Transcript Global Environments Overview

Global Environments
Stage 4 Geography
Types Of Global Environments And Their
Location
• Coasts
• Coral reefs
• Deserts
• Grasslands
• Mountains
• Polar lands
• Rainforests
• Rivers
• Tundra
• Wetlands
Coasts
Definition:
• A coast or coastal area is the areas of land
and sea bordering the shoreline and
extending seaward through the breaker
zone. Coastal areas throughout the world
are under enormous environmental stress,
which is caused by a wide range of factors,
including pollution and the destruction and
deterioration of marine habitats.
Location:
• Due to coasts bordering countries, they are
located on the edge of the majority of the
world's continents. Australia's most utilised
coast is the East coast of Australia where
fishing, recreation and tourism are some of
the main activities that occur here.
Coral Reefs
Definition:
•
A coral reef is a wave-resistant structure resulting from
cementation processes and the skeletal construction of
hermatypic corals, calcareous algae, and other calcium
carbonate-secreting organisms.
•
Coral reefs are warm, clear, shallow ocean habitats that
are rich in life.
•
The reef's massive structure is formed from coral polyps,
tiny animals that live in colonies; when coral polyps die,
they leave behind a hard, stony, branching structure
made of limestone.
Location:
•
Coral reefs develop in shallow, warm water, usually near
land, and mostly in the tropics; coral prefer temperatures
between 21 - 30 °C.
•
There are coral reefs off the eastern coast of Africa, off
the southern coast of India, in the Red Sea, and off the
coasts of northeast and northwest Australia and on to
Polynesia.
•
There are also coral reefs off the coast of Florida, USA,
to the Caribbean, and down to Brazil.
•
Australia's largest and most well known Coral Reef is the
Great Barrier Reef, it is also the largest in the world.
Deserts
Definition
• Deserts cover about one fifth of
the Earth’s surface and occur
where rainfall is less than 50
cm/year.
• Most deserts have a lot of
specialized vegetation, as well
as specialized vertebrate and
invertebrate animals.
• There are four major types of
deserts:
– Hot and Dry, Semiarid, Coastal,
Cold.
Locations
Hot:
• North America
• There are relatively few large
• West Coast of South America
mammals in deserts because
most are not capable of storing • Central Australia
sufficient water and
withstanding the heat.
• North Africa
• Deserts often provide little
shelter from the sun for large
animals.
• Middle East
• The dominant animals of warm Cold:
deserts are non mammalian
• Antarctic
vertebrates, such as reptiles.
• Mammals are usually small, like • Central Asia
the kangaroo mice of North
• Greenland
American deserts.
Grasslands
Definition:
• Grasslands are characterized as lands dominated
by grasses rather than large shrubs or trees.
• In the Miocene and Pliocene Epochs, which
spanned a period of about 25 million years,
mountains rose in western North America and
created a continental climate favorable to
grasslands.
•
Ancient forests declined and grasslands became
widespread.
• There are two main divisions of grasslands:
tropical grasslands (called savannas), and
temperate grasslands.
Location:
• Almost one-fourth of the Earth's land area is
grassland.
• Grasslands are located in:
–
–
–
–
–
North America's interior,
Southeastern South America,
Eurasia,
Africa,
Australia and New Zealand.
Mountains
Definition
• Mountains cover about a fifth of the earth's
surface,
• Mountains are formed by slow but gigantic
movements of the earth's crust.
• Sometimes the crust has folded and buckled,
sometimes it breaks into huge blocks.
• In both cases, great areas of land are lifted
upwards to form mountains.
• Other mountains are formed by the earth's crust
rising into a dome, or by volcanic activity when
the crust cracks open.
Locations
• Mount Everest is the largest mountain in the
world and Mount Kosciusko is the largest in
Australia.
• Are found on all continents and there are even
mountains under the surface of the sea.
Polar lands
Definition
• Polar Environments are very cold lands with
small or absolutely no vegetation.
• The harsh environment makes polar lands
very hard to settle in and they are hardly
populated.
• Polar sea ice is currently diminishing as a
result of global warming
Locations
• Earth's polar regions are the areas of the
globe surrounding the poles also known as
frigid zones.
• The North Pole and South Pole being the
centres, these regions are dominated by the
polar ice caps, resting respectively on the
Arctic Ocean and the continent of
Antarctica.
Rainforests
Definition
• Rainforests are very dense, warm, wet forests.
• They are havens for millions of plants and
animals.
• Rainforests are extremely important in the
ecology of the Earth.
• The plants of the rainforest generate much of the
Earth's oxygen.
• These plants are also very important to people in
other ways; many are used in new drugs that fight
disease and illness.
Locations
• Tropical rainforests are located in a band around
the equator, mostly in the area between the
Tropic of Cancer (23.5° N latitude) and the Tropic
of Capricorn (23.5° S latitude).
• This 4800 km wide band is called the "tropics."
Tropical rainforests are found in South America,
West Africa, Australia, southern India, and
Southeast Asia.
Rivers
Definition
• A river is fresh water flowing
across the surface of the land,
usually to the sea.
• It flows in a channel.
• The bottom of the channel is
called the bed and the sides of
the channel are called the banks.
• Rivers begin in mountains or hills,
where rain water or melting snow
collects and forms tiny streams
called gullies.
• Gullies either grow larger when
they collect more water and
become streams themselves or
meet streams and add to the
water already in the stream.
Some main rivers locations:
• Amazon -South America
• Zambezi -Africa
• Volga -Russia
• Yangtze -China
• Severn -Great Britain
• Thames -England
• Mississippi -United States
Tundra
• There are two types of tundra in the world,
Arctic and Alpine.
• The arctic tundra is at the top of the world
around the North Pole.
• The tops of tall cold mountains are alpine
tundra.
• The most distinctive characteristic of the
tundra soil is its permafrost, a permanently
frozen layer of ground often 2000 feet
thick.
• Shallow rooted tundra plants and
microorganisms grow in the permafrost.
• Animals are adapted to handle cold winters
and to breed and raise young quickly in the
short summers.
• Average yearly temperatures range from -70
degrees F to 20 degrees F.
• Tundra can be found in the high northern
latitudes of the world. The most common
animals found in the tundra are the caribou,
Wetlands
• Wetlands are areas of standing water that
support aquatic plants.
•
Marshes, swamps, and bogs are all
considered wetlands.
• Plant species adapted to the very moist
and humid conditions are called
hydrophytes.
• These include pond lilies, cattails, sedges,
tamarack, and black spruce.
• Wetlands have the highest species diversity
of all ecosystems.
• Many species of amphibians, reptiles, birds
(such as ducks and waders), and furbearers
can be found in the wetlands.
• Wetlands are not considered freshwater
ecosystems as there are some, such as salt
marshes, that have high salt
concentrations—these support different
species of animals, such as shrimp,
shellfish, and various grasses.