The Tundra Biome Tundra is the coldest of all the biomes

The Tundra Biome
Tundra is the coldest of all the biomes. Tundra comes
from the Finnish word tunturi, meaning treeless plain.
It is noted for its frost-molded landscapes, extremely
low temperatures, little precipitation, poor nutrients,
and short growing seasons. Dead organic material
functions as a nutrient pool. The two major nutrients
are nitrogen and phosphorus. Nitrogen is created by
biological fixation, and phosphorus is created by
precipitation.
Characteristics of tundra include:
1.
2.
3.
4.
5.
6.
7.
Tundra along the Colville River,
Alaska.
Extremely cold climate
Low biotic diversity
Simple vegetation structure
Limitation of drainage
Short season of growth and reproduction
Energy and nutrients in the form of dead organic material
Large population oscillations
Tundra is separated into two types:
•
•
Arctic tundra
Alpine tundra
Arctic tundra
Arctic tundra is located in
the northern hemisphere,
encircling the north pole
and extending south to the
coniferous forests of the
taiga. The arctic is known
for its cold, desert-like
conditions. The growing
From left: tundra near Churchill, Manitoba, Canada; tundra in the
season ranges from 50 to
Arctic National Wildlife Refuge, Alaska.
60 days. The average
winter temperature is -34°
C (-30° F), but the average summer temperature is 3-12° C (37-54° F) which enables this biome
to sustain life. Rainfall may vary in different regions of the arctic. Yearly precipitation, including
melting snow, is 15 to 25 cm (6 to 10 inches). Soil is formed slowly. A layer of permanently
frozen subsoil called permafrost exists, consisting mostly of gravel and finer material. When
water saturates the upper surface, bogs and ponds may form, providing moisture for plants.
There are no deep root systems in the vegetation of the arctic tundra, however, there are still a
wide variety of plants that are able to resist the cold climate. There are about 1,700 kinds of
plants in the arctic and subarctic, and these include:
•
•
•
low shrubs, sedges, reindeer mosses, liverworts, and grasses
400 varieties of flowers
crustose and foliose lichen
All of the plants are adapted to sweeping winds and disturbances of the soil. Plants are short and
group together to resist the cold temperatures and are protected by the snow during the winter.
They can carry out photosynthesis at low temperatures and low light intensities. The growing
seasons are short and most plants reproduce by budding and division rather than sexually by
flowering. The fauna in the arctic is also diverse:
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•
•
•
•
Herbivorous mammals: lemmings, voles, caribou, arctic hares and squirrels
Carnivorous mammals: arctic foxes, wolves, and polar bears
Migratory birds: ravens, snow buntings, falcons, loons, sandpipers, terns, snow birds, and
various species of gulls
Insects: mosquitoes, flies, moths, grasshoppers, blackflies and arctic bumble bees
Fish: cod, flatfish, salmon, and trout
Animals are adapted to handle long, cold winters and to breed and raise young quickly in the
summer. Animals such as mammals and birds also have additional insulation from fat. Many
animals hibernate during the winter because food is not abundant. Another alternative is to
migrate south in the winter, like birds do. Reptiles and amphibians are few or absent because of
the extremely cold temperatures. Because of constant immigration and emigration, the
population continually oscillates.
Alpine tundra
Alpine tundra is located on
mountains throughout the
world at high altitude where
trees cannot grow. The
growing season is
approximately 180 days. The
nighttime temperature is
usually below freezing.
Unlike the arctic tundra, the
soil in the alpine is well
drained. The plants are very
similar to those of the arctic
ones and include:
•
From left: alpine tundra in Mt. Rainier National Park,
Washington; Dall Sheep in the Arctic National Wildlife
Refuge, Alaska.
tussock grasses, dwarf trees, small-leafed shrubs, and heaths
Animals living in the alpine tundra are also well adapted:
•
•
•
Mammals: pikas, marmots, mountain goats, sheep, elk
Birds: grouselike birds
Insects: springtails, beetles, grasshoppers, butterflies
The Tundra Biome: Facts
The Tundra Biome is one of the most unique Biomes in the world. Covering one tenth of the
earth's land area it is a substantial Biome. The Tundra is located above the tree line towards the
North pole. As you can see in the picture. It is the least inhabited Biome in the world when it
comes to humans. Because the tundra is not use to human activity it is most susceptible to
change and damage from human use or pollution. Oil spills damage the plants, land and animals
that live along the coast a great deal.
Because of its northern location there are many substantial
Facts about the Tundra Temperature: The Tundra has extremely cold temperatures. The summer
high is around 40 degrees F. The coldest winter temperature gets down to a nipping -25 degrees
F. That's much colder than any Biome in the world.
Land: The Tundra is permanently covered by a layer of frozen soil, or permafrost. The
permafrost itself can reach between 300 to 1,500 feet deep. The permafrost severely hinders
makes plant growth in the tundra.
Day Length: Because of the Tundra's northern position, during the winter, sometimes only a few
hours or less of sunlight occur. In contrast, in the summer, the sun is almost up 24 hours a day.
Types of Tundra: There are two different types of Tundra, Polar Tundra and Arctic Tundra. Polar
Tundra is found close to the earth's poles and Arctic Tundra is found above the tree level in high
mountain ranges.
Precipitation: The average yearly precipitation in the Tundra is usually less than 15 inches.
In the summer months, the sun shines all the time, even at midnight.
The poles were not always so cold. The movement of the plates that make up the earth's suface,
plus the warming and cooling of the planet, have caused the cold condtions that are present
today.
As the sea freezes, the salt rises to the surface as crystals called ice flowers.
The only tree that grows in the tundra is the dwarf willow tree. It grows to a maximum of four
inches tall.
The arctic tundra is at the top of the world -- around the North Pole.
Animals are adapted to handle cold winters and to breed and raise young quickly in the very
short and cool summers.
Temperatures during the arctic winter can dip to -60 F (-51 C)! The average temperature of the
warmest month is between 50 F (10 C) and 32 F (0 C). Sometimes as few as 55 days per year
have a mean temperature higher than 32 F (0 C). The average annual temperature is only 10 to
20F (-12C to -6C).
The soil is often frozen. Permafrost, or permanent ice, usually exists within a meter of the
surface. Water is unavailable during most of the year.
Annual precipitation is very low, usually less than 10 inches (25 centimeters).
What is Tundra?
The meaning of the word ‘Tundra’ is ‘an area where the growth of trees is prevented due to low
temperatures and short seasons that enable growth’.
These kind of geographic areas are found near the North Pole and the South Pole. Thus, there is
the Arctic Tundra and there is the Antarctic Tundra. There is another type of Tundra region,
which is known as the Alpine Tundra.
In the tundra ecosystem, the vegetation primarily consists of mosses and lichens, and dwarf
shrubs and grasses.
Tundra Facts: Arctic Tundra
The Arctic Tundra region is situated near the North Pole. The soil in the area is called
‘permafrost’ which means ‘permanently frozen soil’. At least 25 to 90 centimeters of the ground
is frozen. Thus it is impossible for trees to grow here. Due to this, vegetation is very hard to grow
and very sparse to find. Moss, lichen and heath can be found on rocks in this barren landscape.
The people who live in the Arctic Tundra are mostly nomadic tribes consisting of reindeer
hunters such as the Nenets and the Nganasan.
The Tundra climate consists of only two seasons: winter and summer. The region is frozen for
the most part of the year. The average temperatures range from -28 Degrees Celsius (-18.4
Degrees Fahrenheit) to -50 Degrees Celsius (-58 Degrees Fahrenheit). During the summers the
ice melts and forms streams, lakes, marshes and bogs. This makes the ground quite soggy. The
temperatures during summer months range from 12 Degrees Celsius (53.6 Degrees Fahrenheit)
to 3 Degrees Celsius (37.4 Degrees Fahrenheit). There is some amount of precipitation, but only
in the summer months, ranging from 15 to 25 centimeters annually.
It is during these summer months, that plants grow and reproduce.
The interesting part about the Tundra Climate is that it is quite windy, with winds that blow
upwards of 30 to 60 miles per hour.
