Geography 7.3.3 Threats to Tropical Rainforest

Causes of Tropical Rainforest Deforestation

• Deforestation is the felling and clearance of trees

• Malaysia, Brazil, India and Indonesia are experiencing the highest levels of deforestation in the world

  • The Malaysian government has in the past failed to provide the Food and Agriculture Organisation (FAO) with figures for forest loss

What are the six main human causes of deforestation?

• Wildfires are a natural cause of deforestation:

  • The frequency and severity of wildfires have increased this is linked to human induced climate change

Climate change

• n addition to direct threats to the tropical rainforest there are indirect threats

• Climate change is the most significant 

  • The rainforest is dependent on high levels of precipitation 

  • Climate change impacts on the amount and frequency of rainfall

• It is estimated that the drought in 2015/16 and the wildfires that resulted led to the destruction of around 2.5 billion trees and plants

• Recent droughts have occurred in 2005, 2010, 2015/16 and 2020

• Droughts can lead to the rainforest emitting CO2 rather than absorbing it

• Droughts led to stress on the ecosystem due to

  • Decomposer organisms and insects dying as the leaf litter is too dry

    • This will lead to a decrease in soil fertility and impact on the nutrient cycle

  • Trees and plants lose more leaves than usually decreasing the supply of food

    • Fewer leaves will mean less evapotranspiration which may further decrease the amount of rainfall

  • Lack of food for herbivores reduces animal populations and impacts on the food web

  • Reduced nutrient input into streams and rivers impacts on the aquatic life

• Higher temperatures may lead to the death of animals: colonies of flying fox bats have been wiped out by increased temperature

  • This impacts on the food web

c

c