Biodiversity

• Biodiversity is the variety of all the different species of organisms on earth, or within an ecosystem
• A great biodiversity ensures the stability of ecosystems by reducing the dependence of one species on another for food, shelter and the maintenance of the physical environment
• Many human activities are reducing biodiversity and only recently have measures been taken to try to stop this reduction
• Rapid growth in the human population and an increase in the standard of living mean that increasingly more resources are used and more waste is produced
• Pollution can occur

  • In water, from sewage, fertiliser or toxic chemicals
  • In air, from smoke and acidic gases
  • On land, from landfill and from toxic chemicals
• Pollution kills plants and animals which can reduce biodiversity
• Humans reduce the amount of land available for other animals and plants by building, quarrying, farming and dumping waste
• The decay or burning of the peat releases carbon dioxide into the atmosphere
• Large-scale deforestation in tropical areas has occurred to

  • Provide land for cattle and rice fields
  • Grow crops for biofuels
• Levels of carbon dioxide and methane in the atmosphere are increasing, and contribute to ‘global warming’
• Scientists and concerned citizens have put in place programmes to reduce the negative effects of humans on ecosystems and biodiversity

  • Breeding programmes for endangered species
  • Protection and regeneration of rare habitats
  • Reintroduction of field margins and hedgerows in agricultural areas where farmers grow only one type of crop
  • Reduction of deforestation and carbon dioxide emissions by some governments
  • Recycling resources rather than dumping waste in landfill