factors affecting biodiversity

• why is biodiversity threatened by humans?

  • human population is growing
  • deforestation- cutting down of trees and therefore habitats and organisms to absorb carbon dioxide from the atmosphere
  • agriculture- creation of land/space for farming
  • climate change- green house gas emissions affect the environment
• what are the three main human causes of the reduction of biodiversity?

  • deforestation
  • climate change
  • agriculture
• what are the ways in which deforestation affects biodiversity?

  • reduces trees present in area
  • if only specific tree felled, species diversity reduced
  • destroys habitats and food sources, reducing species diversity again
  • animals forced to migrate to other areas- raises biodiversity of those areas but decreases biodiversity in original ones
• how does agriculture affect biodiversity?

  • deforestation- to increase land available for crops
  • removal of hedgerows- removes plant species and is a destruction of habitat
  • use of pesticides and herbicides- destroys pest species and destroys food source for other organisms- reduces species diversity
  • herbicides- kills weeds. plant diversity is reduced, animal diversity reduced by destruction of a food source
  • monoculture- lowers plant biodiversity, less food sources for animals
• how does climate change affect biodiversity?

  • melting of polar ice caps- loss of habitat, animals must migrate further north for colder conditions
  • rising sea levels- flooding of habitats, saltwater flows upriver, reducing freshwater habitats
  • less rainfall- plant species fail to survive, leading in rise to drought resistant species eg xerophytes
  • insect life cycles and populations change as they adapt to climate change, they are key pollinators of plants and this could affect the lives of plants too