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ECOSYSTEMCONCEPTSandECOLOGY
BasicConceptsand
Principles
2DepartmentofBIOLOGY,CAS‐UPManila
• Earthistheonlyplanetwherethereislife.
• WhydoesEarthhavewind,clouds,andrain?
• WhydoesEarthhaveweatherelementswhichthemoonandotherplanetsdonothave?
• Themostimportantfactorsthatmakeweatherchangespossiblearesun,air,andwater
3DepartmentofBIOLOGY,CAS‐UPManila
• Earth’sperfectsizeandmass,crucialtoaplanet’sabilitytodevelopanatmosphereandsustainlife
• “Anotherfascina;ngcoincidenceisthatonlyatmosphereswithbetweentenandtwentypercentoxygencansupportoxida;vemetabolisminahigherorganism”(Nature’sDes+ny)
• Ourexis;ngmagne;cfieldcreatesakindof“forcefield”aroundourplanet,protec;ngusfromdirectinterac;onwiththesun’ssolarwind—whichcouldblowawayouratmosphereandwithittheabilitytosustainlife
DepartmentofBIOLOGY,CAS‐UPManila 4
• CommunityoflivingthingsontheEarth
• SumofallecosystemsonEarth
• LivingorganismsofthebiospheredependononeanotherandontheotherdivisionsoftheEarth’sphysicalenvironment:– ATMOSPHERE(gaseousenvelope)– HYDROSPHERE(watersupply)– LITHOSPHERE(crust:soilsandrocks
DepartmentofBIOLOGY,CAS‐UPManila 5
• TheEarthenvironmentisthehome(habitat)ofallformsoflifeincludinghumans.
• Alllifeformsdependontheproperfunc;oningofourenvironment!
• Toappreciatetheintricaciesandimportanceoftheenvironment,however,itisnecessarythatcertainecologicalprinciplesbeexplained
DepartmentofBIOLOGY,CAS‐UPManila 6
Humans are biological organisms, all our
activities have a bearing on ecology
“Justaswehumansareconstrainedbythelawsofphysicswhenwebuildairplanesandbridges,weshouldalsobeconstrainedbytheprinciplesofecologywhenwealterthe
environment”
• CoinedbyErnstHaeckel(1869)
• “oikos”–house• “logos”‐studyof
• EARTHislikeagreatestateinwhichthelivingorganismsandthephysicalenvironmentinteractinanimmenseandcomplicatedwebofrela;onships
• ECOLOGY,then,isthestudyoftheinterac;onsamongorganismsandbetweenorganismsandtheirphysicalenvironment
DepartmentofBIOLOGY,CAS‐UPManila 7
• Rela;onshipwithEcology– Study of the interrelationship between
living organisms and their animate and inanimate environment
• Ecologyisthebasictoolofenvironmentalscience
DepartmentofBIOLOGY,CAS‐UPManila 8
ECOSYSTEM–basicunitandprobablythemostimportantconceptinecology
TwoTypesofSystem:1. Opensystem–
presenceofinputsandoutputs(maUerandenergy)
3. Closedsystem–noexchangeofmaUerandenergy(usuallyarXficiallymade,e.g.
DepartmentofBIOLOGY,CAS‐UPManila 9
• NEGATIVEFEEDBACKMECHANISM– Bringsthesystembacktotheidealstate– Devia;on‐counterac;nginputs
• Homeosta;cPlateau‐min/maxareawithinwhichthenega;vefeedbackmechanismcans;llfunc;on
• POSITIVEFEEDBACKMECHANISM– Increasingtendencytobeawayfromsetpoint– Devia;on‐accelera;nginputs– Homeosta;cplateauexceeded
• Ex.Geometricincreaseinthepopula;on» Developmentofcancerandkidneystones» Parturi;onorchildbirth
DepartmentofBIOLOGY,CAS‐UPManila 10
DOYOUTHINKTHISISANECOSYSTEM?
