Nature^83
FORESTS
Habitats dominated by trees and
shrubs are called forests. They
include tropical rainforests, cool-
climate coniferous forests, and
temperate broad-leaved forests.
These habitats all teem with life.GRASSLANDS
Wherever it is too dry for forests to
grow, or too wet for deserts to form,
grasslands appear. The two main
types are the tropical African
savannah and temperate grasslands,
such as the South American pampas.WETLANDS
Wherever salt or fresh water cannot
easily drain, a wetland forms.
Wetlands cover over 6 per cent of
the Earth’s surface. They include
marshes, swamps, waterlogged
forests, peat bogs, and river deltas.
WHY ARE WETLANDS IMPORTANT?
Many wetlands contain a large diversity of
species, including birds, mammals, reptiles,
insects, amphibians, and plants. Wetlands
also serve as nurseries where young fish and
other aquatic animals grow and develop.
1 FLAMINGOS
These tropical wetland birds live on salty lakes and lagoons.
They pump water through their beaks, filtering out shrimps
and other small aquatic animals for food.
WHY ARE RAINFORESTS SO FULL OF LIFE?
Evergreen trees continuously grow and
provide food in the constant warm and wet
climate of tropical rainforests. A huge variety
of animals feed and shelter at all levels, from
the forest floor to its canopy. Tropical
rainforests contain half of all animal and
plant species. Yet they cover only about
10 per cent of the Earth’s surface.HOW DO GRASSES SURVIVE GRAZING?
Grasses can withstand constant grazing
because they sprout from the bottom, not
from the tips. The more they are eaten, the
more they grow. Grasslands support a wide
variety of animals that eat grasses, as well
as those that prey on grass-eaters.1 THREE-TOED SLOTH
This South American mammal spends most of its days
hanging upside down from the branches of rainforest trees.1 AFRICAN SAVANNAH
The hot African savannah is home to vast herds of grazing
animals, including these wildebeest and zebra. They in turn
are hunted by predators such as lions and leopards.1 STAG BEETLES
These fighting stag beetles live in broad-leaved forests. As
young larvae they fed on rotting wood. As adults they feed
upon the sap of tree trunks.Stag beetles
use their massive jaws to fight
over mates and territoryWHAT ARE MANGROVE SWAMPS?
These are the salt-water wetlands, populated
by mangrove trees, found along tropical
coastlines. Mangrove swamps teem with life,
and they also help to protect the coastline
from tropical storm damage.
HOW DOES A PEAT BOG
DIFFER FROM A SWAMP?
Peat bogs form in cool, wet places where a
lake fills with soil and vegetation. Swamps
are found in places, such as river deltas,
where water moves slowly enough to create
permanent flooding. Plentiful vegetation
provides food and homes for swamp animals.
HOW CAN SO MANY PLANT-EATING
SPECIES LIVE IN THE SAVANNAH?
The African savannah supports many species
of plant-eaters, some of which eat different
parts of grasses, while others eat different
savannah plants. Zebras, for example, eat the
coarse, tough tops of grasses, while
wildebeest prefer their leafy, middle parts.WHY DO MANY SMALLER GRASSLAND
ANIMALS LIVE UNDERGROUND?
There are few trees in the grasslands to
provide shelter, so burrowing protects the
animals from enemies. Burrows also protect
against extreme weather conditions.FIND OUT MORE. Deserts 84 • Mountains 84 • Polar Habitats 84