1. 3.3 Energy Flow in Ecosystems

2. POINT > Identify ways we conceptualize energy flow through ecosystems POINT > Describe food chains POINT > Describe food webs POINT > Describe ecological pyrami ds

3. A food chain is a series of steps in which organisms transfer energy by eating and being eaten

4. Each step in a food chain is called a trophic level The first level is always a producer

5. Each step is called a trophic level Consumers make up all the other levels Primary consumer (First Level) Secondary consumer (Second) Tertiary consumer (Third) Quaternary consumer (Fourth)

6. Arrows always point to where the energy is going

7. Phytoplankton: A mix of algae, the primary producers Zooplankton: A diverse mix of protists and tiny animals consuming the phytoplankton PhytoplanktonZooplanktonSmall Fish Large Fish Whale Ex. A marine food chain:

8.  What trophic level are the “small fish”?  Which organisms are the tertiary consumers? PhytoplanktonZooplanktonSmall Fish Large Fish Whale Ex. A marine food chain:

9. Food webs are more complicated networks of feeding interactions composed of many food chains

10. Ex. Antarctic Ecosystem

11. Everglades Marshland Ecosystem

12. Ecological pyramids show the relative amount of energy or matter contained at each trophic level in a food chain or web

13. Energy Pyramid: Shows relative amount of energy available at each trophic level Light Chemical Producer Primary Consumer Secondary Consumer Tertiary Consumer

14. Energy Pyramid: On average, only about 10% of energy available to a level is passed on Light Chemical Producer Primary Consumer Secondary Consumer Tertiary Consumer 100% 10% 1% 0.1%

15. Energy Pyramid: About 90% gets used up by the organism for various functions or is lost as heat Light Chemical Produce r Primary Consumer Secondary Consumer Tertiary Consumer Heat 100% 10% 1% 0.1% Maintaining Homeostasis

16. WB CHECK: How much energy is lost between two trophic levels? What are the primary producers in a marine food web?

17. Biomass Pyramid: Shows relative amount of living organic matter at each level Usually given as a mass per area

18. Numbers Pyramid: Shows relative number of individuals at each level

19. WB CHECK: In a biomass pyramid, where is the greatest amount of biomass, the top or bottom? True or False: A population of large predators has more total biomass than a population of smaller prey animals.

20. Read pages 73-78 Assess Page 78 #1-2 Workbook pages 345-348