Energy Flow and Food Webs

1. Energy Flow and Food Webs Ms. Petrauskas

2. The spheres Hydrosphere: all of the earths water (as a solid, liquid or gas) Lithosphere: the earths solid outer layer (rocks, earth etc.) Atmosphere: the layer of gases surrounding the earth Biosphere: the zone around the earth where life can exist ( part of the lithosphere, hydrosphere and atmosphere)

3. Source of all energy… • Radiant energy- the energy radiated from the sun • Composed of ultraviolet rays and visible light • 70% absorbed by the hydrosphere and the lithosphere and converted to thermal energy • Thermal energy warms the earth • The rest goes back to space

4. Solar Radiation Distribution

5. Photosynthesis • Light energy is used by some organisms and is converted to chemical energy (plants, some algae and some protists) • Carbon dioxide + water sugar + oxygen • Carbon, Oxygen, and Hydrogen are rearranged via light energy into sugar and oxygen Light Energy

7. Cellular Respiration • The process by which sugar and oxygen are converted to carbon dioxide and water to provide energy for the cell (Ex. Human cells use sugar to make energy) • Sugar +Oxygen carbon dioxide +water

8. Equilibrium • A balance of photosynthesis and cellular respiration are part of a stable and healthy ecosystem

9. Trophic levels • Autotroph –producer • Primary consumer – herbivore • Secondary consumer – usually carnivore or omnivore • Tertiary consumer- usually carnivore/ omnivore/ detrivore • Decomposer

10. A. Autotrophs (Producers) • Organisms that photosynthesize ( produce their own food) • Ex. Plants, algae and some bacteria

11. B. Heterotrophs (Consumers) • Organisms that must consume (eat) other organisms to obtain energy and building materials • 4 types of consumers depending on what they eat. (Herbivores, Carnivores, Omnivores, Scavenger/ Detrivores)

12. 1. Herbivore • Eat only plants • Ex. Deer, giraffes, cows, pandas, humming birds, grasshoppers

13. 2.Carnivores • Eat only animals (including insects) • Ex. Killer whales, praying mantis, lions, tigers, wolves, hawks

14. 3.Omnivore • Eat both plants and animals • Ex. Bears, robins, raccoons, blue jays, fox, humans

15. 4. Scavengers/Detrivores • Feed on dead or decaying animal matter • Ex. Crows, crayfish, vultures –Scavengers • Ex. Worms, wood beetles

16. C. Decomposers • Another trophic level • Consume remaining dead or decaying material • Break down organic matter to its nutrients • Nutrients are returned to the soil • Ex. Mould, yeast, mushrooms

17. Food chain • A series of predator-prey relationships (predators eat prey) • Each chain begins with the sun • Producers are next as they use the sun’s energy to produce glucose • Consumers eat the producers • Decomposers return nutrients to the soil

20. Create your Own food chain • Start with the sun producer  primary consumer secondary consumer tertiary consumer  end with the quanternary consumer or decomper • Arrows point in the direction of energy flow. TRY IT!!!!!!

21. Food Webs • A more accurate way to show feeding relationships within a community • Consumers feed on many species, therefore reducing the vulnerability of any one prey species and reliability on one prey species • Useful to see what happens when one species is removed from the web or added to the web (invasive species)

24. Ecological Pyramids • Display relationships between trophic levels. As the pyramid narrows it shows that energy has been lost • Can represent energy, biomass or numbers of organisms

25. Energy loss • As one organism consumes another energy is transferred • Some energy is lost as thermal energy • Consider how much heat you lose compared to a plant! • Only 10% of the energy consumed by one trophic level is passed onto the next trophic level

26. 10% is transferred between trophic levels

27. Create your own…..start with 1,000,000J of energy 100 J 1,000J 10,000J 100,oooJ

28. Analogy • Cut a pie into 10 equal slices • Only 1 piece is available to the next trophic level • Cut that slice into 10 smaller slices • Only 1 of those is available to the next trophic level

29. Biomass Pyramid: mass of all living organisms in an area

30. Normal