Human-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件

HumanImpactonResourcesandEcosystems

HumanImpactonResourcesand1Whatdidwedo?HumanspeciesexploitmineralresourcesandusenaturalecosystemTheyarealteredWesuccessbecausewehaveabilitytochangeoursurroundingsButHuman-Altereddoesnotequateto“Better”Whatdidwedo?HumanspecieseWhydoesecosystemmatter?Alllifeonearth,includinghumanlife,reliesonEcosystemservices–cleanair,cleanwater–renewableresources,etcForthefirsttimeinhistory,humanactionsareinfluencingecosystemsataglobalscale.–TheconsequencesforecosystemservicesarepoorlyunderstoodWhydoesecosystemmatter?AllSome“ecosystemservices”•purificationofairandwater•mitigationofdroughtsandfloods•generationandpreservationofsoilsandtheirfertility•detoxificationanddecompositionofwastes•pollinationofcropsandnaturalvegetation•dispersalofseeds•cyclingandmovementofnutrients...•Howmuchcanwedegradeanecosystem,andstillreceivetheseservices?Some“ecosystemservices”•purPollutionPollution-Anythingreleasedintotheenvironmentthataffectsanorganism’ssurvivalandreproduction.Human–peopleproduceinlargeenoughquantitiesthatitinterfereswithourhealthorwell-being.Olddays:smallpop.+simplemanner=dilutednaturalwaste,biodegradableNow:generatedfasterthanitcanbedegraded.PollutionPollution-AnythingFormsofpollution,fromhealthconcernstoannoyanceFormsofpollution,fromhealtSeveralfactorsdeterminetheimpactofasocietyonnaturalresources.Impactofapop.=Pop.Size/AreaoccupiedxDegreeoftechnologicaldevelopmentPopulationsizePopulationdensityDegreeoftechnologicalDevelopment

alwaysunderestimated,purchasefromotherpart,effectindistantplaces.SeveralfactorsdeterminetheThroughouthistory,humanshavesoughttechnologicalsolutionstocombatecosystemdegradation.Short-termsolutionsThroughouthistory,humanshavEcosystemsModifiedbyHumanUseAgriculturalRangelandsForestsAquaticEcosystemsWildernessSpeciesExtinctionEcosystemsModifiedbyHumanUAgricultureEcosystem40%oftheworld’slandsurfacehasbeenconvertedtocroplandandpermanentpasture.Removeoriginalvegetation(whatisit?),substitutedbyexoticdomesticatedcropsandanimals.Pop.Increase,morelandornewtech?AgricultureEcosystem40%ofthForestsEcosystemsForestserviceClimatemodification…Protectorofwatershed…DeforestationForwoodorland,lostofhabitatornicheExposethesoiltoincreaseerosionTropicalforestdecrease0.6%peryear,temperateforestnosignificantchangeForestsEcosystemsForestserviHuman-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件TropicaldeforestationThelossoftropicalrainforestcreateslocalenvironmentalproblemofenormousmagnitude,butfortheworld’speopletheimpacts,suchasclimatechange,arelong-term.

TropicaldeforestationForestmanagementClearcuttingvs.patch-workclearcuttingReforestationLumbercompany:fastgrowinghybridtreesplantation,onlyeconomicvalue.ExoticNodiversityForestmanagementClearcuttingRangelandEcosystemFromaridandsemiaridlandssupportgrassesorshrubsDomesticatedanimals,exoticspeciesSelectiveeating–plantsoeciesNativeanimalsOvergrazing-desertificationRangelandEcosystemFromaridaHuman-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件Desertification土壤荒漠化Overgrazingandmiss-farmingconvertaridandsemiaridareatodeserts.Thelossofvegetationincreaseerosionbywindandwater.