Another interesting fact about the Tundra region is that in the summer months when the ice
begins to melt, it cannot be absorbed into the ground. This is because only the upper layers of the
permafrost melt, while the bottom layers are still frozen.
The tundra ecosystem is also very low in biodiversity. There are only about 1700 varieties of
plants and about 48 varieties of land mammals found in the tundra region. The main animal
population in the Arctic Tundra consists of reindeer, polar bears, arctic fox, arctic hare, snowy
owls, lemmings and musk ox.
It is interesting to note that the Tundra region is also a vast storehouse of natural resources such
as oil and uranium. It is because of these natural resources that many nations have turned their
attention to these areas on the globe.
Tundra Facts: Antarctic Tundra
The Antarctic Tundra is found in the South Polar areas of the Earth. However this area is quite
cold and does not support vegetation. It is always covered with ice fields.
However, at the fringes of the Antarctic Peninsula, there are areas of rocky soil which do support
vegetation. One can find about 300 varieties of lichens, 700 varieties of aquatic algae, and about
100 varieties of mosses. There are not many large sized mammals found in the Antarctic Tundra.
This area is the home of species such as the Penguins and Seals.
Alpine Tundra
Alpine tundra is that area of the earth’s surface which does not support any vegetation due to its
high altitudes. This can happen anywhere on the surface of the earth. This area also can contain
permafrost soils.
Tundra Ecosystem: Threats
As mentioned above, the Arctic Tundra is a vast reservoir of oil and uranium. Due to this many
countries are exploring for oil in these regions. This can severely damage the delicate balance of
the tundra ecosystem.
Another threat is that about a third of the world’s soil bound carbon is found in these regions. So
when the permafrost melts in the summers, this carbon gets released into the atmosphere, adding
to the ‘Greenhouse Effect’. Since carbon is a greenhouse gas, this adds into the threat of Global
Warming, which again forms a vicious cycle by causing more of the permafrost to melt each
year.
Over a period of time, this could radically alter the lives of the living species of animals, but also
flora and fauna, and subsequently the lives of all the people on the surface of the earth.
Many scientists and researchers are therefore spending a lot of time and effort into trying to
analyze and reduce this growing threat to the tundra ecosystem
Only a few species live in this difficult environment. The food chains are short, and vulnerable
to stresses. Permafrost under the temporarily thawed ground makes water drainage impossible,
so there are many small lakes and puddles, and much of the ground is soggy. When all the water
freezes it becomes unavailable to life forms, and so creates a sort of cold drought in which
animals and plants may die of thirst. The detritus eaters, bacteria, fungi, and tiny soil organisms,
work very slowly because the cold temperatures slow down chemical reactions. Available
nutrients in the soil are therefore scarce, even though undigested material lies on the surface of
the ground.
Plants in this biome are small, perhaps four inches high. They form little cushions or mats that
lie closely on the ground. The albedo of the plants is less than that of the surrounding soil, which
lets them absorb a little more of the solar heat. The ground is a little warmer than the air, so the
plants stay as close to the ground as possible. Some of them have little hairs on their stems to
hold warmer air as the cold winds blow. The vegetation consists of grasses, wild flowers, sedges,
mosses, dwarf willows, and lichens. Many of the plants are perennials so that they can store food
from season to season. Most can reproduce vegetatively from underground shoots, as sudden
freezing storms can occur at any time, and make seed production a gamble.
The musk oxen eat the plants, but their predators do not live in this biome. The musk oxen
reproduce slowly, and the availability of vegetation limits the size of their herds. They are driven
toward the predators when food becomes scarce.
The lemmings and the foxes are linked: more lemmings lead to more foxes, and more foxes
lead to fewer lemmings. Their numbers fluctuate, but stay within the carrying capacity of the
vegetation. When there are too few lemmings, the foxes starve.
The snowy owl also hunts the lemmings. Snowy owls will leave the area when lemmings
become scarce, and many do not return, but are killed by predators outside the tundra.
Some parts of the tundra have additional animals: seasonally migrating birds, arctic mice,
snowshoe hares, voles, and ptarmigans. Some areas even have migrating reindeer or caribou. The
population dynamics remain carefully balanced, however. The plant communities are fragile, and
the availability of light, warmth, and nutrients places absolute limits on the growth possible.
An Energy Pyramid in the Tundra Biome
The tundra biome covers many hundreds of square miles, and conditions vary from place to
place. Some areas are richer in plant life than our example here, others are even more desolate.
The part of the tundra that is being described is covered with shallow pools of water and lowgrowing plants. It ix populated mainly by lemmings, snowy owls, and arctic foxes. The square
meter that we are basing our calculations on is all above water. When figuring out population
densities, one would have to allow for perhaps 20% to 35% water in calculating land areas.
The tundra is a challenging environment, and the short growing season limits plant growth.
The tundra produces only 600 Kilocalories per square meter per year for the herbivores to eat.
Here is a diagram of the energy available at teach trophic level.
You can see how much energy per square meter is available at each trophic level.
Primary Producers: (Plants)
The work of the plants is called the first trophic level. The total amount of plant tissue produced
represents about 600 Kilocalories per square meter per year. However, some of this material,
such as woody stems, may be indigestible. Edible material includes shoots, small leaves, small
flowers, and starchy tubers in which energy is stored for the next season.
Primary Consumers: (Herbivores)
These are the lemmings. The lemmings consume the 600 Kilocalories, most of which are burned
up in metabolism. The body has many necessary functions, breathing, circulating the blood,
maintaining the heat of the body, digestion, repair and growth, eliminating wastes, running
around, and reproduction. This burns up most of the Kilocalories that the animals eat. Of the
food that they eat, about10% is stored as an animal body. This would be somewhere between
(600 * .10 = 60) Kilocalories that another animal could eat. Of course, the lemming is not totally
digestible -- bones, hair, and teeth may or may not be digested. The lemmings and other prey
animals are the second trophic level.
Secondary Consumers (Carnivores)
Snowy owls and arctic foxes eat the lemmings. A snowy owl eats 12 lemmings a day, bones,
teeth, fur and all. Again, most of the calories go to keeping the owl alive and fueling its
metabolism. If some mythical predator were to eat owls it would get only six Kilocalories per
square meter per year. Snowy owls and foxes can survive on the third trophic level, but there are
no tertiary consumers that eat them.
The food chain here supports only three trophic levels because carnivores have to cover a lot of
ground to find enough to eat.
Detritus Eaters (waste eaters and recyclers)
There are bacteria and other tiny life forms that recycle organic waste material. The low
temperatures of the tundra mean that they process wastes slowly, but they do help to keep the
system going.
Another way to illustrate an energy pyramid is by using the pictures of the animals, like this.
A Food Web in the Tundra Biome
The Tundra Biome
Return to Introduction to Biomes
The Tundra
The Tundra Biome provides examples of adaptation to extreme conditions. About a fifth of
the land surface of the earth is tundra.
The tundra biome is found next to the icy zones in the arctic. (If there were land at those
latitudes in the southern hemisphere, tundra might be found there, too, but this is not the case on
earth right now.) There is also Alpine Tundra high on the slopes of mountains. The first part of
this page is about arctic tundra. The two kinds of tundra have many characteristics in common,
including a very short growing season and an absence of trees.
During most of the year, temperatures on the tundra are below freezing, and may sometimes
drop to as low as -70 degrees Fahrenheit. There are powerful winds that can blow up to 100
miles an hour. As a result of the cold, the water in the ground freezes: the ground can be frozen
to a depth of 2000 feet or more. In some places only a few inches of the top part of the ground
thaw out in the summer, in other places several feet may be thawed. The part of the ground that
thaws is called the active layer. This layer is very wet, because the water from the melted ice
cannot drain away. The frozen ground that never thaws out is in the grip of permafrost, and is
called the permafrost layer.
Although the tundra may get less than five inches of
precipitation a year, the area is still very wet in summer.
(One inch of precipitation (rain) = about ten inches of
snow.) The water that comes from the melting ice has
nowhere to go. During the summer, the whole landscape
is one of open, gently rolling ground, covered with many
small lakes and ponds. The ground between the ponds is
soggy. During this time, the days are close to 24 hours
long, so that there is light for the little plants that grow
wherever the ground is not under water. On a warm day
the temperature may rise to 50 degrees Fahrenheit.
