1. Soil Organisms

2. 22 species What creatures live in soil? Harvester Ant Colony

3. Fauna Macro Mammals, reptiles, insects, earthworms Micro Nematodes, Protozoa, Rotifers Flora Plant roots, algae, fungi, actinomycetes (filamentous bacteria), bacteria unicellular 20,000 species

4. Macrofauna: Earthworms Earthworm cast Casts: earthworm’s wastes Eat soil organics: 2-30 times of their own wt. five pairs of hearts 1,000,000 per acre Mostly intestine 22 ft. long (Afr. and Aus.)

5. Earthworms Abundance of earthworms Abundance of earthworms –10-1,000/m 3 –3,000 species Benefits of earthworms Benefits of earthworms -soil fertility by producing cast -aeration & drainage -size & stability of soil aggregates

6. Mycorrhizae symbiosis Association between fungi & plant root Increased SA (up to 10 times) Increased nutrient uptake, especially P Soil Fungi 10 - 100 billion/m 2 Cell with a nuclear membrane and cell wall Most versatile & most active in acid forest soils Yeasts, molds, mushrooms Tolerate extremes in pH (bacteria do not)

7. Mycorrhizae Fungi 1.Ions in solution 2.Movement from solution to root (diffusion) Phosphorous granule Root hair Fungal hyphae

8. –Fungi provide nutrients –Plant root provides carbon –Ectomycorrhiza Root surfaces and cortex in forest trees –Endomycorrhiza Penetrate root cell walls agronomic crops- agronomic crops- corn, cotton, wheat, & rice Symbiosis

9. Soil Bacteria 10-100 trillion/m 2 Single-celled organisms Rapid reproduction Small (<5 µ m) Mostly heterotrophic Autotrophic Bacteria Impact the availability of soil nutrients (N,S)

10. Quantification of Soil Organisms

11. Numbers of organisms –Extremely numerous –1,000,000-1,000,000,000 /g soil –10,000 species /g soil Biomass –1-8% of total soil organic matter Metabolic activity –Respiration: CO 2 –Proportional to # & biomass Quantification of Soil Organisms Three Criteria

12. Organisms#/g soilBiomass (g/m 2 ) Microflora Bacteria10 8 -10 9 40-500 Actinomycetes10 7 -10 8 40-500 Fungi10 5 -10 6 100-1,500 Algae10 4 -10 5 1-50 Fauna Protozoa10 4 -10 5 2-20 Nematodes10 -10 2 1-15 Mites1 -10 1-2 Earthworms1 -10 10-150 Soil Organisms in Surface Soils Note those in White

13. Basic Classification of Organisms Food Oxygen Energy Source

14. Based on food: live or dead Detritivores Eat dead tissues: Fungi, bacteria Herbivores – –Eat live plants Insects, mammals, reptiles Predators –Eat other animals Insects, mammals, reptiles Insects, mammals, reptiles

15. Aerobic –Active in O 2 rich environment –Use free oxygen for metabolism Anaerobic –Active in O 2 poor environment –Use combined oxygen (NO 3 -, SO 4 -2 ) Based on O 2 demand

16. Autotrophic (CO 2 ) Autotrophic (CO 2 ) –Solar energy (photoautotrophs) –Chemical reaction w/inorganic elements N, S, & Fe (chemoautotrophs) N, S, & Fe (chemoautotrophs) Based on energy & C source Heterotrophic  Energy from breakdown of organic matter Most Numerous

17. Organisms are Major Determinants of Water Quality and the Impact or Availability of Water Pollutants Metals (Hg, Pb, As) Nutrients (N, P) Organic Chemicals (PCBs, Dioxins)

18. Autotrophic: produce complex organic compounds from simple inorganic molecules and an external source of energy. The Earliest Organisms Chemoautotrophs, Cyanobacteria, Plants Organic = Carbon-containing 3.5 bya

