland. Europe's "far north" region, which includes Scandinavia and Iceland, is also part of the arctic tundra. In Asia, the tundra stretches from the coast of the Arctic Ocean in Russia to Siberia in the east. Denali National Park in Alaska covers more than 6 million acres (2.4 million hectares) of land. It is home to many plants that are rarely found anywhere else in the world.

Antarctica is Earth's southernmost point. There is a tundra region on the Antarctic Peninsula, as well as on several of the islands surrounding the continent, including South Georgia. Tundra can also be found in higher altitudes. Alpine tundra is located throughout the mountain ranges of western North America, as well as the Andes Mountains of South America. Other alpine tundras are located in the central European Alps and the Himalayas, a mountain range that stretches throughout Asia.

Caribou are found above tbe tree line in arctic North America and Greenland.

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Mount McKinley, in Alaska's Deniili National Park, is 20,320 feet (6,194 meters) tall. The word Himalaya conies from an ancient language called Sanskrit, and means "abode of snow." The Himalayan mountain range was named after its peaks, which are the tallest in the world and are covered with snow year-round.

WHERE IN THE WORLD?

T

undras are found in specific parts of the world. This map shows where the world's major tundra regions are located. Find the place where you live on the map. Is the place where you live near a tundra region? If not, which tundra region is closest to you? Why do you think tundra is located only in certain parts of the world?

Arctic Ocean

South America

N

Tundra

A

1000 0

500

2000 kilometers 1000

miles

Atlantic Ocean

Southern Ocean

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BIOMES

Cool Climates undra is characterized by fast-moving winds, snow, ice, and freezing temperatures. These regions also experience very short summers. When the Sun shines, plants sprout from the ground, and animais hunt for food for the winter. The tundra is a land of extremes. Winters in the tundra begin in September and last for 7 to 9 months. Depending on where the tundra is located in the world, winters can experience temperatures between 18° and -40'' Fahrenheit (8° and -40° Celsius). Though temperatures rarely rise above 50° F {10° C), some tundra regions experience 3 or 4 months of summer weather. Summer temperatures in the tundra can change very quickly. The average summer temperature is about 32° E (0° C). Tundras are also characterized by the amount of light they receive from the Sun. Earth spins on a tilted axis, an imaginary line that runs through the center of the planet. This means the Sun's rays never shine directly on the North Pole. In winter, the North Pole is far away from the Sun. Therefore, the Sun never rises above the horizon in the world's arctic tundras. Darkness lasts for 24 hours. In summer, the North Pole is nearer to the Sun. The temperature does not change much, but the Sun never sets.

Streams and lakes in the tundra are often fed by melted snow from glaciers.

The coldest average tundra temperatures have been recorded in Siberia, where they have reached -40''F (-40° C). In Siberia, rivers freeze so thick the ice is strong enough to hold the weight of cars and trucks. People use the rivers as roadways in winter.

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Glaciers are estimated to store 75 percent of tbe world's fresh water.

Tundra is always shifting, moving, and changing. Elements, including wind, precipitation, and ice, have helped form the tundra over millions of years. These elements cause changes every day.

Glaciers Glaciers are large, slow-moving masses of snow and ice. During the Ice Age between 2 million and 10,000 years ago, glaciers covered much of Earth. About 10,000 years ago, Earth's temperature began to rise. Huge chunks of ice broke away and began to drift southward over the land. Glaciers moved soil, deposited rock, and flattened the tundra landscape. Glaciers continue to move across the tundra. This keeps the land flat.

Icebergs Icebergs are enormous chunks of ice that have broken away from glaciers.

Icebergs help shape the tundra coastline. They pull soil, rocks, and other items in their path into the ocean with them.

Wind In some tundra regions, winds can reach up to 86 miles {140 kilometers) per hour. Trees do not grow in arctic tundra zones, so winds gather speed as they whip snow, ice, rocks, and the seeds of plants across the flat landscape.