The plants in the tundra zone are only about four inches high. Many of them are perennials,
building up food reserves in their roots from year to year. The plants consist of grasses, sedges,
mosses, little flowering plants, and tiny dwarf willow bushes. They grow in shapes that protect
them from the cold, drying winds -- in dense round cushions, or mats that hug the ground. Some
of them have reddish leaves to get as much energy as possible from the sun. In the rocky places,
lichens grow on the rocks. (Lichens were very early land plants, and are a partnership between an
alga and a fungus. They have no roots.) Tundra plants must grow rapidly, because the growing
season lasts for only six to ten weeks. Many of the plants reproduce vegetatively, by growing
new roots and shoots, rather than by making seeds. Spring starts in June when the ice begins to
melt, and winter returns by September.
The earth in the tundra biome is not really considered to be a true soil. Dead plant material
decomposes very slowly because it is so cold. (Chemical changes occur more quickly with more
heat.) Water expands when it turns to ice, and the constant melting and freezing of the top of the
ground moves the ground around. This results in the ground being full of hollow spaces which
serve as tunnels for the lemmings that live in this biome. It also makes it impossible for plants
like trees, who have strong permanent root systems, to live there.
Animal Life
Lemmings
Lemmings are small rodents. They eat plants, weigh between an ounce and four ounces and
are three to five inches long. They look rather like hamsters, and may be brownish or dark gray
in the summer, when they live in tunnels in the ground. They have short tails and fur on their
foot pads to help them to keep warm. In winter lemming fur turns white, and the little creatures
make tunnels under the snow and eat the plants that they find.
The lemmings use the r reproductive strategy, breeding very rapidly, hoping that some
members of their group can survive despite predators and difficult weather conditions. After a 20
day pregnancy the mothers produce litters of 6 to 9 babies, and the mothers soon become
pregnant again. A lemmiing can have 3 litters a year. More than half of the new lemmings are
female, and when they are a month old they can also become pregnant.
Arctic Foxes
Arctic foxes are year round predators in the
tundra biome. These small, dainty little animals
are about the size of a cat, weighing six to ten
pounds. They have the warmest fur of any
mammal, and look fluffy. Their short legs,
small ears, and short noses are adaptations to
reduce their surface area in the cold climate.
They are brownish in the summer and white in
the winter. They hunt lemmings, chasing them
down in the summer and listening for them
under the snow in the winter time. They are
very tough little animals and will travel great distances when food is scarce.
Arctic foxes are very well adapted to the cold. They even have fur on the bottoms of their
feet. Their metabolic rate increases when the temperature drops to -50 degrees Celsius: at -70
degrees Celsius they start shivering.
Arctic foxes may have one or two litters of pups a year, but one litter is usual in the difficult
circumstances of the arctic tundra. Litter size is related to the food supply. They may have no
pups, or only one or two, when food is scarce, and as many as twenty five when food is
abundant. A normal sized litter would be six to twelve pups. However, most of these puppies
will die of starvation before they are six months old. The puppies are weaned between two to
four weeks of age, and survival on their own is difficult.
Because of the flexibility of their reproductive patterns, arctic foxes can respond quickly to
increases in the number of lemmings. When there are more lemmings the foxes have more pups,
and more pups survive. The increase in predators reduces the number of lemmings. Then some
of the foxes starve. This is repeated in four year cycles, although mild or severe winters also
have an effect on the population numbers.
Snowy Owls
Snowy Owls are well adapted to tundra life,
although they will leave the area to search for
food in particularly severe winters.
They are small predators, weighing two to
four pounds. They are about two feet tall and
have a wing span that often exceeds five feet.
Unlike most owls, they hunt in the daytime as
well as at night. This is an adaptation to the 24
hour daylight that the tundra enjoys in summer.
They also change color, being brown in the
summer and white in the winter.
Snowy owls prey on lemmings and eat about a dozen lemmings each a day. They nest on the
ground on the highest and driest part of the tundra: there are no trees in the tundra biome.
The female lays 8 - 10 eggs and incubates the eggs for 33 days. The young start developing in
the eggs as soon as the eggs are laid, so that the owlets are different sizes. This is a kind of
insurance against sudden storms or food shortages that might kill some of the chicks. The young
are ready to leave the nest in 16 days and begin to fly at around the age of 52 days. The parents
are kept busy feeding the owlets.
Musk Oxen
Small herds of musk oxen also roam
the tundra. Groups of 10 or 12 of these
peaceful grazers eat the small plants
and lichens. They are very hardy, and
covered with thick, soft, very warm fur.
They weigh from 500 to 1000 pounds,
and are between 3 and 6 feet high at the
shoulder. Although the tundra does not
support wolves, wolves do attack musk
oxen when they wander into the
bordering lands. Musk oxen have horns
for protection. When they are attacked
they form a circle with all the adults facing out and the young calves in the center.
Musk oxen use only a sixth of the food that cattle need, so they must be processing what they
eat very efficiently. They take three years to mature and then bear calves in alternate years. The
calves drink milk for nine months, while also eating plants. Contrast this slow reproduction rate
with the frenzied reproduction of the lemmings. These animals are using the K Reproduction
Strategy.
Other Animals
Other animals found on the tundra in summer include reindeer, caribou, arctic hares, and
snow shoe rabbits. Reindeer and caribou migrate across the tundra, eating lichen and plants.
Arctic voles and mice are also seen. Migrating birds may nest in the tundra areas near the ocean,
where there is more choice of food. Ptarmigans are birds that stay in the arctic year round and
change their brown feathers to white when winters come. Summer insects include mosquitoes
and black flies.
This Fragile Ecosystem
Notice that this biome has short food chains and only a few species of animals. This is
representative of a challenging biome with a fragile ecosystem. Although the systems function
smoothly, the balance could be destroyed if a single type of animal were to be wiped out by
disease, over-hunting, or predation. The plant systems are also fragile, and the ground bears the
marks of human traffic for many years. There is an interesting contrast between the incredible
hardiness of the animals and plants that live here and their vulnerability to outside stressors for
which they are not prepared.
The Alpine Tundra
Tundra environments also exist in the
mountains above the tree line. The high
meadows are sprinkled with mountain
flowers in the summer. These areas are close
to the forest area below, so there are more
species of animals present than are found in
the Arctic tundra. Animals are not totally
dependent on the tundra vegetation, and can
get food from lower elevations or migrate
down the mountain as winter comes on.
Marmots make their homes here, and
mountain goats and sheep spend their
summers in the rocky crags.
FOOD WEB IN THE
TUNDRA
On top are the small
predators such as the
snowy owl and artic
fox. Most small
predators feed off the
lemmings which are
the KEYSTONE
ANIMAL to the food
web as they are very
populoous and
widely consumed.
Above the small
predators, are larger
predators such as the
polar bear, which are
not shown on this
chart.
In the middle are the
primary consumers
such as lemmings,
musk oxen and
insects who feed on
the limited plant life
avaliable.
On the bottom there
are the primary
producers, or the
plants. These are very
limited resources,
which are thrown off
by the slightest lack
of sunlight and water
avaliable to them.
The permafrost in the
ground also throws
off the drainage of
the water leaving the
plants there hard to
digest.
This ecosystem is
extremely fragile
because of the lack of
plant life so if tthe
primary consumers
can't find enough
food, the predators
can't eat. Therefore,
the population
continually oscillates
+
+
Tundra Food Web
=
and the extinction of
just one species has
the threshold to
destroy this
ecosystem.
The word Tundra finds its origin in a Finnish word tunturia, which means treeless plain. In fact,
the tundra is a plain with a permanently frozen soil that can be 9 inches to 3 feet thick. Tundra is
located in the Arctic regions. Of all biomes, the tundra biome is the coldest, with extreme
temperatures that can reach minus 25 degree Fahrenheit (-31°C). It is also the simplest of all
biomes because only limited life forms can subsist in its environment. The dead organic matter
constitutes the pool of nutrients, resulting in nitrogen and phosphorus aided by low
precipitations. Because of these factors, no deep rooted tundra plant can grow on this soil. Yet
there are about 1700 species of tundra plants mostly perennial forbs, dwarfed and stunted shrubs,
liverworts, or grasses. They constitute the food web for the herbivorous animals and other tundra
animals. The tundra only has two main seasons: winter and summer. The spring and fall last only
short periods of time.
