World Biomes

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World Biomes

• Polar desert
• (Polar barren)

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Introduction

• Polar deserts on the Earth cover nearly 5 million
  square kilometers and are mostly bedrock or
  gravel plains. Sand dunes are not prominent
  features in these deserts, but snow dunes occur
  commonly in areas where precipitation is locally
  more abundant.

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Climate

• Polar deserts are areas with annual precipitation
  less than 250 millimeters and a mean temperature
  during the warmest month of less than 10 C.
• In the winter, temperatures can be as low as -30
  - -60 C
• Also the winds have an enormous effect on the
  weather. They bring dramatic storms with
  visibility reduced to less than 100 feet.
• The year is divided about equally between day
  (summer) and night (winter) owing to the
  continuous position of the Sun above or below the
  horizon during these seasons.

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Distribution of biome

• At the North Pole is the Arctic Ocean, lying in
  the midst of islands and landmasses (the
  northernmost being Greenland) and the Canadian
  arctic archipelago. In all lowland areas the
  extreme cold is relieved with above-freezing
  temperatures for a month or more each year,
  allowing for a varied plant and animal life.
• The South Pole is occupied by the continent of
  Antarctica, the mountains of which project
  through the world's greatest ice cap. No more
  than about 4 percent of the Antarctic's land is
  capable of sustaining life, while only the coast
  of Graham Land on the Antarctic Peninsula and
  several off-lying islands are warmed each year by
  above-freezing temperatures.

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Soil

• Considerable cover of a soil crust, which
  develops in sites exposed to continued surface
  runoff from melting snow for some of the short
  growing season.

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Plants

• Plants cover less than five percent of this
  ecoregion because of the very cold temperatures,
  short growing season, and dry soil. Heath,
  mosses, and lichens are hardy enough to survive
  in the harsh climate, and flowering plants such
  as the Arctic poppy have blossoms that track the
  sun during the day, concentrating the suns heat
  on themselves.

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Arctic Poppy
Plants in Antarctica
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Animals

• All the wildlife is connected with sea, because
  there is very little food on land.
• Vast colonies of seabirds can be found nesting on
  the cliffs of this ecoregion.
• Not many animals spend all year there.

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Harp seal
Walrus
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Polar bear
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Atlantic Puffin
Seabird colony
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Beluga
Narwhal
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• Adelie penguin

Emperor penguin
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Antarctic Petrel
Southern Fulmar
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Leopard seal
Southern elephant seal
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Blue whale
Killer whale
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People I

• Few direct threats exist for this ecoregion,
  simply because humans are largely absent. But
  where humans have tread, this ecoregion has
  suffered. Plans for a northern shipping route
  through the Russian Arctic could open up oil,
  gas, and other natural resources for
  exploitation. This could increase the risk of oil
  spills and introduce species such as rats to the
  ecoregion, which could have drastic consequences
  for nesting seabirds.
• The Novaya Zemlya area has a unique problem. It
  has been serving as a test area for nuclear
  weapons and suffers from elevated levels of
  plutonium, cesium, and other radioactive
  pollutants.

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People II

• Global climate change could upset the balance of
  life in the ecoregion by melting ice, raising
  temperatures, and upsetting the food chain.
• Ozone depletion threatens to leave the Antarctic
  open to dangerous amounts of the suns
  ultraviolet radiation. And pollution both from
  scientific expeditions and a growing tourism
  industry could also become threats if not well
  managed.

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