Precipitation Ice, snow, and water cause the tundra to shift and change. When water melts in the tundra, it is often trapped beneath the soil or in shallow pools or lakes. Water that does not evaporate freezes wben temperatures drop. When water freezes, it expands. This creates cracks in the surface of the land.

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Different Types of Tundra 11 tundra regions have very cold climates, few plants, little precipitation, and very short summers. Tundras are divided by their geographic location into two types, arctic tundra and alpine tundra.

Arctic Tundra Arctic tundra is found mainly around the North Pole. This includes parts of North America, Europe, and Asia. In the arctic tundra, plants can only grow for 50 to 60 days. Plants with roots have difficulty growing in the thick permafrost. Even so, the growing season occurs in summer, when the ground's top layer is less frozen. Water from rain, and melted snow or ice gathers in ponds or bogs, and provides plants with the water they need to grow.

Alpine Tundra Alpine tundra is found near the top oftall mountains. The growing season in these regions can last for 180 days. Some tree species, including dwarf trees, grow in alpine tundras. Temperatures in alpine tundras are very cold, and winds move very fast. Melted snow or ice drains into mountain streams that carry the water to lower mountain regions.

The tundra beyins on the border of another biome called the boreal forest, or taiga. This is a strip of evergreen forests that grow in cold climates. In the arctic tundra surrounding the North Pole, some areas of permafrost are more than 2,000 feet (610 m) deep. From the sky, regions of tundra covered in polygons look like giant honeycombs. Some cracks that make up polygons are up to 10 feet (3 m)

Lichens and mosses are among the

wide and 30 feet (9 m) deep.

few plants that are suited to the cold temperatures of Greenland's tundra.

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In the summer, the surface layer of the permafrost melts, creating a hog in the tundra.

Polygons Polygons are giant cracks in the tundra's surface. They are named after the five-sided shape they resemble. Polygons form over many years. In summer, the soil thaws, and the earth expands and contracts. This causes cracks to form. These cracks fill with water. In winter, the water freezes and expands. Ice is forced aboveground. Over time, a network of shallow cracks forms across the tundra's surface. Wetlands, polygons, and pingos are common tundra land formations.

Wetlands In summer, large areas of arctic tundra are wet and swampy. When snow and ice melt, they form meltwater. Water cannot drain properly on the tundra's flat land. It becomes trapped in pools. The water does not absorb into the frozen ground. Water from some pools evaporates or is used by plants. Deeper pools form wetland areas and shallow lakes, which freeze during winter.

Pingos Pingos are giant mounds of soil and decaying phnx matter that reach up to 100 feet {30 m) high and 1,000 feet {305 m) wide. Pingos form when plants die in lakes that trap meltwater. In winter, the lakes freeze and expand, causing the dead plants and soil to rise to the surface. Each year a new layer of trapped water, plants» and soil builds over the last layer.

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Technology in the Tundra ne of the greatest dangers the tundra faces is global warming. Global warming occurs when greenhouse gases are trapped in Earth's atmosphere and create heat. This raises the temperature on the planet. Over the past 100 years, Earth's temperature has risen 1° F (-17° C). This increase has had a negative impact on the tundra biome. The coldest places on Earth are the first to experience the negative effects of global warming. Polar icecaps are large glaciers at the northernmost part of Earth. Heat from global warming could melt the polar icecaps. If these icecaps melt, the oceans will rise, changing the land humans, plants, and animals inhabit. It is important that the tundra remain a barren, frozen place. Scientists can monitor changing levels of greenhouse gases hy taking samples of ice or snow.