19. Autotrophs – Plants, Algae, Cyanobacteria Produce complex organic compounds from carbon dioxide using energy from light. 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 light simple inorganic molecule complex organic compound energy Primary producers – base of the food chain

20. Heterotrophs Derive energy from consumption of complex organic compounds produced by autotrophs Autotrophs store energy from the sun in carbon compounds (C 6 H 12 O 6 ) Heterotrophs consume these complex carbon compounds for energy carbon compounds (C 6 H 12 O 6 ) autotrophs Heterotrophs

21. Organisms Anaerobic live in low-oxygen environments Aerobiclive in high oxygen environments Heterotrophs Heterotrophs: use carbon compounds for energy - consumers Aerobic heterotrophsAnaerobic heterotrophs

22. Aerobic Heterotrophs and Anaerobic Heterotrophs

23. Aerobic Heterotrophs Obtain the energy stored in complex organic compounds by combining them with oxygen C 6 H 12 O 6 + Oxygen = energy Live in high-oxygen environments Consume organic compounds for energy

24. C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O Aerobic Respiration + energy

25. C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O Electron poor Electron richElectron poor Electron rich The energy is obtained by exchanging electrons during chemical reactions. 2880 kJ of energy is produced Aerobic respiration is very efficient, yielding high amounts of energy

26. Anaerobic Heterotrophic Organisms Can use energy stored in complex carbon compounds in the absence of free oxygen The energy is obtained by exchanging electrons with elements other than oxygen. Nitrogen (NO 3 ) Sulfur (SO 4 ) Iron (Fe 3+ ) Live in low-oxygen environments Consume organic compounds for energy

27. C 6 H 12 O 6 + 3NO 3 - + 3H 2 O = 6HCO 3 - + 3NH 4 + Anaerobic respiration C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O Electron poor Electron richElectron poor Electron rich Aerobic Respiration Electron rich Electron poor Electron rich

28. C 6 H 12 O 6 + 3NO 3 - + 3H 2 O = 6HCO 3 - + 3NH 4 + 1796 kJ C 6 H 12 O 6 + 3SO 4 2- + 3H + = 6HCO 3 - + 3HS - 453 kJ C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O 2880 kJ Anaerobic respiration is less efficient and produces less energy.

29. The oxygen status of soil/water determines the type of organisms aerobic or anaerobic High-oxygen Low-oxygen Oxygen status impacts availability of nutrients as well As the availability and toxicity of some pollutants

30. Example: Eutrophication Photosynthetic life O2O2 bacteria Nutrient Additions Nutrient addition increases primary productivity (algae) Sunlight is limited at greater depth Photoautotrophs die and become food for aerobic heterotrophs Aerobic autotrophs consume oxygen Oxygen content in water is reduced If oxygen is reduced sufficiently, aerobic microbes cannot survive, and anaerobic microbes take over

31. SO 4 -2 HS - O2O2 NO 3 - SO 4 -2 Respiration and Still Ponds C 6 H 12 O 6 + 3SO 4 2- + 3H + = 6HCO 3 - + 3HS - Heterotrophic Organisms oxygen Aerobic heterotrophs consume oxygen Anaerobic heterotrophs Use nitrate instead of O 2 Anaerobic heterotrophs Use sulfate instead of O 2

32. Organisms and Nutrients

33. Nitrogen

34. The most limiting essential element in the environment Nitrogen and Soil Surface soil range: 0.02 to 0.5% 0.15% is representative 1 hectare = 3.3 Mg

35. Biological/Plant Nitrogen Amino acids Proteins Enzymes Nucleic acids (DNA) Chlorophyll Component of living systems Strongly limiting in the Environment

36. Deficiency Chlorosis – pale, yellow-green appearance primarily in older tissues.

37. Excess Enhanced vegetative growth – lodging Over production of foliage high in N Delayed maturity Degraded fruit quality

