2 Essential questions What limits the production in ecosystems? How do nutrients move in the ecosystem?How does energy move through the ecosystem?
3 Ecosystem All the organisms in a community plus abiotic factors ecosystems are transformers of energy & processors of matterEcosystems are self-sustainingwhat is needed?capture energytransfer energycycle nutrients
4 Ecosystem inputs nutrients cycle inputs energy nutrients biosphereenergy flows throughconstant input of energynutrients cycleMatter cannotbe created or destroyedDon’t forget the laws of Physics!nutrients can only cycleinputsenergynutrients
5 Generalized Nutrient cycling consumersconsumersconsumersproducersdecomposersdecomposersnutrients ENTER FOOD CHAIN = made available to producersnutrients made available to producersreturn to abiotic reservoirDecomposition connects all trophic levelsabiotic reservoirabiotic reservoirgeologic processesgeologic processes
6 Carbon cycle abiotic reservoir: CO2 in atmosphere enter food chain: photosynthesis = carbon fixation in Calvin cyclerecycle:return to abiotic:respirationcombustionCarbon cycleCO2 inatmosphereDiffusionRespirationPhotosynthesisPlants and algaePlantsAnimalsIndustry and homeCombustion of fuelsCarbonates in sedimentBicarbonatesDeposition ofdead materialDepositionof deadmaterialFossil fuels(oil, gas, coal)Dissolved CO2
7 Nitrogen cycle Atmospheric nitrogen Carnivores Herbivores Birds Plants abiotic reservoir:N in atmosphereenter food chain:nitrogen fixation by soil & aquatic bacteriarecycle:decomposing & nitrifying bacteriareturn to abiotic:denitrifying bacteriaAtmosphericnitrogenCarnivoresHerbivoresBirdsPlankton withnitrogen-fixingbacteriaPlantsDeath, excretion, fecesFishNitrogen-fixingbacteria(plant roots)Decomposing bacteriaamino acidsexcretionAmmonifying bacteriaNitrogen-fixingbacteria(soil)loss to deep sedimentsNitrifying bacteriaDenitrifyingbacteriasoil nitrates
8 Phosphorus cycle abiotic reservoir: rocks, minerals, soil enter food chain:erosion releases soluble phosphateuptake by plantsrecycle:decomposing bacteria & fungireturn to abiotic:loss to ocean sedimentPhosphorus cycleLandanimalsPlantsAnimal tissueand fecesUrineSoluble soilphosphateDecomposers(bacteria andfungi)Loss indrainageRocks andmineralsPhosphatesin solutionDecomposers(bacteria & fungi)Animal tissueand fecesAquaticanimalsPlants andalgaePrecipitatesLoss to deep sediment
9 Water cycle Solar energy Transpiration Evaporation Precipitation abiotic reservoir:surface & atmospheric waterenter food chain:precipitation & plant uptakerecycle:transpirationreturn to abiotic:evaporation & runoffWater cycleSolar energyTranspirationWater vaporEvaporationPrecipitationOceansRunoffLakesPercolation in soilAquiferGroundwater
11 Breaking the water cycle Deforestation breaks the water cyclegroundwater is not transpired to the atmosphere, so precipitation is not createdforest desertdesertification
12 Repairing the damage The Greenbelt Movement planting trees in Kenya restoring a sustainable ecosystemestablishing democracyempowering womenWangari MaathaiNobel Peace prize 2004
13 Effects of deforestation 40% increase in runoffloss of water60x loss in nitrogen10x loss in calciumloss into surface water80nitrate levels in runoff40loss out of ecosystem!of nitrate (mg/l )Concentration4Deforestation2Why is nitrogen so important?1965196619671968Year
14 Energy flows through ecosystems sunsecondary consumers(carnivores)loss of energyloss of energyprimary consumers(herbivores)producers (plants)
15 Food chains Trophic levels sun feeding relationships Tertiary consumerTrophic levelsfeeding relationshipsstart with energy from the suncaptured by plants1st level of all food chainsfood chains usually go up only 4 or 5 levelsinefficiency of energy transferall levels connect to decomposerstop carnivoreLevel 3Secondary consumercarnivoreLevel 2Primary consumerheterotrophsherbivoreLevel 1ProducerautotrophsFungiDecomposersBacteria
16 Inefficiency of energy transfer sunInefficiency of energy transferLoss of energy between levels of food chainTo where is the energy lost? The cost of living!17%growthenergy lost to daily livingonly this energy moves on to the next level in the food chain33%cellularrespiration50%waste (feces)
17 Ecological pyramid sun Loss of energy between levels of food chain can feed fewer animals in each level1100100,0001,000,000,000
18 What is your ecological footprint?! Humans in food chainsDynamics of energy through ecosystems have important implications for human populationshow much energy does it take to feed a human?if we are meat eaters?if we are vegetarian?What is your ecological footprint?!
19 Food webs Food chains are linked together into food webs Who eats whom?a species may weave into web at more than one levelbearshumanseating meat?eating plants?
20 Any Questions?? We’re working on a lot of them!