Required Practical 7 - measure the population size of a common species in a habitat. Use sampling techniques to investigate the effect of a factor on the distribution of this species.

Question 1

What is the method for random sampling?

Answer 1

• Place two 20m tape measures at a right angles
• Use a bag with numbers 1-20 in to generate random coordinates
• Place a quadrat on the random coordinate and count the amount of daisies in the quadrat
• Repeat this until you have 10 samples
• Estimate the amount of daisies in the whole area by dividing the total area by the area sampled and multiplying by the number of daisies counted in the sample

Question 2

What is the independent variable?

Answer 2

Position of quadrats (coordinates)

Question 3

What is the dependent variable?

Answer 3

• Number of daisies in two different areas

- Soil depth

Question 4

What are the control variables?

Answer 4

Size of quadrat

Question 5

What is the method for measuring the affect of soil depth on the distribution of a species?

Answer 5

• Use a transect line to see how the number of daisies changes
• Place a tape measure along a piece of land and place a quadrat at equal intervals along it
• Like before, count and record the number of daisies in each quadrat