TUriDRAS

The tundra is an important laboratory for scientists who study the effects of global warming. Scientists measure the climate, weather, and the rate at which glaciers and permafrost are melting. Scientists use weather stations, weather balloons, and ocean buoys to monitor tundra temperatures. Weather stations record daily temperatures, storms, and other clues to help scientists measure activity in the tundra. Weather balloons calculate gas levels in Earth's atmosphere. Ocean buoys take the temperature of the surrounding water. They also measure water levels and can alert scientists if there are any changes. All three of these tools provide important information to scientists from some of the coldest and most dangerous parts of the tundra. Other scientists study the soil and surface of the tundra. Scientists can analyze a soil sample to determine how fast glaciers are melting. They also use large drills to cut pieces of glaciers or layers of permafrost. From these drillings, they can tell how quickly glaciers are melting.

Pollution and greenhouse gases first became a concern during the Industrial Revolution. This was a period in history when people began using machines to help tliem make the things they needed. Scientists also study the effects of global warming on the creatures oi the tundra. Experiments and long-term studies have focused on animals as large as the polar hear and as small as the neniatode worm.

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LIFE IN THE TUNDRA

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emperatures, winds, and lack of precipitation make it difficult for plants and animals to survive in tundras. Still, the biome is home to tens of thousands of unique creatures and plants.

PLANTS The tundra is home to about 600 plant species. Lichens are plants made up of algae and fungi. Lichens have no roots. This allows them to grow on the rocky surface of the tundra. Grasses, sedges, shrubs, and trees also grow on the tundra. Most tundra plants grow low to the ground. This protects the plants from cold temperatures and strong winds that can uproot them.

Tundra swans summer in Canada's north.

BIRDS During the summer months, the tundra is home to thousands of migratory birds, including ducks, owls, sandpipers, and plovers. When winter arrives with its colder temperatures, most birds fly to warmer climates. They return to the area when the warmer temperatures come again. Very few birds live on the tundra year-round.

INSECTS

Lichens grow best in undisturbed habitats.

A few insect species, including black flies, deer fties, and mosquitoes, call the tundra home. To keep from freezing, some insects replace their body's water with an antifreeze substance called glycerol. Insects also rely on the Sun's warmth to keep them from freezing.

MAMMALS

FISH A N D WHALES

Many tundra nnammals have found ways to survive in the extreme temperatures. To survive the freezing winters, some tundra mannmals, such as the polar bear, hibernate, or sleep, and save energy. Others, including the arctic fox, burrow, or dig, underground to protect themselves from the harsh climate. Some, such as the muskox, have thick fur or long coats that help to keep their bodies warm.

The waters surrounding the arctic tundra are filled with fish and whales that do not mind the freezing-cold surface temperatures. Water in the Arctic Ocean is also very cold, but whales have thick layers of blubber, or fat, to keep them warm. Beluga whales live in the frigid waters of the Arctic and subarctic.

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The red fox can be found on the tundra.

Lichens, Plants, an Lichens Lichens look like orange, red, green, black, gray, or white splotches on the dark tundra floor. Reindeer moss, one type of lichen, is an important source of food for caribou. Lichen can grow up to 4 inches (10 centimeters) tall.

Arctic Cotton Arctic cotton, a type of grass that can grow up to 1 foot (30 cm) tall, sways in the cold tundra breezes. The plants have puffy white cotton at their tips, which peopie who live in the tundra collect and use to insulate, or trap heat in, their clothing and boots.

Tundra flowers are in bloom for only about 6 weeks.

Flowering Plants Flowering plants wash the tundra in color in the summer. As the weather warms, the top layer of soil thaws, allowing flowers to take root. Many flowers grow in the tundra, including arctic lupine, saxifrage, and yellow poppies. These flowers grow close to the ground or closely together so that heat from the soil does not escape. Their bright red, orange, blue, and pink colors attract insects. This helps the flowers spread the pollen and seeds they need to survive from year to year. Many animals, including ptarmigans and bears, eat blueberries.

Shrubs Shrubs are common in alpine tundra regions and the more southerly regions of the arctic tundra. Bearberries are low shrubs that have bright red berries. The shrubs get their name because bears eat their fruit.

