Explain how overgrazing by cattle reduces biodiversity in a grassland ecosystem.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Farmers sometimes allow too many cattle to graze on grassland. This is called overgrazing.
Model answer (4 marks)
Overgrazing removes or destroys plant species, reducing the variety of vegetation in the grassland.
This loss of plant diversity means fewer food and shelter options for animals.
Animals that rely on those plants therefore lose their resources.
The decline in animal species further reduces overall biodiversity in the ecosystem.
This loss of plant diversity means fewer food and shelter options for animals.
Animals that rely on those plants therefore lose their resources.
The decline in animal species further reduces overall biodiversity in the ecosystem.
Examiner tips
- Use the exact terms from the mark scheme – ‘remove/destroy plant species’, ‘reduce variety of plant species’, ‘animals lose resources’, ‘decrease variety of animal species’.
- Show the causal chain clearly – each sentence should link one point to the next.
Mark scheme (4 marks)
- Overgrazing removes plant species / destroys vegetation
- This reduces the variety of plant species in the ecosystem
- Animals that depend on those plants for food / shelter lose their resources
- This causes a decrease in the variety of animal species, reducing overall biodiversity
Key terms in this question
Related
- Revision notes: Biodiversity and the effect of human interaction on ecosystems →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →