A local authority began a conservation scheme to restore a drained peat bog.
Scientists sampled ground beetles using 20 pitfall traps at the same sites. The traps were left for the same length of time in May before the scheme began and four years after it began.
| Ground beetle species | Number caught before the scheme | Number caught four years after the scheme began |
|---|---|---|
| A | 76 | 28 |
| B | 54 | 22 |
| C | 0 | 17 |
| D | 0 | 14 |
| E | 0 | 11 |
| Total | 130 | 92 |
The scientists also measured the percentage cover of sphagnum moss.
| Time of measurement | Percentage cover of sphagnum moss (%) |
|---|---|
| Before the scheme | 6 |
| Four years after the scheme began | 24 |
The larvae of one insect species feed only on sphagnum moss. A bird species feeds on the adult insects.
Compare the biodiversity and the total abundance of ground beetles in the samples before the scheme and four years after the scheme began. Use the data in the table.
Explain how the change in percentage cover of sphagnum moss could affect the abundance of the insect species and the bird species.
Evaluate whether these results provide enough evidence that the conservation scheme affected ground beetle biodiversity.
109 exam-style questions on OCR GCSE Biology 6.1 Monitoring and maintaining the environment, covering 6.1.1 Field investigation of distribution and abundance, 6.1.2 Human interactions and biodiversity, 6.1.3 Maintaining biodiversity, and 6.1.4 Environmental change and distribution of organisms. Each one has a worked solution and a mark scheme showing where the marks go.