Childrens Illustrated Encyclopedia

ECOLOGY AND FOOD WEBS

176

HABITAT

A habitat is a place where a certain animal or plant usually lives. There are several

characteristic habitats, such as oak forests, mangrove swamps, and chalk cliffs.

A habitat often has one or a few main plants, such as the pampas grass, which

grows in the grassland habitats of South America. Certain characteristic animals

feed on these plants. Some animals live in only one or two habitats; the desman,

for example, is a type of muskrat found only in fast-running mountain streams.

Other animals, such as red foxes and brown rats, are able to survive in many

different habitats. The coral reef shown here is one of Earth’s richest habitats

in terms of species, but the water is poor in nutrients.

Today, falcons and other birds of prey

are rare. Many have died as a result

of the pesticides used by farmers

to kill insects on farm crops.

PESTICIDES
Farmers and gardeners use pesticides to kill
insects that are pests on vegetable and cereal
crops. In 1972, the insecticide called DDT
was banned in the United States because
it caused great damage to wildlife. When
DDT is sprayed on crops, some of it is
eaten by herbivores such as mice and
squirrels. The insecticide builds up
inside the animal’s body. A bird of prey
such as a hawk eats the animal, and the
DDT becomes concentrated (builds
up) in the bird’s body. The DDT causes
the bird to make very thin or deformed
eggshells, which break and kill the
developing chicks inside. Since DDT
was banned, the number of falcons
has slowly risen.

Wetland Savanna Tropical rain

forest

BIOME

A biome is a huge
habitat, such as a tropical

rain forest or a desert.
The deserts of Africa,

Central Asia, and North
America each have

distinct kinds of plants
and animals, but their

ecology is similar. Each of
these large habitats, or

biomes, has a big cat as a
top predator—the

caracal (a kind of lynx)
in Africa, the puma in

North America, and
Pallas’s cat in central

Asia. The major types of
plants that grow in a

biome are determined by
its climate. Areas near

the equator with very
high rainfall become

tropical rain forests, and
in cold regions near the

Arctic and Antarctic, only
tundra plants can survive.

Desert

The map above shows the main types of large habitats,

or biomes, in the world. Each color on the map represents

a different kind of biome, as shown by the key below.

Temperate forest Coniferous forest

Temperate

grassland

Tundra Mountains

Europe

North

America

Africa

Asia

Australia

South

America

Find out more

Animals

Birds

Conservation

and endangered species

Desert wildlife

Lake and river wildlife

Plants

Pollution