CGP - Amazon Rainforest case study

• Amazon Rainforest


  Largest tropical rainforest in the world, covering 40% of the South American landmass
• Amazon Rainforest

  • Located in South America
  • Has a hot, very wet climate
  • Vegetation is very dense
• Many groups of indigenous people live in the Amazon rainforest
• Biodiversity of the Amazon Rainforest


  • Up to 1 million plant species
  • Over 500 species of mammals
  • Over 2000 species of fish
• The Amazon Rainforest is home to many endangered species, including the Amazonian manatee, black caiman, and the pirarucu
• Water Cycle

  Affects the Amazon to be very wet - there is a lot of evaporation over the Atlantic Ocean, and the wet air is blown towards the Amazon, contributing to high rainfall
• Evaporation


  High in the rainforest itself, which increases the amount of precipitation
• Canopy


  Dense, meaning interception is high, so less water flows into rivers than might otherwise be expected, and it does so more slowly
• The water cycle affects the Amazon environment - it is populated by species that are adapted to high humidity and frequent rainfall
• Carbon Cycle

  The Amazon rainforest stores lots of carbon in its vegetation and soil, so it's a carbon sink
• Increasing concentration of CO2 in the atmosphere


  Has led to increased productivity in the Amazon rainforest because the vegetation is able to access more CO2 for photosynthesis, increasing the amount of biomass
• Increased CO2 sequestration by the Amazon rainforest


  Has made it an even more important carbon store
• It has been suggested that although trees are growing more quickly, they're also dying younger, so we may not be able to rely on the Amazon rainforest to continue to be such an effective carbon sink in the future
• Deforestation


  Lots of deforestation takes place in the Amazon, e.g. to exploit the timber or to use the land for farming
• Deforestation in the Amazon


  Reduces the rate of evapotranspiration, meaning less water vapour reaches the atmosphere, fewer clouds form and rainfall is reduced, increasing the risk of drought
• Deforestation in the Amazon


  Reduces the amount of leaf litter, so humus isn't formed, and the soil cannot support much new growth, limiting the amount of carbon that is absorbed
• Deforestation in the Amazon


  Means fewer trees to remove CO2 from the atmosphere and store it, increasing atmospheric CO2 and enhancing the greenhouse effect and global warming
• Many of the effects of deforestation in the Amazon can lead to reduced vegetation growth, which can amplify changes to the water and carbon cycles, creating a positive feedback loop
• Climate change

  Can severely impact tropical rainforests, with increasing temperatures and decreasing rainfall leading to drought, which can destroy large areas of forest and release lots of CO2 into the atmosphere
• Scientists predict that a 4°C temperature rise could kill 85% of the Amazon rainforest, resulting in lots of carbon being released into the atmosphere as the dead material decomposes, and less carbon dioxide being taken in from the air by trees for photosynthesis
• Selective logging


  Only some trees (e.g. just the oldest ones) are felled, with most left standing, which is less damaging to the forest than felling all the trees in an area
• Replanting


  New trees are planted to replace the ones that are cut down, ensuring the same types of tree are planted to maintain the variety of trees and help the local carbon and water cycles return to their initial state
• Environmental laws to protect the Amazon Rainforest


  • Laws banning the use of wood from forests that are not managed sustainably
  • Laws banning excessive logging
  • Laws controlling land use, e.g. the Brazilian Forest Code requiring landowners to keep 50-80% of their land as forest
• National parks and nature reserves

  Set up to protect rainforests, such as the Central Amazon Conservation Complex in Brazil, which protects biodiversity while allowing local people to use the forest in a sustainable way
• Within national parks and nature reserves, damaging activities such as logging can be monitored and prevented