Battle for the biosphere

Definitions

Ecosystem - An area made up of living things and their non-living environment

Biome - A very large ecosystem

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Location of biomes

Tundra - North, around Arctic circle

Tropical rainforests - Located between the tropics, around the equator

Desert - Around the tropics, North Africa

Coniferous forest - Lower latitudes of North America, Europe and Asia

Deciduous forest - Mid-Europe, Asia

Temperatures higher on equator than poles

• The sun is more concentrated on the equator
• The sun's rays have to pass through a larger area of atmosphere at the poles so lose more energy

Rains more on the equator than the tropics

• On the equator the sun's energy is highest so the air is warmed and rises resulting in low pressure and high precipitation
• This air then moves towards the tropics where it descends resulting in high pressure and low precipitation
• This is called a Hadley cell

Soil type - Nutrient rich soils encourage the growth of ecosystems

Distance from sea - Coastal areas are warmer in summer and mild in winter whereas inland areas are hot in summer and cold in winter

Altitude - For every 100m climbed, the temperature drops by 1°C

Regulates atmosphere

• Forests give out oxygen due to photosynthesis - purifying the atmosphere and regulating the climate
• Forests remove carbon dioxide from the atmosphere (carbon sink) - this reduces global warming

Maintains soil health

• Forests provide leaf litter which forms humus - this makes the soil more fertile for growing crops

Influences hydrological cycle

• By trapping silt, forests keep water pure
• Forests protect watersheds from soil erosion and intercept precipitation - preventing flooding
• Reefs and mangroves provide protection from coastal storms

Food

• Fish - source of protein
• Goji berries - vitamins and minerals
• Oranges - vitamin c
• Crops - carbohydrate

Raw materials

• Bamboo - Scaffolding
• Rubber - car tyres
• Timber - building material

Medicine

• Periwinkle - used to fight leukaemia
• St John's work - Treatment for depression
• Quinine - Painkiller and material treatment

Mining

• Gold, copper, diamonds etc. are being mined both legally and illegally
• This is because there are many gold deposits in the Amazon
• This is destroying the rainforest due to the use of hydraulic mining techniques, blasting of river banks and the construction of new roads

Timber

• Trees are cut down for wood that are then dragged through the forest
• This wood is used for building and furniture
• This is destroying the rainforest due to large trees being cut down and construction of new access roads

Plantation farming

• Large areas of rainforest are being cleared for palm oil plantations
• This palm oil is used in processed food, cosmetics and soap
• The plantations replace tropical rainforests - the removal of trees is done using the slash and burn technique which releases carbon dioxide and destroys many animal habitats

Cattle ranching

• Forests are being cleared so cattle can be kept
• This means more cattle can be kept to produce products such as beef and leather
• Cattle ranching is the leading cause of deforestation in the Amazon and decreases the nutrients in the soil, limiting regrowth

Subsitence farming

• People settle along roads in the rainforest
• They don't have the money to buy farms or land but need food
• A third of tropical rainforest deforestation is caused by subsitence farming

Population growth

• To meet increasing food demand the UN estimated in 2005 that another 90 million hectares of new land needed to be bought into agriculture
• Human overpopulation is the driving force behind deforestation → need to meet the rapidly increasing food demand
• It is destroying the rainforest as forest land is being turned into agricultural land and a lot of the rural poor are turning to the rainforests to feed and shelter themselves → degrading the water and increasing soil erosion

Climate change

• Rainforests are dying out due to climate change - this process is speeding up
• When rainforests die, they are likely to be replaced by savannah biomes → rainfall levels drop as savannah vegetation holds less moisture → the rainforest can no longer establish itself
• Some climate change scientists believe 55% of the Amazon rainforest will be destroyed by 2030
• The reduced levels of transpiration could affect the levels of water in major rivers and the circulation of ocean currents

Pollution

• Forests are affected by air and water pollution produced from industrial and commercial activities
• An increase in industrialisation and agricultural land around the world is leading to the destruction of rainforests
• This is because acid rain (whichis increasing due to industrialisation) destroys rainforests and fertilisers and pesticides used in agricultural land next to the rainforest affect rainforest life

Globalisation

• Globalisation encourages deforestation due to the conversion of rainforests into agricultural land (especially in developing countries)
• In countries like Brazil, much of its produce is exported → production of goods such as soy beans (from 15,000 tonnes to 6 million tonnes) increased → increased deforestation
• This is destroying the rainforest due to deforestation to create more space for agriculture → very little farmland can be turned back to rainforests as farming crops causes irreversible damage to the soil
• As Brazil is developing rapidly due to exports, the government is unlikely to stop deforestation

• Total protection - No form of activity is allow to take place
• Conservation - preservation, protection or restoration of the natural environment
• Total exploitation - No protection of the environment at all
• Sustainable management - a technique that seeks to make any harvesting or consumption of natural resources as environmentally friendly as possible, ensuring resources aren't depleted for future generations

• The Ramsar convention was signed in 1971 by 153 states
• 1700 wetlands now have special protection covering 1.5 million square kilometres e.g. Norfolk Broads, Rhone Delta
• The convention follows a 'wise use' policy → both conservation and sustainable use of wetlands is important

Benfits of global strategy

• Involves developed and developing countries
• More funding shared between countries
• Can share knowledge and technology

Difficulties of global strategy

• It's hard to get everyone to agree as there may be conflict
• Hard to find an agreement that benefits everyone

• There is a core and buffer area:
  • Core →total protection → no-one lives there & no human activity
  • Buffer → sustainable development → people can live here and some activities are allowed but the environment is still carefully managed
• Sustainable management:
  • Community involvement e.g. ecotourism
  • Looking to the future e.g. replanting trees, total protection of core area, afforestation
  • Eco-friendly e.g. ecotourism, afforestation
  • Pro-poor e.g. allowing people to continue farming

Advantages of local management

• Specifically tailored to that environment so strategy maximises standard of living for locals
• Increases community involvement → locals may be more motivated
• Less likely to be conflict

Disadvantages of local management

• Lack of funding and resources
• May not have the knowledge or skills