Week 11 nutrient cycles

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Carbon and Global Warming
Nitrogen Cycle and Fertilisers

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  • Saprobiotic organisms
  • Search youtube for “300 years of fossil fuels in 300 seconds”
  • Graphs uses 1978 as a reference point
  • Water availability, density of planting, genetic variety of rice, nutrient availability etc. Monitor variable that can’t be controlled
  • Migration: Lower to higher latitudes
  • Saprobiotic organisms
  • Haber process requires high temperatures and pressures to achieve what nitrogenase does at environmental temperatures
  • Haber process requires high temperatures and pressures to achieve what nitrogenase does at environmental temperatures
  • Clay and humus particles are negatively charged, NH4+ ions stick to particles, No3- ions repelled by particles
  • Clay and humus particles are negatively charged, NH4+ ions stick to particles, No3- ions repelled by particles
  • Paddy fields contain a lot of cyanobacteria fixing nitrogen gas into ammonia.
  • Have a look at page 98 - 99
  • Use google earth to show caspian sea, great lakes – lake Erie, UK coast etc
  • 15/99 = 15.15%, Chla = Chlorphyll a, DO = dissolved oxygen, Nuisance/toxic blooms = frequency of algal blooms, SAV = submerged aquatic vegetation
  • Pollution from duck farms, correlation between P in water and phytoplankton, but actual cause is N which is taken up quickly by phytoplankton and so is not measurable in water.
  • Addition of carbon and nitrogen alone had no effect, phosphates caused algal bloom. Done in 1974 led to ban on phosphates
  • Week 11 nutrient cycles

    1. 1. Nutrient Cycles Nutrient Cycling Carbon Cycle Global Warming Nitrogen Cycle
    2. 2. Nutrient Cycles <ul><li>95% of an organism is made up of only six elements: </li></ul><ul><li>Carbon – from CO 2 to all organic molecules </li></ul><ul><li>Oxygen – from CO 2 to all organic molecules </li></ul><ul><li> Hydrogen – from H 2 O to all organic molecules </li></ul><ul><li>Nitrogen – from nitrates to all proteins </li></ul><ul><li>Phosphorous – phosphates to proteins </li></ul><ul><li>Sulphur – sulphates to proteins </li></ul>
    3. 3. Nutrient Cycles <ul><li>95% of an organism is made up of only six elements: </li></ul><ul><li>Carbon – from CO 2 to all organic molecules </li></ul><ul><li>Oxygen – from CO 2 to all organic molecules </li></ul><ul><li> Hydrogen – from H 2 O to all organic molecules </li></ul><ul><li>Nitrogen – from nitrates to all proteins </li></ul><ul><li>Phosphorous – phosphates to proteins </li></ul><ul><li>Sulphur – sulphates to proteins </li></ul>(Photosynthesis)
    4. 4. Nutrient Cycles <ul><li>95% of a living organism is made up of only six elements: </li></ul><ul><li>Carbon – from CO 2 to all organic molecules </li></ul><ul><li>Oxygen – from CO 2 to all organic molecules </li></ul><ul><li> Hydrogen – from H 2 O to all organic molecules </li></ul><ul><li>Nitrogen – from nitrates to all proteins </li></ul><ul><li>Phosphorous – phosphates to proteins </li></ul><ul><li>Sulphur – sulphates to proteins </li></ul>(absorbed from soil by roots of plants)
    5. 5. Nutrients in air soil and water Producers consumers decomposers photosynthesis feeding decay respiration and excretion feeding Unavailable organic nutrients coal, oil, peat Unavailable inorganic nutrients, mineral in rocks fossilisation burning erosion
    6. 6. The Carbon Cycle What is a carbon sink?
    7. 7. The Carbon Cycle burning respiration photosynthesis
    8. 8. Global Warming and the Greenhouse Effect
    9. 9. The Greenhouse Effect G.H. gases don’t absorb visible wavelengths of light What would reflect solar radiation? What form does the energy become when absorbed by the Earth? G.H. gases can absorb and re-emit infra red radiation
    10. 10. Global Dimming
    11. 11. The Effects of Global Warming <ul><li>Is the conclusion that the Earth’s global temperature is increasing valid? </li></ul><ul><li>Can you criticise the conclusion? </li></ul><ul><li>Is this evidence that humans are the cause? </li></ul>
    12. 12. The Effects of Global Warming <ul><li>Is this evidence that humans cause global warming? </li></ul><ul><li>Any criticisms? </li></ul>
    13. 13. Global Warming and Crop Yields Why are food prices predicted to increase due to global warming? How will increased CO 2 effect crop yields? How will increased temperature effect crop yields? So what’s the problem….?
