1. Loss of Energy in a Food Chain
Energy Pyramid – it is a diagram in which each trophic level is represented by a block, and the blocks are stacked on top of one another, with the lowest trophic level on the bottom. The width of each block is determined by the amount of energy stored in the organisms at that trophic level.

2. Loss of Energy in a Food Chain
During every transfer of energy within an ecosystem, energy is lost as heat. Some of it is also lost through respiration, reproduction, and other life processes. At each trophic level, the energy stored by the organisms is about 1/10 of that stored by the organisms in the level below. (In other words, 90% of the energy is lost & 10% is transferred.)

3. What is happening to the energy in a food chain?

4. Energy Pyramid

5. “Rule of 10”

6. Energy Pyramid

7. How much energy???
?? J
?? J
5,000J

8. How much energy???
?? J
7000 J
?? J

9. Why do food chains not tend to exceed four-five levels?
Too much energy is lost at
each level to allow more
levels.
There is not enough
energy available to sustain
further life.

10. Pyramid of Biomass
Biomass is the total mass of dry organic matter per unit of area. Biomass is related to the abundance of organisms at each trophic level. Each trophic level contains less biomass than the previous trophic level.
A biomass pyramid shows the mass of consumer tissue supported by each level below it.

11. Pyramid of Biomass Mass of 1 Owl = 5kg Mass of 5 voles = 10kg
Mass of 1000 grass plants = 50kg

12. Biomagnification
Biological magnification occurs if a pollutant such as DDT, mercury, or a PCB , is picked up by an organism and is not broken down or eliminated from its body. Instead, the pollutant collects in body tissues.

13. Biomagnification:

14. Biomagnification:
Biological magnification occurs if a pollutant is picked up by an organism and is not broken down or eliminated from its body. Instead, the pollutant collects in body tissues.
The higher up the food chain, the more concentrated the pollutant becomes.
This process is called biomagnification (or bioamplification).