1. Trophic Levels, Energy transfer and Pyramids

2. Producers Sunlight is the main energy source for life on earth
Also called autotrophs
Use light or chemical
energy to make food
1. Plants
2. plant-like protists (algae)
3. Bacteria

3. Consumers
Organisms that rely on other organisms for their energy and food supply
Also called heterotrophs

4. Trophic Levels – is the position an organism occupies in a food chain
Trophic Levels – is the position an organism occupies in a food chain. It refers to food or feeding.

5. Trophic Levels (feeding levels)3 2 1

6. Food Chain

7. Food webs are multiple food chains.

8. Food Webs
Food webs show ALTERNATIVE PATHWAYS other possible pathways through which an organism can obtain energy

9. Food webs

10. 1st 2nd producer Grass Mouse Primary consumer Grasshopper Frog Owl
Energy Level
Producer, primary consumer, secondary consumer, tertiary consumer?
Grass
Mouse
Grasshopper
Frog
Owl
Hawk
1st
producer
2nd
Primary consumer

11. Secondary and tertiary consumer
Energy Level
Producer, primary consumer, secondary consumer, tertiary consumer
Grass
1st
Producer
Mouse
2nd
Primary consumer
Grasshopper
Frog
3rd
Secondary consumer
Owl
3rd and 4th
Secondary and tertiary consumer
Hawk

13. Transfer of Energy
Energy lost from chain “link” to “link” is significant!
Each level above only gets 10% of the energy from below

14. Energy lost from one trophic level (energy level) to the next level can be represented by a pyramid
4⁰ CONSUMERS
3 CONSUMERS
2 CONSUMERS
1 CONSUMERS
PRODUCERS

15. ENERGY PYRAMID
1 J
10 J
100 J
1,000 J
10,000 J

17. Ecological Pyramid
Which level has the most energy?
Which level has the most organisms?
Which level has the least organisms?
Which level has the least energy?