Biodiversity

• Biodiversity

  The variety of living things within an ecosystem (a habitat and all the living things in it)
• Diverse

  To show variety
• Measuring biodiversity

  1. The number of different species within an ecosystem

  2. The differences between individuals of the same species
• An ecosystem of high biodiversity would have a large number of different species
• An ecosystem of high biodiversity would have a wide range of differences within one species
• Humans rely on a whole range of plants and animals
• We rely on plants to remove carbon dioxide and release oxygen into the atmosphere
• We rely on crops for food and certain plants and microorganisms for medicines
• We rely on animals such as cows, sheep and fish for food and we rely on trees for building materials
• A reduction in biodiversity would make it less likely that we had all of the resources that we currently depend on
• Other organisms rely on each other, too
• All animals depend on producers at the start of a food chain, either directly or indirectly
• Interactions within the environment are in a delicate balance
• When the balance is upset, for example, by decreasing the number of species, it can have a knock-on effect on other living things
• How animals all depend on producers, either directly or indirectly

  1. Depend on producers directly

  2. Depend on producers indirectly
• Consequences of a lack of biodiversity

  • In ecosystems of high biodiversity, food chains are complex with organisms having a choice of food
  • In ecosystems of lower biodiversity, food webs are simpler
  • If a change occurs to remove one species from a simple food web, this could have a devastating effect on other organisms
• Importance of species being able to adapt to changes

  • Variation within a species means that some organisms are likely to be well adapted to survive a change, even if all organisms are not
  • Where biodiversity is low within a species, a change in the environment could result in that species becoming endangered
• The numbers of a species being so low that it could become extinct is called 'biocritical'
• Organisms in a food web

  • Producers
  • Consumers (e.g. plankton, cod, elephant seal, orca, leopard seal)