38. N Distribution/Cycling Atmosphere Soil / soil O.M. Plants, animals N 2, NO, N 2 O NH 4 +, NO 3 -, R – NH 2 Proteins, amino acids Organic Nitrogen (plant tissue, Soil Organic Matter): R – NH 2 During organic decomposition, R – NH 2 is usually broken down to NH 4 + NH 4 + is converted to NO 3 - by soil microorganisms

39. Mineralization: Decomposition of organic forms releasing nitrogen into the soil, generally as NH 4 + Immobilization: Plant uptake of mineral nitrogen, removing it from the soil and incorporating into plant tissue. Forms: mineral and organic Organic: plant/tissue NR-NH 2 Mineral: soil N NH 4 +, NO 3 - Cycling in the Environment

40. Ammonium and Nitrate NH 4 + R – NH 2 organic mineral Mineralization Immobilization NH 4 + or NO 3 - R – NH 2

41. Cycling of Nitrogen N2N2 X R-NH 2 R-NH 2 is organically bound form of nitrogen NH 4 + Decomposition Of O.M. Uptake by plant Uptake by plant NO 2 - NO 3 - nitrosomonas nitrobacter NH 4 + is exchangeable, NO 3 - is not

42. Atmospheric Nitrogen Fixation

43. Forms of Nitrogen N2N2 X R-NH 2 R-NH 2 is organically bound form of nitrogen NH 4 + Decomposition Of O.M. Uptake by plant Uptake by plant NO 2 - NO 3 - nitrosomonas nitrobacter NH 4 + is exchangeable, NO 3 - is not

44. Rhizobium Symbiotic Biological Nitrogen Fixation Symbiosis between plant roots and rhizobium bacteria Nodules are packed with Rhizobium N2N2 NH 4 +

45. Residue from legume crops is usually high in N when compared with residue from other crops and can be a major source of N for crops that follow legumes in rotation. Most of the N contained in crop residue is not available to plants until microbes decompose the plant material. alfalfa range from 100 to 150 lbN/acre Soybeans range from 20-40 lb/acre N Contributions Nitrogen and Legumes

46. Nitrogen Fixation is Difficult and Specialized N 2 + 6H 2 2NH 3 Fixing N 2 is energetically “expensive” NNTriple bond –Must use energy to break these bonds

47. Artificial Nitrogen Fixation Haber - Bosch Process - Artificial Fixation of Nitrogen Gas: –200 atm –400-500 o C –no oxygen yield of 10-20% Produces 500 million tons of artificial N fertilizer per year. 1% of the world's energy supply is used for it Sustains roughly 40% of the world’s population

48. Nitrogen and Food Irrigated land expected to expand by 23% in 25 years 70% of water used Food production has grown with population Crop Varieties Fertilizers

49. Nitrogen Fertilization NO 3 - Negative Exchange sites Loss of Productivity Leaching to groundwater, surface water NO 3 - NH 4 +

50. Some Areas of Florida are Susceptible

51. Approximately 250 million years ago

52. Approximately 150 - 200 million years ago Flooded, stable platform Subject to marine sedimentation FL platform/plateau For the next several million years the platform was dominated by carbonate sedimentation Late Jurassic Sedimentation: settling of particles from a fluid due to gravity

53. Carbonate Deposition/Sedimentation Marine Calcium and Magnesium Carbonate CaCO 3 MgCO 3

54. Florida platform was a flooded, submarine plateau dominated by carbonate deposition FL platform CaCO 3 Between about 150 Mya and 25 Mya

55. *

56. The Eocene and Oligocene limestone forms the principal fresh water-bearing unit of the Floridan Aquifer, one of the most productive aquifer systems in the world Eocene: 55 – 34 million years ago Oligocene: 34 – 24 million years ago The Eocene and Oligocene Limestone

57. carbonates Prior to 24 Mya Marine Carbonates Between 150 and 25 Mya, Florida was dominated by carbonate deposition

58. Continental Influences highlands Sediments

59. Isolation of the Florida Peninsula Suwannee Current Georgia Channel Sediments

60. Lowering of Sea Levels, Interruption of Suwannee Current Suwannee Current Events of the Late Oligocene Epoch, approximately 25 Mya Raising of the Florida Platform

