Sampling

• What technique do scientists use to determine species abundance and distribution?

  Sampling
• What are abiotic factors?

  Non-living environmental factors
• How do abiotic factors affect organisms?

  They influence the number of different organisms
• What is random sampling used for?

  To compare numbers of organisms in areas
• What is a quadrat?


  A square frame for sampling organisms
• How do you use a quadrat in sampling?

  Place it on the ground and count organisms
• What hypothesis was investigated regarding ferns?

  Fewer ferns are found in light conditions
• What types of plants were counted in light conditions?

  Dandelions, daisies, and ferns
• Why is it important to place the quadrat multiple times?

  To ensure valid and representative results
• What is the equation for estimating total population size?

  Total population size = (total area / area sampled) * organisms counted
• What is a transect?

  A line used for sampling across a habitat
• How do you carry out sampling along a transect?

  Count organisms at intervals along the line
• What should you do to ensure valid results when using a transect?

  Carry out the transect multiple times
• What are the steps for using quadrats in random sampling?

  1. Place the quadrat randomly on the ground.
  2. Count the number of organisms inside.
  3. Repeat at multiple random locations.
  4. Calculate averages for valid results.
• What are the steps for sampling along a transect?

  1. Place a tape measure across the habitat.
  2. Use a quadrat at set intervals along the transect.
  3. Count the organisms in each quadrat.
  4. Repeat the process for valid data.
• How do light conditions affect fern populations?


  • Fewer ferns are found in light conditions.
  • More ferns are found in dark conditions.
  • This can be tested using random sampling.