DepartmentofBIOLOGY,CAS‐UPManila 11
BIOTICCOMPONENTS ABIOTICCOMPONENTS• Producers
– GreenPlants– Algae(Phytoplankton)
• Consumers– Herbivores– Carnivores– Omnivores
• Decomposers– Detri;vores– Truedecomposers
– Bacteriaandfungi
• Clima;cFactors– Light– Temperature
– Precipita;on– Wind
– Humidity
• EdaphicFactors– SoilNutrients– SoilMoisture
– SoilPh• HydrologicalFactors
– PhysicochemicalfactorDepartmentofBIOLOGY,CAS‐UPManila 12
THEABIOTICFACTORS
DepartmentofBIOLOGY,CAS‐UPManila 13
• Lightaffectsthefollowingac;vi;es– rateofphotosynthesis(blueandred420‐660nm)
– flowering,dormancy,andleaffall
– migra;onandhiberna;on– nes;ngbehavior
• Temperature– directeffectonmetabolismbycontrollingbodychemistryand
reac;ons(incTincrateofreac;ons)
– affectsotherenvironmentalfactorssuchasmoistureavailability
DepartmentofBIOLOGY,CAS‐UPManila 14
• Precipita;on/Moisture– Waterasauniversalsolvent,mediumforbiochemical
processes– Verylimi;nginterrestrialenvironment;determinesthetype
ofvegeta;oninagivenenvironment
• Atmosphere/Wind
– Majorreservoirofnutrientsimportanttolife
– Windac;onacceleratestranspira;onprocess– Strongwindsmayinducephysicaldamageonplantstructure
anddistribu;onofseedsandsmallanimals
DepartmentofBIOLOGY,CAS‐UPManila 15
• SoilContent– Morenutrientsinsoilforplantgrowthmeansgreaterproduc;vity– “LawoftheMinimum”byJustusvonLiebig(1837),thegrowth
andsurvivalofplantsdependonthenutrientthatisleastavailable
• SoilMoisture– Increasewateravailabilitygenerallymeansgreaterproduc;vity;
waterisarawmaterial
• SoilAcidity– determinesthesolubilityandavailabilityofessen;alinorganicsalts
inthesolu;on
DepartmentofBIOLOGY,CAS‐UPManila 16
• Canmodifytheclima;cfactorsintheenvironmentespeciallylight,temperature,moisture,andpressure– Al;tude–dropof5.5˚Cper1000mincrease
inal;tude
– Aspect–north‐facingslopeandsouth‐facingslope(lowmoisture,highT,highevapora;on)
DepartmentofBIOLOGY,CAS‐UPManila 17
THEBIOTICFACTORS
DepartmentofBIOLOGY,CAS‐UPManila 18
• AgroupsoforganismsthatcanusetheenergyinsunlighttoconvertwaterandcarbondioxideintoGlucose(food)
• AutotrophsarealsocalledProducersbecausetheyproduceallofthefoodthatheterotrophsuse
• Withoutautotrophs,therewouldbenolifeonthisplanet
• Ex.PlantsandAlgaeDepartmentofBIOLOGY,CAS‐UPManila 19
• Autotrophsthatgettheirenergyfrominorganicsubstances,suchassalt
• Livedeepdownintheoceanwherethereisnosunlight
• Ex.BacteriaandDeepSeaWorms
DepartmentofBIOLOGY,CAS‐UPManila 20
• Organismsthatdonotmaketheirownfood
• AnothertermforHeterotrophisconsumerbecausetheyconsumeotherorganismsinordertolive
• Ex.Rabbits,Deer,Mushrooms
DepartmentofBIOLOGY,CAS‐UPManila 21
• Scavengers/Detri;vores–feedonthe;ssueofdeadorganisms(bothplansandanimals)
– Ex.–Vultures,Crows,andShrimp
• Herbivores–eatONLYplants– Ex.–Cows,Elephants,Giraffes
• Carnivores–eatONLYmeat
– Ex.–Lions,Tigers,Sharks
• Omnivores–eatBOTHplantsandanimals
– Ex.–BearsandHumans
DepartmentofBIOLOGY,CAS‐UPManila 22
4LAWSOFECOLOGY
1. EVERYTHINGISCONNECTEDTOEVERYTHINGELSE
2. EVERYTHINGMUSTGOSOMEWHERE
3. NATUREKNOWSBEST
4. THEREISNOFREELUNCH
DepartmentofBIOLOGY,CAS‐UPManila 23
HOWDOESANECOSYSTEMWORK?
