Download Location: The Amazon Rainforest, Brazil, an LEDC in South America

Location: The Amazon Rainforest, Brazil, an LEDC in South America
What the case study shows: The structure, climate, vegetation, uses, damage to and management of an ecosystem
Location:
Tropical rainforests are located on near the
equator. Usually between 25 degrees north and
south of the equator. The equatorial rainforests
are; The Amazon- South America, Congo/ ZaireAfrica; Indonesia- Asia.
Causes of damage by people:
Logging –expensive trees sold
to MEDCs to make furniture.
Population increase – new
settlements and roads are
built for Brazil’s growing
population.
Cattle Ranches – land is sold,
trees are cut down so cattle
can graze on shrub layer.
Food sold to MEDCs
Minerals – expensive minerals
like iron are mined and sold
to pay off Brazil’s debt.
Hydro-electric power (HEP) –
dams are built so HEP can be
generated to power Brazil’s
growing population &
industry.
CALLED DEFORESTATION
Vegetation Soil:
No seasons so flowers,
fruit and seeds available all
year. 4 layers
Emergents – highest trees
45m
Canopy – Thickest layer
30m
Under canopy – 15m
Shrub – 5m
Trees have thick buttress
roots due to thin soil.
Soil poor as nutrients
quickly removed by trees.
Dead vegetation quickly
decayed so plenty of
nutrients on top soil.
Nutrient Cycle:
Most nutrients in
the tropical
rainforest are in
the plants and
trees. When the
plants/ trees/
leaves die then
these nutrients are
broken down and
replaced back into
the soil by
decomposers
(fungi). These
nutrients can be
taken up again by
other fast growing
plants. This is a
continuous cycle.
Water cycle:
The sun heats up the earth.
By 9 o’clock it is 25 degrees.
By midday it is 30 degrees.
Evaporation occurs (changing
of a liquid to a gas). This gas
cools and condenses to form
thick black clouds. This leads
to afternoon thunderstorms
(heavy precipitation)
everyday. By early evening
the precipitation has stopped
and the sun goes down. Plants
protect the soil from heavy
rainfall (Interception) and
decrease the surface runoff
and infiltration rates. This
happens every day. This is a
continuous cycle.
Preventing deforestation:
Sustainable Forestry
 Replant any trees cut down. (reforestation).
 Replant trees in layers- mimics the rainforest (Agroforestry).
 Selective logging where most trees are left standing. (only cut down the trees
that are needed- that way soil remains protected)
 Create a national park zone- no deforestation can take place.
 Create demand for wood from sustainable forests.
Money
 Eco- tourism- money used from tourist to conserve rainforest. People are
taught to conserve. Reduce debt owed to foreign governments if rainforest is
conserved.
Laws
 Ban the sale of wood from unsustainable forests. Ban deforestation.
 Protect rainforest with police and wardens.
Deforestation&Vegetation
Cutting down trees stops
nutrients reaching soil as
there are no leafs. Heavy
rain then washes thin soil
away.
Strong winds blow the soil
away. Where soil remains
the nutrients get washed
down through the soil
(leached). Soil becomes
infertile so little tree
growth.
Deforestation &
nutrient cycle
Trees cut down.
Therefore there is
no leaf fall. As
there is no leaf fall
decomposers have
no job to do and
nutrients are not
replaced back into
the soil to be used
by other trees.
Eventually the soil
will become
infertile.
Deforestation & the Water
Cycle
Trees are cut down so less
evapotranspiration. Fewer
trees so less interception of
rainfall and increased surface
runoff. Less infiltration
means more surface runoff of
rain water. More surface run
off leads to soil erosion as
there are less tree roots to
bind the thin layer of soil
together. This causes floods
and landslides. Rivers blocked
with soil which causes floods.
Climate:
High temperature all year of around 26oC. This
means a continual growing season.
Very high rainfall of 2000mm a year. Rain is
convectional due to high temperature. Rain falls
all year.
Rainfall is high as pressure in this area is low- this
means that air is rising therefore condensation is
occurring therefore there are clouds and rain.
