1. Energy Movement Through Ecosystems
Section 1.11

2. Why is Solar Energy Important?
All forms of life are dependent on solar energy for life
We need it for plants to grow and to keep earth warm enough for us to survive
Photosynthesis – The process by which green plants use sunlight to produce sugar
6CO H2O + sunlight O2 + C6H12O H2O
Carbon dioxide + water + sunlight oxygen + sugar + water

4. Of the 0.023% of sunlight, how does the energy disperse throughout food chains and food webs?
Food Web – a series of interlocking food chains
When talking about
food webs and energy,
new terms are used
to describe producers
and consumers/
decomposers.

5. Autotrophs
Plants or algae which make their own food using the sun’s energy through photosynthesis
Previously called producers

6. Heterotrophs
Animals, fungi and bacteria that must eat or decompose plants or animals (and their waste) to get their energy
Previously called consumers (herbivores, carnivores, omnivores) / decomposers

7. Why New Terms?
Each of the feeding levels (producer, primary consumer, secondary consumer….) is called a trophic level
Every time something is consumed in a food chain, energy is passed along
Less and less energy is passed along each time because some of the energy is used for life processes (maintaining body temperature, digestion, growing, movement etc)

8. ECOLOGICAL PYRAMID # of Organisms Decreases Available Energy Decreases
3rd TL
2˚ Consumers
Available Energy Decreases
2nd TL
1˚ Consumers
1st Trophic Level (TL)
Producers
Solar Energy

9. With these new terms and previous old terms, we can place labels on organisms within food chains and food webs
Handout: Energy Loss in a Food Chain (The Energy Pyramid)

11. The higher the trophic level in a food chain, the more energy is lost
Consuming plants (which are the lowest trophic level) allows for the least amount of energy to be lost