DepartmentofBIOLOGY,CAS‐UPManila 24
• Significance:makesenergyavailabletoallcomponentsoftheecosystem
• Nature:“unidirec;onallinearflow”» “Ma0ercirculatesenergydissipates”
• TwoLawsofThermodynamics–governsthe“one‐way”flowofenergythroughtheecosystem
DepartmentofBIOLOGY,CAS‐UPManila 25
• Whenazebraeatsthegrass,itdoesnotobtainalloftheenergythegrasshas(muchofitisnoteaten)
• Whenalioneatsazebra,itdoesnotgetalloftheenergyfromthezebra(muchofitislostasheat)
• Thetwo(2)previousexamplesofenergytransfershowthatnoorganismEVERreceivesalloftheenergyfromtheorganismtheyjustate
• Only10%oftheenergyfromonetrophiclevelistransferredtothenext–thisiscalledthe10%law
DepartmentofBIOLOGY,CAS‐UPManila 26
• GrazingFoodChain
– startsfromagreenplantbasethengoestograzingherbivores,andontocarnivores;– mostcommonindeepaqua;csystemsbutcanalsobefoundinterrestrial
• grasscowman• phytoplanktonzooplanktonplank;vorespiscivorescatdog“lasenggo”
cannibals
• DetritalFoodChain
– fromdeadorganicmapertomicroorganismsandthentodetri;voresandtheirpredators– mostcommoninterrestrialandshallowwaters
• deadleavesmitescarnivorousmites• dungbacteriamicrobialconsumers
• Parasi;cFoodChain
– Inwhicheithertheproducerorconsumerisparasi;zed– Foodpassestoasmallerorganismthanalargerone.
• e.g.termitesTriconympha
DepartmentofBIOLOGY,CAS‐UPManila 27
• MostorganismseatmoretheJUSToneorganism
• WhenmoreorganismareinvolveditisknowasaFOODWEB
• Foodwebsaremorecomplexandinvolvelotsoforganisms
DepartmentofBIOLOGY,CAS‐UPManila 28
No;cethatthedirec;onthearrowpoints→thearrowpointsinthedirec;onoftheenergytransfer,NOT“whatatewhat”
• Anecologicalpyramidshowstherela;onshipbetweenconsumersandproducersatdifferenttrophiclevelsinanecosystem
• Showstherela;veamountsofenergyormapercontainedateachtrophiclevel
• ThePyramidshowswhichlevelhasthemostenergyandthehighestnumberoforganisms
DepartmentofBIOLOGY,CAS‐UPManila 29
DepartmentofBIOLOGY,CAS‐UPManila 30
• Thetotalmassoftheorganicmaperateachtrophicleveliscalledbiomass
• Biomassisjustanothertermforpoten;alenergy–energythatistobeeatenandused.
• Thetransferofenergyfromoneleveltoanotherisveryinefficient(10%Law)
DepartmentofBIOLOGY,CAS‐UPManila 31
BiogeochemicalCyclingintheEcosystem
Allmapercycles...itisneithercreatednordestroyed...
