Page 9 - The World About Us

Emperor penguins
2.1.2
1.1.1

What are the flora and fauna of the Polar regions?

Much of the Arc c is an ocean with fig.17 Caribou out on the Alaskan tundra.
a permanently frozen layer of sea ice
on the surface. Polar bears hunt their
seal prey on the Arc c sea ice during the
winter months, o en coming close to
starva on during the summer when the
more southerly ice melts.
The Arc c land area is dominated by
a biome called the tundra. This is a vast
expanse of land covering around 11.5
million square kilometres. The ground
here is permanently frozen, as
permafrost below a surface layer which
only melts briefly each summer.
tree-less plain and desolate mountains. escape the cold, moving south in winter.
Each summer only the shallow
There are around 1,700 species of Antarc ca is 99% covered in snow
surface layers of the ground melt, plants adapted to grow in the harsh and ice and so plants are very limited
allowing low-growing shrubs, grasses condi ons of the tundra. Many animals, on the con nent. Those plants that do
and alpine plants to grow on a thin and such as reindeer or snow geese, migrate exist are mostly mosses (100 species)
poor soil. The tundra appears as a vast
to the tundra for the summer and then and liverworts (25 species).
Seas teeming with life fig.18 Krill, a Southern Ocean Adélie penguins. Fur seals, elephant

The seas of both the Arc c and keystone species. A single ‘swarm’ and Weddell seals hunt the fish-rich
Southern Oceans are very produc ve. can contain up to waters, res ng up on the shores and ice
In summer, blooms of phytoplankton 200 million flows. Crabeater seals are hunted by
form the founda on of complex food tonnes. the fearsome leopard seal. These are, in
turn, hunted by orca or killer whales.
webs. Shrimp-like krill rise to the
surface to feed on the plankton. The eighteen species of squid found
in the Southern Ocean prey on young
An es mated 379 million tonnes of
krill live in the Southern Ocean fish and krill. In turn, they are prey for
providing food for fish and squid, as of Antarc ca may appear barren, the larger fish, seals, orca and sperm
well as seals and baleen whales, such as waters teem with life. Many birds and whales. An es mated 36 million tonnes
of squid are consumed by other marine
the blue and minke species. This makes sea mammals which visit Antarc c
life in the Southern Ocean each year.
the simple krill one of the keystone waters also breed there.
species of Southern Ocean
Many thousands of penguins breed KEY TERMS
Krill also support ocean-faring birds, on the shores of Antarc ca, including
such as shearwaters. So while the land thousands of gentoo, emperor and
Arctic: the region north of 66 ⁄ North
in latitude, dominated by the tundra
regions and the Arctic Ocean.
Antarctic: region south of 66 ⁄ South
Sperm whales
Baleen whales Orca in latitude, dominated by the continent
of Antarctica and the Southern Ocean.
Penguins
Keystone species: a species that is
critical to maintaining the relationships
Elephant Leopard seals Seabirds in an ecosystem. This could be as a
seals source of food or as a predator which
controls other elements in the
Fish Other seals ecosystem.
Krill
Polar regions: both the Arctic and the
Squid fig.19 A simplified Antarctic, close to the North and South
Antarctic food web. Poles, with latitudes greater than 66 ⁄ .
Phytoplankton and Zooplankton

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Ecosystems have distinct distributions and characteristics.