DesertificationExtinction500millionto5-10million,98%extinctionNaturalselection,mostlytobeextinct:Lowpop.DensityFoundinsmallareaSpecializednicheLowreproductiverateExtinction500millionto5-10HumanAcceleratedExtinctionFood–preyspeciesOrnament–animalskin,ivoryPest–tiger,wolfHabitatalterationQuestion?Whyworry?HumanAcceleratedExtinctionFoHuman-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件HumanImpactsonMarineSystems•fewsystemscannowbeconsidered'natural‘-allhavebeenmodified,eventhedeepoceans•humanactivityhaschangedmarinecommunitiesin5majorwaysglobalclimatechangeover-fishingofmarineorganismsinvasionsofexoticspecieschemicalpollutionandeutrophicationlossoralterationsofphysicalhabitatsHumanImpactsonMarineSystemOver-Fishing•fisheriesexploitationchangesmarineecosystemsmorerapidlyandoverlargescalesthanmostothereffects•leadstochangesin:distributionandabundanceofspeciesbodysize(sizeforreproduction)diversityoforganismsinsystemdynamicsoffoodwebs(lossofpredators)Over-Fishing•fisheriesexploiHuman-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件HabitatDamage•commercialfishinggearsareoftenverydestructivetohabitats•loststructureandfeaturescrucialforsupportingfisheryANDothercomponentsoftheecosystem•inmajorregionsoftheworldremoteimageryshowseverymetreofseabedasbeingtrawledmultipletimes•nowseeingdeclinesinrecruitmentofmanyspeciesthatneedhabitatasnurseryareaHabitatDamage•commercialfisFig.p.95鱼类食物链污染Lipcancerofbullhead,insometributariesoftheGreatLakes,mayreach84%Fig.p.95鱼类食物链污染LipcancerofEcosystemImpacts•fisheriesoftentargettop-levelpredatorshighfoodandeconomicvalue(e.g.tuna)•thesespeciesoftenhaveenormousimpactontherestoftheecosystemso-called"KEYSTONE"species•historicalremovalfromover-fishingnowimplicatedinmajorecosystemcollapsesincluding;coralreefstropicalseagrassbedskelpforestsEcosystemImpacts•fisheriesoaquaculture?•SomeProblemstobeSolved

clearingofcoastalvegetationforfishfarms(e.g.mangroves)•pollutionfromfishfarmrunoffinputofdiseasesandnutrients•introductionofnewgeneticstockintowildpopulation•strongdependencyonwild-caughtfishinordertoprovidefoodforaquacultureaquaculture?•SomeProblemstoHuman-Impact-on-Resources-and-Ecosystems人类对资源和生态系统的影响课件CulturalEutrophication•nutrientslimitingtoprimaryproducers•excessiveloadingofnutrientsintowaterbodies=culturaleutrophicationhumanandanimalwasterunoffoffertilizersdepositionofnitrogenfromindustrialreleases,carexhaustsanddirectindustrialdischarges•mostcontrolattempts-pointsource•non-pointsourcereleasesimportantamountsCulturalEutrophication•nutriNuisanceAlgalBlooms•increasedloadingofnutrientstoestuariesenhancesfrequencyandintensityofnuisancealgalblooms••increasedalgalproductiondoesnottranslatetohighsecondaryproductionplantsusuallytoxicorinediblenofish,consumealgaeNuisanceAlgalBlooms•increasFig.5.19mayinvolvetoxicforms,releasetoxicantmortalityofclamsandfishanoxicinbottomwaters,lowDO-'deadzones'onbottomofestuariesFig.5.19mayinvolvetoxicforNaturalResourceStructuresandprocessesthathumancanusefortheirownpurposesbutnotcreate.Sunlight,metal,scenery,soil.Renewableresources:canbeformedorregeneratedbynaturalprocess.ie.Soil,forest;butnotinexhaustibleNonrenewableresources:fossilfuelandmineral.NaturalResourceStructuresanMineralResourceFormedmillionsofyearsagoQuestionBreak:Whatisit?Include…andCharacteristicinChinaUnevendistributionthroughouttheworldinternationalexchangeDisproportionateshareN.A.5.1%worldpopulation,30%consumptionMineralResourceFormedmillioCostsAssociatedWithResourceExploitationEconomic-monetarycostsnecessarytoexploittheresourceEnergy-energyexpendedexploitingtheresourceEnvironmental-environmentaleffectofresourceexploitation(oftendeferred)CostsAss