1. APES Biogeochemical Cycles

2. Nutrient Cycling – Biogeochemical Cycles Building blocks of life macronutrients (CHOPNS) Building blocks of life macronutrients (CHOPNS) Carbon  base for organic life forms; carbohydrates, proteins, nucleic acids, lipidsCarbon  base for organic life forms; carbohydrates, proteins, nucleic acids, lipids Hydrogen  hydrogen bonding (only with N, O, and F)Hydrogen  hydrogen bonding (only with N, O, and F) Oxygen  aerobic respirationOxygen  aerobic respiration Phosphorus  limiting factor in aquatic systems; teeth and bones; ATPPhosphorus  limiting factor in aquatic systems; teeth and bones; ATP Nitrogen  DNA, proteins; plant nutrient; limiting factor in marine systemsNitrogen  DNA, proteins; plant nutrient; limiting factor in marine systems Sulfur  DNA, proteinsSulfur  DNA, proteins Types of Cycles Types of Cycles Gaseous  C, O, N, S, H 2 OGaseous  C, O, N, S, H 2 O Sedimentary  PSedimentary  P

3. Carbon Cycle Photosynthesis - main mechanism to fix carbon into a useable form Photosynthesis - main mechanism to fix carbon into a useable form CO 2 + H 2 O C 6 H 12 O 6 + O 2CO 2 + H 2 O C 6 H 12 O 6 + O 2 Energy is consumed, carbohydrates are produced, oxygen is given off as a waste productEnergy is consumed, carbohydrates are produced, oxygen is given off as a waste product Chemosynthesis Chemosynthesis CO 2 + S 2- + H 2 O  (CH 2 O) n + SO 4 2-CO 2 + S 2- + H 2 O  (CH 2 O) n + SO 4 2- Aerobic Respiration Aerobic Respiration C 6 H 12 O 6 + O 2 ---  CO 2 + H 2 OC 6 H 12 O 6 + O 2 ---  CO 2 + H 2 O Energy is produced, oxygen is consumed and CO 2 is put back into the atmosphereEnergy is produced, oxygen is consumed and CO 2 is put back into the atmosphere Average Residence Time Average Residence Time Atmosphere  3 years (mainly as CO 2 gas)Atmosphere  3 years (mainly as CO 2 gas) Soils  25 – 30 years (Carbonate sediments, rocks)Soils  25 – 30 years (Carbonate sediments, rocks) Ocean  1500 years (marine sediments, oceans)Ocean  1500 years (marine sediments, oceans) h

4. Human Impacts on the Carbon Cycle Combustion of Fossil Fuel Combustion of Fossil Fuel H x C y + O 2  CO 2 + H 2 O (Complete combustion)H x C y + O 2  CO 2 + H 2 O (Complete combustion) DeforestionDeforestion Loss of a carbon sink Loss of a carbon sink Slash and burn techniques Slash and burn techniques New Carbon vs. Old Carbon New Carbon vs. Old Carbon Climate Change Climate Change Warmer oceans – may release more CO 2, increases in CO 2 can increase the acidity of the oceansWarmer oceans – may release more CO 2, increases in CO 2 can increase the acidity of the oceans Warming permafrost can release more CH 4Warming permafrost can release more CH 4

5. Carbon dioxide Concentrations

6. Carbon Cycle with Global Flux

7. Nitrogen Cycle Major store – atmosphere (molecular nitrogen – N 2 ) Major store – atmosphere (molecular nitrogen – N 2 ) Limiting nutrient in marine ecosystems Limiting nutrient in marine ecosystems Nitrogen fixation – atmospheric nitrogen is converted into NH 3 Nitrogen fixation – atmospheric nitrogen is converted into NH 3 Abiotic - N 2 O, HNO 3Abiotic - N 2 O, HNO 3 BioticBiotic Rhizobium bacteria – found in the root nodules of legumes Rhizobium bacteria – found in the root nodules of legumes Azotobacter Azotobacter Cyanobacteria Cyanobacteria Nitrification (NH 3 to NO 2 - to NO 3 - ) Nitrification (NH 3 to NO 2 - to NO 3 - ) Nitrosomas – ammonia to nitrite ionsNitrosomas – ammonia to nitrite ions Nitrobactor – nitrite to nitrate ionsNitrobactor – nitrite to nitrate ions Assimilation Assimilation Ammonium and nitrate ions by plants through their roots. DNA, proteins, amino acids (ionic)Ammonium and nitrate ions by plants through their roots. DNA, proteins, amino acids (ionic) Animals assimilate nitrogen by eating plants (organic)Animals assimilate nitrogen by eating plants (organic)

