10.3 species diversity and human activity

Question 1

Explain how farming practices increase the productivity of agricultural crops.
[5 marks]

Answer 1

1. Fertilisers/minerals/named ion (added to soil);
2. Role of named nutrient or element e.g. nitrate/nitrogen for proteins / phosphate/phosphorus for ATP/DNA;
3. Pesticides/biological control prevents damage/consumption of crop;
4. Pesticides/weed killers /herbicides/weeding remove competition;
5. Selective breeding / genetic modification (of crops);
6. Glass/greenhouses enhance temp/CO2/ light;
7. Ploughing aerates soil/improves drainage;
8. Ploughing/aeration allows nitrification/decreases denitrification;
9. Benefit of crop rotation in terms of soil nutrients/fertility/pest reduction;
10. Irrigation/watering to remove limiting factor;
11. Protection of crops from birds/pests/frost by covers/netting etc.;

Question 2

give examples of how farming has directly removed habitats and reduced species diversity

Answer 2

• removal of hedgerows and grubbing out woodland
• creating monocultures
• filling in ponds and draining marchlands
• over- grazing of land

Question 3

give examples of how farming has indirectly removed habitats and reduced species diversity

Answer 3

• use of pesticides and inorganic fertilisers
• escape of effluent from silage stores and slurry tanks into water courses
• absence of crop rotations
• lack of intercropping or undersowing

Question 4

examples of conservation techniques

Answer 4

• A shape hedgerows
• plant hedges not fences
• leave wet corners
• maintain pond and create other ones
• plant native trees on land with low species diversity
• reduce use of pesticides
• use organic fertilisers
• use intercropping
• create natural meadows
• use hay not grass for silage
• leave cutting on verges and field edges
• introduce conservation headlands