There are about 250,000 flowering plants in the world. Only 500 of these plants live in the tundra. Plants prevent permafrost from melting. They protect the frozen ground from warmer temperatures aiid sunliyht. Boarberry leaves have betin used lo treat illnesses for thousands of yeiirs. The area that separates forest from tundra is called the tree line. The tree line marks the point where it is too cold for trees to grow.

Tundra meadows are moist because of poor drainage. This allows for the growth of lush plant life.

Mammals Polar Bears Polar bears are easily recognized by their cream-colored coats. They are the world's largest land carnivores, or meateating animals. Polar bears can weigh up to 990 pounds {450 kilograms). Polar bears have found special ways to stay warm in the frozen climate. Beneath their thick fur, they have a 3-inch {8-cm) layer of fat, or blubber, that keeps them from becoming too cold.

Caribou Caribou belong to the deer family. They live in huge herds. Caribou constantly migrate over long distances to avoid cold or look for food. Their thick fur coats

Polar bears can smell prey as far as 20 miles (32 km) away.

keep them warm. Each of their hairs is hollow and traps warmth from their bodies to keep them from freezing.

Wolves Where there is a herd of caribou, a pack of wolves is never far behind. A full-grown arctic wolf stands 3 feet (91 cm) tall and weighs about 175 pounds {79 kg). Arctic wolves only kill what they can eat. Caribou is their main prey, but they also eat lemmings, arctic hare, and muskox. They store food in their stomachs. This food is then regurgitated to feed their young. Gray wolves live in packs of up to twenty individuals.

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Grizzly bears live in tbe tundra. During thii warmer montbs, grizzlies hunt for salmon and eat berries. In winter, they move to caves farther south to hibernate. '

Muskoxen have kmg, shaggy coats to keep them warm. They also bave long, pointed horns to protect them from predators. Tbough muskoxen look like bufl^alo,

they are related Ko goatí:. C;iiribou bave wide hoofs that help them to keep a steady footing on the uneven tundra floor. Tbey use tbeir Lemmings make paths along tbe ground

hoofs to dig through snow for mos:î

called runways, which they use for

to eat.

finding food.

Lemmings

Two types of lemmings live in

Lemmings are small, mouse-like creatures. Lemmings range from 3 to 6 inches (8 to 15 cm) long and weigh 0.5 to 4 ounces (14 to 113 grams). They burrow in tunnels underground. When food is scarce, lemmings leave their tunnels to move to another region. They run across the tundra, refusing to stop. They do not even eat during their migration. They swim across water, such as streams or rivers. Sometimes lemmings try to cross the ocean. They climb over top of each other. In the process, many drown.

and brown lemmings. In winter,

tbe tundra—collared lemmings

I

collared lemmings turn from brown to wbite. Tbeir wbite fur belps tbeim ciimouflage, or blend in, with theii surroundings and hide from predators.

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Birds, Whales, Fish, and Insects Birds Gulls and ravens fly high above the frozen tundra. These birds brave the cold year-round. Others, such as the arctic tern, arrive in spring and migrate to South America in winter. The arctic tern has a 31-inch (79-cm) wingspan— more than twice the length of its body. This helps the bird make the long journey to and from the tundra. The ptarmigan is one of the few birds that lives on the tundra all year. About the size of a small chicken, the ptarmigan

A

Killer whales can swim at speeds up to 30 miles (50 km) per hour.

has a stout body, short tail and legs, and short, rounded wings. The ptarmigan is covered with feathers, even on its beak and feet. Foot feathers help the bird walk on top of soft snow.

Whales Beluga and orea whales breach, or come above water for air, in the Arctic Ocean off the coast of the tundra. Oreas are sometimes called killer whales, even though they are not likely to harm humans. The nickname comes from their scientific name Orcinus orea. In Latin, orcinus means "bringer of death." Whales feed on plankton and smaller fish in the ocean.

Glaucous-winged gulls are commonly found in Alaska in the summer.