It is very hot because it is fairly close to the
equator therefore the sun has a shorter distance
to travel. This means that less heat is lost, so it
warmer. Also the surface area is smaller- heat is
more concentrated.
Location: Alaska inside the Arctic Circle in the Northern Hemisphere and Antarctica inside the Antarctic Circle in the Southern Hemisphere
What the case study shows: the threats to the tundra cold environment of Alaska and the polar cold environment of Antarctica & how the threats are managed.
Climate Graph
Threats to the environment in Alaska
Threats to the environment in Antarctica
 The fragile tundra environment is at huge risk
 The last great wilderness on earth, a polar cold
from oil spills.
environment, is under threat from a variety of
factors.
 Oil exploitation – Alaska is the biggest oil
producing state in the USA. Oil is extracted and  Tourism – around 23000 tourists visited
then transported 1200km from Prudhoe Bay in
Antarctica in 2008. The tourists land on
north Alaska to the terminal of Valdez in the
Antarctica by small boat and cause
south by the Trans Alaskan Pipeline.
environmental damage.
 In 2006 1m litres of oil leaked from a corroded
 Mining – huge deposits of oil are under the ice
pipe at Prudhoe Bay polluting an area covered
and the rising price of oil would make it
in rare grass and home to Caribou.
economically possible to extract it.
 Oil is transported out of Valdez by oil tanker.
 Global Warming – as well as melting ice, global
warming also causes krill (the main producer in
 In 1989 the Exxon Valdez tanker ran aground in
the food chain) to die. This means that the
Prince William Sound releasing 42m litres of oil
primary and secondary consumers further up the
into the sea. 390000 seabirds, 300 seals, 250
food chain are under threat as there is less food.
bald eagles & 22 killer whales died. Fishermen
lost their jobs.
 Science – there are a huge amount of scientific
research bases in Antarctica which produce a
 The US government wants to open up new
huge amount of waste.
oilfields in the Arctic National Wildlife Refuge.
Reasons for the cold and dry climate
How the threats are managed in Alaska
How the threats are managed in Antarctica
1. Latitude – Alaska and Antarctica are where the
 Land Use Restrictions – the Arctic National
 The Antarctic Treaty was signed in 1991 by the
sun’s rays cover large parts of the curve of the
Petroleum Reserve is an area where any oil
world’s most powerful countries t keep
earth. This means that the heat is spread out
drilling can take place and people can use the
Antarctica as a natural reserve devoted to peace
over a wider area and the sun’s rays have to pass
area recreationally (fishing, hunting etc). In the
and science and place where all activities must
through a large amount of atmosphere. The sun’s
1002 Area companies can search for oil, but are
have a limited impact on the environment.
rays lose heat.
not YET allowed to drill for it. People are not
 Tourism – the International Association of
2. Antarctica is colder than Alaska because of its
allowed to use the area. People and oil
Antarctic Tour Operators has formed and agreed
permanent ice cover as ice reflects heat rather
companies are banned from the Arctic National
to promote responsible tourism to keep the
than absorbs it.
Wilderness Area.
wilderness (which attracts the people in the first
3. Antarctica is colder than Alaska because of its
 Renewable Energy – developing a sustainable
place) in tact.
altitude (height).
source of renewable energy is the only way to
 Mining – All mining is banned for the next 50
4. Antarctica is colder than Alaska because its
manage the tension between the global
years.
interior is a greater distance from the warm
economy needing oil to keep us wealthy and
 Science – Most waste is taken away from the
ocean.
also protect the environment. Wind power,
continent, but sewage and food waste is
5. Antarctica is colder than Alaska because of its
tidal power, solar power are all examples.
biologically treated and then burnt. Experiments
cold katabatic winds flowing over the cold ice
with using renewable energy to power the
from the South Pole to the edge of the continent.
research bases are starting.
Location: The Sahel Africa
What the case study shows: The climate, causes of desertification and solutions to desertification in the Sahel.
Location: On or above the Tropic
of cancer and the Tropic of
Capricorn.
