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Cycling of Matter Matter Cycling in Ecosystems • Nutrient or Biogeochemical Cycles – Natural processes that recycle nutrients in various chemical forms in a cyclic manner from the what to what?? and back again Matter Cycling in Ecosystems • Nutrient or Biogeochemical Cycles – Natural processes that recycle nutrients in various chemical forms in a cyclic manner from the nonliving environment to living organisms and back again Nutrient Cycles (Open or Closed? System) Energy Flow (Open or Closed? System) • Water • Carbon • Nitrogen • Phosphorus • Sulfur • Rock • Soil • Energy Flow Nutrient Cycles (Closed System) Energy Flow (Open System) • Water • Carbon • Nitrogen • Phosphorus • Sulfur • Rock • Soil • Energy Flow Biogeochemical Cycle Locations • ?????sphere – Water in the form of ice, liquid, and vapor – Operates local, regional, and global levels • Atmospheric – Large portion of a given element (i.e. which??? gas) exists in gaseous form in the atmosphere – Operates local, regional, and global levels • Sedimentary – The element does not have a gaseous phase or its gaseous compounds don’t make up a significant portion of its supply – Operates local and regional basis Biogeochemical Cycle Locations • Hydrosphere – Water in the form of ice, liquid, and vapor – Operates local, regional, and global levels • Atmospheric – Large portion of a given element (i.e. Nitrogen gas) exists in gaseous form in the atmosphere – Operates local, regional, and global levels • Sedimentary – The element does not have a gaseous phase or its gaseous compounds don’t make up a significant portion of its supply – Operates local and regional basis Nutrient Cycling & Ecosystem Sustainability • Natural ecosystems tend to balance – Nutrients are recycled with reasonable efficiency • Humans are ???????? rates of flow of mater – Nutrient loss from soils – Doubling of normal flow of nitrogen in the nitrogen cycle is a contributes to global warming, ozone depletion, air pollution, and loss of biodiversity • Isolated ecosystems are being influenced by human activities Nutrient Cycling & Ecosystem Sustainability • Natural ecosystems tend to balance – Nutrients are recycled with reasonable efficiency • Humans are accelerating rates of flow of mater – Nutrient loss from soils – Doubling of normal flow of nitrogen in the nitrogen cycle is a contributes to global warming, ozone depletion, air pollution, and loss of biodiversity • Isolated ecosystems are being influenced by human activities Carbon Cycle Carbon Cycle Role of Carbon? building block of organic molecules (name these 4 polymers????) – essential to life; currency of energy exchange – chemical energy for life stored as bonds in organic compounds; Which???? greenhouse gas – traps heat near Earth's surface & plays a key role as "nature's thermostat". Carbon Cycle Role of Carbon? building block of organic molecules (carbohydrates, fats, proteins, & nucleic acid) – essential to life; currency of energy exchange – chemical energy for life stored as bonds in organic compounds; carbon dioxide (CO2) greenhouse gas – traps heat near Earth's surface & plays a key role as "nature's thermostat". Carbon Cycle main processes: movement in atmosphere: atmospheric C as which gas?? (0.036% of troposphere); primary production: what process?? (= carbon fixation) moves C from atmosphere to organic molecules in organisms; movement through food web: C movement in organic form from organism to organism; aerobic ?????: organic molecules broken down to release CO2 back to atmosphere; Name this process: organic molecules broken by burning down to release CO2 back to atmosphere; dissolving in oceans: C enters as to form what 2 compounds??? movement to sediments: C enters sediments, primarily as calcium carbonate (CaCO3); Carbon Cycle main processes: movement in atmosphere: atmospheric C as CO2 (0.036% of troposphere); primary production: photosynthesis (= carbon fixation) moves C from atmosphere to organic molecules in organisms; movement through food web: C movement in organic form from organism to organism; aerobic respiration: organic molecules broken down to release CO2 back to atmosphere; combustion: organic molecules broken by burning down to release CO2 back to atmosphere; dissolving in oceans: C enters as to form carbonate (CO32–) & bicarbonate (HCO3–); movement to sediments: C enters sediments, primarily as calcium carbonate (CaCO3); Carbon Cycle • Respiration—organisms breathe and give off CO2 • Photosynthesis—plants take in CO2, water and energy from the Sun to produce carbohydrates • Living things act as exchange pools for carbon Carbon Cycle • Carbon locked in the plant carbohydrates passes to other organisms through food chain • When organisms die, bodies decompose through activities of fungi and bacteria in soil, which releases CO2. Carbon Cycle • Dead organisms buried and subjected to extreme heat and pressure becomes oil, coal and gas (fossil fuels) • Combustion of fossil fuels releases carbon into atmosphere • Volcanic action also releases