2. This enormous biome, extremely uniform in
appearance, covers a fifth of the earth's surface.
3. GENERAL CHARACTERISTICS
*Extremely cold climate
* Low biotic diversity
* Simple vegetation structure
* Short season of growth and reproduction
* Energy and nutrients in the form of dead
organic material
5. Sun’s oblique angle – receive little solar energy
Low Temperatures – 29 degrees celsius to 7
degrees celsius (winter) and not more than 10
degrees celsius (summer)
Short summer days – 6 to 10 weeks. sun shines
almost 24 hours a day.
Long winter – 9 months. almost 24 hours night
6. Poor soil – reduced decomposition due to cold
climate
Strong winds
Cold and dry climate – precipitation 6 to 10 inches
of rain per year
latitude – Arctic tundra or Alpine tundra
Permafrost – layer of permanently frozen subsoil
(600 meters deep)
7. ARCTIC TUNDRA
Arctic tundra is found almost entirely in the Northern
Hemisphere. In the southern hemisphere it is found on
isolated islands off the coast of Antarctica as well as the
Antarctic peninsula. It can also be found in Northern portions
of Canada, Alaska, Greenland, and the United States
8. ARCTIC TUNDRA
higher latitude
Short growing season – 50 to 60 days
permafrost
vegetation – protects the permafrost through
shading and insulation
Freezing and thawing of the upper layer of soil –
unique, symmetrically patterned landforms. Action
of frost
Cryoplanation – molding of the landscape by frost
action
13. ALPINE TUNDRA
Alpine tundra is located on mountains throughout the world at
high altitude where trees cannot grow. It is not found in
distinct areas as the arctic tundra. Alpine tundra is scattered
in many regions all around the world.
14. ALPINE TUNDRA
permafrost – high elevations
little
Short growing season – 160-180 days
soils are drier – only alpine wet
meadows and bogs have similar soil
moisture as the Arctic tundra
precipitation (snowfall and humidity) –
higher but steep topography induces a
rapid water runoff
20. LowTemperatures and Extreme
Seasonality Control Tundra
Productivity and Nutrient Cycling
21. Primary production on the tundra is low, a
consequence of low temperature and a
short growing season ranging from 50-60
days in the high Arctic to 160 days in the
low-latitude alpine tundra.
These physical constraints result in a low
availability of nutrients that further function
to reduce productivity
22. Dead organic matter functions as the
nutrient pool, but most of it is not directly
available to plants.
Because the tundra soil does not store
available nutrients in any great
quantity, plants depend on the release of
nutrients for decomposition, the uptake of
which is often aided by mycorrhizae
23. Leaching or removal of nutrients is
minimal, occurring mostly at the beginning of the
growing season. Melting snow releases nutrients
frozen over winter in the litter, excreta of
animals, and microbes.
24. A rapid upward movement of nutrients early in
the season at the expense of below-ground
biomass supports fast shoot growth. *
Sixweeks into the growing season, plants start
to send nutrients below-ground.
As the cold approaches, the above ground
tissues die, and their dead parts add to the
accumulation of organic matter.
Nutrients leached from the dead leaves are
accumulated by mosses or are frozen into place
until the following summer’s snowmelt
27. Plant Adaptations
Growing close together and
low to the ground are some
of the adaptations that plants
use to survive. This growing
pattern helps the plant resist
the effects of cold
temperatures and reduce the
damage caused by the
impact of tiny particles of ice
and snow that are driven by
the dry winds
28. Only plants with shallow root systems grow in the
Arctic tundra because the permafrost prevents
plants from sending their roots down past the active
layer of soil.
Plants also have adapted to the Arctic tundra by
developing the ability to grow under a layer of snow
Plants lose water through their leaf surface. By
producing small leaves the plant is more able to
retain the moisture it has stored.
29. CARIBOU MOSS
Although it is called caribou moss, it is actually a
lichen.
Lichens are two separate organisms. They are
made up of fungi and algae, which live and grow
together. The spongy threads of lichens support
and protects the algae. The tissues of lichens
aren't easily damaged by frost. .
30. LABRADOR TEA
It will grow up straight in the
southern latitudes of the tundra,
but in the colder northern
latitudes it will creep over the
ground forming a carpet.
PASQUE FLOWER
31. Because of the cold
wind, most plants are small
perennial groundcover
plants which grow and
reproduce slowly. They
protect themselves from
the cold and wind by
hugging the ground. Taller
plants or trees would soon
get blown over and freeze.
When plants die they don't
decompose very quickly
because of the cold. This
makes for poor soil
conditions.
32. Many flowering plants of
the alpine tundra have
dense hairs on stems and
leaves to provide wind
protection or red-colored
pigments capable of
converting the sun's light
rays into heat. Some
plants take two or more
years to form flower
buds, which survive the
winter below the surface
and then open and
produce fruit with seeds
in the few weeks of
summer.
33. WHAT DOES THE SNOW DO TO HELP THE
PLANTS?
Snow beds are found where large amounts of snow
accumulate– this provides a continuous supply of
water throughout the growing season
Snow patch communities occur where wind driven
snow accumulate in shallow beds– this layer of
snow protects the plant beneath. Although, the
plants have a shorter growing season.
36. POLAR BEAR
Polar Bears do not enter true hibernation in the
winter as this is a period of hunting, however, some
Polar Bears and pregnant females in particular will
enter a deep sleep where their heart rates will drop.
They have two layers of fur which is so warm that
adult bears can easily overheat when they run.
Most of the sun's rays reach their black skin, which
absorbs the heat and keeps the polar bear warm.
37. Their teeth and claws are
very sharp so they can
catch their prey easily
(seal).
