living world

• nutrient cycle 


  leaf litter and biomass breaks down with assistance of decomposers, adds nutrients to the soil, weathered rocks and rainwater adds nutrients to the soil (allows growth of plant species)

  if there is heavy rainfall , nutrients can be washed away, if trees are deforested they can no longer produce leaf litter which adds nutrients to the soil. plants can no longer take up nutrients, nutrients are lost from the soil as roots cant stabilise the nutrient rich topsoil.
• nutrient cycling is rapid in the rainforest as the warm temperatures speed up decomposition and high levels of rainfall promote plant growth and can cause soil erosion.
• causes of deforestation 


  logging - extracting timber for wood products

  development- eg: trans amazonian highway (4k km long)

  energy: dams have been creating to generate hydroelectric power , source of renewable energy

  mining

  agriculture: 90 % - 80% cattle farming and 10% crop production
• impacts of deforestation - soil erosion

  deforestation causes soil to become loose and erode away

  once the top layer of soil has gone, little can grow again.

  grazing and plantations do little for soil fertility.

  as soil becomes less fertile , more lands end up being cleared.
• loss of biodiversity

  deforestation leads to destruction of habitats.

  137 species of plant and animals are lost daily, around 50k per year.

  this can have a knock on effect on food webs causing more species to decline.

  around 25% of all drugs on the market are derived from plants , meaning less people with diseases be treated.
• decline on indigenous tribes

  in brazil , there’s only 240 tribes left, compared to over 300 in 1900.

  many indigenous people have been forced out of the rainforest

  many have been made to move to cities.

  few have adjusted well and been able to fit into modern life.

  it has also resulted in conflict between loggers + tribe members.
• contribution to climate change

  deforestation can have an impact on local and global climates.

  trees and plants absorb co2 , helps to reduce global warming.

  machine and fire are used to clear the land which releases co2.
• river pollution


  mercury used in gold mining process leaks into rivers polluting them

  fertilisers used in agriculture can run off into rivers.

  this can lead to skin irritation and eutrophication .
• water


  as trees are felled it disrupts the water meaning the area becomes drier and warmer.

  this can be an issue for the agricultural sector as it is harder to grow crops.
• economic development 


  using the land for mines means people are giving jobs, meaning they can gain more money to improve their standard of living.

  improved infrastructure such as roads opens areas up for industrial development and tourism, which causes economic growth.

  lastly minerals such as gold and products such as palm oil can be found and sold for profit.