4.7 Energy Efficiency

The diagram is a pyramid of energy.
- of the 100 percent of the producer, only 10 percent make it to the primary consumer
- of the 100 percent of the producer, only 1 percent make it to the secondary consumer.
Question: what are the causes of the losses that we are seeing?

Simple food chain (e.g.)
1) producer ( grass ) 100 Kj eaten by the herbivore
2) primary consumer ( mouse ) since 10% - only 10 Kj of the original will become part of the mouse's body and tissues.
Why? = The mice have to walk around and find their food - carry the process of respiration. Not  all of the 100 Kj of energy is available to the mouse e.g. mice cannot digest cellulose so the plant cell wall cannot be digested and the energy is lost in the form of feces. Therefore, 90Kj of the energy is lost through respiration and undigested food
3) secondary consumer ( owl ) - will only be able to assimilate 1Kj. When the owl eats the mouse, only one percent will make it this far. The losses to the owl are = respiration, energy for movement, energy for flight, energy for digestion. However, some energy is also lost in the form as feces.

All organisms will finally die.
They will be broken by the micro-organisms = decomposers