Tundra Food Web
There are permanent resident species and migratory ones. Some of the most common permanent
tundra animals found are some bird species as well as mammals such as the Arctic fox or the
Arctic hare or caribous. Most tundra animals are large. The weather conditions of the tundra
biome require these species to have a large amount of feathers or fur to provide thick body
insulation. In addition, as winter covers the land, their insulated coats turn from summer brown
to entirely white. The short growing season enables these animals to feed enough to form the
thick layer of fat. It will provide them both energy and a protection against the cold.
In the tundra biomes, the animal population varies in size, sometimes in response to the change
in population in other species. For example, the lemming consumes some of the plain vegetation.
During the summer when there is food, they breed with astounding speed. One female produces
five or six babies in a litter and does so, four or five times in a single season. In a few months,
she may have produced thirty young. The babies grow so quickly that the first to be born in the
spring can themselves reproduce before the winter returns. If vegetation is insufficient, some of
the newborn will die and the population will decrease.
Fluctuations in the number of predators can also greatly affect species existence. The snowy owl
is a predator of the lemming. It will emigrate from the tundra if the lemming is scarce, and might
travel south, sometimes beyond South-Virginia. Many of these snowy owls die when they
attempt to return to the plains.
The migratory species such as the caribou will only remain in the tundra plains during the
summer season. The herd moves as much as 50 miles a day (over 80 km) following the same
route each year. In places, paths have been worn 18 inches deep (45 cm) where the animals have
passed century after century. They have to keep traveling in order to find enough food to sustain
them all. Caribous will migrate south to avoid winter but will return to the plains to breed when
the winter ends. The Arctic tern, a white seabird, migrates from the Arctic where it breeds, to the
Antarctic.
The location of the tundra affects its environmental conditions. There two major types of Tundra:
The Arctic and Alpine Tundra
The Artic Tundra
It is the youngest on earth as it was formed only 10000 years ago while the earth formation
started 12 billion years ago. Located in the northern hemisphere at latitudes 55° to 70° north, it
covers and encircles the North Pole. Found on about 20% of the Earth's surface, the temperature
averages -34° F in winter, and between 37° F and 54° F. (3 to 12 °C) in the summer. Depending
on its location on the Pole it is referred to as the high, middle or Low Arctic tundra.
The high Arctic Tundra is found on islands located on the Arctic Ocean. The Arctic Archipelago
and some of the Queen Elizabeth Islands constitute this tundra biome. On its grounds are found
mosses and lichens that grow on rock surfaces, which are a vital part of the tundra food web for
herbivorous mammals and other tundra animals. The temperatures range between 90° F in the
northern parts to -9° F in the South (32 to -23 °C). It is a dry, cold climate, with very little
precipitation. One kind of tree manages to live on these lands in surprisingly large quantity: it is
the Arctic willow growing extremely slowly lying flat on the ground.
The middle Arctic tundra is only found on the leveled plains of the Arctic Coasts, in the northern
territories, and at outmost northern part of Quebec. The north central area has temperatures from
32 in the summer to -22° F in the winter (0 °C to 30 °C). Rock polygons are created as a result of
the thawing of frost of the ground. The energy that generates from its activity will permit
microhabitats to develop and give life to Arctic tundra plants; the drenched center of these
polygons enables moss to grow, while the dryer circling ring allows for the formation of forbs.
These tundra plants give the effect of a patterned ground.
The Low Arctic tundra is the last type. It is where the driest soil but also where the thickest
permafrost can be found. It is located at the most extreme northern part of the Labrador,
extending to the Eclipse River, at the border of Quebec. Some woody shrubs can grow in its
extremely cold conditions. No trees can grow on its soil.
The Alpine Tundra
Located on the higher slopes of the Northern Hemisphere Mountains, the alpine tundra offers a
climate and environment different from that of the Arctic. Although the seasons are different, in
some areas, the cold temperature and thinner soils allow for tundra plants to take over where
trees cannot grow. The alpine tundra has a short growing season and temperature go below
freezing at night. The major difference with the Arctic tundra is its dry soil.
In addition, there are some lands in Antarctica that resemble the tundra biome on the Northern
hemisphere but with much colder temperatures. The soil is constantly covered with snow and ice.
As a result, it is not an ideal environment for the typical tundra vegetation to form or for the
typical tundra animals to subsist.
Tundra Biome Endangered
The tundra food web is limited to a few numbers of tundra plants and animals. Disrupting this
equilibrium is an easy process; the disappearance of one species could affect the entire
ecosystem. In addition, in Alaska for example, natural resources have brought more human
interference. Finally, global warming seems to represent to biggest threat to this ecosystem, be
thawing the permafrost that is typical of Tundra, and devastated this biome.
FOOD CHAIN
All living organisms of the biosphere are related to each other by a common factor, i.e., food,
which contains not only energy but also materials in usable forms that are needed by the
organisms.
We know that green plants manufacture their own food with the help of sun's energy and from
common elements derived from air, water and soil. These green plants are, therefore, called the
autotrophs. The autotrophs are the chief source of potential energy for the living world. Hence
they are called the producers. When the producers are eaten by some animal, the energy of the
producers is passed on to the animal which is called consumer. The primary consumer is eaten
by another animal which is called the secondary consumer which may be eaten by a tertiary
consumer and so on. This pathway of energy transfer from one organism to another constitutes a
food chain. For example, in a forest community, grass is eaten by a deer which, in turn, is eaten
by a lion. This flow of energy from grass (producer) to deer (primary consumer) and then to lion
(secondary consumer) is called a food chain.
tundra-biome.
POSTE D BY MY F OOD REC I PES AT 0 3 : 1 8 0 COMMENTS
L A B E L S : TUNDRA FOOD CHAIN
Characteristic features of tundra biome
Characteristic features of tundra biome
Characteristic features of tundra biome are:
a) Ground surface is spongy, uneven as a result of freezing and thawing. This is because the
plains of tundra are covered with snow, ice and frozen soil most of the year (permafrost).
b) Extreme cold climate with temperature ranging from -30oC to -40oC in winter.
c) Highest summer temperature is only about 10o C , only for a very brief period. During this
time upper 10 - 20 cm deep surface region melt forming ponds, marshes and bogs in the
depressions on terrain plain
d) Annual precipitation (mostly as snow) is below 25 cm.
Flora
Vegetation in tundra is very sparse. Hence, it is also called 'arctic desert'. It exhibits very low
species diversity.
a) Biome is virtually treeless and is comprised of only Lichens (Cladonia - Reindeer moss) and
Mosses (Sphagnum - Peat moss) forming the main vegetation.
b) Other plants growing are sedges, heaths, grasses, dwarf birches (Betula) and dwarf willow
trees (Salix).
c) Plants are mostly shallow rooted and they often possess xerophytic adaptations.
d) Bilberries, dwarf huckleberries, low flowering herbs also grow in tundra.
Fauna
a) No amphibians and reptiles are found.
b) Insects like biting flies, dipteran flies (black flies), mosquitoes etc are found here.
c) Migratory birds like water fowls are seen in summer. Other birds found here are snow - owl,
snow - grouse (ptarmigan) etc.
d) The caribou, musk ox, arctic hare, arctic fox, lemming, polar bear and weasels are the
mammalian residents of tundra. Some of them hibernate in winter in caves and others migrate to
coniferous forests.
Productivity of tundra is estimated to be 200 k cal/m2/year. Recovery from any disturbance is
very slow in tundra as it is a very delicate and fragile biome.
Tundra Food Chain
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L A B E L S : TUNDRA FOOD CHAIN
What is the food chain of the tundra and also the food web?
What is the food chain of the tundra and also the food web?
Producers: Grasses and Caribou Mosses
Carnivores: Polar Bears and Arctic Wolves
Herbivores: Caribou and Lemmings
Omnivores: Arctic Fox and Brown Bears
Decomposer: Bacteria and Fungi
Tundra Food Chain....