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There are more types of insect than any other creature in tbe tundra Tbe average male orea weighs between 7 and 10 tons |8 and 11 tonnes). Oreas travel in groups of five to thirty. These groups are called pods. With no trees in the tundrii, snowy owls have adapted by building neüts on the ground.

Mosquitoes feed through a long, thin tube.

Fish There are few species of fish in the tundra because there is so little water. The fish that live in this biome have adapted to their surroundings. The Alaska blackfish, which is found in North America and parts of Asia, can breathe air. This allows it to live in very little water.

Insects In the summer, black flies and mosquitoes swarm above the warm, damp wedand areas in the tundra. Springtails do not have wings. They use their hooked tails to bounce through the air like fleas. Insects provide food for birds and other animals. They are very important to life in the tundra.

Walruses migrate to the tundra in summer. Like the trunks of trees, a walrus's tusks have rings. Each ring represents 1 year of its life.

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Endangered Tundra he tundra's plants and animals seem very strong, since they have adapted to harsh weather, extreme temperatures, and a lack of constant food sources. However, the tundra is very fragile, and many of the creatures that call the biome home are endangered. Hunting is the biggest threat to the animals of the tundra. Polar bears are enormous and can run quickly, but hunters that want their fiir have threatened these animals with extinction. Muskoxen have been faced with extinction more than once. In the 1900s, the large beasts were hunted for their meat, horns, and coats. By 1917, there were only hundreds of the animals left. Since then, laws have been passed to protect these animals. Scientists continue to find ways to increase muskoxen populations. Muskoxen form a circle around younger members of the herd as defense and protection. Unfortunately, this makes them easy prey for hunters.

TUMDRAS

Pollution caused by human development and industries also harms the tundra. Pollution damages the tundra in the form of acid rain. Harmful chemicals become trapped in the rain. These chemicals poison plants and animals that need water to survive. Pollution also contributes to global warming. Many of the tundra's plants and animals can only survive in a cold environment. If Earth warms too much, many of these life forms will disappear.

The northern fur seal is considered a vulnerable species. Between the eighteenth century and 1911, these seals were hunted for their fur.

Seals are endangered in the tundra. Some people kill seals because they are helieved to threaten fish populations. Oil spills threaten tundra plants and animals. Large ships carrying oil to other countries sometimes collide with icebergs, spilling oil. Oil coats the water and living creatures. Tn save the disappearing polar bear species, Canada, the United State:», Russia, Norway, and Greenland sugned an agreement in 1967 that made hunting bears illegal.

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WORKING IN THE TUNDRA

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he people who study the land, plants, and animals in the tundra must have a strong background in history, math, and science. There are many types of jobs that involve studying the tundra, including anthropology, biology, and paleontology. Many people who work in the tundra study ecology.

RESEARCH SCIENTISTS •

Duties: collecting and recording data in desert environments

•

Education: bachelor of science degree

•

Interests: Earth science, ecosystems, science, geology, biology

Research scientists study the plants, animals, and climates of the tundra.They work with assistants to find ways to protect living creatures that call the tundra home. For example, they track the migration patterns of animals such as caribou and birds. Research scientists also study the effects of global warming on the permafrost layer.

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PROFESSORS • Duties: teaching students about biomes and ecology • Education: doctoral degree • Interests: science, ecology, environment

ENVIRONMENTAL CONSULTANTS • Duties: studying environments and determining ways to protect them • Education: bachelor's degree in environmental design or natural resource management • Interests: environment, nature, conservation Environmental consultants study the ways in which pollution and human interaction with the tundra cause it harm. They find ways to protect the unique environment from dangers such as oil spills.

Professors in colleges and universities teach a number of subjects, such as anthropology, that relate to the tundra. Native peoples often have an understanding of the climate, animals, and plants that share their tundra home. Learning about the people who live in the lundra can help scientists understand the biome.

ECO CHALLENGE I

What is a biome?

Are there tundra regions on all of Earth's continents?

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How much of the planet is covered hy tundra?

What is a glacier?

