Required Practical 12

Question 1

Describe how you could investigate the effect of an environmental factor on the abundance of a species in a habitat (random sampling)

Answer 1

• divide area into grids
• generate coordinates using a random number generator
• place quadrat here and count number of named species (only count if over 50% in to standardise)
• repeat a large number of times and calculate mean

Question 2

Explain the importance of a large sample size

Answer 2

• minimises the effects of anomalies
• ensures sample is representative of the population

Question 3

Describe how you could investigate the effect of an environmental factor on the distribution of a species in a habitat (systematic sampling)

Answer 3

• place a transect line across an area with an environmental gradient
• place quadrats at regular intervals and record number of organisms and light intensity using a light meter
• repeat in parallel areas and calculate a mean