1. Ecology …the study of …….. OUR house…..
…the study of how organisms interact with each other and their environments

2. MATTER CYCLES
FACTORS INTERACT
ENERGY FLOWS

3. ENERGY FLOWS

4. Trophic Levels
Energy moves from one organism to another when it is eaten
Each step in this transfer of energy is know as a trophic level
The main trophic levels are producers, consumers, and decomposers

7. When energy flows as organic matter through the trophic levels of an ecosystem, MUCH of it is LOST at each link in a food chain Why?
CLUE
When you burn energy to run a mile in gym where does that energy come from?

8. Transfer of Energy
When a zebra eats the grass, it does not incorporate all of the energy the grass has into its body (much of it is not digested and used for energy to live)

9. Transfer of Energy
When a lion eats a zebra, it does not keep all of the energy from the zebra in its body….

10. Plant material eaten by caterpillar
Does all the energy this caterpillar eats get passed to the bird who eats him?
Plant material eaten by caterpillar
100 kilocalories (kcal)
35 kcal
Cellular respiration
50 kcal
Feces
15 kcal
Growth

12. Transfer of Energy
No organism EVER keeps all of the energy from the organism they just ate
Only ~10% of the energy from one trophic level is really transferred to the next – this is called the 10% law

15. Ecological Pyramid
An ecological pyramid shows the relationship between organisms different trophic levels in an ecosystem
Shows the relative amounts of energy or matter and number of organisms contained at each trophic level

16. Ecological Pyramid

18. Biomass
The total mass of the organic matter at each trophic level is called biomass
Biomass is just another term for potential energy – energy that has yet to be eaten and used.

20. Decomposers:
What is a decomposer and what do they do? What trophic level would you put them at?
Derive their energy from the dead material left by all trophic levels
Are often left off of most pyramids and food chain diagrams

21. 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?