4.3

4.3 Describe the use of quadrates as a technique for sampling the distribution of organisms in their habitats

Sand Dune to sample the population of daisies in the area

Sample needs to be random, no bias introduced. Sample needs to be representative. It has to be large enough that the estimate is as close to the true population as possible.

From a bird’s eye view, you set up a grid system with equal sizes.

Random numbers are generated for the x and the y coordinates. For example, (1, 1)

Count the number of daisies in the shaded square.

We need a representative sample: the bigger the better. 10 quadrates or the 10% of the actual area

Quadrate	Number of Daisies per m2
1	4
2	6
3	2

Add up the right column and divided by the number of quadrates: Average number of daisies per m²

You can use this to compare the difference in number of daisies between quadrates.