Quadrats

• Aim : estimate an organisms population or observe population density change over distance by sampling
• step 1: place a 1m^2 quadrat in random grid positions in an area using a random number generator, and count organisms (ideally sample 10% of the area )
• step 2: calculate the mean number per m^2, then multiple by the total area to give an estimate of the population
• step 3: to observe variation in population density. over distance move Quadrat along a transect and record number per m^2
• step 4 : plot population density against distance (this can also be a kite graph)

  BIOTIC factors that affect this are caused by organisms (e.g. predators)

  ABIOTIC factors are not (e.g. surface)