cpac 15

• Quadrat


  A square frame used to sample a small area of habitat
• Purpose of the investigation


  • Investigate the effect of different sampling methods on estimates of the size of a population taking into account the safe and ethical use of organisms
• Factors affecting distribution of a species

  • Type of quadrats used when sampling
  • Size of quadrats
• Equipment


  • 0.5m x 0.5m quadrat
  • 1m x 1m quadrat
  • 2x tape measure
  • Random number generator
  • Clipboard
• Method


  1. Choose a single species to measure abundance of

  2. Choose a 10x10m area to take samples from

  3. Use a random number generator to generate at least 10 sets of random coordinates

  4. Place the quadrat at each of the coordinates, placing the bottom left corner on the coordinate

  5. Record percentage cover for the chosen species

  6. Record how many of the organisms of the chosen species touch the pins of the quadrat

  7. Record the number of organisms within the quadrat for the chosen species

  8. Repeat steps with the bigger 1mx1m quadrat
• Risk Assessment


  • Biohazard: Allergies, soil bacteria, contamination - Wash hands after practical, Seek assistance
  • Slippery surfaces: Slip hazard - Wear appropriate footwear, Don't run, Seek appropriate medical attention
• Graph/Analysing Data


  1. Work out mean percentage ground cover for the frame and point quadrat

  2. Work out the mean density per m2 for the different sized quadrats

  3. Construct a bar chart or histogram

  4. Perform a statistical test such as t-test
• Conclusion


  • Determine if there is a significant difference between density per m2 for the different sized quadrats
  • Determine if there is a significant difference between mean percentage cover for the different types of quadrat