Tropical Rainforests

• Tropical Rainforests


  Around the equator, between the tropics
• Tropical Rainforests


  • Higher temperature (20-28°C)
  • High rainfall (1000 mm/year)
  • Wet season for several months
  • Excess water on the ground, sometimes floods
• Plants in Tropical Rainforests

  • Trees are evergreen - due to continual growing season
  • Tall dense vegetation
  • Lots of epiphytes
  • Sunlight does not reach the forest floor
• Epiphytes


  Plants that live on other living plants, taking nutrients and moisture from the air
• Tropical Rainforests have a higher level of biodiversity
• Animals in Tropical Rainforests

  • Contains more animal species than any other ecosystem
• Soil in Tropical Rainforests

  • Not very fertile - heavy rain washes nutrients away
  • Surface nutrients from decayed leaf fall
  • Very thin soil - rapid decay in warm, moist conditions
  • Intense leaching removes nutrients from topsoil, redeposits them further down
• Latosols


  Red-coloured, nutrient-poor soils in tropical rainforests
• Water cycle in Tropical Rainforests

  Water will soak into the soil, then dissolve and transport nutrients about
• Indigenous people in Tropical Rainforests

  • Hunt, fish, grow vegetables to live
  • Sustainable system
• People are exploiting rainforests for commercial gain
• Deforestation, mining, timber harvesting, roads and settlements are the main threats to tropical rainforests
• Deforestation leads to loss of biodiversity, extinction of important/medicinal plants, and indigenous people having to abandon their traditional lifestyle
• Interdependent ecosystem


  One change works on the entire system, as all parts are dependent on each other
• Warm, moist climate helps fungi and bacteria to decompose dead plant material rapidly, keeping the soil high in nutrients</b>
• Nutrient cycle in Tropical Rainforests

  1. Plants pass on their nutrients when eaten by animals

  2. Nutrients go back to the soil when animals die

  3. Encourages rapid vegetation growth
• Reducing tree cover


  Increases risk of drought
• Trees stabilise the soil

  Provide protection from heavy rainfall, preventing nutrients from washing away
• Adaptations of Plants in Tropical Rainforests

  • Emergent trees grow tall to compete for sunlight
  • Canopy plants have large surface area to absorb maximum sunlight
  • Flexible stems that turn to face the sun
  • Drop leaves gradually, can grow all year
• Adaptations of Animals in Tropical Rainforests

  • Many animals spend their lives high up in the canopy
  • Some are camouflaged to hide from predators
  • Low light levels on the forest floor, so animals have sharp senses of smell
  • Birds have short, pointed wings to manoeuvre easily
  • Some have suction cups or flaps of skin to climb or glide between trees
• Deforestation rates are increasing in Southeast Asia
• Malaysia


  Largest exporter of palm oil, leading to large areas being converted to oil palm plantations
• Causes of deforestation in Malaysia

  • Commercial farming (palm oil)
  • Logging (for furniture, paper, etc.)
  • Road building (for mining, energy projects, etc.)
  • Mineral extraction (precious metals, oil and gas)
  • Agriculture (slash and burn)
  • Tourism and population growth
• Deforestation leads to economic development but loss of the value of tropical rainforests, global warming, loss of biodiversity, soil erosion, river pollution, and displacement of indigenous tribes
• Sustainability


  Existing and developing without depleting natural resources for future generations
• Strategies for sustainable management of tropical rainforests in Malaysia

  • Selective logging
  • Replanting
  • Education
  • Ecotourism
  • International agreements
  • Debt reduction