To measure the species richness on the school field in areas in which the grass is regularly and irregularly cut.
What are the totals and means for the two different locations?
|Number of plant species per quadrat on cut area of the school field||1||2||1||2||3||1||3||1||1||1||2||3||2||1||1|
|Number of plant species per quadrat on uncut area of the school field||3||2||4||6||1||1||1||4||5||3||6||4||5||3||4|
A total of 25 and a mean of 1.7 on cut school field and a total of 52 and a mean of 3.5 on uncut school fields.
What conclusions can you draw here? [4 marks]
The mean of the number of plant species in the cut school field is lower than on the uncut school field (1 mark). There is a mean of 1.7 different species per quadrat on the cut grass (1 mark). The number of plant species per quadrat on the uncut field is over twice this at 3.5 (1 mark). Therefore, there is greater species richness on the school field in uncut areas (1 mark).
What limitations might there be in drawing these conclusions?
In this example, the students only placed 15 quadrats. Completing more would allow them to be more confident in their conclusions.