Human impact: Ecology: Biology: GCSE (9:1)

• Human impact

  Many human activities are reducing biodiversity and only recently have measures been taken to try to stop the reduction of biodiversity

  
• Factors negatively affecting biodiversity

  Poaching, habitat destruction such as deforestation, farming, palm plantations, mining, illegal animal trade, pollution, climate change, physical barriers, urban developments, ocean acidification

  
• Biodiversity


  The variety of all the different species of organisms on Earth, or within an ecosystem

  
• Conservation


  A human movement to prevent species from extinction, prevent habitat loss and maintain biodiversity

  
• Modern issues


  Rapid growth in the human population and an increase in the standard of living means more resources are used and more waste is produced

  
• Waste management


  Unless waste and chemical materials are properly handled, more pollution will be caused

  
• Pollution in water


  Can occur as sewage, fertiliser or toxic chemicals that can harm aquatic organisms

  
• Pollution in the air


  Caused by harmful smoke and acidic gases such as sulfur dioxide or nitrous oxide that can lead to acid rain

  
• Pollution on land

  Can build up as landfill waste and can exist as toxic chemicals that can accumulate in a food chain

  
• Indicator species


  An organism that is used to indicate the quality of a water source, if mayfly larvae are present the water source is clean, if tubifex worms are present the water source is polluted

  
• Eutrophication


  Where fertiliser run-off provides nutrients to algae in water which is then decomposed by bacteria, starving aquatic environments of oxygen in the process and causing other aquatic organisms to die off

  
• Bioaccumulation


  Chemicals such as pesticides that are harmlessly consumed by small organisms can accumulate in the apex predators of a food chain and cause them significant harm

  
• Land use

  Humans reduce the amount of land available for other animals and plants by building, quarrying, farming and dumping waste

  
• Peat bogs


  Destroyed to produce garden compost which reduces the area of habitat and significantly reduces biodiversity

  
• Burning peat


  The decay or burning of peat releases significant levels of carbon dioxide into the atmosphere, that would normally have been locked up in peat bog areas

  
• Cheap compost

  Easily available compost containing peat that can be used to increase food production

  
• Deforestation


  The large-scale destruction of habitats and trees that would typically display high biodiversity

  
• Reasons for deforestation


  To provide land for cattle and rice fields or to grow palm plantations for palm oil or crops for biofuels