People in the Tropical Rainforest

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People in the Tropical Rainforest

• S4
• Standard Grade

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The Amazon Rainforest

• Can It Survive ?
• Will it Survive ?

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Peoples Use of the Environment

• Describe the use of this environment by the
  native inhabitants (i.e. before development).
• Describe and quote examples of a range of present
  day uses of this environment.

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Peoples use of the Environment

• Uses of the rainforest include-
• 1. logging the valuable timber resources
• 2. mining the valuable minerals which lie
  beneath this largely unexploited area e.g.
  oil and metallic ores
• 3. farming a. by native inhabitants i.e. slash
  burn cultivation
• b. by migrants from the overcrowded towns.
  These people tend to clear and cultivate
  small plots of land beside the lumber roads.
  Their impact is large as they arrive in their
  thousands.
• c. by large cattle ranches. These clear
  thousands of hectares using bulldozers or
  firebombs and plant the land in grass.
• 4. increasing discovery of medicinal uses of many
  plants in the forest.

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Who lives in the Rain Forest?

• Tropical rain forests are full of life. Not only
  do millions of plants and animals live here, but
  many people also call the rain forests home.
• Indigenous, or native, people have lived in the
  rain forests for thousands of years.
• Native tribes of the rain forest have their own
  traditions and languages. They have learned how
  to use plants to treat many illnesses.
• All indigenous people share strong ties to the
  land. The rain forest is so important for their
  culture, so they want to take care of it.

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Native People of the Rainforest
For centuries, the Rainforest has been used as a
home for many different cultures and tribes.
The native people of the rainforest do not live
in houses like ours. They have a different
lifestyle to our own.
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Slash and Burn

• Shifting cultivation how it is practiced
• Small patches of land are cleared by chopping
  vegetation and girdling trees
• When vegetation has dried, it is burned
• These techniques give shifting agriculture the
  name slash-and-burn
• With digging sticks or hoes, farmers plant a
  variety of crops in the clearings

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Amazon Basin
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Slash and burn clearings
Note that these are often found beside
rivers. Why do you think they are found there ?
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Subsistence Agriculture 1

• Subsistence agricultureinvolves food production
  mainly for the family and local community rather
  than for market
• Farmers keep few if any livestock, often relying
  on hunting and fishing for much of their food
  supply
• Has proved an efficient adaptive strategy
• Slash-and-burn farming may return more calories
  of food for the calories spent than modern
  mechanized agriculture
• Has achieved sustainability for millennia in the
  absence of a population explosion

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Subsistence Agriculture 2

• How it is practiced
• Intertillagethe practice of planting taller,
  stronger crops to shelter lower, fragile ones
  from tropical downpours
• Intertillage reveals a learning acquired over
  many centuries
• Little tending of the plants is necessary until
  harvest time
• No fertilizer is applied to the fields
• The same clearings may be planted for four or
  five years until the soil loses it fertility
• New fields are prepared and old fields may be
  abandoned for 10 to 20 years

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Why are the Rain Forests disappearing?

• Little, by little, people are destroying the rain
  forests. They cut down trees for lumber and clear
  them away to provide land to grow crops on.
• Rain forests once covered an area almost twice
  the size of the continental United States. Today,
  only half of the rain forests remain.
• People all over the world must work together to
  save the beautiful, unique rain forests before it
  is too late.

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The Amazon is being destroyed

• The Amazons resources are being exploited by
  huge corporations
• Deforestation is destroying hundreds of hectares
  of rainforest every day.

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What is deforestation

• Deforestation is the cutting down of trees.
• Why do we do this ?
• Slash and burn farming
• New ranchlands.
• To build new roads and settlements
• To harvest tropical hardwoods
• To mine minerals

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Causes of Deforestation

• Tropical forests are destroyed for several
  reasons.
• There is and increasing demand for both farm and
  grazing land, which results in the burning and
  clearing of rain forests for agriculture
  production.
• Another cause of deforestation is the continued
  the world need for timber for furniture and
  building.

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How does deforestation effect us?

• Deforestation effect us when we cut down the
  trees we got less oxygen.
• Burning of the forest increases the amount of
  carbon dioxide in the atmosphere and this
  increase is contributing to global warming.

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How much rainforest is left ?

• All of the rainforests combined cover an
  astounding 5.5 billion acres of land worldwide.
  Unfortunately, they are being destroyed by an
  average of 70 hectares a day. At this rate, the
  rainforests will be completed destroyed in 40
  years. These diverse but delicate ecosystems are
  said to hold over fifty percent of all plant and
  animal species on Earth, but sadly may see the
  extinction of 5 to 100 of these species a year.
  We have already seen mass destruction of the
  rainforests in the last 60 years. What used to
  make up15 of the Earth's land, now only
  comprises 7.
• .

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Causes of Deforestation in Brazil
Government policies

• Relocation of Brazilian capital to Brasilia in
  the 1950s.

• Construction of highways to integrate country.
• Bélem-Brasília, Cuiába-Santarém, Transamazon
  highways, Northen Perimeter Road.

• Encouragement of large scale entrepreneurs to
  develop the Amazon after 1973 oil crisis.
• Tax policies that facilitate clearance of land.
• Amazon Development Agency, Amazon Development
  Bank. and Amazon agencies

• Timber activities.

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Commercial Logging

• The exportation of timber provides a
• major source of income.

• The damage caused by logging is extensive and
  the timber industry can be held responsible for
  at least 40 of deforestation.

• Although the government has a policy that
  requires loggers to replant the areas they
  deforest, many do not follow this practice.

• The loss of biodiversity, the extinction of many
  species and the increased number of floods that
  have resulted from logging are not worth the
  little profit that is received.

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Cattle Ranching

• Much of the land being cleared is used for cattle
  ranching.