32DepartmentofBIOLOGY,CAS‐UPManila
• Definedasthemovementofelementsandcompoundsthatareessen;altolife– Materialsaretransportedthroughorganisms,theatmosphere,waterandlandinaseriesofCYCLES
• “Bio”–life,par;cipa;onoforganisms
• “Geo”‐abio;cenvironmentassourceofnutrients• “Chemical”–natureofsubstancesbeingcycled
“Biogeochemistry”(GEHutchinson)DepartmentofBIOLOGY,CAS‐UPManila 33
• Gaseoustype–thereservoiristheatmosphereand/orhydrosphere(e.g.N2,CO2,O2)
• Sedimentarytype–thereservoiristheEarth’scrust(e.g.Phosphorus)
• Linkagetype–thereservoirincludesmajorpathwaysinair,water,andcrust(e.g.sulfur)
DepartmentofBIOLOGY,CAS‐UPManila 34
• Pollu;on–accumulaXonofachemicalformthatishigherthanthestandards
• Non‐biodegradablesubstances–changetoformnewchemicalstructurewherenoorganismhasyettouXlizeit
• ReducXonoftheconcentraXonofotherchemicalforms–limitsgrowthofthesubsequentcomponentsofthecycle
• Eutrophica;on‐thechannelingofasubstancetootherpathways(greateramountsofphosphatesinaquaXcsystems)
DepartmentofBIOLOGY,CAS‐UPManila 35
• FlowofH2O
• Mediatesnutrientcycleandasmajorenergydissipa;onpathway
• Processes– Precipita;on– Run‐offandinfiltra;on– Evapora;on– Condensa;on
DepartmentofBIOLOGY,CAS‐UPManila 36
• Freshwater– 3%oftheworld’swatersupply
• Moreconsump;onthansupply
• Pumpingwatersfromaquifers‐notanormalpartofthewatercycle
• Garbageandwastespollutethewaterandclogdrainagesystemsinducesflooding
• Asphal;ng–renderthegroundimpervioustowaterblocksinfiltra;on
DepartmentofBIOLOGY,CAS‐UPManila 37
Pollu;on
–achangeintransferrateofwaterandnutrientsthatcanleaddirectlyorindirectlytoadegradaXonofhumanhealthordegradaXonof
plantandanimallife
• Type:Gaseous(21%)
• MajorReservoir:Atmosphere
• Forms:FreeandMolecularOxygen
• Sources:– Photosynthesisfromproducers– PhotodissociaXonofWaterVapor
• FateofFreeO2:1. Reachhigherlevelsoftrophosphereandreducedtoozone
(providesprotecXonbyfilteringoutthesun'sUVrays)2. Mayreactwithchemicalsandorganiccompoundsofthe
earth’scrust3. MaybeusedupincellrespiraXonwhichreleaseCO2tobe
usedbyautotrophstoproducemoreO2
DepartmentofBIOLOGY,CAS‐UPManila 38
• CFC’s(chlorofluorocarbons)depleteozonelayer“ozonehole”
• Eutrophica;on(nutrientenrichmentfromagriculturalanddomesXcwastes)leadstodepleXonofoxygeninwater
• Combus;onoffossilfuelsandremovalofvegetaXon(deforestaXon)depletethesupplyofoxygenintheatmosphere
DepartmentofBIOLOGY,CAS‐UPManila 39
• Type:GaseousCycle
• MajorReservoir:Atmospherebutalsocalciumcarbonateinshellsandlimestone,aswellasfossilfuels
• Significance:Majorelementoforganiccompounds;buildingblocksofallbiomolecules
• Processes– PhotosynthesisremovesCO2whilerespiraXonandcombusXonaddCO2
totheatmosphere.– CO2fromairandwatercombinetoformbicarbonate(HCO3)–sourceof
carbonforaquaXcproducers.Carbonicacidmakesrainwateralsoslightlyacidic.
