factors affecting biodiversity

• deforestation 


  = permanent removal of large areas of forest to provide wood for building and fuel.
• problems from deforestation

  • directly reduces number of trees present in an area
  • if only 1 type of tree is felled- species diversity is reduced
  • reduces number of animal species present in an area- destroys habitat, food source- in turn reducing other species.
  • animals forced to migrate to other areas.
• monoculture= production of only one crop, areas of land being used to grow one species.

  • it lowers biodiversity as only one species of plant is present.
  • few animals will be supported by only one type of plant, this results in low biodiversity levels.
• climate change, key findings:

  • warming trend over last 50years is nearly twice that for previous 100years.
  • average amount of water vapour in atmosphere has increased.
  • average amount of global ocean down to depths has increased. Ocean is absorbing 80% of heat added to climate system- sea level rises.
  • average artic temperatures have increased at twice the average rate.
  • sea level rose by 1.8mm per year
• continued:

  • mountain glaciers and snow cover have declined- contributed to rising sea levels
  • upward trends in amount of precipitation have been observed.
• problems from climate change:

  • melting polar ice caps could lead to extinction of the few plant and animal species
  • rising sea levels from melting ice caps and thermal expansions of oceans could flood low-lying land, Saltwater would flow up river reducing habitats of freshwater plants and animals.
  • higher temperature and less rainfall would result in some species failing to survive, leading to drought resistant species. The loss of drought resistant species of plant would lead to loss of some animal species dependent on them as a food source.
• continued:

  • insect life cycles and populations will change to adapt to climate change. Insects are key pollinators of plants so if the range of insects changes it could affect the lives of plants causing extinction. Insects carry may pathogens, so could lead to a spread of tropical diseases.