1. Ecology
Scientific study of interactions between organisms and their environment.

2. Interdependence An organisms ability to interact with their :
Non-living environment
Other organisms
Survival depends on these interactions

3. Interdependence 6
owl
stoat
fox
rat
rabbit
beetle

4. Energy Pyramid?
Only about 10 % of the energy available within one trophic level is transferred to organisms at the next trophic level. 4

5. Where does all the energy go?
Organisms use energy for body functions: growing, moving, reproducing, some non-digestable, some prey escape
The rest is lost as heat!!!
Discuss with period 5 5

7. Honors ?’s 
Give at least 3 reasons for the low rate of energy transfer within ecosystems (from one level to the next)
Explain why food chains usually don’t have more than 3 to 4 levels.

8. Honors-Draw an Energy Pyramid
It must have 4 trophic levels (minimum)
Label each level based on how the organisms in that level get their energy
Calculate how much energy will be at each level if the bottom level starts with 6,200,000 calories (kcal)

9. Energy Pyramid
Trophic Levels
Only about 10 % of the Energy in one level is transferred to the next. 1 10
100
Most of the remaining energy is used by the animal for life process. What is left is released as heat into the environment.

10. Biomass Pyramid

11. Pyramid of Numbers

12. Ecological Pyramids Biomass Pyramid
Biomass the total amount of living tissue within a given trophic level.

13. Pyramid of Numbers

14. Ecological Pyramids Pyramid of Numbers
A pyramid of numbers shows the relative number of individual organisms at each trophic level.