An ecologist sampled communities of ground beetles in two woodlands, Site P and Site Q, using pitfall traps. The table below shows the abundance of each species recorded:
| Species | Site P | Site Q |
|---|---|---|
| Carabus violaceus | 24 | 10 |
| Pterostichus madidus | 3 | 9 |
| Nebria brevicollis | 2 | 6 |
| Abax parallelepipedus | 1 | 5 |
Using the formula for the index of diversity:
d=N(N−1)∑n(n−1) d = \frac{N(N-1)}{\sum n(n-1)} d=∑n(n−1)N(N−1)which of the following shows the correct index of diversity (ddd) for each site and the correct ecological conclusion?
dSite P≈1.55d_{\text{Site P}} \approx 1.55dSite P≈1.55 and dSite Q≈4.10d_{\text{Site Q}} \approx 4.10dSite Q≈4.10; Site Q is more stable because it has a higher species evenness.
dSite P≈0.64d_{\text{Site P}} \approx 0.64dSite P≈0.64 and dSite Q≈0.24d_{\text{Site Q}} \approx 0.24dSite Q≈0.24; Site P is more stable because it has a higher index value.
dSite P≈1.55d_{\text{Site P}} \approx 1.55dSite P≈1.55 and dSite Q≈4.10d_{\text{Site Q}} \approx 4.10dSite Q≈4.10; Site P is more stable because the dominance of Carabus violaceus reduces competition.
dSite P≈1.53d_{\text{Site P}} \approx 1.53dSite P≈1.53 and dSite Q≈3.72d_{\text{Site Q}} \approx 3.72dSite Q≈3.72; Site Q is more stable because it has a higher index value.
24 exam-style questions on OCR A A Level Biology Biodiversity. Each one has a worked solution and a mark scheme showing where the marks go.