1. 1 Energy Flow Through an Ecosystem Food Chains, Food Webs, Energy Pyramids copyright cmassengale

2. 2 Begins with the SUNBegins with the SUN PhotosynthesisPhotosynthesis 6CO 2 + 6H 2 O + sunlight & chlorophyll  6C 6 H 12 O 6 + 6O 2 copyright cmassengale

3. 3Photosynthesis Chemical reaction where green plants use water & carbon dioxide to store the sun’s energy in glucose Chemical reaction where green plants use water & carbon dioxide to store the sun’s energy in glucose ENERGY is stored in glucose ENERGY is stored in glucose Glucose is stored as starch in plants Glucose is stored as starch in plants copyright cmassengale

4. 4 Organisms that can make glucose during photosynthesis are called Organisms that can make glucose during photosynthesis are called PRODUCERS. copyright cmassengale

5. 5 Producers use most of the energy they make for themselves. copyright cmassengale

6. 6 The energy that is not used by producers can be passed on to organisms that cannot make their own energy. copyright cmassengale

7. 7 Organisms that cannot make their own energy are called CONSUMERS. copyright cmassengale

8. 8 Consumers that eat producers to get energy: Are first order (1 st ) or primary consumers Are herbivores (plant- eaters) copyright cmassengale

9. 9 Most of the energy the primary consumer gets from the producer is used by the consumer. copyright cmassengale

10. 10 Some of the energy moves into the atmosphere as heat. copyright cmassengale

11. 11 Some energy in the primary consumer is STORED & not lost to the atmosphere or used by the consumer itself. This energy is available for another consumer (predator). copyright cmassengale

12. 12 A Consumer that Eats Another Consumer for Energy: Is called a secondary or 2nd order consumer Is called a secondary or 2nd order consumer May be a carnivore or a omnivore May be a carnivore or a omnivore May be a predator May be a predator May be a scavenger May be a scavenger copyright cmassengale

13. 13 Most of the energy the secondary consumer gets from the primary consumer is used by the secondary consumer. copyright cmassengale

14. 14 Some of the energy is lost as heat, but some energy is stored and can passed on to another consumer. copyright cmassengale

15. 15 A consumer that eats a consumer that already ate a consumer: Is called a 3rd order or tertiary consumer Is called a 3rd order or tertiary consumer May be a carnivore or a omnivore May be a carnivore or a omnivore May be a predator May be a predator May be a scavenger May be a scavenger copyright cmassengale

16. 16 Consumers that eat producers & other consumers Are called omnivores Omnivores eat plants and animals copyright cmassengale

17. 17 Consumers that hunt & kill other consumers are called predators. The animals that are hunted & killed are called prey. copyright cmassengale

18. 18 Consumers that eat other dead consumers are called scavengers copyright cmassengale

19. ENERGY FLOW IN ECOSYSTEM How does energy flow in an ecosystem? What is an energy pyramid? What is a trophic level?

20. ENERGY ENTERS ECOSYTEM All energy in ecosystem comes from the sun First law of Thermodynamics: Energy cannot be created or destroyed (but it can be transformed into stored energy & heat)

21. ENERGY LEAVES ECOSYSTEM Second law of thermodynamics: Energy is lost as energy is transformed In ecosystem, when energy is transformed, some energy is lost as HEAT

22. ENERGY PATHS 3 ways to illustrate energy flow 1. Food Chain: Single path 2. Food Web: many paths 3. Food Pyramid

23. FOOD CHAINS A food chain shows the path of energy from one organism to the next energy flows from producers to consumers arrows point to who is eating (plant is eaten by herbivore) Usually decomposers are left out

24. FOOD WEBS A food web shows all feeding relationships in an ecosystem (made of many food chains) A food web shows all feeding relationships in an ecosystem (made of many food chains)

25. FOOD WEBS Typically, food webs go like this: PRODUCER CONSUMER (HERBIVORE) CONSUMER (CARNIVORE) CONSUMER (OMNIVORE) DECOMPOSER remember: decomposers receive energy from all other organisms in an ecosystem remember: decomposers receive energy from all other organisms in an ecosystem

26. FOOD CHAINS AND WEBS Practice! Draw a food chain that includes the following organisms: Practice! Draw a food chain that includes the following organisms: grasshopper grasshopper mouse mouse grass grass owl owl Now label the organisms as producers, consumers (which type?), or decomposers Now label the organisms as producers, consumers (which type?), or decomposers PRODUCER CONSUMER (HERBIVORE) CONSUMER (CARNIVORE)

27. FOOD CHAINS/WEBS & ENERGY PYRAMIDS Food chains/webs can be written as a pyramid: Producers form the base of the pyramid Consumers form the upper layers Consumers form the upper layers

28. ENERGY PYRAMIDS A level of the energy pyramid is called a TROPHIC LEVEL Each trophic level represents the energy for those organisms Top Consumer Energy stored by Secondary Consumers Energy stored by Primary Consumers ENERGY STORED BY PRODUCERS The energy pyramid shows energy flow in an ecosystem:

29. TROPHIC LEVELS Energy is lost with each trophic ~90% is released to the environment as heat ~10% of the energy is used Only about 10% of the energy from one level is passed on to the next level

30. QUICK REVIEW Practice! If 100% of the energy is available at the first trophic level, what percentages of the energy are available at the second and third trophic levels? 100% 10% 1%

31. QUICK REVIEW! All organisms in an ecosystem need _______ from food to live. An energy ________ shows how much food energy is passed from one ________ to another through food chains. __________ have the largest spot at the base of the pyramid. Altogether, only about _____ of the food energy at each level gets passed up to the next level. energy pyramid Producers 10% organism