biodiversty

• main ways in which humans reduce the amount of land available

  • building houses
  • shops
  • industrial sites
  • roads
  • farming
  • waste disposal
• ways which we can reducing using as much land

  • recycle rubbish
  • build fewer houses
  • more flats which take up less land
  • uses public transport so fewer roads needed
• food chain


  is a model that shows the feeding relationships between plants and animals in an environment
• 
  

  two gases that pollute the air are sulfur dioxide which causes acid rain and carbon dioxide which contributes to global warming
• two toxic chemicals that can be washing into streams and lakes from farms are pesticides and herbicides
• if sewage or fertilisers pollute water it leads to eutrophication which reduces the oxygen concentration of the water
• biodiversity


  number of different species of living organisms/plants and animals found in a particular habitat
• natural ways carbon dioxide is removed from the atmosphere

  • photosynthesis
  • dissolving in water
  • dissolving in rain
  • being used by sea organisms for shells/skeletons
• ways which deforestation causes a rise in carbon dioxide levels in the air


  • removing plants, means they no longer take in carbon dioxide for photosynthesis
  • burning the wood, releases more carbon dioxide that was locked in the wood
  • micro-organisms decay all the debris left behind, releases carbon dioxide as they respire
• how does sewage lead to eutrophication


  • sewage contains organic matter / mineral ions / nutrients
  • so algae / water plants grow on the surface of the water
  • algae / plants underneath top layer do not get enough light for photosynthesis
  • so they die
  • and microorganisms / decomposers decay them
  • using up all the oxygen in the water
  • so fish / aerobic creatures die too
  • water becomes sterile
• acid rain


  • coal (fossil fuel) is burnt
  • greenhouse gases produced - eg. carbon dioxide, sulfur dioxide
  • sulfur dioxide reacts in rain to make acid rain
  • harms organisms / plants around
• removing tropical rainforests, more rice fields and greater industrialisation effect


  • methane is given off from rice fields
  • industrial areas burn fossil fuels which further increase carbon dioxide in the atmosphere
  • deforestation increase the carbon dioxide due to the decay / decomposition of trees
  • as methane and carbon dioxide are greenhouse gases
  • and greenhouse gases increase the earths temperature, and contribute to greenhouse effect
• effects of global warming


  • climate change - extreme weather changes, affects peoples homes and living environment by them being destroyed
  • sea levels rising - more land being flooded, destroyed homes and ecosystems
• importance to prevented organisms becoming extinct


  • organisms produce useful substances for humans
  • duty to preserve for future generations
  • effect on other organisms, food chain effects since interdependence
  • loss of environmental indicators