biodiversity

• biodiversity: the variety of living organisms present in an area.

  • species are interconnected, so the removal of one species can affect the other.
• an increasing population has caused biodiversity to be lost in a number of ways:

  • deforestation
  • agriculture
  • hunting and overfishing
  • pollution
• deforestation


  • produces wood for building and fuel
  • creates space for roads, buildings and agriculture
  • food sources / homes that have been lost can affect the predator species
• hunting + overfishing


  hunting decreases the target species' population, other marine species may also be caught and killed. hunting may allow the unchecked growth of some plants species, which them outcompete other plants, reducing biodiversity.
• effects of an increasing population


  • puts pressure on the environment because we take land and resources to survive.
  • people demand a higher standard of living (cars, phones) - so we use more raw materials and energy. this means we're taking more and more natural resources quickly.
  • many raw materials are being used up quicker that they're being replaces
  • waste - causes harmful pollution like sewage and toxic gases
  • negatively impact local + global biodiversity
• land use


  humans reduce the amount of land resources available to other animals and plants:

  • building
  • farming
  • dumping waste
  • quarrying for metal ores
• land use: habitat destruction

  • woodland clearance - often done to increase the area of farmland and can result in the reduction in the number of tree species, reducing biodiversity. also destroys the habitats of other organisms - species will die or be forced to migrate elsewhere, further reducing biodiversity.
• land use: habitat destruction

  • mono culture- when areas of land are used to grow a single crop (africa - palm oil plantations). efficient way to grow crops for farmers but can lead to a reduction in biodiversity - because habitats are cleared to make way for the large fields that are normally used for monoculture.
• land use: impact of waste on land

  pollution from waste produced by human activities kills plants and animals.

  • toxic chemicals for farming - pesticides + herbicides.
  • bury nuclear waste underground, dump household waste in landfill sites
  • sewage, toxic chemicals can pollute lakes river and oceans, affecting the plants and animals that rely on them.
  • chemicals used on land can be washed into water.
  • smoke and gases can pollute the air - sulfur dioxide causes acid rain.
• hunting


  hunting reduces their numbers, can result in the extinction of species if too many individuals are killed.

  the removal of a particulae species from an area reduces the biodiverstiy of that ecosystem. the reduction (or removal) can have knock on effects in an ecosystem and negatively impact food chain, which could cause further decrease in biodiversity.
• conservation of species: protecting habitats


  includes things such as controlling water levels to conserve wet land and coppicing (trimming tress) to conserve woodlands. tis allows organisms to continue living in their natural habitat.
• conservation of species: introduction of harmful species


  some shemes aim to prevent the introduction of harmful species that would threaten local biodiversity - e.g those that could reduce numbers of a species by competing with it or eating. n example of this in the UK is the control of grey squirrels, which compete with the native red squirrel and caused their populations to decline.
• conservation of species: protected area for organisms


  protected areas include places like national parks and nature reserves. both organisms and habitats are protected by restricting the development of land - building houses and using the land for farming. marine ecosystems are used to restrict fishing.
• conservation of species:protected areas away from their natural habitat


  animals - zoos , plants - botanical gardens and seed banks. in these areas, organisms and habitats are protected in these areas by restricting the development of land. safe areas can also be used to increase numbers of particular organisms before they are released into the wild - captive breeding, useful for reintroducing organisms if they become extinct in the wild.
• maintaining biodiversity: benefits to humans


  • protecting the human food supply
  • ensuring minimal damage to food chains.
  • providing future medicines (from plants)
  • providing industrial materials and fuels.
• ecotourism


  focuses on the appreciation of nature and its conservation whilst having a minimal negative impact on the local ecosystem. maintaining areas with high biodiversity provides an opportunity for ecotourism.

  ecotourism helps bring money into areas where conservation work is taking place. tourists spending money at ecotourism attractions also helps fund conservation work.
• challenges: maintaining biodiversity


  • agreements about conservation schemes can be difficult to arrange.
  • conservation schemes can be difficult to monitor.
• environmental changes: distribution


  1. change in the availability of water - animals can migrate as the rainfall patterns change
  2. change in atmospheric gases - distribution of air pollution
  3. change in temperature - seasonal factors, geographic factors or humans interaction
• consequences of global warming


  • high temps cause seawater to expand, ice melts = sea level rises.
  • distribution of wild plants and animals changes at temp + rainfall increases and change.
  • changes in migration patterns
  • biodiversity could be reduced if some species are unable to survive a change in climate, leading to extinction.