Distribution and Abundance

• The abundance of an organism is how many individuals you find in an area (population).
• The distribution of an organism is where an organism is found in a habitat.
• Collecting ground insects

  • Pooters
  • Sucks insects into the jar
  • Pitfall traps
  • Catches insects in a trap in the ground

  
• Collecting animals from Long grass and water


  • Nets
  • Sweep net
  • Pond net
• A quadrat studies the distribution of small organisms.
• First sample = marked

  Population size = (number in first sample x number in second sample) / (number in second sample previously marked)
• The distribution of organisms is affected by:

  • Abiotic features
  • Temperature
  • Moisture level
  • Light intensity
  • Soil pH
  • Biotic features
  • eg. competition
• Transects are used to investigate distribution

  1. Mark out a line in an area you want to study using a tape measure.
  2. Place a quadrat at the start of the line and count and record the organisms you find in the quadrat.
  3. Then, instead of randomly placing your quadrat, move in regular intervals along the line.
• Kite diagrams show the abundance and distribution of organisms.

  
• Human interactions that impact ecosystems

  • Habitat destruction
  • Impact of waste on land (Pollution)
  • Hunting
• Conservation of species helps protect biodiversity, by protecting species and/or their habitat.
• Conservation schemes

  • Protecting habitats (eg. controlling water levels)
  • Controlling or preventing the introduction of harmful species (eg. grey squirrels in UK)
  • Creating protected areas for organisms (eg. nature reserves)
  • Protecting organisms in safe areas away from their natural habitat (eg. a zoo)
• Maintaining biodiversity promotes ecotourism.