    14. 14. Global Warming and Crop Yields: Rice Maximum temperature Minimum temperature Light Intensity <ul><li>How Science Works: </li></ul><ul><li>Which variable would you control? </li></ul><ul><li>Can you explain why you need to control each variable? </li></ul><ul><li>What would you do if you couldn’t control a particular variable? </li></ul>
    15. 15. Global Warming and Crop Yields: Rice Is there a correlation? What is the relationship between yield and minimum temperature? What is the relationship between yield and light intensity?
    16. 16. Global Warming and Crop Yields: Rice What has the biggest effect on yield? Which factors will change due to global warming? How can we explain this effect?
    17. 17. Global Warming and Migration What will happen to these biomes as the global temperature increases? How will organisms respond? Describe this in terms of niches.
    18. 18. Global Warming and Migration
    19. 19. Global Warming and Crop Pests <ul><li>How will global warming effect insect pests? </li></ul><ul><li>Why will new pests be able to survive in the UK? </li></ul><ul><li>Crop yields will decrease unless… </li></ul><ul><li>How will global warming change our farming practices? </li></ul>
    20. 20. Its all about the bacteria!
    21. 21. Nutrients in air soil and water Producers consumers decomposers photosynthesis feeding decay respiration and excretion feeding Unavailable organic nutrients coal, oil, peat Unavailable inorganic nutrients, mineral in rocks fossilisation burning erosion
    22. 22. The Nitrogen Cycle <ul><li>Why do living organisms need nitrogen? </li></ul>What is the largest nitrogen sink on the planet? What is the problem with N 2 gas as a source of nitrogen?
    23. 25. The Nitrogen Cycle <ul><li>Nitrogen-fixing bacteria </li></ul>Nitrogen-fixing bacteria in root nodules.
    24. 26. The Nitrogen Cycle <ul><li>Nitrogen Fixing Bacteria </li></ul><ul><li>“ Free living” in soil: Azobacter , Clostridium </li></ul><ul><li>Mutualism in plants: Rhizobium </li></ul><ul><li>In aquatic systems: Cyanobacteria </li></ul><ul><li>Lightning </li></ul><ul><li>Provides energy needed to break N 2 bonds </li></ul><ul><li>Produces Nitric Acid </li></ul><ul><li>Dissolves in rain, adding nitrate ions to soil </li></ul>
    25. 27. Nitrogen Cycle <ul><li>Rhizobium and Leguminous Plants: </li></ul>Invade plant through root hairs Live in specialised root nodules
    26. 28. Nitrogen Cycle <ul><li>Plant releases chemicals </li></ul><ul><li>Bacteria attracted to root </li></ul><ul><li>Bacteria trigger cell division </li></ul><ul><li>Infection </li></ul><ul><li>Nodule formation </li></ul><ul><li>8) Nodule has vascular tissue </li></ul>
    27. 29. Nitrogen Cycle <ul><li>All nitrogen fixing is carried out by Nitrogenase </li></ul>Where does all the energy come from? What industrial process achieves this reaction? 16ATP 16 ADP + 16Pi 8 NADH+H + NAD + N 2 2NH 3 + H 2
    28. 30. Nitrogen Cycle <ul><li>All nitrogen fixing is carried out by Nitrogenase </li></ul>NH 3 is toxic, bacteria and plant quickly convert it to glutamine. What is glutamine? Why is this a mutualistic relationship? 16ATP 16 ADP + 16Pi 8 NADH+H + NAD + N 2 2NH 3 + H 2 glutamine
    29. 31. The Nitrogen Cycle <ul><li>Nitrogen-fixing bacteria </li></ul>Nitrogen-fixing bacteria in root nodules. Nitrite bacteria Nitrate bacteria
    30. 32. Nitrogen Cycle <ul><li>Nitrifying Bacteria </li></ul><ul><li>NH 3 dissolves readily in soil water </li></ul>Nitrite bacteria: Nitrosomonas Nitrate bacteria: Nitrobacter Nitrate ions diffuse freely in soil water and are more readily absorbed by plants. What type of reaction do these bacteria carry out? NH 3 + H + NH 4 + 2NH 4 + 3O 2 2NO 2 - + 2H 2 O + 4H + 2NO 2 - + O 2 2NO 3 -
