4.7 Energy efficiency

Why is only 10% of energy passed from one trophic level to the next?


- Not all energy available to next consumer...lost in:

   - Consumer's life processes (Respiration)
   - Undigested food (faeces)

e.g. 90kJ of plant's energy used by aphid for above, 10kJ left for next consumer

...Because the 90% is used by the consumer (not producer, e.g. grass) for life processes, and in undigested food.