61. Exposure of Limestone The Oligocene marked the beginning of a world wide cooling trend and lower sea Levels. Erosion cavities Due to acidity

62. Rejuvenation of Appalachians, weathering, increased sediment load sediments Miocene Epoch: began approximately 24 Mya Sediments were sands, silts, clays

63. Sediments Filling in the Georgia Channel Early Miocene (~ 24 Mya)

64. Sediments Rising sea levels allow sediments to become suspended in water and drift over the platform

65. Siliciclastics Covered the Peninsula Sands And Clays

66. 1.Deposition of Eocene/Oligocene Limestone (55 – 24 Mya) 2.Raising of the Florida platform 3.Lowering of sea levels, interruption of the Suwannee Current 4.Infilling of the Georgia Channel with sediments derived from Appalachian/continental erosion 5.Sea level rise, lack of Suwannee current. 6.Suspended siliciclastic sediments settle over the peninsula 7.These sediments blanket the underlying limestone forming the upper confining layer for the Floridan Aquifer. Summary

67. 55 – 24 million years ago Clays and Sands (low permeability) Surface Siliciclastics (sandy) (highly permeable) The Floridan aquifer is a confined aquifer. The water-bearing unit is permeable limestone. Low Permeability Confining Unit (poor water movement) Unconfined aquifer is extensive throughout the state of Florida Low permeability rock (confining) Permeability: the ease with which water moves through material

68. Calcium Carbonate CaCO 3 The Water-bearing Unit is Extremely Productive Magnesium Carbonate MgCO 3 How does this material hold and deliver water? limestone

69. Carbonate Dissolution Acid (H + ) dissolves calcium carbonate Carbonates are made porous by acid dissolution

70. Carbon dioxide dissolved in water produces carbonic acid CO 2 + H 2 O = H 2 CO 3 (carbonic acid) H 2 CO 3 => H + + HCO 3 - Acid Rainfall is naturally acidic

71. CaCO 3 + H + = HCO 3 - + Ca 2+ Acidity from rainfall reacts with CaCO 3 and dissolves the carbonate rock. (solid)(solution) (acid) (solution) CO 2 + H 2 O = H 2 CO 3 H 2 CO 3 => H + + HCO 3 - Dissolution Cave Dissolution Cavities

72. Caves and Solution Cavities Acid dissolves calcium carbonate CaCO 3 + H + = HCO 3 - + Ca 2+ Carbonates Clayey Deposits Channels and Caves

73. Karst Topography Characterized by sinkholes, springs, depressions, lakes

74. Sinkhole Lakes Florida is Dominated by Karst Topography

75. Sinkhole formation depends on the material overlying the carbonate water-bearing unit Thin, sandy covering Thick sands up to 200 ft thick and some clays Cohesive clays up to 200ft Very thick clays > 200ft. Miocene clays have been eroded and shaped throughout their history resulting in extreme variability in thickness across the state.

76. The Importance of Sinkholes and Sinkhole Lakes Hydrologic connections between the surface and the underlying limestone are maintained.

77. Florida: Nitrates (NO 3 - ) Nitrates do not interact significantly with soil material and can move rapidly to groundwater. Areas where the aquifer confining unit is thin are also particularly vulnerable. What areas are particularly vulnerable? Areas where natural groundwater recharge occurs The unconfined, surficial aquifer

78. residential and commercial septic systems in rural areas about 300 row crop and vegetable farms 44 dairies with more than 25,000 animals 150 poultry operations with more than 38 million birds Lower Suwannee River Watershed Nitrates NO 3 Drinking water standard: 10 ppm

79. Possible sources of nitrate in the ground water in the vicinity of the river include fertilizer, animal wastes from dairy and poultry operations, and septic-tank effluent. Nitrate concentrations were higher in the measured springs than in the river. Flow Groundwater Nitrate Discharge to Rivers

80. Next: Phosphorus