Describe four harmful effects of deforestation on the environment.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (4 marks)
1. Loss of habitat leads to the extinction of species that lived there.
2. Soil erosion increases because tree roots no longer anchor the soil, reducing soil fertility.
3. Flooding risk rises as trees that slow water movement and absorb it are removed.
4. Carbon dioxide levels rise because fewer trees absorb CO₂, contributing to global warming.
2. Soil erosion increases because tree roots no longer anchor the soil, reducing soil fertility.
3. Flooding risk rises as trees that slow water movement and absorb it are removed.
4. Carbon dioxide levels rise because fewer trees absorb CO₂, contributing to global warming.
Examiner tips
- Use the exact wording from the mark scheme, e.g. "loss of habitat" and "soil erosion". Include all four points in separate sentences. Show clear cause–effect links.
- common_mistakes
- :
- Writing vague phrases such as "trees are cut down" without linking to the specific harmful effects. Omitting one of the four required points. Using UK spelling inconsistently (e.g. "flooding" vs "flooding" – both fine, but keep consistency).
Mark scheme (4 marks)
- Deforestation can lead to the extinction of species that lived in the destroyed habitat.
- Without tree roots to anchor the soil, soil erosion occurs, reducing soil fertility.
- Deforestation increases the risk of flooding because trees slow the movement of water to the ground and allow water to be absorbed into the soil.
- Fewer trees means less carbon dioxide is absorbed by photosynthesis, so carbon dioxide levels in the atmosphere increase, contributing to global warming.
Key terms in this question
Related
- All Cambridge International IGCSE Biology (0610) revision notes →
- How to answer a "Describe" question →
- Decode the mark scheme abbreviations →
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