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FIND OUT MORE. Coasts 59 • Ice 58 • Mountains 45

84 Nature

MOUNTAINS

Land that is 600 m (1,970 ft) or

more above the sea is a mountain.

The higher you climb, the thinner

the air, the lower the temperature,

and the faster the wind speed are.

Only the toughest species survive.

DESERTS

This dry and hostile habitat often

receives less than 10 cm (4 in) of

rain each year. Deserts are very hot

by day, but cooler at night. Few

animals and plants have adapted

to survive these difficult conditions.

HOW DO DESERT PLANTS SURVIVE?

Some plants, such as cacti, have deep, wide-

spreading roots to reach available water, and

small leaves and waterproof skins that limit

evaporation. Others spend most of their life

cycle as seeds. When rare rains arrive, they

sprout, flower, and produce seeds within two

weeks. This event is called a desert bloom.

WHAT ARE MOUNTAIN ZONES?

Mountains have various zones of vegetation.

Deciduous woodlands cover the foothills.

These rise up to coniferous forests, which can

survive the colder, windier conditions. Above

the tree line (where trees can no longer grow)

is an alpine meadow of hardy plants. Next is

bare rock, capped by a snow field.

WHICH ANIMALS LIVE ON MOUNTAINS?

Each vegetation zone has its typical species.

Woodlands and forests provide habitats for

grazers, such as deer and birds. Meadows are

home to rodents and rabbits and, in summer,

insects and the birds that eat them. Goats

and sheep live on the rocky crags, and birds

of prey circle above, in search of food.

DO THE ARCTIC AND ANTARCTICA DIFFER?

The Arctic surrounds the North Pole and is

a frozen ocean. Animals such as polar bears

and arctic foxes live on the ice sheet.

Antarctica surrounds the South Pole, is

a frozen continent, and has few animals.

The ocean around it is rich in nutrients

and supports fish, seabirds, seals, and whales.

1 PENGUINS

Several species of penguins live, feed, and breed in and

around Antarctica. Their dense waterproof feathers

and layers of fat help to keep them warm.

1 EDELWEISS

Short, tough plant species, such as this Swiss edelweiss, can

survive in the alpine meadow. Here above the tree line,

winds are fierce and biting, and soils are thin and rocky.

1 SCORPION

Like many desert animals, this scorpion is active at night,

when temperatures are lower. Once a scorpion has detected

its prey, it grips and then stings it.

1 WELWITSCHIA

This plant grows in the extremely dry Namib Desert. It

survives by using its large leaves to absorb condensation

from fog that rolls off the nearby ocean at night.

Sting at the end of

jointed flexible tail is

used for self-defence

and to kill prey

Snow field at the top

of a mountain is too

cold and windy for

most living things

Chinstrap penguins

gather on an iceberg

in Antarctica

Strap-like leaves

absorb water

vapour

POLAR HABITATS

Cold, icy polar habitats exist at the

Earth’s North and South poles. Polar

regions have short summers, and

long, harsh winters. Only animals

that have adapted, with thick fur,

for example, survive there.

1 WALRUSES

These marine mammals live in herds in Arctic coastal waters.

Walruses are tough-skinned, with a thick layer of blubber

(fat) to protect them from the cold.