1. ENERGY FLOW THROUGH AN ECOSYSTEM

2. Learning Targets I can explain how energy flows through an ecosystem using the following terms: food chain, food web, consumer, producer I can describe relationships between trophic levels in an ecosystem using the following terms: pyramid of energy, pyramid of numbers, pyramid of biomass.

3. Food Chains

4. Producers AKA autotrophs organisms that can convert energy from the sun into food (auto = self; troph = feeder)

5. Consumers AKA heterotrophs organisms that rely on other organisms for food (hetero = other; troph = feeder) A.Herbivores – organisms whose main source of energy is plant matter B.Carnivores – organisms whose main source of energy is animal matter C.Omnivores – organisms who eat both plant and animal matter D. Detrivores - organisms that feed on plant and animal remains and other dead matter E. Decomposers – organisms that obtain energy by breaking down dead organic matter

6. Food Chain Series of steps in an ecosystem in which organisms transfer energy by eating and being eaten What is the ultimate source of energy for all food chains?

7. Food Chain Series of steps in an ecosystem in which organisms transfer energy by eating and being eaten What is the ultimate source of energy for all food chains? The Sun

8. Food Web Network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem Why does a food web provide a better picture of the energy flow situation in an ecosystem than a food chain?

9. Bioaccumulation Increasing concentration of a harmful substance in organisms at higher trophic levels in a food chain (AKA biological magnification or biomagnification)

10. Ecological Pyramids There are three types of ecological pyramids: 1.Pyramid of numbers 2.Pyramid of biomass 3.Pyramid of energy

11. Pyramid of numbers Draw a pyramid of numbers for the following food chain: lions zebra grass

12. Pyramid of numbers Draw a pyramid of numbers for the following food chain: lions zebra grass zebras lions

13. Pyramid of numbers Draw a pyramid of numbers for the following food chain: hawks sparrows beetles oak tree

14. Pyramid of numbers Draw a pyramid of numbers for the following food chain: hawk sparrows beetles oak tree beetles sparrows hawk

15. Pyramid of biomass Draw a pyramid of biomass for the following food chain: lions zebra grass Biomass = total amount of living tissue within a given trophic level

16. Pyramid of biomass Draw a pyramid of numbers for the following food chain: lions zebra grass zebras lions

17. Pyramid of biomass Draw a pyramid of biomass for the following food chain: hawks sparrows beetles oak tree

18. Pyramid of biomass Draw a pyramid of biomass for the following food chain: hawk sparrows beetles oak tree beetles sparrows hawk oak tree

19. Pyramid of Energy Pyramids of Energy always look like a pyramid 10% rule = only about 10% of the energy at one trophic level is available to organisms at the next trophic level

20. Why is only about 10% of the energy available at one trophic level passed to the next trophic level? 1.Organisms use much of the energy they obtain to provide for their own life processes (cellular respiration). 2.Some digested matter is egested in the feces. 3.Not all of the organism is actually eaten.

21. Why do you rarely see more than five trophic levels in a food chain?

22. Because the available energy decreases by 90% at each trophic level, there would not be enough energy available to organisms at higher trophic levels.

25. http://www.ailwyn.schoolzone.co. uk/frames/newscience/practice%2 0sats%20questions/7pyr.htm