Concept to UnderstandMatter, in the form of nutrients, cycleswithin and among ecosystems and in thebiosphere, and human activities arealtering these nutrient cycles.
Nutrient CyclesDriven by solar energy and gravityReservoirs – storage sites where nutrientsaccumulate and remain there for sometimeConnect all organisms through timeNutrient Cycles - Water, Carbon,Nitrogen
Hydrologic (Water) Cycle Water cycle is powered by the sun 1. Evaporation 2. Transpiration - evaporates from plant surfaces 3. Condenses (in atmosphere) 4. Precipitation
Hydrologic Cycle Water vapor in the atmosphere comes from theoceans 84% Over land, ???% of water reaching the atmospherecomes from transpiration 90% Only 0.024% of water is available for human use (toosalty, ice, too deep underground)
Animation: Hydrologic Cycle
Increasedfloodingfrom wetlanddestructionCondensationEvaporationfrom oceanClimatechangeInfiltrationand percolationinto aquiferCondensationOceanLakes andreservoirsIce andsnowSurfacerunoffSurface runoffAquiferdepletion fromoverpumpingPointsourcepollutionReduced recharge ofaquifers and floodingfrom covering landwith crops andbuildingsGroundwatermovement (slow)RunoffPrecipitationto landPrecipitationto oceanTranspirationfrom plantsEvaporationfrom landFig. 3-12, p. 49ProcessesProcesses affected by humansReservoirPathway affected by humansNatural pathway
Carbon Cycle Carbon – basic building block of organic molecules(carbohydrates, fats, protein, DNA) Carbon dioxide (CO2) also controls warming and cooling ofthe Earth.
Carbon Cycle Major cycle processes Photosynthesis – remove from air make sugars Aerobic respiration – release CO2 into air Burning Fossil fuels add CO2 to the atmosphere andcontribute to global warming
Animation: Carbon Cycle
RespirationForest firesDeforestationDiffusionCarbon dioxidedissolved in oceanCarbonin limestone ordolomite sedimentsMarine food websProducers, consumers,decomposersTransportationCarbon dioxidein atmosphereCarbonin animals(consumers)Plants(producers)Animals(consumers)DecompositionRespirationCompactionCarbonin fossilfuelsCarbonin plants(producers)Burningfossil fuelsPhotosynthesisFig. 3-13, p. 51ProcessesReservoirPathway affected by humansNatural pathway
Nitrogen CycleNitrogen- needed for proteins and DNAMulticellular plants and animals cannotutilize atmospheric nitrogen gas (N2)So how do we get Nitrogen?Eating other organisms
Nitrogen CycleNitrogen fixation- lightning, somebacteria, and legumes (beans) (convert Nto ammonia then Nitrate)Nitrate is fertilizer
Nitrogen Cycle Added to soil by farmers – runs off causingproblems for local streams or lakes
Nitrogenin atmosphereNitrogenloss to deepocean sedimentsNitrogen oxidesfrom burning fuelNitratesfrom fertilizerrunoff anddecompositionNitrogenin oceansediments Ammoniain soilVolcanicactivityElectricalstorms Nitrogenin animals(consumers)BacteriaNitratein soilNitrogenin plants(producers)Nitrificationby bacteriaDenitrificationby bacteriaUptake by plantsDecompositionFig. 3-14, p. 52ProcessesReservoirPathway affected by humansNatural pathway