8. Nitrogen Cycle Con’t Ammonification Ammonification Nitrogenous wastes and organic matter are broken down by decomposersNitrogenous wastes and organic matter are broken down by decomposers NH 3 is producedNH 3 is produced Denitrification – anaerobic bacteria Denitrification – anaerobic bacteria Ammonia and nitrates are broken down by denitrifying bacteriaAmmonia and nitrates are broken down by denitrifying bacteria N 2 and N 2 O are producedN 2 and N 2 O are produced Human Impacts Human Impacts Combustion of fossil fuel –NO x  photochemical smog, acid rainCombustion of fossil fuel –NO x  photochemical smog, acid rain Fertilizers (Haber cycle) – nitrogen runoff, excess nutrients  eutrophication  algae blooms  dead algae are decomposed  declines in DO  potential death of fish; N 2 O into the atmosphere  N 2 O is both a greenhouse gas and an ozone depleting compoundFertilizers (Haber cycle) – nitrogen runoff, excess nutrients  eutrophication  algae blooms  dead algae are decomposed  declines in DO  potential death of fish; N 2 O into the atmosphere  N 2 O is both a greenhouse gas and an ozone depleting compound Planting excessive nitrogen-fixing cropsPlanting excessive nitrogen-fixing crops Runoff from feedlots - manureRunoff from feedlots - manure

9. N 2 Cycle with Fluxes

10. Increases in Nitrogen due to Anthropogenic Sources

11. Sulfur Cycle Gaseous Cycle Gaseous Cycle Major Store – rocks – Fe 2 S or CaSO 4 Major Store – rocks – Fe 2 S or CaSO 4 Natural Sources Natural Sources Volcanoes – SO 2  H 2 SO 4Volcanoes – SO 2  H 2 SO 4 DMS – dimethyl sulfide from the ocean DMS – dimethyl sulfide from the ocean H 2 S from decayH 2 S from decay Human Impacts Human Impacts Combustion of coal and petroleum release SO x  leads to the formation of H 2 SO 4  contributes to the formation of acid rainCombustion of coal and petroleum release SO x  leads to the formation of H 2 SO 4  contributes to the formation of acid rain Smelting operationSmelting operation Ice core samples  large increase in S since the industrial revolutionIce core samples  large increase in S since the industrial revolution

12. Sulfur Cycle

13. Phosphorous Cycle Sedimentary Cycle Sedimentary Cycle Major Stores Major Stores Phosphate rockPhosphate rock Marine sedimentsMarine sediments Mined as the mineral apatite – Ca 3 (PO 4 ) 2 (largest mine near Tampa, FL) Mined as the mineral apatite – Ca 3 (PO 4 ) 2 (largest mine near Tampa, FL) Guano Guano Limiting nutrient in freshwater ecosystems Limiting nutrient in freshwater ecosystems Fixed by mycorrihizae fungi (keystone species) Fixed by mycorrihizae fungi (keystone species) Human impacts Human impacts Removing phosphorous faster then it can be replenished in through the phosphorous cycle – non renewable resourceRemoving phosphorous faster then it can be replenished in through the phosphorous cycle – non renewable resource Fertilizers  Excess nutrients  eutrophication  algae blooms  dead algae are decomposed  declines in DO  potential death of fishFertilizers  Excess nutrients  eutrophication  algae blooms  dead algae are decomposed  declines in DO  potential death of fish Phosphate containing detergentsPhosphate containing detergents

14. Phosphorous Cycle with Fluxes

15. Hydrologic Cycle Driven by the sun and gravity 71% of the earth’s surface is covered by water ~97 % is salt water (average salinity is 35 ppt or 3.5% ~3% is fresh water ~.024% is available for consumption Evaporation (conversion of water into water vapor) Transpiration (evaporation from leaves (stoma) of water extracted from soil by roots and transported throughout the plant) Condensation (conversion of water vapor into droplets of liquid water Precipitation (rain, sleet, hail, snow)

16. Hydrologic Cycle Con’t Human Impacts Groundwater Depletion Groundwater Depletion Clearing Vegetation Clearing Vegetation Dams and water diversion projects Dams and water diversion projects Infiltration (movement of water into soil) Infiltration (movement of water into soil) Percolation (downward flow of water through soil and permeable rock formations to groundwater storage areas called aquifers Percolation (downward flow of water through soil and permeable rock formations to groundwater storage areas called aquifers Runoff (downslope surface movement back to the sea to resume the cycle) Runoff (downslope surface movement back to the sea to resume the cycle)

17. Hydrologic Cycle

18. Hydrologic Cycle with Human Impacts

19. Any Questions?