The New Childrens Encyclopedia

HABITATS

61

BIOMES OF THE WORLD

Ecologists group similar types of ecosystem into areas

called biomes. Each type of biome, such as a tropical

rain forest, has the same sort of climate and habitat as

other rain forests around the world, but the species it

contains may be different. Hot, wet, tropical biomes

have many more species than cold or dry ones.

Biodiversity is a measure of the variety of species in an ecosystem. All

species have a role to play in the ecosystem. To understand an ecosystem

properly, scientists have to identify all the organisms living there and find

out how they interact. These researchers are collecting moths. Then they

can protect any species or groups of species that are important to

that ecosystem.

Africa

PACIFIC

OCEAN

ATLANTIC

OCEAN

SOUTHERN

OCEAN

INDIAN

OCEAN

Asia

Many species face

extinction.These

groups are the

most threatened.

The northern

hemisphere has

a wide range of

biomes, but those

lying on the

equator have a

greater diversity

of species.

Invaders When new species

are introduced to an

area they can have a

devastating effect on

the ecosystem. Cane

toads (right) were

brought in to eat

beetles in Australian sugar

fields, but became pests as they

also eat other animals.

Evolution Every part of the world has

species that do not live anywhere else.

These are called native species and have

evolved to suit the local conditions.

These tree ferns only grow wild in

New Zealand.

O
 Nearly 1.65 million species of plant

and animal are known to exist.

O
 Almost 1 million of those species

are insects.

O
 More amphibians face extinction than

any other animal group.

O
 About 5,000 new species are

discovered every year, mostly insects.

O
 Rain forests are the most biodiverse

regions on Earth.

FAST FACTS

Australasia

and Oceania

Antarctica

Percentages of threatened species

Mammals 21%Birds 12%Amphibians 30%Corals 11%Woody plants 33%

Equator

BIODIVERSITY

AND ECOLOGYENVIRONMENT

S. America

Coral reef

Desert

Rain forest

Temperate

forest

Mountain

Polar

Freshwater

Grassland

N. America

Boreal forest

Europe