Tropical Rainforests

• What is a tropical rainforest?

  A warm, wet ecosystem located within the Tropics (Tropic of Cancer and Tropic of Capricorn)
• Characteristics of a tropical rainforest

  Extremely high rainfall (double the amount the UK receives). Have a distinct wet season where there is more rainfall. Temperatures are high, around 26-27 degrees: also are consistent throughout the year. Soils are nutrient deprived and infertile since its washed away and dissolved quickly by intense rainfall, this is known as leaching . This leads to an infertile, iron-rich soil called latosol. Decomposition is fast due to the hot and humid conditions. The decomposed matter produces nutrients which is absorbed by plants.
• Plant adaptations

  Buttress Roots - large roots which ensure tall trees are kept stable

  Drip-Tip - tapered end of a leaf allowing excess rainfall to drip off the leaf ensuring the leaf doesn't get too wet as it could lead to rotting

  Epiphytes - leaves that grow on other plants, since they're higher up they receive more sunlight
• Animal adaptations

  Camouflage - To hide from predators, animals camouflage by blending in with sticks and vegetation

  Size - to ensure they can move through the dense vegetation, animals adapt to be a smaller size so they can move easier

  Poisons and venoms - animals adapt to the threat of being eaten by developing poisons and carrying venoms
• Interdependence in Rainforests

  This is some out of the many examples of interdependence in a rainforest

  
• Causes of methods of deforestation (in the Amazon)

  Subsistence Farming - farmers who farm for personal use usually use slash-and-burn to clear land. This method is now not sustainable as less time is being left for the rainforest to recover before it is burnt again.

  Logging - the process of cutting down trees for wood. Results in habitats being completely destroyed, vegetation being severely disrupted and animals being displaced. Also, land is left bare which exposes the soil to rainfall which causes soil erosion
• Slash-and-Burn


  They cut down trees and use the wood for materials and the land is left to dry out. They then burn the remains of the trees and the nutrients from the ash is released into the soil. After a few years of planting crops, the land becomes infertile and farmers leave the land to recover and move onto a different area
• Impacts of deforestation (in the Amazon)

  Erosion - no roots for soil to hang on means it is easily washed and blown away.

  Climate change - Trees not only absorb carbon dioxide from our air, they also store carbon. When trees are cut down more carbon dioxide is released and less is absorbed
• What makes tropical rainforests extremely valuable?

  Clean Water - The Amazon provides 20% of the world's fresh water

  Atmosphere - Provides moisture to areas around the world via atmospheric circulation

  Carbon sink - They hold and store a lot of carbon dioxide meaning they're important carbon sinks and slow global warming
• Strategies to manage rainforests sustainably

  Selective logging - Only mature trees are cut down and younger trees are left in the ecosystem to grow. Also are cut to fall away from other trees so it doesn't damage them.

  Ecotourism -  "responsible travel" to natural areas that conserves the environment. Can provide income to indigenous populations and fund conservation efforts