QUESTION 7 (4 marks)
Species richness (S) can be determined using the Menhinick՚s Index, where s is the number of different species represented in a sample and N is the total number of individual organisms in the sample.
s
N
Sampling of two communities (Community A and Community B) were completed, with Community A having S = 0.5 for the six species identified. The results for Community B are shown in the table.
Community B | |
Species | Number of individuals |
A | 12 |
B | 15 |
C | 19 |
D | 22 |
E | 25 |
F | 7 |
Use S to compare Community A with Community B.
QCAA guide · typeset solution
QCAA sample response and mark allocation
7 | Community B has greater richness than Community A. Community B has a same number of different species as Community A (i.e. 6); however, Community A must have been for a larger sample. | • states that S = 0.6 [1 mark] • states that Community B has greater richness than Community A [1 mark] • states that Community A and Community B have same number of species [1 mark] • infers that Community B’s sample size is smaller than Community A [1 mark] |
QCAA sample response and marking criteria reproduced from the official guide.
Compare your working with the guide above.