L A B E L S : TUNDRA FOOD CHAIN
THE TUNDRA FOOD WEB
THE TUNDRA FOOD WEB
Tundra Food Chain :
- small predators such as the snowy owl and artic fox. Most small predators feed off the
lemmings which are the KEYSTONE ANIMAL to the food web as they are very populoous and
widely consumed. Above the small predators, are larger predators such as the polar bear, which
are not shown on this chart.
- the primary consumers such as lemmings, musk oxen and insects who feed on the limited plant
life avaliable.
- the primary producers, or the plants. These are very limited resources, which are thrown off by
the slightest lack of sunlight and water avaliable to them. The permafrost in the ground also
throws off the drainage of the water leaving the plants there hard to digest.
This ecosystem is extremely fragile because of the lack of plant life so if tthe primary consumers
can't find enough food, the predators can't eat. Therefore, the population continually oscillates
and the extinction of just one species has the threshold to destroy this ecosystem.
Tundra food chain..
what-is-food-chain-of-tundra
LABELS: TUNDRA FOOD CHAIN
What is the food chain of the tundra ?
What is the food chain of the tundra ?
The Tundra food chain are as follow :
Producers: Grasses and Caribou Mosses
Carnivores: Polar Bears and Arctic Wolves
Herbivores: Caribou and Lemmings
Omnivores: Arctic Fox and Brown Bears
Decomposer: Bacteria and Fungi
Tundra Food Chain....
tundra-food-web.
L A B E L S : TUNDRA FOOD CHAIN
Tundra (Artic) Habitat
Tundra (Artic) Habitat
Where is the Tundra Habitat?
The tundra habitat is at the top of the world, near the North Pole.
How much of the earth is Tundra?
About one fifth of the earth's land is Tundra
What is the ground like?
The ground is permanently frozen 10 inches to 3 feet (25 to 100 cm) down so that trees can't
grow there
How do plants grow on the solid ground?
The bare and sometimes rocky ground can only support low growing plants like mosses, heaths,
and lichen. During the brief summers, the top section of the soil may thaw out allowing plants
and microorganisms to grow and reproduce. However, these plants and microorganisms become
dormant during the cold winter months.
Is there another type of Tundra other than artic tundra?
Yes, it is called alpine tundra and is found on the tops of tall, cold mountains.
How do animals survive in this habitat?
Animals are adapted to handle cold winters and to breed and raise young quickly in the very
short and cool summers.
What living things are found in the Tundra?
Herbivorous mammals: lemmings, voles, caribou, arctic hares and squirrels
Carnivorous mammals: arctic foxes, wolves, and polar bears
Migratory birds: ravens, snow buntings, falcons, loons, ravens, sandpipers, terns, snow birds, and
various species of gulls
Insects: mosquitoes, flies, moths, grasshoppers, blackflies and arctic bumble bees
Fish: cod, flatfish, salmon, and trout
Tundra
Arctic tundra is a vast open plain, a treeless landscape in the polar regions of the Northern
Hemisphere (Alaska, Canada, Greenland, Iceland, Norway, Finland, and Russia) where extreme
weather and permafrost limit flora to a stunted vegetative cover (lichens, mosses, and grasses).
Only a few species of hibernating mammals (musk ox, wolf/fox, and bear) live year-round in the
tundra while other animals (caribou/reindeer, geese, and snowy owls) migrate during the warmer
months.
Alpine tundra is found throughout the world and consists of high-altitude ecosystems (generally
above 3,000 meters depending on the latitude) similar to those of the arctic. The forest-tundra, a
transition zone that parallels the boreal forest to the south, consists of patches of continuous
forest cover interspersed with tundra-like open areas. In spite of the extremely cold and dry
characteristics that significantly reduce the level of human intervention, the tundra remains one
of earth’s most fragile ecosystem, sensitive to disturbances and generally unable to restore itself
once degraded: a simple food web indicates a delicate balance among species with little room for
adaptation.
Large-scale extractive industries (oil, gas, and minerals) in Russia and Alaska pose the greatest
ecological threat to the tundra ecosystems. The expansion of agriculture/livestock, vehicular
traffic, and tourism are also creating additional pressures that have resulted in significant
degradation. In certain parts of the arctic tundra, erosion is emerging as a serious problem due to
permafrost thaw, overgrazing, and deforestation.
WEBSITES USDA Forest Service provides a brief description of the Arctic tundra.
UNEP Global Environmental Outlook 1 (1997) addresses the major environmental concerns
of the arctic region.
UNEP Global Environmental Outlook 3 (2002) has a brief summary on arctic ecosystems.
US Bureau of Land Management addresses the issues facing Alaska’s Cold Desert.
International Polar Year (2007-2008) aims to provide better observation and understanding of
the Earth’s polar regions, and to focus the world’s attention on their importance.
The We – State of the Planet – Arctic combines news articles and environmental analysis of
the arctic tundra including past environmental degradation and future challenges.
Tundra is the global biome that consists of the treeless regions in the north (Arctic tundra) and
high mountains (alpine tundra). The vegetation of tundra is low growing, and consists mainly of
sedges, grasses, dwarf shrubs, wildflowers, mosses, and lichens. The word "tundra" is derived
from the Finnish word "tunturi," which refers to the upland treeless parts of hills and low
mountains free of woodlands.
Tundra climates are extremely cold and snowy in winter. Summers are cool. The southern or
lower limit of trees corresponds roughly to a mean July temperature between 10 and 12 degrees
Celsius (50 and 53.6 degrees Fahrenheit), but in maritime areas the limiting summer temperature
can be lower. Low shrubs, less than about 1 meter (3.2 feet) tall, and peaty soils are common
near treeline. In the northern extremes and at higher elevations, the landscapes are predominantly
barren with scattered wildflowers, such as purple mountain saxifrage and Arctic poppies,
mosses, and lichens. Most of the Arctic tundra regions are underlain by permafrost, ground that
is permanently frozen beneath a shallow layer of soil that thaws annually.
Tundra ecosystems have a variety of animal species that do not exist in other regions, including
the Arctic hare, musk oxen, lemmings, Arctic ground squirrels, and ptarmigan. Other animals
migrate annually to the Arctic including caribou and many species of birds.
The Arctic tundra is the least exploited of Earth's biomes. It is a unique biological laboratory for
scientists to study unaltered ecosystems. The chief ecological concerns in the Arctic tundra are
cumulative impacts of oil and mineral exploitation, roads, tourism, and long-range transport of
air pollution from industrial centers to the south. Global warming is likely to have its greatest
effect on tundra. Major concerns are the fate of permafrost and the carbon contained in Arctic
peat. Decomposition of this carbon could increase the concentration of carbon dioxide in the
atmosphere.
Read more: Tundra ‐ Biology Encyclopedia ‐ body, animal, major, temperature, common, species, transport http://www.biologyreference.com/Ta‐Va/Tundra.html#ixzz0l5x4Bya4 Although the Tundra Biome is one of the most inhospitable habitats in the world, there are
surprisingly quite a few interesting tundra plants and tundra animals that exist here.
The world’s major habitats, characterized by the dominant forms of plant and animal life that
exist in them, are known as biomes. Each biome’s location is defined by the climate of the
region.
What are the Types of Tundra Biome?
Extremely cold temperatures and frozen, treeless landscapes characterize the tundra biome.
While some sources claim that the word ‘tundra’ originates from the Kildin Sami term ‘tundar’,
which means ‘treeless mountain track’ or ‘uplands’, others say that it has been derived from the
Finnish ‘tunturia’, meaning ‘barren land’. The tundra is divided into two types: The Arctic
Tundra, which is also present in Antarctica, and Alpine Tundra. The ecological boundary region,
or ecotone, which demarcates the tundra and the growth of forest, is referred to as the timberline
or tree line.
Where is the Tundra Biome found?
The Arctic tundra lies between the North Pole and the taiga or the coniferous forests. In North
America, it occurs in Greenland, Canada and Northern Alaska, in northern Europe, it is mainly
found in Scandinavia, and in northern Asia, it is found in Siberia.