What are pingos? How do they form?

What are weather balloons used for in the tundra? /

What is lichen? How do people in the tundra use arctic cotton?

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What animal is the world s largest land carnivore? What are the biggest threats to animals in the tundra?

Answers

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fTAYINCi WARM

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any animals in the tundra have thick fur coats, extra layers of fat, or feathers to keep them warm. In this activity, you can see how having these extra layers help tundra animals stay warm. Blubber helps keep marine mammals warm in coot water.

MATERIALS • • • • • • • • •

tablespoon lard or shortening sandwich bag paper towel packing tape ice and water bucket thermometer stopwatch gloves made from a variety of materials, such as rubber, cotton, wool, or neoprene

1. Scoop a large amount of lard or shortening into a sandwich bag. 2. Turn another sandwich bag inside out. Place this bag inside the bag of lard or shortening. Line up the top of both bags. 3. Using a paper towel, wipe the tops of both bags clean. Then, tape the tops closed, leaving a small opening for your hand. 4. Fill the bucket with water. Using the thermometer, measure the water

temperature. Add ice until the temperature is between 48° and 64° F (9° and 18° C). 5. Place your bare hand in the ice water. Use the stopwatch to time how long you can keep your hand in the water. 6. Next, repeat the experiment wearing different gloves. For each glove, time how long you can keep your hand in the water. 7. Finally, put your hand inside the bag of lard or shortening. How long can you keep your hand in the water? Which protective covering kept your hand warmest?

FURTHER RESEARCH

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ow can I find more information about ecosystems, tundra, and animals?

Libraries have many interesting books about ecosystems, tundra, and animals. Science centers and aquariums are great places to learn about ecosystems, tundra, and animals. The Internet offers some great Web sites dedicated to ecosystems, tundra, and animals.

BOOKS Gellhorn, Joyce. Song of the Alpine: The Rocky Mountain Tundra Through the Seasons. Boulder, CO: Johnson Books, 2002. Goetz, Delia. Arctic Tundra. New York, NY: William Morrow, 2000. Moore, Peter D. Tundra. New York, NY: Facts on File, 2005.

W i B SITES Where can I learn more about the tundra and other biomes?

The World's Biomes www.ucmp.berkeley.edu/glossary/ gloss5/biome/index.html How can I learn more about tundra?

Tundra Biomes www.worldbiomes.com/biomes _tundra.htm

Walker, Tom. Caribou: Wanderer of the Tundra. Portland, OR: Graphic Arts Center Publishing Company, 2000.

How can I learn more about ecology?

Kids Do Ecology www.nceas.ucsb.edu/nceasweb/kids/ecology/faq.html

GLOSSARY algae: organisms that live in the water and make their own food

greenhouse gases: atmospheric gases that can reflect heat back to Earth

altitudes: the height of something aboveground

hemisphere: one of two halves of Earth

anthropology: the study of humans and their customs bogs: spongy, damp land ecosystem: a community of living things sharing an environment endangered: in danger of becoming extinct

migratory: to move from one place to another organisms: living things paleontology: the study of fossils regurgitated: to spit up sedges: grass-like plants that live in marshes or wet environments

fungi: living things that get their food from plants or animals

INDEX alpine tundra 5, 7,12,19 Antarctica 6, 7, 29 arctic tundra 5, 6, 10, 11, 12, 13, 17, 19 birds 5, 16, 22, 23, 26 climate 10, 11, 12, 15, 16,17, 20, 26, 27 fish 17,22,23,25 glaciers 10, 11, 14, 15,28 global warming 14, 15, 25, 26 grasses 4, 5, 16, 18 icebergs 11,25 insects 16, 18, 22, 23

lichen 5,12,16,18, 28, 29 mammals 17, 20 North Pole 5,10,12 permafrost 6,12,13,15,19, 26 pingos 13,28,29 polygons 12, 13 trees 6,11,12,16,18, 19,23 wetlands 13, 23