A large forested area is cleared to build a road. Some of the cut wood is burned over two years. Plants begin to grow on unused land beside the road.
Scientists estimate the carbon dioxide transferred each year.
| Time | Carbon dioxide released by burning wood in tonnes | Carbon dioxide removed by photosynthesis in tonnes |
|---|---|---|
| Year before clearance | 0 | 5200 |
| Year 1 after clearance | 9600 | 800 |
| Year 2 after clearance | 4400 | 1200 |
| Year 3 after clearance | 0 | 1600 |
Assume these are the only transfers of carbon dioxide during the three years after clearance.
Calculate the net increase in the amount of carbon dioxide in the atmosphere during Years 1 and 2 after clearance.
Give your answer in tonnes.
Use the data to explain why clearing the forest continues to affect atmospheric carbon dioxide after the burning has stopped.
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.