The Antarctic tundra occurs on various Antarctic as well as sub-Antarctic islands, which include
the Kerguelen Islands, the South Sandwich Islands, and South Georgia.
The Alpine tundra can be found at very high elevations on frozen mountaintop regions. In North
America, it occurs in Mexico, U.S.A., Canada, and Alaska. In South America, it is found in the
Andes Mountains. In northern Europe, it is found in Sweden, Russia, Norway, and Finland. In
Africa, it can be found in Mt. Kilimanjaro. And in Asia, it occurs in the Himalayan Mountains,
which is located in Southern Asia, and in Mt. Fuji, in Japan.
What are the Conditions in the Tundra Region?
The Arctic Tundra is considered to be the youngest biome in the world, having been formed
10,000 years ago. Located in the latitudes 55 degrees to 70 degrees north, this vast and treeless
territory covers approximately 20 percent of the surface of the Earth, encompassing the North
Pole. Of all the biomes in the world, the tundra is considered to be the coldest. With less than 10
inches of rain in a year, it is also the driest.
The main seasons of the tundra region are winter and a short summer. The summers in the tundra
sometimes last just for 6-10 weeks, while the winters are long. Spring and fall are just brief
interludes that occur between the winter and summer. In the winter, the nights can go on for
weeks, with the sun barely rising, and the temperature often plummeting as low a -94 degrees F.
Due to the Arctic tundra being as close as it is to the North Pole, the days in the summer are 24
hours long, which is the reason the Arctic is also referred to as the ‘Land of the Midnight Sun’.
The temperature in the summer rarely rises above 50 degrees F, which is just sufficient enough
to thaw the top layer of the ground, which is referred to as permafrost. Due to the rain and
melting snow in the summer, the soil on the surface gets very soggy. The permafrost, which lies
about six inches below the surface, remains frozen throughout the year.
Another characteristic feature of the Arctic tundra is that it is very windy, with winds blowing at
30-60 miles per hour (48-97 kilometers).
What are the Plants that Grow in the Tundra Biome?
Considering the extremely inhospitable conditions of the tundra biome, there are as many as
1,700 different plant species that grow here. The tundra plants consist mostly of mosses, grasses,
lichens, sedges, and shrubs. About 400 types of flowers bloom in the growing season, which
lasts just for 50-60 days. Except for a few birches in the lower altitudes, no trees grow in the
tundra. Because of the permafrost, trees cannot send their roots into the ground. Although in
some parts of the tundra willows do grow, but only up to about 8 cm, or 3 inches, high.
Developing over thousands of years, most of the vegetation have adapted to the conditions in the
tundra by growing in a dense mat of roots. Except where the soil is fertilized by animal
droppings, the soil is low in minerals and nutrients.
Being too dry and cold for vegetation to grow, the Antarctica tundra is mostly covered by large
expanses of ice fields. However, in some parts of the region, especially the Antarctic Peninsula,
there are areas where there is rocky soil which can support vegetation. The plant species that
exist here are aquatic and terrestrial species of algae, which occur in the exposed soil and rock
areas around the shore, liverworts, mosses, and lichens. The two flowering species of plants, the
Antarctic pearlwort and Antarctic hair grass can be found in the western and northern parts of the
Antarctic Peninsula.
Do any Animals live in the Tundra Region?
Even though there is not much biodiversity, with only about 48 species of land mammals
occurring in the tundra biome, there are surprisingly large numbers of each species. The tundra
animals mainly are slightly modified forms of deer, bears, foxes, wolves, rodents, hares, and
shrews. In North America, there are large caribou herds, which are called reindeer in Eurasia,
which feed on plants and lichens. Smaller musk-oxen herds also roam about the frozen regions.
The predators of the tundra biome are polar bears, arctic foxes, and wolves. Some of the smaller
mammals are lemmings and snowshoe rabbits.
Although there are not too many types of insects to be found in the tundra, however, tiny midges
that bite, mosquitoes, deer flies, and black flies do occur, which can make the summers in the
tundra quite miserable. The mosquitoes that occur in the tundra prevent themselves from freezing
by substituting the water in their bodies with glycerol, which acts like an anti-freeze. The marshy
regions of the tundra are where migratory birds like plovers, sandpipers, and harlequin flock to in
the summers.
Due to it being isolated from other continents, the Antarctic tundra, in contrast with the Arctic
tundra, is devoid of large mammal species. Sea birds and sea mammals, such as penguins and
seals, however, do occur in areas close to the shore, while small mammals like cats and rabbits
have been introduced by humans on some of the sub-Antarctic islands.
As is evident, the Tundra Biome is not a useless and cold wasteland. In fact, its very nature
makes the environment very fragile, and the animals and plants that have made the tundra their
home have adapted themselves incredibly intricately to its short, although abundant, summers
and cold, long winters. They exist on a precarious edge, hence, the most minor of stresses can
lead to their destruction.
Animal Photo Galleries
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Grassland Biome: Animals and Plants
Marine Biome - Marine Biology
Desert Biome: Animals and Plants
Fresh Water Biomes
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Biomes of the World
Tropical Rainforest Biome: Plants and Animals
Tundra Climate Facts
Taiga Biome: Taiga Animals and Plants
Tundra Food Chain
Tundra Biome Facts
Marine Biome Plants
Marine Biome Facts
Deciduous Forest Biome
Deserts, grasslands, rainforests, coral reefs, and tundra may seem quite different, but they are all
examples of biomes. A definition for biome is "a living community characterized by distinctive
plant and animal species and maintained under the climatic conditions of the region." Biomes are
made of many similar ecosystems (communities of organisms and the environments in which
they live).
A biome is characterized by abiotic (nonliving) factors such as geography and climate and by
biotic (living) factors such as plant and animal species.
Life in any biome includes producers (plants and other photosynthetic organisms) and
consumers (organisms that obtain their energy from producers). These consumers may be
further classified as herbivores (plant eaters), carnivores (meat eaters), or omnivores (feed on a
combination of animals and plants).
In addition, all ecosystems are dependent on detritivores (decomposers) -- bacteria and other
microorganisms that obtain energy from breaking down organic matter.
The flow of energy from the sun through an ecosystem can be illustrated in a food chain, such as
this generalized one:
Generalized food chain.
Energy is lost in the form of heat at each level of a food chain, which means that the number of
individuals at each successive level decreases. For example, within a food chain there are always
more producers than primary consumers, and more primary consumers than secondary
consumers or tertiary consumers. Decreasing available energy and population sizes in a food
chain are illustrated by an energy (or ecological) pyramid:
Image courtesy of Wikimedia.
While food chains are a useful teaching tool, their simplicity doesn't usually capture the complex
relationships within a biome or the fact that any one organism may be part of several food
chains. A food web, which illustrates the overlap between multiple food chains, more accurately
captures the flow of energy in an ecosystem.
A food web shows overlap between multiple food chains in an ecosystem.
Living organisms in any biome interact through a variety of relationships. Organisms compete
for food, water, and other resources. Predators hunt their prey. Some organisms coexist in
mutually beneficial relationships (symbiosis), while others harm organisms for their own benefit
(parasitism). Still others benefit from a relationship that neither helps nor harms the other
organism (commensalism).
Biomes (and their food webs) can change as a result of natural hazards or human activities.
Changes in environmental conditions may limit the availability of resources (food, water, space
or shelter), reducing the number of organisms that can survive in a given environment. A change
at any level of a food web will impact all other organisms in that web in some way. Some species
are considered keystone species because of the critical role they play in an ecosystem's food web.
Examples of keystone species include grizzly bears, sea stars, and sea otters.
TUNDRA
The tundra is a biome characterized by an extremely cold climate, little precipitation, poor
nutrients, and a short growing season. Other characteristics include low biodiversity, simple
plants, limited drainage, and large variations in populations.
There are two types of tundra: arctic and alpine. Arctic tundra is located in the Northern
Hemisphere; alpine tundra is located at high elevations on mountains throughout the world.
Tundra is also found to a limited extent in Antarctica - specifically, the Antarctic Peninsula.
