Simplifying food webs
Food production can be increased when a greater proportion of the chemical energy in a crop remains within food chains that lead to humans.
Crop pests divert some of this energy because they consume plant biomass and enter other food chains. Pest damage may also cause plants to allocate resources to defence rather than growth, lowering crop net primary production (NPP).
Reducing pest populations therefore helps preserve crop biomass and limits the transfer of energy into food chains that do not contribute to human food.
Methods described for controlling crop pests include:
- chemical pesticides
- biological pest control
Exam Tip: Build the explanation as a chain: fewer pests → less crop tissue eaten → less energy diverted to other food chains → more plant biomass available for human consumption.