• Forest is being converted to pasture for these
  ranchers at a rate of about 35,000 square
  kilometers per year.

• Ranches are not very economic and ranchers
  hardly ever make a profit off of the livestock.

• What makes this scheme so profitable is the land
  speculation associated with it.

• One of the current policies states that anyone
  who clears an area of land can lay claim to it,
  and cattle require large tracts of land. The
  mineral rights below this land are also owned by
  the person who clears it.

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Cash Crop Plantations

• Those used for Industrial Forestry and Export
  Crops are major Causes of deforestations.

• Those that are dominant in the Amazon region
  are of rice and sugar cane.

• The profits made from these plantations are not
  used to support the inhabitants of the Amazon, so
  they are forced to utilize more of the land to
  support their families.

• This results in an increase in the degradation
  of the land and a declining resource base.

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Causes of Deforestation of the Rainforest
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Annual Destruction of Tropical Forests in the
World(millions of hectares)
Source World Rainforest Movement
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What does the Rainforest have to offer me?
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We should be concerned about the Amazon
rainforest because... the rainforest gives us...

• food products
• exotic animals
• indiginous people
• medicinal plants

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Indigenous Peoples

• Native peoples have unique cultures and languages
  which are threatened by Amazon exploitation

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Medicinal Plants

• Potentially, cures for many devastating diseases
  may be found in the rainforest flora.

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Unique Animal Species

• Many native Amazon species exist nowhere else on
  earth

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Time is running out

• Once these unique and precious resources are
  gone, they can never be replaced.

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Experts suggest changing from slash burn land
use to sustainable development
This can be achieved by - Better plant seeds Use
of fertisisers Use of pesticides Use of
weedkillers.
Do we really want this ?
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How do we do this?

• Educate the local people
• Educate globally

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What Else Can We Do ?

• Reduce our use of tropical hardwoods.
• Reduce our use of cattle products from ranches in
  the tropical rainforest.

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Any Suggestions on How We Can Reduce -

• Timber exploitation ?
• Cattle products from ranches in the tropical
  rainforest ?

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Peoples Abuse of this Environment

• Give a range of examples of how use /
  exploitation of this environment has led to
  damage to the environment.

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Peoples abuse of the environment

• If the forest is damaged, e.g. by fire, it can
  naturally regenerate but where people destroy
  thousands of hectares and attempt to farm this
  land a number of problems may occur which leave
  the land of little use. Soil erosion, with the
  heavy rain, can strip the bare land of its
  essential soil or the hot sun can bake the land
  as hard as concrete.
• The rainforest is essential as a home for insects
  plants (50 of the planets plants animal
  species live here). Many of the plants are
  valuable sources of medicines drugs (many yet
  undiscovered). It also provides us with a
  valuable source of oxygen, without which CO2
  would increase with resultant global warming. It
  is also the home of native people whose lives and
  lifestyles are being destroyed.

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Why shouldnt we cut down rainforests?

• Rainforests - very high diversity of animal and
  plant life (lots of different kinds)
• Very difficult to replace - not many nutrients in
  the soil so once the plants are gone it is hard
  to grow any plants in that area
• Add oxygen to the atmosphere (40)
• but also use much oxygen by decay

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Long-Term Consequences of Deforestation

• Increased loss of biological diversity of many
  plant and animal species

• Destruction of forest based societies

• Increasing numbers of
• Floods
• Droughts
• Soil Erosion Problems

• Depletion of the forest canopy which protects
  against high winds and soil erosion

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Ecological Concerns 1 -Erosion

• The soil underlying the plants and vegetation on
  the floor of the rainforest is generally poor due
  to most of the nutrients being tied up in the
  vegetation.

• As the forest is cut down, the nutrients are
  washed out of the soil, and eventually transfers
  this area into a wasteland stripped of everything
  but unpalatable grasses.

• These soils are covered with ironstone which is
  rapidly leached out of the soil when exposed to
  direct rainfall.

• This ironstone becomes oxidized and is converted
  into a hard, brick-like substance which is
  impossible to grow anything on.

• If this process continues, these rich forests
  will be turned into a field of unworkable rock
  with no profits being generated at all.

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Ecological Concerns 2 -Floods

• One of the most important functions of the
  rainforest is to control rain water.

• The continuous clearing of forest land
  increases surface runoff because a large
  proportion of the water reaches the surface and
  is not caught by the trees.

• The soil is not able to absorb the large amounts
  of water due to soil compaction on the surface.

• Therefore the water runs directly to local
  streams and rivers which causes them to flood.

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Ecological Concerns 3 - Droughts

• As deforestation lowers the quality of the soil,
  it prevents proper absorption and water
  retainment.

• There is a continuous drought-flood cycle,
  which consists of massive floods during monsoon
  periods of rain and devastating droughts during
  the dry seasons.

• This water is then not allowed to travel to
  local streams and rivers to replenish them, and
  eventually drying them up.

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Rainforest landscape before Deforestation
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Rainforest Landscapeafter Deforestation
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Rainforest Destruction
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Stage B

• Deforestation is taking place as the trees are
  being cut down.

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Q1a
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Stage D

• Soil erosion is taking place as the sun bakes the
  soil and the rain washes away the topsoil forming
  gullies.

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v
Need for timber Valuable trees in the
rainforest Space needed for roads and
settlements Land needed for ranching Valuable
minerals to mine
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v
Loss of wildlife habitat Effects on the
atmosphere Removing trees causes soil
erosion Local tribes are moved out by force The
soil quickly loses its fertility
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Another Viewpoint

• There has been much concern by environmentalists
  about the loss of forests in the Amazon area.
• A survey in 1996, however,suggested only 12 of
  the Amazon was considered to be changed
  significantly.