– Similarly,whenaquaXcorganismsrespire,CO2isreleasedandcombinewithwatertoformHCO3.HCO3(water)=CO2(air)
DepartmentofBIOLOGY,CAS‐UPManila 40
DepartmentofBIOLOGY,CAS‐UPManila 41
Theglobalcarboncycleincludestheearth'satmosphere,oceans,vegeta+on,soilsandfossilfuels
• Increasedu;liza;onandburningoffossilfuel(oil,gas,coal)torunautomobiles,industry,andmachineries
• Massivedeforesta;on
• Wasteincinera;on,etc
DepartmentofBIOLOGY,CAS‐UPManila 42
CO2
• Type:GaseousCycle
• Majorreservoir–ATMOSPHERE
• Importance–Essen;alformanybiologicalprocesses,cons;tutespartofproteins(aminoacids),inbasesofnucleicacidsthatmakeupDNAandRNA
• 79%ofatmosphereismadeupofnitrogen(N2)butthisisINERT
• Itmustbefixedfororganismstou;lizeitDepartmentofBIOLOGY,CAS‐UPManila 43
• USEOFNITROGENFERTILIZERS– Humanuseofnitrogenfer;lizerscausesrunoff,leadingtoeutrophica;onin
aqua;csystems(e.g.eutrophica;on)
• NITRATESLEACHINGINTOGROUNDWATER– Nitrogenlevelindrinkingwaterrises– Alargeriseofnitrogenindrinkingwatersuppliesleadsto
Methemoglobinemia/Blue‐BabySyndrome
• NITROGENOXIDESRELEASEDTHROUGHCOMBUSTION– Burningoffossilfuel+automobiles:sourceofnitrogendioxide– Ozone+PANPhotochemicalSmog
• LIVESTOCKRELEASEOFLARGEAMOUNTSOFAMMONIA(FROMWASTES)
– Theammoniareleasedfromwastesoflivestockcanhavedetrimentaleffectsonfishandotherorganisms
– Thereisreduc;onindiversityDepartmentofBIOLOGY,CAS‐UPManila 44
• Type:PurelySedimental
• Majorreservoir–Earth’scrust
• Gradualcycle‐Ithasnogaseousphase– Phosphorousnormallyoccursinnatureaspartofphosphateion.– Mostphosphatesfoundassaltsinoceansedimentsorinrocks.– Over;me:geologicprocessescanbringsedimentsfromoceanto
land,andweatheringcanbringitfromlandtoocean
• Importance– Phosphorouscons;tuentofnucleicacidsinDNA,andenergy
currencyofcellATP.– Phosphorous‐alsofoundinbones,inphospholipidswhicharefound
inbiologicalmembranes.
DepartmentofBIOLOGY,CAS‐UPManila 45
• Humansminephosphateoresforuseinfer;lizerproduc;onanddetergents
• Humanac;onscouldleadtoeutrophica+onofaqua+csystemswhichcausealgalblooms
• AlgalbloomscausefishkillsDepartmentofBIOLOGY,CAS‐UPManila 46
• Type:Sedimentarycyclewithatmosphericcomponent
• Majorreservoir–inorganicsulfurinrocksandfossilfuel
• BiologicalImportance– Sulfurisanimportantelementinprotoplasmwhichisanimportantcomponentofsomeaminoacids.
– Sulfurispartofproteins,vitaminsandhormones
DepartmentofBIOLOGY,CAS‐UPManila 47
• Humansproducesulfurdioxidefromindustryandinternalcombus;onenergy
• Sulfurdioxidecanprecipitateontosurfaceswhereitcanbeoxidizedtosulfateinthesoilwhichistoxictosomeplants
• Sulfurdioxidecanbeoxidizedtosulfateinatmosphereassulfuricacidwhichisamaincons;tuentofacidrain– Acidraincanaffectchemicalbalanceoflakes.– Itacceleratesweatheringincarbonaterocks.– Leadstoforestsdamageathigheleva;ons
DepartmentofBIOLOGY,CAS‐UPManila 48