ul liCh 55 Ecosystems Jeff Jewett ACS June 2010 Ver 1li liEcosystem ul liSum of all organisms in an area AND all the abiotic factors with which they interactli ul ul liCommunities PLUS abiotic factorsli ul ul liBoundaries are rarely clear-cut may depend on scale of questionli ul li liCh 55 Key Topics ul liConservation of EnergyMassli ul ul liGPPNPP and limitationsli ul ul liEnergy Transfer pyramids of energybiomassli ul ul liBiogeochemical Cycles C N H 2 0li ul ul liHuman impact on biogeo Cyclesli ul ul li ul liGlobal warming eutrophication biomagnification acid rain ozone holeli ul li ul li liEnergy Flows Matter Cycles ul liEnergy enters usually as sunlightli ul ul liConverted to biomass chemical energy by autotrophsli ul ul liPassed to heterotrophs incl decomposersli ul ul liDissipated as heatli ul li liEnergy Flows Matter Cycles 2 ul liChemical elements C N P are cycled between abiotic and biotic parts of ecosystem Law of Conservation of Massli ul ul liMatter continuously cycles not created or destroyedli ul ul li2 nd law of Thermodynamics:li ul ul liEnergy conversions are never 100% efficient therefore some is always lost as heatli ul ul liEcosystems require constant input of energyli ul li liTrophic Levels ul liAutotrophs = primary producers redundantli ul ul li ul liPhotoautotrophs rely on light for energy by FAR the most commonli ul li ul ul li ul liChemoautotrophs oxidize naturally occuring inorganic compounds as fuel common in hot springs deep-sea volcanic ventsli ul li ul ul liAll of the ecosystem depends on autotrophs!li ul li liTrophic Levels 2 ul liHeterotrophsli ul ul li ul lidepend directly or indirectly on autotrophsli ul li ul ul li ul lieat things that are alive or were aliveli ul li ul ul li ul liConsumers decomposers detritivoresli ul li ul ul li ul liDetritivores fungus bacteria insects FBI eat detritus non-living organic material such as feces dead critters fallen leaves woodli ul li ul ul li ul liConsumers primary secondary tertiary...