Chapter 2: Energy Flow and Nutrient Cycles Support Life in Ecosystems

1. Chapter 2: Energy Flow and Nutrient Cycles Support Life in Ecosystems

3. Today • Virtual lab http://www.mhhe.com/biosci/genbio/virtual_labs/BL_03/BL_03.html • Diagram page 76 textbook • Nutrient cycling (CARBON) • Stores • 6 main processes C is cycled • Anthropogenic effects • Workbook pages

4. A 54-year old sealed terrarium (planted in 1960)no fresh air or water

5. 2.2 Nutrient Cycles in Ecosystems • Earth’s biosphere acts like a sealed terrarium where nutrients and wastes are recycled • Carbon, nitrogen and phosphorus cycles move nutrients in and out of terrestrial and aquatic ecosystems • Where does the water you drink come from?

6. 2.2 Nutrient Cycles in Ecosystems Human activities can upset the natural balance of nutrient cycles: - land clearing - agriculture - industry - motorized transportation

7. Nutrient Cycling • Nutrients: chemicals that are needed for plant and animal growth and other life processes. • Are accumulated in atmosphere, oceans, and land masses • Stores: location of nutrient accumulation

8. Nutrient Cycling • Nutrient Cycling: movement in and out of stores • Caused by biotic and abiotic processes • Cycles are near balance (input = output) You need to know about C, N, & P cycles But O and H are also needed for life

9. Carbon Cycle

10. Carbon Stores • All living things contain carbon in their cells How carbon is stored: • Short term stores - vegetation on land, in oceans - animals and decaying OM in soil - atmosphere as CO2 - top layers of ocean

11. Carbon Stores • Long-term stores: - intermediate and deep oceans - coal deposits - marine deposits and sedimentary rock

12. Carbon Stores Where is most carbon stored?

13. Carbon Stores • Sedimentation: • Traps many long-term carbon stores • Layers of soil/decomposing OM get buried • turn into rock/coal/oil/gas by SLOW geological processes

14. Carbon Stores • Limestone (CaCO3 ) forms from shell deposits on ocean floor • Long-term carbon stores are aka carbon sinks

15. Carbon Cycle Carbon is cycled through ecosystems by: • Photosynthesis • Cellular respiration • Decomposition

16. #1) Photosynthesis chemical reaction in plants and cyanobacteria where sunlight (solar energy) is used to make glucose (chemical energy) Sun + 6H20 + 6CO2→C6H12O6 + 6O2 (sun + water + carbon dioxide → sugar + oxygen)

17. #1) Photosynthesis • recycles carbon and oxygen through ecosystems By eating plants, consumers obtain energy and take carbon into their cells.

19. #2) Cellular Respiration • Opposite of photosynthesis • chemical reaction in mitochondria of cells where oxygen is used to liberate energy from glucose. 6O2 + C6H12O6 -> 6CO2 + 6H2O + energy

21. #3) Decomposition • the breaking down of dead organic matter • Decomposers (bacteria + fungi) convert organic molecules (carbohydrates) back into carbon dioxide.

23. Today • Nutrient cycling (CARBON) • Review 6 main processes C is cycled • What are YOU doing? • PHosphorUs and Nitrogen (Phun with a P-H!)

24. You’re the next contestant! • http://www.bcscience10.com/docs/puzzles/section02_1_puzzle/index.html • One lucky volunteer gets to click the link and be the host while I check WB 24-26 • You have 10 minutes…

26. Other ways carbon is cycled #4) Ocean processes (CO32-) sediments, marine organisms remember CaCO3! We made some in a lab. #5) Volcanic eruptions release CO2 #6) CO2 is rapidly released during forest fires (slowly for decomposing trees)

28. Human activities and the carbon cycle • Industry, motorized transportation, land clearing • Industrial revolution (160 yrs ago)CO2 levels increased by 30% from increase of fossil fuel burning • Increase in CO2 in the previous 160 000 ya was 1-3% • We release C from long-term stores FAST (coal, oil, gas)

29. Anthropogenic effects • Burning fossil fuel reintroduces C to the cycle that was removed in a long term store • CO2, a greenhouse gas, is the most common form of carbon absorbs heat in atm. • Contributes to global climate change

30. Anthropogenic effects? • Clearing land reduces amount of carbon taken from atmosphere by plants during photosynthesis • Farm plants remove CO2, but less than natural vegetation

31. Agriculture: cows are carbon culprits • Our obsession with cows is causing almost 10% of global warming emissions http://qz.com/128662/our-obsession-with-cows-is-causing-almost-10-of-global-warming-emissions/#/h/15425,1/ • Cows release methane from digestion (23x stronger than CO2) • Feed is not environmentally friendly

33. Breaking down the carbon cycle • http://www.bcscience10.com/media/EP_carbon_cycle.swf

35. Carbon cycle • http://www.bcscience10.com/protect/flash_u1_carbon_cycle.html

36. Today • Nutrient cycling (CARBON) • Review 6 main processes C is cycled • What are YOU doing? • PHosphorUs and Nitrogen (Phun with a P-H!) • BONUS CHALLENGE… tell me what you learned about nutrient cycling from THE link that was NOT covered in class (5 marks maximum, handed in at beginning of next class)

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