ARCTIC TUNDRA
Arctic tundra is found along the northern coasts of North America, Asia, and Europe, and in
parts of Greenland. It extends south to the edge of the taiga (a biome characterized by coniferous
forests). The division between the forested taiga and the treeless tundra is known as the
timberline or tree line.
Location of arctic tundra across the Northern Hemisphere. Image courtesy of Wikimedia.
The tundra is known for cold conditions, with an average winter temperature of -30 degrees F (34 degrees C), and an average summer temperature ranging from 37 degrees to 54 degrees F (3
degrees to 12 degrees C). The growing season lasts from 50 to 60 days. The biome is also
characterized by desertlike conditions, with an average of six to ten inches (15 to 25 cm) of
yearly precipitation, including snow melt. Winds often reach speeds of 30 to 60 miles (48 to 97
km) an hour.
Another hallmark of the tundra is permafrost, a layer of permanently frozen subsoil and
partially decayed organic matter. Only the top nine or ten inches of soil thaw, leading to the
formation of bogs and ponds each spring.
Ice wedges in the permafrost can crack and cause the formation of polygonal ground. This
picture also illustrates the formation of ponds as the snow melts each spring. Photo courtesy of
U.S. Fish and Wildlife Service.
Tundra and taiga permafrost stores about one-third of the world's soil-bound carbon. Warming
Arctic temperatures due to climate change are causing the permafrost to thaw, releasing the
carbon in the form of carbon dioxide (a greenhouse gas). Additional carbon dioxide in the
atmosphere will intensify warming, leading to increased thawing and the release of even more
carbon dioxide. This positive feedback loop thus has the potential to significantly increase the
rate and effects of climate change.
Approximately 1,700 species of vascular plants are found across the Arctic tundra, including
flowering plants, low shrubs, sedges, grasses, and liverworts. Lichens, mosses, and algae are also
common. In general, tundra plants are low growing, have shallow root systems, and are capable
of carrying out photosynthesis at low temperatures and with low light intensities.
Animals found in the Arctic tundra include herbivorous mammals (lemmings, voles, caribou,
arctic hares, and squirrels), carnivorous mammals (arctic foxes, wolves, and polar bears), fish
(cod, flatfish, salmon, and trout), insects (mosquitoes, flies, moths, grasshoppers, and blackflies),
and birds (ravens, snow buntings, falcons, loons, sandpipers, terns, and gulls). Reptiles and
amphibians are absent because of the extremely cold temperatures. While many of the mammals
have adaptations that enable them to survive the long cold winters and to breed and raise young
quickly during the short summers, most birds and some mammals migrate south during the
winter. Migration means that Arctic populations are in continual flux.
A generalized food web for the Arctic tundra begins with the various plant species (producers).
Herbivores (primary consumers) such as pikas, musk oxen, caribou, lemmings, and arctic hares
make up the next rung. Omnivores and carnivores (secondary consumers) such as arctic foxes,
brown bears, arctic wolves, and snowy owls top the web. Bacteria and fungi play the important
role of breaking down organic matter and returning nutrients to the soil for re-use. Of course, the
exact species involved in this web vary depending on the geographic location.
\
A generalized tundra food web. Exact relationships and species depend on geographic location.
The interconnected nature of a food web means that as numbers of one species increase (or
decrease), other populations change in response. An often-discussed tundra example is the
lemming population. Lemmings are small rodents that feed on plants. Populations of lemmings
fluctuate radically (from large populations to near extinction) in regular intervals. While
scientists believed that populations of lemming predators (foxes, owls, skuas, and stoats) also
fluctuated in response to these changes, there is now evidence that suggests that the predators
themselves drive the changes in lemming populations.
Climate change is affecting tundra ecosystems in many ways. Thawing permafrost not only
releases carbon dioxide but also leads to coastal erosion- an increasing problem in Alaska where
villages are at risk. Warming also means that seasons are arriving earlier - a shift not only in
temperatures but also in the emergence and flowering of plants. Biologists suspect that a
mismatch between plant availability and calving is increasing mortality rates of caribou calves.
Finally, species distributions may change as birds and other animals shift their range or
migration patterns in response to changing temperatures.
ANTARCTIC TUNDRA
Much less extensive than Arctic tundra, Antarctic tundra is found on the Antarctic Peninsula and
several Antarctic and subantarctic islands. These areas have rocky soil that supports minimal
plant life: two flowering plant species, mosses, algae, and lichens. Antarctic tundra does not
support mammals, but marine mammals and birds inhabit areas near the coast. All species in
Antarctica and the Antarctic Islands (south of 60 degrees S latitude) are protected by the
Antarctic Treaty.
LINKS
The World's Biomes
http://www.ucmp.berkeley.edu/exhibits/biomes/index.php An overview of biomes and
information on six major types: freshwater, marine, desert, forest, grassland, and tundra.
Biomes and Ecosystems
http://www.windows.ucar.edu/tour/link=/earth/ecosystems.html General information about
biomes and ecosystems, with links to pages about tundra, taiga, temperate forest, tropical
rainforest, desert, grassland, and ocean biomes. This site may also be used with upperelementary students.
Geography4Kids: Biosphere
http://www.geography4kids.com/files/land_intro.html Includes pages on ecology, ecosystems,
food chains, populations, and land biomes. Appropriate for use with upper-elementary students.
NATIONAL SCIENCE EDUCATION STANDARDS: SCIENCE CONTENT STANDARDS
The entire National Science Education Standards document can be read online or downloaded
for free from the National Academies Press web site. The following excerpt was taken from
Chapter 6.
Teaching about biomes (including the tundra) can meet a wide variety of fundamental concepts
and principles, including:
K-4 Life Science
The Characteristics of Organisms
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Organisms have basic needs. For example, animals need air, water, and food; plants
require air, water, nutrients, and light. Organisms can survive only in environments in
which their needs can be met. The world has many different environments, and distinct
environments support the life of different types of organisms.
Organisms and their Environments
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All animals depend on plants. Some animals eat plants for food. Other animals eat
animals that eat the plants.
An organism's patterns of behavior are related to the nature of that organism's
environment, including the kinds and numbers of other organisms present, the availability
of food and resources, and the physical characteristics of the environment. When the
environment changes, some plants and animals survive and reproduce, and others die or
move to new locations.
All organisms cause changes in the environment in which they live. Some of these
changes are detrimental to the organism or other organisms, whereas others are
beneficial.
Humans depend on their natural and constructed environments. Humans change
environments in ways that can be either beneficial or detrimental for themselves and
other organisms.
K-4 Science in Personal and Social Perspectives
Changes in Environments
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Environments are the space, conditions, and factors that affect an individual's and a
population's ability to survive and their quality of life.
Changes in environments can be natural or influenced by humans. Some changes are
good, some are bad, and some are neither good nor bad. Pollution is a change in the
environment that can influence the health, survival, or activities of organisms, including
humans.
Some environmental changes occur slowly, and others occur rapidly. Students should
understand the different consequences of changing environments in small increments
over long periods as compared with changing environments in large increments over
short periods.
5-8 Life Science
Populations and Ecosystems
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A population consists of all individuals of a species that occur together at a given place
and time. All populations living together and the physical factors with which they interact
compose an ecosystem.
Populations of organisms can be categorized by the function they serve in an ecosystem.
Plants and some microorganisms are producers - they make their own food. All animals,
including humans, are consumers, which obtain food by eating other organisms.
Decomposers, primarily bacteria and fungi, are consumers that use waste materials and
dead organisms for food. Food webs identify the relationships among producers,
consumers, and decomposers in an ecosystem.
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For ecosystems, the major source of energy is sunlight. Energy entering ecosystems as
sunlight is transferred by producers into chemical energy through photosynthesis. That
energy then passes from organism to organism in food webs.
The number of organisms an ecosystem can support depends on the resources available
and abiotic factors, such as quantity of light and water, range of temperatures, and soil
composition. Given adequate biotic and abiotic resources and no disease or predators,
populations (including humans) increase at rapid rates. Lack of resources and other
factors, such as predation and climate, limit the growth of populations in specific niches
in the ecosystem.
5-8 Science in Personal and Social Perspectives
Populations, Resources, and Environments
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When an area becomes overpopulated, the environment will become degraded due to the
increased use of resources.