Also, their claws aid them
in digging out the snow in
making snow den’s for the
women to give birth
38. Repeated freezing and thawing can destroy living
tissue. The Alaska blackfish overcomes this
problem by producing chemicals within its body that
lowers the freezing temperature of cell fluids. Much
like the antifreeze we add to the water in our
vehicles, the "antifreeze" of the Alaska blackfish
prevents the formation of large ice crystals within its
cells, even at low temperatures. The Alaska
blackfish can survive temperatures of-20 degrees C
(4 F) and the complete freezing of some body parts,
including their heads, for up to several days.
39. ARCTIC FOX
The Arctic fox has adapted to
its environment by growing
long fur that changes color
with the season for
camouflage. Its
legs, ears, and muzzle are
short to conserve heat, and
uses its tail like a muffler
when cold.
41. CARIBOU
The caribou lives in the arctic tundra, Their
large, spreading hooves support the animal in
snow in the winter and marshy tundra in the
summer. Caribou are also great swimmers and
use their feet as paddles. They can also lower their
metabolic rate and go into a semi-hibernation
when conditions get very harsh.
Caribou have special microorganisms in their
stomachs which let them digest lichen.
42. ERMINE- SHORT-TAILED WEASEL
Their ermine paws have claws which
enables it to dig. The front feet are
smaller than the back which helps it
fit into small, tight spaces. The coat
of the ermine changes with the
seasons and camouflages it from
predators. In winter the ermine's coat
is white blending in with the snowy
environment. In warmer seasons the
fur turns brown again matching the
color of the landscape.
43. SOME COMMON ADAPTATIONS OF RESIDENT
ANIMALS IN THE ARCTIC AND ALPINE TUNDRA:
- short and stocky arms and legs. - thick, insulating
cover of feathers or fur. - color changing feathers or fur:
brown in summer, and white in winter. - thick fat layer
gained quickly during spring in order to have continual
energy and warmth during winter months. - many tundra
animals have adapted especially to prevent their bodily
fluids from freezing solid. - resident animals like the
ptarmigan and the ground squirrel use solar heating to
stay warm and save energy. Both animals stay out in the
sun to warm up and during the summer when the weather
is warm, seek shade to cool off.
45. OVERHUNTING
The overhunting of endangered species in the early
1900s resulted in the eradication of animals such
as the musk oxen in the Alaskan tundra, which
sailors coveted for the food and clothing it offered.
Eventually, governments began to recognize the
issue and responded by enacting laws to protect
the tundra animals. Because of this, musk oxen and
caribou numbers are slowly rising again in places
such as Canada where they were once close to
extinction.
46.
47. SABER-TOOTHED
TIGER
Smilodon became extinct
at the end of
the Pleistocene around
10,000 BC, a time which
saw the extinction of
many other large
herbivorous and
carnivorous mammals.
Prehistoric humans, who
reached North America at
the same time and are
known to have hunted
many of the species that
disappeared, are often
viewed as responsible for
this extinction wave.
48. POLLUTION AND GLOBAL WARMING
Global warming will continue to have an inevitable
effect on the tundra, the world's most fragile biome.
Rising temperatures will melt glaciers and
permafrost, flood the surrounding areas and kill the
delicate plant species.
49. Polar bears are in
danger of extinction
due to the climate
change that is
melting their habitat.
Their main prey is
seals, who live on
the ice; the less ice
there is, the fewer
seals there are for
the polar bears to
eat.
50.
51. Climate change
and hunting have
WOOLLY MAMMOTH long been blamed
for forcing the
mammoth into
decline at the end
of the Pleistocene
era about 10,000
years ago.
Researchers
estimate that the
last mammoth
died out 4,000
years ago.
52. OIL DRILLING
The Arctic holds the world's largest remaining
untapped gas reserves and some of its largest
undeveloped oil reserves. A significant proportion of
these reserves lie offshore, in the Arctic's shallow
and biologically productive shelf seas. According to
the oil industry, the Arctic is the final frontier for
petroleum development.
53. Oil drilling pollutes the water, land and air surrounding the
tundra. Russia's nickel mines serve as a vivid example of
the effect that oil drilling can have on the habitat. Many
plants and animals have either been killed or have
permanently fled the area after the area became
contaminated by the harmful gases and materials
released during drilling.
54. On January 3, 1959, Alaska gained statehood along with
its natural resources. Rich oil deposits was one of the
many natural resources found in this vast area causing a
new breed of fortune hunters to come to Alaska. On
March 24th, 1989, millions of gallons of oil spilled into the
ocean when Exxon Valdez (an oil tanker) crashed into a
reef. This spill affected all of the wildlife greatly, tens of
thousands of seabirds, salmon, herring, and halibut were
killed from a disaster that wouldn't have happened except
for the intervention of man. An estimate was made that
100,000 birds died in the oil spill, something that could
have been avoided. Even though the bulk of the oil was
finally cleaned up, some of it still lingers there.
55.
56. OVERDEVELOPMENT
Building roads and structures in the tundra has
attracted much more human traffic to an area
where merely stepping on the fragile plant species
can kill them. Without plants to contain the soil, the
earth quickly erodes and threatens to destroy the
entire biome.
57. Footprints and tire tracks can be visible for many
years after they were made. When the sun hits the
ruts it causes the permafrost to melt. This causes
erosion and the ruts get bigger, and eventually the
ruts turn into gullies. Tracks made during WW II
have grown so large that some of them are now
lakes.
Notas del editor
To carry out photosynthesis in extremely cold conditions and for flowering plants to bear flowers
The algae haschlorophyll which can make food. This is called a symbiotic relationship. Lichen can make food when the temperature gets very low and there is little light.
They have two layers of fur which is so warm that adult bears can easily overheat when they run.Most of the sun's rays reach their black skin, which absorbs the heat and keeps the polar bear warm.