Biodiversity & Human Impact

• Biodiversity CIE IGCSE definition : The variety of different species of organisms in a particular environment, or on earth.
• High biodiversity = better environment.
• Human development has reduced biodiversity, due to destruction of habitats and over-exploitation of resources.
• Land is needed for building, farming, disposing of waste, and quarrying.
• Bogs are destroyed to make compost - reducing biodiversity in that ecosystem.
• Burning peat releases CO2 - contributing to global warming.
• CO2 and Methane contribute to global warming
• Deforestation reduces biodiversity - usually done to create farmland.
• To calculate % absorbed between trophic levels :

  Biomass at 2nd level ÷ Biomass at 1st level × 100 = #
• Food Security :

  • changing diets
  • growing environments
  • fuel & energy prices
  • cost of farming
  • conflicts
• Biomass : the total mass of living material
• Farmers are trying to farm more efficiently : increasing biomass input whilst reducing wasted biomass.
• Sustainable Fishing :

  • ensures that fish are not caught quicker than they can breed - using nets with holes in allow the smaller fish to escape and breed, whilst still catching adult fish