carbon Carbon Cycle • Carbon Reservoirs: – Is where??? because CO2 is soluble in water – And here??? that contain carbon in the form of calcium carbonate (marble and limestone) Carbon Cycle • Carbon Reservoirs: – Oceans because CO2 is soluble in water – Earth’s rocks that contain carbon in the form of calcium carbonate (marble and limestone) Carbon Cycle • Human impacts: – Removal of what???: decreases primary production (decreases carbon fixation) – Add carbon and CO2 by burning fossil fuels, wood and other biomass material (slash and burn in tropics) – Increased CO2 can alter global ???? Carbon Cycle • Human impacts: – Removal of vegetation: decreases primary production (decreases carbon fixation) – Add carbon and CO2 by burning fossil fuels, wood and other biomass material (slash and burn in tropics) – Increased CO2 can alter global climate Water Cycle Water Cycle main processes: (1)??: conversion from liquid to vapor form (surface to atmosphere). (2)??: evaporation from leaves of water extracted from soil by roots & transported through the plant (surface to atmosphere). movement in atmosphere: transport as vapor. (3)??: conversion of vapor to liquid droplets. precipitation: movement as rain, sleet, hail, & snow (atmosphere to surface). (4)???: movement into soil. (5)?? downward flow through soil to aquifers. flow in aquifers: belowground flow of water. runoff: surface flow downslope to ocean or other body of water. Water Cycle main processes: evaporation: conversion from liquid to vapor form (surface to atmosphere). transpiration: evaporation from leaves of water extracted from soil by roots & transported through the plant (surface to atmosphere). movement in atmosphere: transport as vapor. condensation: conversion of vapor to liquid droplets. precipitation: movement as rain, sleet, hail, & snow (atmosphere to surface). infiltration: movement into soil. percolation: downward flow through soil to aquifers. flow in aquifers: belowground flow of water. runoff: surface flow downslope to ocean or other body of water. Water Cycle • Human Impact: – Withdrawing large amounts of fresh water that is often accompanied by what ???intrusion and this ???? depletion. – Clearing of land for agriculture or habitation • runoff, flood risks, soil erosion, landslides • infiltration – Augmenting pollutions by • Nutrients through runoff • Disturbing natural processes • Introducing infectious agents Water Cycle • Human Impact: – Withdrawing large amounts of fresh water that is often accompanied by saltwater intrusion and groundwater depletion. – Clearing of land for agriculture or habitation • runoff, flood risks, soil erosion, landslides • infiltration – Augmenting pollutions by • Nutrients through runoff • Disturbing natural processes • Introducing infectious agents Nitrogen Cycle Nitrogen Cycle Role of Nitrogen? building block of various essential organic molecules – especially what 2???; L???????? nutrient in many ecosystems – typically, addition of N leads to increased productivity. Nitrogen Cycle Role of Nitrogen? building block of various essential organic molecules – especially proteins & nucleic acids; limiting nutrient in many ecosystems – typically, addition of N leads to increased productivity. Nitrogen Cycle • Needed to make amino acids, proteins, DNA and RNA • 78% of atmosphere is nitrogen • Nitrogen stores include organic matter in soil and oceans • Atmospheric nitrogen is not in form that can be ????????????????? Nitrogen Cycle • Needed to make amino acids, proteins, DNA and RNA • 78% of atmosphere is nitrogen • Nitrogen stores include organic matter in soil and oceans • Atmospheric nitrogen is not in form that can be used directly by most organisms Nitrogen Cycle • Plants absorb N through nitrate ions and ammonium ions • Animals absorb N by consuming organic matter • Decomposers convert ammonia to ammonium compounds through mineralization Nitrogen Cycle Processes (1)???—converts N2 to NH3 – By specialized bacteria (cyanobacteria and actinomycetes in soil and R?????? bacteria in root systems of legumes) – N2 + 3H2 2NH3 (2)???—ammonia converted by aerobic bacteria to nitrite ions then to nitrate ions NH3 by aerobic bacteria NO2- by bacteria NO3- Nitrogen Cycle Processes 1. Nitrogen fixation—converts N2 to NH3 – By specialized bacteria (cyanobacteria and actinomycetes in soil and Rhizobium bacteria in root systems of legumes) – N2 + 3H2 2NH3 2. Nitrification—ammonia converted by aerobic bacteria to nitrite ions then to nitrate ions NH3 by aerobic bacteria NO2- by bacteria NO3- Nitrogen Cycle Processes 3???—plants absorb ammonia, ammonium ions and nitrate ions through their roots which are then eaten by heterotrophs Plant roots + NH3 + NH4+ + NO3- → DNA + amino acids + proteins 4???—decomposing bacteria convert dead organisms and other waste to ammonia or ammonium ions that can be reused by plants Organic material → NH3 + NH4+ Nitrogen Cycle Processes 3. Assimilation—plants absorb ammonia, ammonium ions and nitrate ions through their roots which are then eaten by heterotrophs Plant roots + NH3 + NH4+ + NO3- → DNA + amino acids + proteins 4. Ammonification—decomposing bacteria convert dead organisms and other waste to ammonia or ammonium ions that can be reused by plants Organic material → NH3 + NH4+ Nitrogen Cycle Processes 5???