M4:S2 Biodiversity

• Biodiversity


  The variety of living organisms in an area
• Species


  A group of similar organisms able to reproduce to give fertile offspring
• Habitat


  The area inhabited by a species, including physical and living factors
• Areas with a high biodiversity are those with lots of different species
• Levels of biodiversity


  • Habitat diversity
  • Species diversity
  • Genetic diversity
• Habitat diversity


  The number of different habitats in an area
• Species diversity


  The number of different species (species richness) and the abundance of each species (species evenness) in an area
• Genetic diversity


  The variation of alleles within a species or population
• Sampling to measure biodiversity

  1. Choose an area to sample

  2. Count the number of individuals of each species

  3. Repeat the process to get more samples

  4. Use the results to estimate the total number of individuals or species
• Different organisms require different sampling techniques
• Random sampling


  To avoid bias, the sample should be random
• Types of non-random sampling

  • Systematic
  • Opportunistic
  • Stratified
• Species richness


  The number of different species in an area
• Species evenness


  The relative abundance of each species in an area
• Simpson's Index of Diversity

  A measure of biodiversity that takes into account both species richness and species evenness
• Simpson's Index of Diversity is always a value between 0 and 1, with higher values indicating greater biodiversity
• Genetic diversity can be assessed by calculating the proportion of polymorphic gene loci in a population
• Factors affecting global biodiversity

  • Human population growth
  • Increased use of monoculture in agriculture
  • Climate change
• Human population growth


  Decreases global biodiversity through habitat loss, over-exploitation, urbanisation, and pollution
• Increased use of monoculture in agriculture


  Decreases global biodiversity through habitat loss, destruction of local species, and loss of heritage crop varieties
• Climate change


  Affects global biodiversity by changing species' habitats and ranges, causing extinctions
• Maintaining biodiversity is important for ecological reasons, such as protecting species and maintaining ecosystem functions
• All of this makes the future look a bit bleak deforestation, loads of different species dying out and climate change
• Now you know why biodiversity's at risk, it's time to take a look at why it's so important and worth saving
• Biodiversity


  The variety of life within and between organisms
• Importance of Biodiversity


  • To Protect Species, Including Keystone Species
  • To Maintain Genetic Resources
  • To Reduce Soil Depletion
  • Aesthetic Reasons
• Keystone species


  Species on which many of the other species in an ecosystem depend and without which the ecosystem would change dramatically
• Genetic resources


  Any material from plants, animals or microorganisms, containing genes, that we find valuable
• Genetic resources provide


  • Food and drink
  • Clothing
  • Fuels
  • Drugs
  • Other industrial materials
• Genetic resources allow us to adapt to changes in the environment
• Monoculture


  Growing a single variety of a single crop
• Continuous monoculture


  Planting the same crop in the same field without interruption
• Continuous monoculture causes soil depletion because the nutrients required by the crop are gradually used up</b>
• The economic costs of soil depletion include increased spending on fertilisers and decreased yields
• Areas rich in biodiversity provide pleasant, attractive landscapes that people can enjoy
• The more biodiversity in an area the more visitors the area is likely to attract
• Keystone species


  Species that are essential to the functioning of the ecosystem
• If the number of herring decline

  It can affect both the salmon and the bear populations
• If worm numbers decline

  Soil quality will be affected, which will affect the growth of plants and the amount of food available to animals
• In situ conservation


  On site conservation - protecting species in their natural habitat