2. Energy and Ecology

3. Ecosystem Components Producers – Basis of an ecosystem’s energy – Autotrophs: perform photosynthesis to make sugars – Chemotrophs: Bacteria which use minerals from deep-sea vents to make energy Consumers – Heterotrophs: Consumes others for energy – Omnivores, herbivores, carnivores, decomposers, detritivores

4. Defined: Feeding level of an ecosystem Trophic levels consist of producers, consumers, and decomposers ~10% of energy is passed to the next level – ~90% used by the organism or lost as heat – Food chains contain few trophic levels

5. 1 st trophic level = Producers Autotrophs (perform photosynthesis) Bottom of food chain Ex: Plants, algae, cyanobacteria

6. 2 nd trophic level = Primary consumers Feed on producers Herbivores (plant eaters)

7. 3 rd trophic level = Secondary consumers Feed on primary consumers Omnivores and carnivores

8. 4 th trophic level = Tertiary consumers Feed on secondary consumers Omnivores and carnivores

9. 5 th trophic level = Quaternary consumers Feed on Tertiary consumers Omnivores and carnivores

10. Rarely shown on food chains Feed on any food chain level when it dies Detritivores: Feed/ingest dead matter Decomposers: secrete enzymes to break down dead matter and then absorb the nutrients

11. What’s wrong with this food chain? The arrows are pointing the wrong direction. This implies that the plant eats the grasshopper.

12. The arrows are pointing the wrong direction. This implies that the grasshopper eats the mouse.

13. What’s wrong with this food chain? The arrows are pointing the wrong direction. This implies that the mouse eats the snake.

14. What’s wrong with this food chain? The arrows are pointing the wrong direction. This implies that the snake eats the hawk.

15. Much better… The arrows show the direction that energy is passed up the food chain.

16. Label the tropic levels in this energy pyramid

17. Defined: Group of interrelated food chains Arrows show direction energy (nutrients) travel Analysis Trace 2 food chains from this food web.

18. producer Primary consumer Secondary consumer Tertiary consumer Highlight a food chain from this food web. Then label each trophic level.

19. producer Primary consumer Secondary consumer Tertiary consumer Quaternary consumer Highlight a food chain from this food web. Then label each trophic level.

20. Defined: Group of interrelated food chains Arrows show direction energy (nutrients) travel Analysis Trace 2 food chains from this food web. What could happen if the grasshoppers die out due to pesticide use?

21. Spider death (no more grasshoppers to eat) Blue jay death (less spiders to eat) Squirrel increase (less owls hunting them) Owl death (less blue jays to eat)

22. YouTube Food Chain Video

23. Kobe Kuiz 1.How many trophic levels are in the following food chain? Apple tree  Worms  Blue Jay  Owl 2.If the tree in the example above makes 15,000 calories of energy from photosynthesis, how much energy is available for each other trophic level? 3.In the food chain above, which is the producer? 4.In the food chain above, which is the primary consumer? 5.In the food chain above, which is the tertiary consumer? 6.Which level consumer are herbivores known as? 7.What is the lowest consumer level possible for a carnivore? 8.Examine the food web on slide #10. Find a complete food chain that is 6 trophic levels from start to finish.