Energy Transfers
- Not all of the energy available at each stage of a food chain is transferred to the next trophic level
- Only around 10% of the chemical energy consumed at each trophic level is passed on to the next
- It can be said that energy is lost from the food chain at each stage
Energy transfer in food chains diagram
Not all of the energy at each trophic level of a food chain is passed on to the next level
- Energy is lost from food chains because only the energy stored in biomass will be passed to the next trophic level; energy used for other processes, or transferred to the environment, is not available to consumers
- Energy may be used for:
- Repairing damaged cells
- Cell maintenance and growth
- Energy may be transferred to the environment in the form of:
- Heat generated during cellular respiration
- Waste materials, e.g. faeces and urine
- Energy losses from food chains explain why food chains are usually relatively short; the energy available at higher trophic levels eventually becomes too small
Energy losses from food chains diagram
Only energy that is converted into new biomass will be passed on to consumers in a food chain; energy that is used in cellular processes or lost as heat or in waste will not be available to higher trophic levels
Note that you do not need to know the term 'net production'