Biodiversity

• What is biodiversity?
• Simpson’s Index of Diversity

  1. A measurement of the total number of organisms compared to the total number of organisms of each species

  2. A high index of diversity means several different species are equally abundant, whereas a low index means one or two species dominate over others
• Species richness

  The number of species in an area
• Types of sampling

  1. Random= no particular system, however aim is still to be representative

  2. Opportunistic= those that are encountered first are chosen

  3. Stratified= population divided into smaller groups based on a characteristic, then sampled

  4. Systematic= follows a particular pattern
• Discuss different types of sampling
• Assessing genetic diversity

  Proportion of polymorphic gene loci = number of polymorphic gene loci / total number of loci
• Differentiate between species richness and species evenness
• Describe how Simpson’s Index of Diversity is used
• Why is sampling important?
• Species evenness

  Whether species have similar numbers
• Biodiversity

  The variety of living organisms. It can be measured in terms of species diversity (number of species in a community), habitat diversity (range of different habitats) and genetic diversity (variety of alleles within a species)
• How can we assess genetic diversity?
• In-situ conservation

  • Marine conservation zones
  • Wildlife reserves
• How can we assess genetic diversity?

  Proportion of polymorphic gene loci divided by the number of polymorphic gene loci over the total number of loci
• Conservation

  The protection and management of species and habitats, in order to maintain biodiversity. Can be in-situ (in an organism’s habitat) or ex-situ (outside an organism’s habitat)
• Factors that affect biodiversity

  • Population growth
  • Deforestation for agriculture
  • Climate change affecting habitats
• Agreements made with the aim of protecting species and habitats

  • Convention on International Trade in Endangered Species (CITES)
  • Rio Convention on Biological Diversity (CBD)
  • Countryside Stewardship Scheme (CSS)
• Ex-situ conservation


  • Seed banks
  • Botanic gardens
  • Zoos
• Reasons to maintain biodiversity

  • Ecological= protecting species, maintaining resources
  • Economic= reducing soil depletion
  • Aesthetic= protecting landscapes