4 AUTOTROPHSUse energy from the sun to make their own food by doing photosynthesis
5 What organelle does photosynthesis take place in? Plant cells take energy from the sun and turn it into foodThis Takes place in the chloroplast of cellsWhat organelle does photosynthesis take place in?
6 What do Plants need to do PHOTOSYNTHESIS? What do Plants make when they do PHOTOSYNTHESIS?
7 EQUATION FOR PHOTOSYNTHESIS WATEROXYGENCO2 +H2O +ENERGYC6H12O6 +O2CARBON DIOXIDEGLUCOSE
8 What affects the rate of PHOTOSYNTHESIS ? WaterCarbon DioxideLight IntensityTemperature
9 HETEROTROPHS Cannot get energy directly from the sun Eat food to get energy
11 What organelle does cellular respiration take place in? All cells take food and turn it into energy the organism can useTakes place in the mitochondria of cellsWhat organelle does cellular respiration take place in?
12 EQUATION FOR RESPIRATION CARBON DIOXIDEATPGLUCOSEC6H12O6 +O2CO2 +H2O +ENERGYOXYGENWATER
13 How Does the Equation for PHOTOSYNTHESIS Relate to the Equation for CELLULAR RESPIRATION?
14 How Does the Equation for PHOTOSYNTHESIS CO2 +CARBON DIOXIDERelate to the Equation for CELLULAR RESPIRATION?CARBON DIOXIDECO2 +
15 How Does the Equation for PHOTOSYNTHESIS WATERCO2 +H2O +CARBON DIOXIDERelate to the Equation for CELLULAR RESPIRATION?CARBON DIOXIDECO2 +H2O +WATER
16 How Does the Equation for PHOTOSYNTHESIS WATERCO2 +H2O +ENERGYCARBON DIOXIDERelate to the Equation for CELLULAR RESPIRATION?CARBON DIOXIDEATPCO2 +H2O +ENERGYWATER
17 How Does the Equation for PHOTOSYNTHESIS C6H12O6 +GLUCOSERelate to the Equation for CELLULAR RESPIRATION?GLUCOSEC6H12O6 +
18 How Does the Equation for PHOTOSYNTHESIS OXYGENC6H12O6 +O2GLUCOSERelate to the Equation for CELLULAR RESPIRATION?GLUCOSEC6H12O6 +O2OXYGEN
19 How Does the Equation for PHOTOSYNTHESIS CO2 +H2O +ENERGYC6H12O6 +O2CARBON DIOXIDEWATERGLUCOSEOXYGENRelate to the Equation for CELLULAR RESPIRATION?C6H12O6 +GLUCOSEO2OXYGENCO2 +CARBON DIOXIDEH2O +ENERGYWATERATP
20 How Does the Equation for PHOTOSYNTHESIS Relate to the Equation for CELLULAR RESPIRATION?The reactants used in photosynthesis are the products made in cellular respirationThe products made in photosynthesis are the reactants used in cellular respiration
21 Ch. 54 - Ecosystems Overview: Ecosystems, Energy, and Matter An ecosystem consists of all the organisms living in a community as well as all the abiotic factors with which they interact
22 Ecosystems can range from a microcosm, such as an aquarium to a large area such as a lake or forest Figure 54.1
23 Regardless of an ecosystem’s size its dynamics involve two main processes: energy flowchemical cyclingEnergy flows through ecosystems while matter cycles within themEcosystems are transformers of energy and processors of matter
24 Laws of Thermodynamics 1st Law – Energy cannot be created or destroyed, but it can be transferred from one form to another.PhotosynthesisLight ChemicalCellular Respiration (processing food)Chemical ChemicalLife’s ActivitiesChemical Thermal2nd Law – As energy moves through a system the amount of usable energy decreases.Rule of 10As energy moves through an ecosystem, only 10% of usable energy is passed to the next trophic level.
25 How organisms get energy The ultimate source of energy on Earth is the SunAutotrophs-get energy from the sun to make foodHeterotrophs-must eat other organisms to get energyCarnivoresOmnivoresHerbivoresDetrivores
26 Trophic Levels (feeding steps) Producers-AutotrophsMostly PlantsPrimary Consumers-1st order heterotrophsEat Producers (herbivores)Secondary Consumers-2nd order heterotrophsEat Primary ConsumersTertiary Consumers-3rd order heterotrophsEat Secondary Consumers (top predators)
27 Energy flows through an ecosystem Entering as light and exiting as heatFigure 54.2Microorganismsand otherdetritivoresDetritusPrimary producersPrimary consumersSecondaryconsumersTertiary consumersHeatSunKeyChemical cyclingEnergy flow
28 Detritivores, mainly bacteria and fungi, recycle essential chemical elements by decomposing organic material and returning elements to inorganic reservoirsFigure 54.3
29 Primary production in an ecosystem is the amount of light energy converted to chemical energy by autotrophs during a given time periodPhotosynthesis determines the energy budget of the entire ecosystem
30 Gross and Net Primary Production The ecosystem’s gross primary production (GPP) is the total primary productionNot all of this production is stored as organic material in the growing plantsNet primary production (NPP) is equal to GPP minus the energy used by the primary producers for respirationOnly NPP is available to consumers
31 Different ecosystems vary considerably in their net primary production and in their contribution to the total NPP on EarthLake and streamOpen oceanContinental shelfEstuaryAlgal beds and reefsUpwelling zonesExtreme desert, rock, sand, iceDesert and semidesert scrubTropical rain forestSavannaCultivated landBoreal forest (taiga)Temperate grasslandTundraTropical seasonal forestTemperate deciduous forestTemperate evergreen forestSwamp and marshWoodland and shrubland1020304050605001,0001,5002,0002,50051525Percentage of Earth’s netprimary productionKeyMarineFreshwater (on continents)Terrestrial18.104.22.168.22.214.171.124.126.96.36.199.61.51.31.00.41253603.0902,2009006008007001401,6001,2001,3002505.61.20.90.04188.8.131.52.184.108.40.206.82.365.024.4Figure 54.4a–cPercentage of Earth’ssurface area(a)Average net primaryproduction (g/m2/yr)(b)(c)
