Quadrats + line transects

• A quadrat -> used to estimate how many of a species there are in a certain area -> a population size
• Method (QER):

  1. create axes using two long tape measures at a right angle
  2. use a random number generator to create coordinate. this means you can place your quandary randomly and avoid bias
  3. place your quadrat at the coordinates and count the number of the species. repeat several times, around 10, to make your answer accurate.
  4. add up all the number of the species in the quadrats and divide by 10 (or whatever number) to work out the mean number in 1m^2
  5. multiply the mean number in 1m^2 by the area of the whole field
• To increase confidence in your results -> increase sample size or area to improve accuracy
• This is a quadrat -> estimate a population size

  
• Line transect = distribution of a population
• A Line transect works out the change in distribution of organisms over a distance
• A Line transect cannot be used to estimate population size
• A tape measure is used for a line transect as well as a quadrat, placed at set intervals along the tape measure , e.g every 10m
• To improve accuracy of line transect: take samples at more frequent intervals
• This is a line transect