—specialized bacteria convert NH3 and NH4+ into NO2- and NO3- and then into N2 and released into the atmosphere NH4+ + NH3 → NO2- + NO3- → N2 + N2O Nitrogen Cycle Processes • 5. Denitrification—specialized bacteria convert NH3 and NH4+ into NO2- and NO3- and then into N2 and released into the atmosphere NH4+ + NH3 → NO2- + NO3- → N2 + N2O Nitrogen Cycle • Human Impact – Burning fuels lead to ??????? rain – Depleting N from ???? by over-planting – Leaching from soil by irrigation and into groundwater – Agricultural runoff leads to e???? (aerobic decomposers break down aquatic bloom, depleting water of dissolved oxygen) – Discharge of municipal what????? – Which??? process: industrial way to make N-rich fertilizer Nitrogen Cycle • Human Impact – Burning fuels lead to nitric acid/acid rain – Depleting N from soil by over-planting – Leaching from soil by irrigation and into groundwater – Agricultural runoff leads to eutrophication (aerobic decomposers break down aquatic bloom, depleting water of dissolved oxygen) – Discharge of municipal sewage – Haber process: industrial way to make Nrich fertilizer Phosphorous Cycle Phosphorus Cycle Role of Phosphorus? essential nutrient for plants & animals – especially building block for ???? And ?????), various fats in cell membranes (??????????), & hard calcium–phosphate compounds (found where?????); limiting nutrient in many ecosystems – typically, addition of P leads to increased productivity, especially for fresh water aquatic systems. Phosphorus Cycle Role of Phosphorus? essential nutrient for plants & animals – especially building block for DNA, other nucleic acids (including ATP; ATP stores chemical energy), various fats in cell membranes (phospholipids), & hard calcium– phosphate compounds (in bones, teeth, & shells); limiting nutrient in many ecosystems – typically, addition of P leads to increased productivity, especially for fresh water aquatic systems. Phosphorous Cycle • P is found in here?????, not in the atmosphere • Found in form of phosphate ion or hydrogen phosphate ion • Production not dependent on bacterial action • P released from terrestrial rock by ???????? • Slow process • Becomes dissolved in soil water and is then taken up by what?????????? Phosphorous Cycle • P is found in sedimentary rock, not in the atmosphere • Found in form of phosphate ion or hydrogen phosphate ion • Production not dependent on bacterial action • P released from terrestrial rock by weathering and action of acid rain • Slow process • Becomes dissolved in soil water and is then taken up by plant roots Phosphorus Cycle NAME THESE main processes: (1)????: P slowly released from rock or soil minerals as phosphate (P043-), which dissolves in H20 & is readily leached; uptake: by plants to form organic phosphates; movement through food web: nucleic acids (including DNA & ATP), certain fats in cell membranes (phospholipids), bones/teeth/shells (calcium–phosphate); break down of organic forms: to phosphate (P043-) by decomposers; (2)???: P043- from soil; burial in ocean sediments: not cycled in short time scale, only over geologic time; Phosphorus Cycle main processes: weathering: P slowly released from rock or soil minerals as phosphate (P043-), which dissolves in H20 & is readily leached; uptake: by plants to form organic phosphates; movement through food web: nucleic acids (including DNA & ATP), certain fats in cell membranes (phospholipids), bones/teeth/shells (calcium–phosphate); break down of organic forms: to phosphate (P043-) by decomposers; leaching: P043- from soil; burial in ocean sediments: not cycled in short time scale, only over geologic time; Phosphorous Cycle How do Humans Impact this cycle?? – M????????, scarring land – Clear c???? tropical areas for agriculture – R????? of animal waste and fertilizers and discharge of municipal sewage plants – Stream runoff causes it to accumulate in lakes increasing growth of bacteria and plants, blocking sun, decrease oxygen, killing life Phosphorous Cycle • Human Impact – Mining, scarring land – Clear cutting tropical areas for agriculture – Runoff of animal waste and fertilizers and discharge of municipal sewage plants – Stream runoff causes it to accumulate in lakes increasing growth of bacteria and plants, blocking sun, decrease oxygen, killing life Sulfur Cycle Sulfur Cycle • Most found in underground rocks and deep oceanic deposits • Released through weathering, gases released from what 2 locations???? • Most enters atmosphere through burning fossil fuels such as what???? Sulfur Cycle • Most found in underground rocks and deep oceanic deposits • Released through weathering, gases released from sea floor vents and volcanic eruptions and venting • Most enters atmosphere through burning fossil fuels such as coal and oil Sulfur Cycle • Makes up proteins and vitamins • Dissolves in water that