A railway depot has an unused strip of land beside its buildings. The strip was covered by short grass.
Managers created a pond, planted a hedge and allowed some areas of grass to grow longer.
Scientists recorded the number of species on the strip before the changes and five years after the changes.
| Group of organisms | Number of species before the changes | Number of species five years after the changes |
|---|---|---|
| Plants | 7 | 16 |
| Invertebrates | 12 | 27 |
| Birds | 3 | 7 |
Calculate the increase in the total number of species recorded after the changes.
Explain why the changes may make the ecosystem on the strip of land more stable.
84 exam-style questions on AQA GCSE Biology 7.3 Biodiversity and the effect of human interaction on ecosystems, covering 7.3.1 Biodiversity, 7.3.2 Waste management, 7.3.3 Land use, 7.3.4 Deforestation, 7.3.5 Global warming, and 7.3.6 Maintaining biodiversity. Each one has a worked solution and a mark scheme showing where the marks go.