    31. 33. Nitrogen Cycle <ul><li>Nitrifying Bacteria </li></ul><ul><li>NH 3 dissolves readily in soil water </li></ul>Nitrite bacteria: Nitrosomonas Nitrate bacteria: Nitrobacter Nitrate ions diffuse freely in soil water and are more readily absorbed by plants. What is the link with eutrophication in lakes and rivers? NH 3 + H + NH 4 + 2NH 4 + 3O 2 2NO 2 - + 2H 2 O + 4H + 2NO 2 - + O 2 2NO 3 -
    32. 34. The Nitrogen Cycle <ul><li>Nitrogen-fixing bacteria </li></ul>Nitrogen-fixing bacteria in root nodules. Nitrite bacteria Nitrate bacteria Denitrifying bacteria
    33. 35. Nitrogen Cycle <ul><li>Denitrifying Bacteria </li></ul><ul><li>Nitrate ions are washed into water table, rivers, lakes and sea. </li></ul><ul><li>Water logged soil and mud is anaerobic </li></ul><ul><li>Denitrifying bacteria use NO 3 - as final electron acceptor in electron transport chain. </li></ul><ul><li> NO 3 - is broken down in N 2 gas, released into atmosphere. </li></ul>
    34. 36. The Nitrogen Cycle <ul><li>Nitrogen-fixing bacteria </li></ul>Nitrogen-fixing bacteria in root nodules. Nitrite bacteria Nitrate bacteria Denitrifying bacteria
    35. 37. Nitrogen Cycle <ul><li>Ammonification </li></ul><ul><li>Ammonia released back into the soil by: </li></ul><ul><li>Decomposition of protein (decay) by fungi and bacteria </li></ul><ul><li>Excretion from animals </li></ul><ul><li>Assimilation </li></ul><ul><li>Nitrogen in protein passed along food chain </li></ul>
    36. 38. The Nitrogen Cycle Nitrogen-fixing bacteria in root nodules. Nitrogen-fixing bacteria Nitrite bacteria Nitrate bacteria Denitrifying bacteria Haber process: fertilisers Lightning
    37. 39. The Nitrogen Cycle <ul><li>What is the relevance of nitrogen fixation in crop rotation? </li></ul><ul><li>Why is good soil drainage important for gardens and arable land? </li></ul><ul><li>How can high crop yields be explained in water logged paddy fields? </li></ul>
    38. 40. Fertilisers, Farm Waste and Water Pollution <ul><li>Why do farmers add fertiliser to their fields? </li></ul><ul><li>What are the advantages and disadvantages of organic and inorganic fertiliser? </li></ul>
    39. 41. One post per idea. Use your real names! Chemical or Organic? http://www.wallwisher.com/wall/kegschgbiology13A
    40. 42. One post per idea. Use your real names! Chemical or Organic? http://www.wallwisher.com/wall/kegschgbiology13b
    41. 43. Eutrophication <ul><li>“ is the natural enrichment of water bodies with nutrients over time ” (succession) </li></ul><ul><li>Accelerated eutrophication is caused by man. </li></ul>
    42. 44. Eutrophication
    43. 45. Eutrophication <ul><li>Fertiliser is leached from fields by rain </li></ul><ul><li>Water is rapidly enriched with nutrients </li></ul><ul><li>Is inorganic or organic fertiliser worse? </li></ul>
    44. 46. Eutrophication Sewage and farm waste be decomposed by bacteria as well as add nutrients to water.
    45. 47. Eutrophication: Data Interpretation What does this chart suggest about eutrophication in the esturies of the USA? What is the percentage of esturaies with high percentage eutrophication? Which indicator suggests there is a lot of eutrophication in the USA? What does the Dissolved Oxygen indicator suggest?
    46. 48. Are these conlusions valid? The East Coast has less eutrophication
    47. 49. Are these conlusions valid? Eutrophication is caused by an increase in human population
    48. 50. Are these conlusions valid? Eutrophication is increased by warmer temperatures.
    49. 51. Are these conlusions valid? Eutrophication is caused by farming.
    50. 52. Eutrophication: The Limiting Factor?
    51. 53. Eutrophication: the limiting factor?

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