Climate:
 The climate here is very hot all
year. Rainfall is low as
pressure in this area is highthis means that air is sinking
so no clouds or rain.
 It is very hot because it is fairly
close to the equator therefore
the sun has a shorter distance
to travel. This means that less
heat is lost, so it warmer. Also
the surface area is smallerheat is more concentrated.
Causes of Desertification
Climate change - Many
years of drought and
average rain has been
decreasing.
Farming - Declining death
rates have caused
populations to increase more food and resources
are needed and fragile areas
have to be farmed.
Overgrazing - Increase in
the numbers of cattle etc
has removed vegetation.
Irrigation - Pumping of
water from underground to
water means tree roots can
no longer reach water.
Deforestation - Trees have
been cut down for fuel and
building materials.
Erosion - When vegetation
is removed, soil is no longer
held together by roots - soil
is eroded by wind and by
water in the wet season.
Vegetation Soil:
Desert plants are adaptive plants are
built to store water, find water quickly
or live with the littlest amount of water
possible:
Boabab Tree – fat trunk, no leaves, deep
roots, thorns.
Acacia Tree – deep tap roots, high
leaves, thorns.
Cactus Tree – thick trunk, no leaves,
deep roots, spiky.
Desert soils are often salty because
whatever little rain that does fall quickly
evaporates from the ground, leaving salt
and other minerals behind. Soils often
have abundant nutrients because they
need only water to become very
productive
Nutrient Cycle:
Most nutrients in the desert
are in the plants and trees.
When the plants/ trees/
leaves die then these
nutrients are broken down
and replaced back into the
soil by decomposers (fungi).
These nutrients can be
taken up again by other fast
growing plants. This is a
continuous cycle. Soils and
have little or no organic
matter.
Water cycle:
Rainfall in the desert often totals a few
inches yearly or, in some regions,
there is absolutely none. When rain
does happen it happens because the
intense heat in the day evaporates
whatever moisture there is in the soil
or on surfaces vegetation.
Evapotranspiration occurs. This gas
cools and condenses causing clouds
and rain. Evaporation rates regularly
exceed rainfall rates. Sometimes rain
starts falling and evaporates before
reaching the ground. Vegetation
intercepts the rain and rain infiltrates
the soil and is quickly taken up by
plant roots. Very little remains in the
soil.
Effect on people
How damage affects vegetation
How damage affects
How damage affects water cycle
When vegetation is removed the soil has nutrient cycle
Heavy rainfall, such as a flash flood
 1000s die due to starvation.
no protection from the sun or the wind.
Trees cut down. Therefore
increases the amount of surface run 1000s fall ill due to
It quickly dries out in the hot sun & is
there is decomposition to
off. As the land is hard and dry, the
malnutrition.
easily blown away by the wind. Without occur. Nutrients are not
rain cannot infiltrate the hard soil and
 1000s fall ill due to drinking
vegetation the plant roots that bind the
replaced back into the soil
flows quickly overland, carrying the
dirty water.
soil together are removed. Soil can be
to be used by other trees.
soil away with it.
 People move to the cities to
easily blown away by the wind. Nothing Eventually the soil will
get away from the problems
can grow in the soil.
become infertile.
adding to the problems of
overcrowding.
Management of desertification:
Reafforestation = the replanting of trees that can grow in the climate. This will help to bind the soil together and aid the nutrient cycle.
Coppicing = encouraging tree regrowth by cutting them back to ground level.
Harvesting branches rather then whole trees = prevent deforestation, soil erosion and desertification. Controlled burning of grassland to avoid wildfires.
Crop rotation to keep a varied supply of nutrients in the soil and prevent soil erosion and desertification.
Stone lines along the soil = contours keep it in place, prevent erosion and improve crop yields. Projects such as this can involve the whole community and give them a sense of
ownership and responsibility.
Managing grazing land = avoids overgrazing, soil erosion and desertification.
Management of the effects of desertification = Short term aid of food, water and medicine is given when the situation is at its worst.