plants absorb through roots in form of sulfates • Animals obtain sulfur from eating plants • Most found in rocks and salts or oceanic sediments • Some in atmosphere from natural and human activities Sulfur Cycle main processes: storage in rocks: much of Earth's S is in rock form (e.g., iron disulfides or pyrites) or m?????????? (sulfates); A????? input from volcanoes, anaerobic decay, & sea spray: S enters atmosphere in form of hydrogen sulfide (HS) & sulfur dioxide (SO2), & sulfates (SO42–); c????????: sulfur compounds released to the atmosphere by oil refining, burning of fossil fuels, smelting, & various industrial activities; movement through f??????: movement through this?? & eventual release during decay; Sulfur Cycle main processes: storage in rocks: much of Earth's S is in rock form (e.g., iron disulfides or pyrites) or minerals (sulfates); atmospheric input from volcanoes, anaerobic decay, & sea spray: S enters atmosphere in form of hydrogen sulfide (HS) & sulfur dioxide (SO2), & sulfates (SO42–); combustion: sulfur compounds released to the atmosphere by oil refining, burning of fossil fuels, smelting, & various industrial activities; movement through food web: movement through food web & eventual release during decay; Sulfur Cycle • Natural – Volcanic eruptions – Certain bacterial functions – decay • Human – Industrial processes producing SO2 and H2S gases (mostly burning coal and oil) Sulfur Cycle 2SO2 + O2 2SO3 SO3 + H2O H2SO4 (acid rain) NH3 + SO2 acid deposition SO2 and sulfate aerosols create health problems, damages crops and buildings, reduce visibility and absorb UV • a??????? and produce cooling effect • • • • Sulfur Cycle 2SO2 + O2 2SO3 SO3 + H2O H2SO4 (acid rain) NH3 + SO2 acid deposition SO2 and sulfate aerosols create health problems, damages crops and buildings, reduce visibility and absorb UV • albedo and produce cooling effect • • • • Sulfur Cycle How do Humans Impact? – Burning of coal and oil and petroleum refining release 2x SO2 into troposphere as nature – Smelting of metal o??? containing sulfur – Using sulfuric acid in industrial processes and manufacture – Refining p???? Sulfur Cycle • Human Impact – Burning of coal and oil and petroleum refining release 2x SO2 into troposphere as nature – Smelting of metal ores containing sulfur – Using sulfuric acid in industrial processes and manufacture – Refining petroleum Nutrient Storehouses Major nonliving & living storehouses of elemental nutrients. You are prepared if you can fill in this info Nutrient Storehouses Major nonliving & living storehouses of elemental nutrients. H???? Brook Experimental Forest • Study on how deforestation affects nutrient cycles • Forest consisted of several watersheds drained by single creek • Impervious bedrock close to surface, prevented seepage of water Hubbard Brook Experimental Forest • Study on how deforestation affects nutrient cycles • Forest consisted of several watersheds drained by single creek • Impervious bedrock close to surface, prevented seepage of water Hubbard Brook Experimental Forest Conclusions • Undisturbed forest ecosystem in dynamic equilibrium—nutrients leaving balanced by ones entering • Inflow and outflow was low compared to levels of nutrients being recycled • D????—water runoff and soil erosion increase or decrease??? causing large increase or decrease?? in outflow of nutrients causing water pollution • Nutrient loss reduced by clearing trees and vegetation in horizontal strips, remaining increase or decrease?? soil erosion Hubbard Brook Experimental Forest Conclusions • Undisturbed forest ecosystem in dynamic equilibrium—nutrients leaving balanced by ones entering • Inflow and outflow was low compared to levels of nutrients being recycled • Deforestation—water runoff and soil erosion causing large in outflow of nutrients causing water pollution • Nutrient loss reduced by clearing trees and vegetation in horizontal strips, remaining soil erosion Nutrient Cycling & Sustainability Are ecosystems self–contained? immature natural ecosystems tend to have major shifts in energy flow & nutrient cycling; over time ecosystems tend to reach an equilibrium with respect to energy flow & nutrient cycling, such that these ecosystems appear self–contained; however, there is considerable exchange of water & nutrients of ecosystems with adjacent ecosystems; human disturbance (clear cutting, clearing, etc.) can cause major loss of nutrients. Nutrient Cycling & Sustainability How does nutrient cycling relate to ecosystem sustainability? the law of conservation of matter enables us to understand major nutrient cycles, and observe that given time natural ecosystems tend to come into a balance wherein nutrients are recycled with relative efficiency; modification of major nutrient cycles may lead to shift in ecosystems, such that current ecosystems are not sustainable; developing a better understanding of energy flow & nutrient cycling is critical to understanding the depth of environmental problems. All things come from earth, and to earth they all return. –– Menander (342–290 B.C.)