Water CyclePrecipitation -> Runoff -> Evaporation-> Transpiration-> CondensationSun powers evaporation, precipitation, and transpirationReservoirs–Surface water (oceans, rivers, lakes), Glaciers, Groundwater (Aquifers), Water Vapor Atmospheric Gas, Living OrganismsImportance Water is essential to living organisms for a variety of reactions and cell processesWater’s high heat storage distribute heat and determine regional and local climatesWater is a greenhouse gas –essential for maintaining Earth’s temperature –BUT too much greenhouse gas can be a bad thingSculpts landscapes It is the universal solvent, often interacts with the movement of other cycles because it transports themThe water cycle is nature’s natural water purifier (evaporation and underground bacteria)Water is a necessity in industry, waste managementHow humans alterOveruse –use faster than it can replenishIncrease pollutants in runoffReduce infiltration –hard paved surfaces prevent recharging of groundwaterAccelerate topsoil erosionIncrease risk of flooding –when we drain and fill wetlands for farming or urban developmentAlter weather –deforestation reduces transpiration of rainforests, the primary source of rainfall in rainforests. Reduced shade also evaporates water before it can permeate the soil.Carbon CycleFound in the atmosphere as a gas (CO2), dissolvable in water, Producers pull carbon from the atmosphere or water for the process of photosynthesisConsumers take in carbon by ingesting producers or other consumersProducers and consumers release carbon as a product of respirationCarbon can be incorporated into marine and terrestrial sedimentsand can be compressed into fossil fuelsReservoirs–theocean is the largest reservoir, calcium carbonate found inshells,marine sediments (decomposers release insoluble carbonates from dead marine organisms)forming limestone as well, fossil fuels (oil, natural gas, coal), tropical rain forests, tundra (permanently frozen plant matter), atmosphere, living organismsImportanceCarbon is the basic building block ofthe four major macromolecules(carbohydrates, lipids, proteins, & nucleic acids) as well as other important organic moleculesCarbon dioxide is a greenhouse gas –essential for maintaining Earth’s temperature –BUT too much greenhouse gas can be a bad thingHow humans alterThe extraction and burning of huge quantities of fossil fuels that have taken millions of years to form have released large amounts of carbon dioxide to the atmosphereThe clear-cutting of carbon-absorbing vegetation (especially tropical rain forests) have released large amounts of carbon to the atmosphereThe increased concentration of carbon dioxide and other greenhouse gases (methane, water) are warming our planet and projected to change Earth’s climate this century
Nitrogen CycleN2cannot readily be absorbed and used by plants and animals, so we rely on electrical discharges (lightening) and nitrogen fixing bacteria to make it usable for plantsAnimals consume plants or other consumers to obtain their nitrogenReservoirs–the atmosphere (78%)Remember “FNAAD, ANPAN”Fixation--------------Ammonia(Bacteria and cyanobacteria combine gaseous N2with hydrogen tomake ammonia NH3and/or ammonia ionsNH4+which they use as anutrient for themselves. They excrete the rest of the ammonia intothe soil or water)Nitrification----------Nitrates, Nitrites(Ammonia not taken up by plants is converted by soil bacteria into nitrate ions NO3-which are easily taken up by the roots of plants)Assimilation----------Proteins(Plants use the ammonia or nitrate ions to produce proteins, nucleicacids, and vitamins. Consumers will ingestplants or otherconsumers and do the same)----Organism Death/Decomposition-----------------------------------------------------------------------------------------------------------------------------------------Ammonification------Ammonia(Decomposer bacteria convert detritus material into ammonia NH3and ammonia ions NH4+)Denitrification--------Nitrogen Gas(Specialized bacteria in waterlogged soil and the bottoms of lakes, oceans, swamps, and bogs covert ammonia NH3and ammonia ions NH4+back into nitrate ions and then into nitrogen gas and nitrous oxide gas. These are released back to the atmosphere to begin the cycle again.)Importance Nitrogen is a key component in macromolecules such as proteins, vitamins, and nucleic acids (DNA and RNA)Nitrogen is a limiting factor for primary productivity Human ImpactsWe add nitric oxide NO to the atmosphere as we burn fuel at high temperatures (cars, jets). This gas is convertedinto nitrogen dioxide gas NO2and nitric acid vapor HNO3which falls to the earth as acid deposition aka acid rain.Anaerobic bacteria break down inorganic fertilizer or organic manure and contribute nitrous oxide N2O to the atmosphere. Nitrous oxide is a greenhouse gas.Deforestation releases large quantities of nitrogen stored in soils and plants, back to a gasAgricultural runoff of fertilizers, animal manure, and sewage discharge add excess nitrates NO3-to bodies of water. This can lead to eutrophication (algal blooms, which bring in more bacteria as algal decomposes, decreasing the oxygen in aquatic environment, often resulting in fish kills)Harvesting of crops, irrigation, and burning or clearing of grasslands and forests can cause nitrogen to wash away from the topsoil.We have more than doubled the annual release of nitrogen from the land due to the inorganic fertilizers Phosphorus CycleVery slow to cycle in comparison to water, carbon, and nitrogenWater erodes away inorganic compounds, that include phosphates, from rocksWater carries dissolved phosphates into the soil where they can be absorbed by producersConsumers take in phosphates by ingesting producersPhosphates can be lost from the cycle for long periods when it is washed to the oceanand held in the marine sediment for millions of yearsReservoirs–Phosphate salts containing phosphate ions, terrestrial rock formations, and ocean bottom sediments. Does not include the atmosphereImportancePhosphate ions PO43-are an important nutrientPhosphate is incorporated into nucleic acids, ADP, and ATP, bones, and teethHuman ImpactsHumans mine phosphate salts which are added to fertilizers and applied to agricultural fields. Excess phosphates from runoff can also cause eutrophicaton (algal blooms, which bring in more bacteria as algal decomposes, decreasing the oxygen in aquatic environment, often resulting in fish kills)Clearing of rain forests causes phosphates to wash awaySulfurCycleVolcanoes release sulfurdioxide (a colorless, poisonous gas with a rotten egg smell). Decomposers in flooded swamps, bogs, and tidal flats also release sulfurdioxide.Sulfate salt particles enter the atmosphere from sea spray, dust storms, and forest fires. Plants absorb sulfate ions, and incorporate them into proteins.Marine algae produce large amounts of volatile dimethylsulfide (DMS –CH3SCH3). DMS is the nuclei/particle around which water droplets condensate (aka cloud seeds) In areas like wetlands and tidal flats, bacteria convert sulfate ions to sulfide ions. These react with metal ions which form metal ores.Reservoirs–underground rocks and minerals in the form of sulfate salts S042-ImportanceEssential nutrient –Used in amino acids, proteins, enzymes, keratinHuman ImpactsChangesin DMS emissions can affect cloud cover and climate(DMSis a byproduct of paper manufacturing)DMS can be converted to sulfurdioxide, then to sulfur trioxide gas, and to sulfuric acid. It can also react with ammonia to produce sulfate salts. These can fall to the earth in the form of acid deposition/acid rain.We refine sulfur containing oil to make gasoline and burn sulfur containing coal and oil, once in the atmosphere it contributes to acid rain.We extract metals such as copper, lead, and zinc from sulfur containing compounds in rocks.