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Battle for the biosphere

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					Battle for the biosphere

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              What to revise
• The distribution of global biomes reflects climate
  as well as other localised factors
• The biosphere acts as a life support system,
  providing a wide range of goods and services
• The biosphere is being degraded by human
  actions
• Management measures, at a variety of scales,
  are being used to conserve the biosphere and
  make human use of it more sustainable
           What is a biome
• A biome is a plant and animal community
  covering a large area of the earth’s
  surface. An example of this is tropical
  rainforest
• All of these together make up the Earth’s
  biosphere
Distribution of global biomes
     Factors affecting biomes
• Climate (temperature, precipitation,
  sunshine hours, humidity)
• Local factors – altitude, geology, relief,
  drainage, soil type, distance inland
  (continentality)
How limiting factors affect the
  edges of the rainforest
Climate patterns affect biome
        distributions.
 The biosphere life-support system
• Acts as a life-support system for the planet,
  helping to regulate the composition of the
  atmosphere, maintaining soil health and
  regulating the hydrological cycle.
• The biosphere naturally interacts in good ways
  with the Earth’s climate, soil and water. It also
  supports people. Plants and animals play a vital
  role in maintaining human life and aiding
  economic development.
What is the value of the biosphere?
• It is a provider of goods and services
Threats to the biosphere        Impacts                                          Examples
                                Commercial logging destroys forest unless        Logging in the rainforests of the Amazon
Deforestation                   sustainable forestry principles are used. It     and Indonesia
                                affects rates of flooding, soil erosion and
                                humus formation.
                                Commercial intensive farming destroys or         Wheat farming in the American Prairies has
Conversion to farmland or       alters the ecosystem. Urban sprawl destroys      removed natural grassland where bison
                                ecosystems and encourages wildfires.             once grazed. Soya beans are grown for
urban use                                                                        Biofuels. The urban sprawl of Los Angeles.
                                Overharvesting causes wild animals to be         Big game such as tigers (India) and rhino
Overharvesting/overfishing      hunted to extinction. Overfishing of some        (Africa). The krill population (Antarctica
                                species such as krill, needed as food for fish   and North Sea) is managed by quotas.
                                farms, destroys food chains.

                                Mining cuts away whole hillsides. Opencast       Removal of forests for mining iron ore in
Mining and energy               mining destroys the surface and restoration      the Brazilian Amazon. Tin mining in
                                is only partly successful. Drilling for oil      Malaysia. Oil drilling in Alaska – a very
                                causes surface damage. Oil tankers cause         fragile environment.
                                oil pollution.
                                Water pollution from sewage, fertilizers and     Too much silt and nutrients kill fish or
Pollution                       industry. Toxic fumes emitted into the
                                atmosphere, destroy species and damage           coral. Acid rain kills forests.
                                ecosystems.
                                Sometimes we introduce new species               Pheasants for shooting. Rhododendrons are
Introduction of alien species   deliberately. More usually they arrive by        alien species which poison the soil so that
                                accident, e.g. via ships or aircraft. Alien      other plants won’t grow there. Mink

                                species often breed well and take over.          escaping from fur farms.

                                Eco-tourism has little impact. But high-         The Galapagos Islands are under threat due
Tourism and recreation          density mass tourism in fragile
                                environments disturbs wildlife.                  to tourism.
     10 facts about the Amazonian rainforest

1.   Many tropical plants are used as industrial raw materials. Plant
     oils, gums, resins, tannin, rubber and dyes all come from the
     rainforest.
2.   Hardwood timber is a valuable resource that can be exported to
     help feed the growing population of rainforest countries like Brazil.
3.   The rainforest tree canopy protects the soil. If it is removed, there
     is a risk of soil being washed away by the convection rain that
     falls daily in Amazonia.
4.   If soil is removed by rain following deforestation, it gets washed
     into the River Amazon. Water temperatures rise as a result of this
     sediment being added, making survival hard for some fish.
5.   The Amazon forest has been described as ‘the world’s lungs’. Its
     trees produce much of the world’s oxygen, which humans
     breathe, while also soaking up carbon dioxide.
6.    The rainforest is a vital store of carbon. If it were to all disappear,
      global carbon dioxide levels would rise considerably – causing
      runaway climate change and faster temperatures and sea level
      rises.
7.    Soils are protected from the drying effect of direct sunlight by the
      shade that trees provide. Soils suffer from the formation of a hard
      crust called laterite if the forest canopy is removed.
8.    The tropical rainforest is a gene pool that the health of the entire
      planet is dependent upon. Millions of plant, insect and animal
      species live in Amazonia. They contain genetic material that can
      provide vital medical resources for the fight against diseases like
      leukaemia.
9.    The population of South America is expected to double in the next
      40 years. South American people want to clear the forest to gain
      living space.
10.   Trees intercept and slow down rainwater as it moves through a
      river’s drainage basin. This helps lower flood risk. Cutting down
      trees can result in greater flooding.
                           Amazonia
•   Amazonia is being degraded by human actions.
The Grande Carajas development         Brought iron mines and aluminium plants to
programme                              places where virgin forest once stood in Brazil.
                                       Use of wood as fuel led to further clearances.
Hydroelectric dams                     The building of hydroelectric dams along the
                                       Amazon’s tributaries flooded forest valleys.
New roads                              The construction of new roads, such as the
                                       Trans-Amazon Highway, leads to forest loss.
Migration of farmers                   Landless farmers migrate into Amazonia along
                                       the new roads. They then cut down forest for
                                       firewood or clear land to grow crops. As a result,
                                       the pattern of deforestation often follows the
                                       road network.

Forest clearance                       Huge areas of forest have been cleared for
                                       commercial agriculture. Major crops such as
                                       soya beans are grown on old rainforest soils in
                                       Brazil. In neighbouring Costa Rica, around one-
                                       third of all cleared rainforest land is used for
                                       cattle ranching.
  Deforestation in the Amazon
• http://www.mongabay.com/brazil.html
How can the biosphere be
      managed?
• Sustainable development – development
  that meets the needs of the present
  without compromising (limiting) the ability
  of future generations to meet their own
  needs.
                   CITES
• Convention on International Trade in
  Endangered Species of Wild Fauna and Flora
• This is an international agreement aimed at
  conserving the biosphere at a global scale
• Signed in 1973 and adopted by 166 countries
• http://www.cites.org/
                Ramsar
• The Ramsar Convention on Wetlands is
  an intergovernmental treaty for the
  conservation and wise use of wetlands
• It was signed in 1971 and adopted by 147
  countries
• Ramsar sites
         Mamiraua Sustainable
         Development Reserve
• Located in the Brazilian state of Amazonas.
• Mamiraua is protected by the international
  Ramsar Convention as a wetland of global
  importance. It is run by the Brazilian
  Government.
• http://video.nationalgeographic.com/video/player
  /environment/habitats-
  environment/rainforests/mamiraua.html
• http://www.bbc.co.uk/amazon/sites/amazonaswil
  dlife/pages/content.shtml
     Managing at a local level
• National policies can be delivered in a
  local area, involving local people.
  Examples: Barnack Hills and Holes or
  Wicken Fen
• http://www.wicken.org.uk/
• http://www.naturalengland.org.uk/ourwork/
  conservation/geodiversity/englands/sites/l
  ocal_ID5.aspx

				
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