Applying the Rules to Environmental Science: Biogeochemical Cycles

1. Applying the Rules to Environmental Science:Biogeochemical Cycles

2. Earth:Matter does not come and go So… matter is constantly recycled on Earth Earth is a closed system to matter

3. Biogeochemical Cycles:Reservoirs & Pathways Atmosphere Biosphere Lithosphere Hydrosphere

4. Some Major Cycles of Matter • Water Cycle • Rock Cycle • Chemical Cycles • Carbon • Nitrogen • Phosphorous • Sulfur

5. Carbon Cycle Atmosphere Biosphere Lithosphere Hydrosphere

6. Carbon Cycle: Reservoirs Atmosphere 1x (= 7.3x1017 grams carbon) Biosphere 3x 55x 35,000x Lithosphere Hydrosphere

7. Respiration& Decay Photosynthesis Carbon Cycle Atmosphere Biosphere Lithosphere Hydrosphere

8. Carbon Transfer:Biosphere Atmosphere Photosynthesis(Atmosphere to Biosphere) Carbon Dioxide + Water + Sunlight --> Sugar + Oxygen Respiration(Biosphere to Atmosphere) Sugar + Oxygen --> Carbon Dioxide + Water + Energy

9. Respiration& Decay Photosynthesis Dissolution Weathering & Volcanism Exsolution Burial & Lithification Photosynthesis Burial & Lithification Carbon Cycle Atmosphere Biosphere Lithosphere Hydrosphere

10. Deforestation: Decrease Photosynthesis Increase Respiration Burning fossil fuels: Increased combustion Human Impacts Carbon Cycle Atmosphere Biosphere Net Effect: Increase in Carbon in Atmosphere Lithosphere Hydrosphere

11. Atmospheric Carbon Dioxide northern winter northern summer

12. Impact

13. Nitrogen Cycle Atmosphere Denitification: bacteria Biosphere • Nitrogen fixation: • bacteria • lightning Absorption Waste &Decomposition Erosion Lithosphere Hydrosphere

14. Nitrogen-Fixing Bacteria in Root Nodules

15. Human Impacts Nitrogen Cycle Atmosphere Biosphere Net Effect: Increase in Nitrogen in water & soil • Nitrogen fixation: • industrial (fertilizer) • combustion Increased Erosion Lithosphere Hydrosphere

16. Phosphorous Cycle Never enters the atmosphere Atmosphere Biosphere Absorption Waste &Decomposition Weathering & Erosion Lithosphere Hydrosphere Absorption Sedimentation

17. Human Impacts Phosphorous Cycle Biosphere Net Effect: Increase in phosphorous in water & “algal blooms”; Depletion in soils Mining, use (fertilizer, detergent, etc.) & increased runoff Lithosphere Hydrosphere More Phos. for organisms

18. Impact:Eutrophication

19. Impact:Red Tide

20. Sulfur Cycle Bacteria Absorption Atmosphere Bacteria Release Biosphere Volcanoes & Weathering Absorption Precipitation Waste &Decomposition Weathering “Evaporation” Sedimentation Lithosphere Hydrosphere Absorption Deep Sea Vents

21. Human Impacts Sulfur Cycle Atmosphere Biosphere Net Effect: Increase in atmosphere (health effects) and acid rain Precipitation” Acid Rain Burning Fossil Fuels Lithosphere Hydrosphere

22. Applying the Rules to Environmental Science:Food Webs

23. Earth:Earth constantly gains & loses energy Heat Earth is a Open System to Energy Sunlight

24. “Life is a struggle of an immense number of organisms, weighing next to nothing, for a small amount of energy.”

25. Producers( Autotrophs) Energy enters the system Tall grass prairie

26. Producers Chlorophyll Photosynthesis Carbon Dioxide + Water + Sunlight --> Sugar + Oxygen

27. Producers Chemosynthesis Hydrogen Sulfide + Carbon Dioxide + Water + Oxygen + Geothermal Heat --> Sugar + Sulfuric Acid

28. Consumers --> Heterotrophs Primary Consumers - eat producers (Herbivores) Secondary Consumers - eat primary consumers (Carnivores) Tertiary Consumers - eat secondary consumers (Carnivores & Omnivores) Decomposers - break down dead organisms Called “Trophic” (Feeding) Levels Represent the flow of energy (food)

29. Called “Trophic” (Feeding) LevelsRepresent the flow of energy (food) Sun Flow of Energy Primary Consumer Secondary Consumer Tertiary Consumer Producer

30. Forms aFood Chain What happens if… we kill off all the mice?

31. Food Webs What happens if… we kill off all the crab eater seals? Food webs are more stable than food chains.

32. Food Webs What happens if… we kill off all the crab eater seals? Food webs are more stable than food chains.

33. Lessons Food webs are more stable than food chains The produces are the key to the entire food web Life is rough at the top

34. 2nd Law of Thermodynamics Energy is lost during conversion Energy & “Trophic” Levels Sun Flow of Energy Primary Consumer Secondary Consumer Tertiary Consumer Producer 1000units 900 lost 100units 90 lost 10units 9 lost 1units About 90% loss each step

36. Shown as a Trophic Pyramid Tertiary Consumers Secondary Consumers Primary Consumers Producers “Energy Units” Measured asBiomass

37. Tertiary Consumers Secondary Consumers Primary Consumers Producers “Energy Units” Measured asBiomass Energy captured and turned into biomass by all producers is called Net Primary Productivity

38. For example:

39. Why does diet mater? If each person required 10 g/m2 food per day: This ecosystem could feed: 1 person on all carnivores 4 people on herbivores 80 people on plants

40. Applying the Rules to Environmental Science:Bioconcentration

41. Bioconcentrationup the Trophic Pyramid Energy degrades… but matter does not Toxin (e.g. heavy metals)

42. Example:DDT High concentrations of DDT weakens egg shells in fish-eating birds & chicks die