RAINFORESTS

• Emergent layer

  Tallest trees, 50m with 4m round trunks
• Canopy layer


  Forms a roof, home to animals
• Under canopy layer

  Little sun, insects birds
• Shrub layer

  Almost no sun, no plants, big cats
• Adaptations

  • Buttress roots - increased surface area, ridges support base, shallow roots in infertile soil
  • Lianas - carried by tree into canopy, get sunlight for their flowers
  • Epiphytes - live on branches in canopy
• Tropical rainforests


  Found along the equator, average temperature 27C
• Water cycle

  1. Daily heavy rain

  2. Trees intercept rain

  3. Some rain reaches ground

  4. Trees take up water

  5. Water evaporates
• Nutrient cycle

  1. Nutrients enter soil

  2. Shallow roots take it up

  3. Trees grow rapidly

  4. Trees shed leaves

  5. Vegetation decays
• Reasons for deforestation

  • Mineral extraction
  • Logging
• Services of rainforest

  • Protection of water sources
  • Soil formation
  • Nutrient storage and recycling
  • Pollution breakdown
  • Contribution to climate sustainability
  • Maintenance of ecosystems
• Impacts of deforestation

  • Loss of biodiversity
  • Climate change
  • Economic gains
  • Economic losses
  • Soil erosion
  • Recovery from events
• Sustainable development

  • Sustainable logging - selective logging and replanting
  • Conservation and education - conservation areas, national parks, for education of science
  • Ecotourism - generates money for rainforest and community while educating
• Causes of deforestation


  -subsistence and commercial farming,

  -logging,

  -road building,

  -mineral extraction,

  -energy development,

  -settlement,

  -population growth
• Impacts of deforestation


  economic development,

  soil erosion,

  contribution to climate change