Factors affecting biodiversity

• why is genetic diversity important?

  without genetic diversity, species lose their ability to evolve or adapt to new situations
• Human activities that can reduce biodiversity

  • Deforestation
  • Hunting
  • Use of pesticides, insecticides and herbicides
• Deforestation

  The permanent removal of large areas of forest to provide wood for building and fuel, and to create space for roads, buildings, and agriculture
• Hunting a specific species

  Will reduce its numbers/population, which may affect a food chain and reduce biodiversity
• Use of pesticides, insecticides, and herbicides has toxic effects in the short-term
• Use of pesticides, insecticides, and herbicides can cause long-term effects by causing changes in habitats/food chains
• Human activity can lead to pollution and the introduction of alien species
• Pollution

  • Release toxic chemicals which will have effects on a wide range of species
  • Disrupt food chains and ecosystems
• Alien species

  • Reduce biodiversity and harm healthy ecosystems
  • Can eliminate native species which may be a vital part of the food chain
  • May spread rapidly to new locations that are free of predators and parasites
  • May act as new predators or competitors which would have originally been absent
• Effects of agriculture on biodiversity

  • Farmers select specific species based on characteristics that give a high yield
  • Deforestation increases area of land available for growing crops or rearing animals
  • Removal of hedgerows reduces number of plant species present in area and destroys habitat of animals
  • Use of pesticides/herbicides destroys peat species and directly destroys food source of other organisms
  • Monoculture production of only one crop supports relatively few species
• Deforestation

  Increases area of land available for growing crops or rearing animals
• Removal of hedgerows

  Reduces number of plant species present in area and destroys habitat of animals
• Use of pesticides/herbicides

  Destroys peat species and directly destroys food source of other organisms
• Monoculture production

  Supports relatively few species and lowers overall biodiversity
• Effects of climate change

  • Increased dominance of drought-resistant species
  • Loss of some animals dependent on food sources
  • Migration of species to higher altitudes
  • Changes in pollinator ranges
  • Potential extinction of species
• Insects can carry pathogens that could spread due to climate change
• Flooding of land could occur due to thermal expansion of oceans
• Species may have to move up mountains due to climate change