32 Overall, terrestrial ecosystems Contribute about two-thirds of global NPP and marine ecosystems about one-thirdFigure 54.5180120W60W060E120ENorth Pole60N30NEquator30S60SSouth Pole
33 Primary Production in Marine and Freshwater Ecosystems In marine and freshwater ecosystems both light and nutrients are important in controlling primary productionThe depth of light penetration affects primary production throughout the photic zone of an ocean or lakeNitrogen and phosphorous are typically the nutrients that most often limit marine production
34 In some areas, sewage runoff which has caused eutrophication of lakes, which can lead to the eventual loss of most fish species from the lakesFigure 54.7
35 Primary Production in Terrestrial and Wetland Ecosystems In terrestrial and wetland ecosystems climatic factors such as temperature and moisture, affect primary production on a large geographic scale
36 Actual evapotranspiration The contrast between wet and dry climates can be represented by a measure called evapotranspirationActual evapotranspirationIs the amount of water annually transpired by plants and evaporated from a landscapeIs related to net primary productionFigure 54.8Actual evapotranspiration (mm H2O/yr)Tropical forestTemperate forestMountain coniferous forestTemperate grasslandArctic tundraDesertshrublandNet primary production (g/m2/yr)1,0002,0003,0005001,500
37 Live, above-ground biomass On a more local scale a soil nutrient is often the limiting factor in primary productionFigure 54.9EXPERIMENTOver the summer of 1980, researchers added phosphorus to some experimental plots in the salt marsh, nitrogen to other plots, and both phosphorus and nitrogen to others. Some plots were left unfertilized as controls.RESULTSExperimental plots receiving just phosphorus (P) do not outproduce the unfertilized control plots.CONCLUSIONLive, above-ground biomass(g dry wt/m2)Adding nitrogen (N) boosts net primaryproduction.30025020015010050JuneJulyAugust 1980N PN onlyControlP onlyThese nutrient enrichment experiments confirmed that nitrogen was the nutrient limiting plant growth in this salt marsh.
38 Energy transfer between trophic levels is usually less than 20% efficient The secondary production of an ecosystem is the amount of chemical energy in consumers’ food that is converted to their own new biomassWhen a caterpillar feeds on a plant leaf only about one-sixth of the energy in the leaf is used for secondary productionPlant materialeaten by caterpillarCellularrespirationGrowth (new biomass)Feces100 J33 J200 J67 J
39 The production efficiency of an organism Is the fraction of energy stored in food that is not used for respirationTrophic efficiencyIs the percentage of production transferred from one trophic level to the nextUsually ranges from 5% to 20%
40 Pyramids of Production This loss of energy with each transfer in a food chain can be represented by a pyramid of net productionFigure 54.11TertiaryconsumersSecondaryPrimaryproducers1,000,000 J of sunlight10 J100 J1,000 J10,000 J
41 One important ecological consequence of low trophic efficiencies can be represented in a biomass pyramidMost biomass pyramids show a sharp decrease at successively higher trophic levelsFigure 54.12a(a) Most biomass pyramids show a sharp decrease in biomass at successively higher trophic levels, as illustrated by data from a bog at Silver Springs, Florida.Trophic levelDry weight(g/m2)Primary producersTertiary consumersSecondary consumersPrimary consumers1.51137809
42 Number of individual organisms Pyramids of NumbersA pyramid of numbers represents the number of individual organisms in each trophic levelFigure 54.13Trophic levelNumber of individual organismsPrimary producersTertiary consumersSecondary consumersPrimary consumers3354,904708,6245,842,424
43 The dynamics of energy flow through ecosystems have important implications for the human population Eating meat is a relatively inefficient way of tapping photosynthetic production
44 Worldwide agriculture could successfully feed many more people if humans all fed more efficiently, eating only plant materialTrophic levelSecondaryconsumersPrimaryproducersFigure 54.14
45 Life on Earth depends on the recycling of essential chemical elements Nutrient circuits that cycle matter through an ecosystem involve both biotic and abiotic components and are often called biogeochemical cycles
46 Biogeochemical Cycles The water cycle and the carbon cycleFigure 54.17Transportover landSolar energyNet movement ofwater vapor by windPrecipitationover oceanEvaporationfrom oceanEvapotranspirationfrom landPercolationthroughsoilRunoff andgroundwaterCO2 in atmospherePhotosynthesisCellularrespirationBurning offossil fuelsand woodHigher-levelconsumersPrimaryDetritusCarbon compoundsin waterDecompositionTHE WATER CYCLETHE CARBON CYCLE
47 The nitrogen cycle and the phosphorous cycle Figure 54.17N2 in atmosphereDenitrifyingbacteriaNitrifyingNitrificationNitrogen-fixingsoil bacteriabacteria in rootnodules of legumesDecomposersAmmonificationAssimilationNH3NH4+NO3NO2 RainPlantsConsumptionDecompositionGeologicupliftWeatheringof rocksRunoffSedimentationPlant uptakeof PO43SoilLeachingTHE NITROGEN CYCLETHE PHOSPHORUS CYCLE
48 Decomposition and Nutrient Cycling Rates Decomposers (detritivores) play a key role in the general pattern of chemical cyclingFigure 54.18ConsumersProducersNutrientsavailableto producersAbioticreservoirGeologicprocessesDecomposers