Sampling

• Abundance - how many organisms there are
• Distribution - where the organisms are
• Ways of sampling;

  • Quadrats (used to measure abundance)
  • Transects (used to measure distribution)
• Sampling is used because it is quicker and easier than counting every single organism.
• Quadrats;

  1. Place a tape measure along the width and length of area used, to form a large grid.
  2. Blindfold, spin and drop quadrant or use random number generator to generate coordinates and place on grip.
  3. Once quadrant is placed down count the number of organisms.
  4. Take several readings.
  5. Find mean of number of organisms per m^2.
  6. Multiply by the area of field used.
• Transects:

  1. Lay a tape measure on the ground in a straight line from a tree.
  2. Place quadrant at 0 m on the transcet line/tape measure.
  3. Record number of organisms in quadrant and record.
  4. Move quadrant down 5m and repeat steps.
  5. Reapt all down the tape measure.
• Estimated size of population = total area/sampled area x average number of organisms