Causes of environmental degradation and resource depletion vary from region to region
and from country to country.
Natural Hazards
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Internal and external processes of the earth system cause natural hazards, events that
change or destroy human and wildlife habitats, damage property, and harm or kill
humans. Natural hazards include earthquakes, landslides, wildfires, volcanic eruptions,
floods, storms, and even possible impacts of asteroids.
Human activities also can induce hazards through resource acquisition, urban growth,
land-use decisions, and waste disposal. Such activities can accelerate many natural
changes.
In physical geography, tundra is an area where the tree growth is hindered by low temperatures
and short growing seasons.
See also:
Earth & Climate
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Tundra
Geography
Global Warming
Forest
Earth Science
Climate
There are three types of tundra: Arctic tundra, Antarctic tundra, and alpine tundra.
In all of these types, the dominant vegetation is grasses, mosses, and lichens.
Trees grow in some of the tundra.
The ecotone (or ecological boundary region) between the tundra and the forest is known as the
tree-line or timberline.
The word "tundra" usually refers only to the areas where the subsoil is permafrost, or
permanently frozen soil.
The arctic tundra is a vast area of stark landscape, which is frozen for much of the year.
The soil there is frozen from 25-90 cm (9.8-35.4 inches) down, and it is impossible for trees to
grow.
Instead, bare and sometimes rocky land can only support low growing plants such as moss,
heath, and lichen.
There are two main seasons, winter and summer, in the polar Tundra areas.
The biodiversity of the tundras is low: 1,700 species of flora and only 48 land mammals can be
found, although thousands of insects and birds migrate there each year for the marshes.
There are few species with large populations.
Notable animals in the arctic tundra include caribou (reindeer), musk ox, arctic hare, arctic fox,
snowy owl, lemmings, and polar bears (only the extreme north)..
The Tundra Biome
Climate:
In the tundra, conditions are cold,
with an annual average
temperature less than 5° C, and
precipitation (mostly in the form
of snow) less than 100 mm per
year (see figure at right). The
summer is brief, with
temperatures above freezing
lasting for only a few weeks at
most. However, this "warm"
summer coincides with periods of
almost 24 hour daylight, so plant
growth can be explosive.
World Distribution:
The map below shows the tundra spreading across the northern hemisphere. Tundra is largely
restricted to the northern hemisphere; there simply is no comparable land mass in the southern
hemisphere with the appropriate climate. The areas of the southern hemisphere at high enough
latitudes is small, and these areas have their temperatures moderated by the proximity of
surrounding oceans. Parts of Greenland extend north far enough that the tundra is replaced by
snow and ice; in contrast Canadian and Russian islands at these latitudes are again influenced by
the surrounding oceans and may thus exhibit tundra conditions. It should be noted that a similar
habitat, alpine tundra, exists in mountains of the alpine biome.
Indicator Plant Species:
A wide variety of plants species can be
found on the tundra, as can be seen in the
accompanying pictures. What most of them
have in common are growth characteristics they tend to grow low to the ground.
Among the common types of tundra plants
are willows, sedges and grasses, many in
dwarf forms compared to their growth
forms in warmer climes. Lichens and
mosses (far below) are also important,
particularly in the harshest climates.
Arctic Tundra Wildflowers - Alaska
Arctic Tundra Wildflowers - Alaska
Polytrichum Moss, photographed in Ohio, not on
the Tundra.
Lichen
Indicator Animal Species:
Caribou & Reindeer (Rangifer
tarandus) are perhaps THE
indicator animal species for the
tundra. The species, Rangifer
tarandus, is panarctic, but
differences are seen between the
representatives in the Old World
and in North America. The
Reindeer is the Old World form,
it is smaller than the Caribou and
has been domesticated. It is
herded by northern peoples
across Europe and Russia.
The caribou is the North
American form. It is larger and
still wild. It migrates from
summer to winter grazing areas,
following the melting of the snow
in the spring. A sizeable herd
remains in the Arctic National
Wildlife Refuge.
Reindeer (Rangifer tarandus)
Above: Reindeer antlers as the
characteristic velvet (the layer of
skin, fur and blood vessels that
nourish the developing antlers) is
being shed at the end of antler
development for the year. Both
male and female reindeer and
caribou have antlers; the
females use theirs for defense
while the males also use theirs in
mating competitions.
Other important tundra animals
include musk oxen, wolves,
ptarmigan, snow geese, tundra
swans, Dall sheep, brown bears
(and polar bears near the coast).
A number of small rodents and
rodent-like animals are crucial
parts of this ecosystem as well.
Reindeer (Rangifer tarandus)
Ecological Notes:
The ecology of the tundra is controlled by the cold climate
and the northern latitude. The former means that a unique
soil structure, permafrost, forms and dominates the
biology. Permafrost is a layer of soil that remains frozen
year-round. The soil above it may thaw during the summer,
but the soil below remains frozen and thus biologically
inactive. Further, the permafrost forms a barrier; in
temperate climes many animals overwinter by burrowing
down into the soil to a point below where the soil freezes.
This is not possible in the tundra soils, and thus animals
must contend with freezing over the winter. It is no
accident that there are no reptiles or amphibians in the
tundra.
The long day length that accompanies the short summer is
a boon to plants, which are able to photosynthesize 24
hours a day in some places. This leads to rapid plant
growth. A surprising number of insects are able to endure
the harsh winters (many as frost-resistant eggs); these also
undergo rapid development in the summer. Many bird
species migrate from southern areas to the tundra each
year for the reduced competition and plentiful insect
Tundra Soil Peeled Back at Level
harvest; this rich diet enables them to rear their young in of Permafrost - Alaska
an otherwise bleak environment.
Threats:
There aren't a lot of people running out to build houses on
the tundra. Development is not a major problem, nor is
there much pressure from human populations (although
pollution problems near human settlements can be severe; it
is a great technical challenge to effect efficient sewage
treatment in a cold environment, for instance). The biggest
threats come from airborne pollutants, which have
brought measurable levels of pollutants such as DDT and
PCB's to even remote areas.
The biggest threat, however, is from oil and gas development and the resulting global
warming. The Arctic National Wildlife refuge mentioned earlier has the misfortune of sitting on
about a 6 month supply of oil. Despite the great difficulty in extracting this oil, corporate
interests and their pet politicians just can't seem to let the idea of drilling here go. Instead of
promoting fuel conservation, which could easily make up for the oil not retrieved from this arctic
paradise, they continue to push the propaganda on the American people that drilling here will
somehow offset high oil prices. An more sever threat comes from global warming, however. As
the planet warms (a result of burning all that fossil fuel from elsewhere), the permafrost melts
and tundra ecosystems collapse. Further, the permafrost contains a significant amount of dead
plant material (grown in earlier and warmer times); as the permafrost warms this material begins
to decay, releasing even more CO2 into the atmosphere and accelerating global warming.
Tour:
Arctic Tundra and Alaska Pipeline - Alaska
During the short summer, the tundra appears
much like a temperate grassland. Ironically,
one of the best ways to access the tundra is via
the highway that accompanies the Alaska
pipeline from Barrow down to Valdez. The
section of pipeline seen here is raised off the
ground by special stands. These stands are sunk
into the permafrost and designed not to conduct
heat lest the warmth from the heated oil (the oil
has to be heated to thin it enough to pump
economically) thaw the permafrost and cause
the pipeline to collapse. Raising the pipeline
also allow caribou to pass under it freely.
During the summer the snow melts; much is
carried away by the streams winding through
the tundra (right), other water collects in small
lakes and wetlands (below left).
Tundra Stream - Alaska
Arctic Tundra - Alaska
Tundra Stream and Alaska Pipeline - Alaska
Arctic Tundra - Alaska
All of these tundra shots (except the reindeer,
which were photographed at the Cleveland Zoo)
were taken by Sarah Beck, Marietta College
class of 2001. In the summer of 2000, Sarah
worked with the Woods Hole Oceanographic
Institute on research they were doing in Alaska.
Sarah was gracious enough to share these
photos with us until we are able to mount our
own expedition to the tundra.
Arctic Tundra and Mountains- Alaska