Tropical rainforest

• Characteristics of a Tropical rainforest:

  • Hot (over 30 degrees)
  • Wet/humid (over 2000mm)
  • Close to the equator (10-15)
  • Layers : Emergents, Canopy, Under canopy, Shurbs and forest floor
  • Soil is reddish brown from leaching, and has a lot of iron in it
• Threats of the tropical rainforest is deforestation, which can be causes by:

  • Farming - large areas being cleared for pastoral farming (animals killed for meat)
  • Logging - trees are cut down so that valuable trees can be accessed and sold
  • Mining - rainforest are rich in natural resources which leads to the development of mines and clearence of tropical rainforest
  • Roads being built - for farmersl, loggers and miners
  • Hydroelectric power (HEP) - large areas being flooded
  • Population - population growth has resulted in land being cleared to build houses
• Tropical rainforest adaptations for plants:

  • Wide buttress roots ~ support tall trees
  • Drip tips ~ allows water to run off quickly and stop algae from growing
  • Tall straight trunks ~ fast growing and most efficient to get to sunlight
  • Smooth bark ~ allows water to run off
• Examples of tropical rainforests are Amazon Rainforest in Brazil and Malaysian Rainforset, in Indonesia.
• Soil in a tropical rainforest lacks nutrients and is infertile because:

  • Most nutrients are found at the surface, in a layer of dead organic matter called humus layer
  • Most trees have shallow roots and absorb nutrients quickly
  • Heavy rain causes leaching and run-off
  • This results in infertile, red and iron rich soil called latosol
• Layers of a tropical rainforest:

  1. Emergent (top) ~ fast growing trees cut light out
  2. Canopy ~ thickest layer, where most animals live
  3. Under canopy ~ limited sunlight
  4. Shrub (bottom) ~ very dark
• Rainfroest adaptations for animals:

  • Slots can camouflage and move very slowly which makes it hard for predators to spot
  • Spider monkeys have large and strong limbs to climb trees
  • Frogs have suction cups for hands and feet to cling on leaves and trees
• Why is the rainforset important?

  1. Biodiversity ~ has largest number of species, half of all plants and animals live there
  2. Climate change ~ absorb carbon dioxide
  3. Climate ~ 28% of world's oxygen comes from rainforests
  4. Medicine ~ 25% of all medicines come form rainforests
  5. Resources ~ hardwood, rubber, nuts, fruit
  6. Water ~ 20% of world's fresh water comes form Amazon basin
  7. Indigenous people ~ they live their