Human-Impact-on-Resources-and-Ecosystems人類(lèi)對(duì)資源和生態(tài)系統(tǒng)的影響課件

HumanImpactonResourcesandEcosystems

Whatdidwedo?HumanspeciesexploitmineralresourcesandusenaturalecosystemTheyarealteredWesuccessbecausewehaveabilitytochangeoursurroundingsButHuman-Altereddoesnotequateto“Better”Whydoesecosystemmatter?Alllifeonearth,includinghumanlife,reliesonEcosystemservices–cleanair,cleanwater–renewableresources,etcForthefirsttimeinhistory,humanactionsareinfluencingecosystemsataglobalscale.–TheconsequencesforecosystemservicesarepoorlyunderstoodSome“ecosystemservices”?purificationofairandwater?mitigationofdroughtsandfloods?generationandpreservationofsoilsandtheirfertility?detoxificationanddecompositionofwastes?pollinationofcropsandnaturalvegetation?dispersalofseeds?cyclingandmovementofnutrients...?Howmuchcanwedegradeanecosystem,andstillreceivetheseservices?PollutionPollution-Anythingreleasedintotheenvironmentthataffectsanorganism’ssurvivalandreproduction.Human–peopleproduceinlargeenoughquantitiesthatitinterfereswithourhealthorwell-being.Olddays:smallpop.+simplemanner=dilutednaturalwaste,biodegradableNow:generatedfasterthanitcanbedegraded.Formsofpollution,fromhealthconcernstoannoyanceSeveralfactorsdeterminetheimpactofasocietyonnaturalresources.Impactofapop.=Pop.Size/AreaoccupiedxDegreeoftechnologicaldevelopmentPopulationsizePopulationdensityDegreeoftechnologicalDevelopment

alwaysunderestimated,purchasefromotherpart,effectindistantplaces.Throughouthistory,humanshavesoughttechnologicalsolutionstocombatecosystemdegradation.Short-termsolutionsEcosystemsModifiedbyHumanUseAgriculturalRangelandsForestsAquaticEcosystemsWildernessSpeciesExtinctionAgricultureEcosystem40%oftheworld’slandsurfacehasbeenconvertedtocroplandandpermanentpasture.Removeoriginalvegetation(whatisit?),substitutedbyexoticdomesticatedcropsandanimals.Pop.Increase,morelandornewtech?ForestsEcosystemsForestserviceClimatemodification…Protectorofwatershed…DeforestationForwoodorland,lostofhabitatornicheExposethesoiltoincreaseerosionTropicalforestdecrease0.6%peryear,temperateforestnosignificantchangeTropicaldeforestationThelossoftropicalrainforestcreateslocalenvironmentalproblemofenormousmagnitude,butfortheworld’speopletheimpacts,suchasclimatechange,arelong-term.

ForestmanagementClearcuttingvs.patch-workclearcuttingReforestationLumbercompany:fastgrowinghybridtreesplantation,onlyeconomicvalue.ExoticNodiversityRangelandEcosystemFromaridandsemiaridlandssupportgrassesorshrubsDomesticatedanimals,exoticspeciesSelectiveeating–plantsoeciesNativeanimalsOvergrazing-desertificationDesertification土壤荒漠化Overgrazingandmiss-farmingconvertaridandsemiaridareatodeserts.Thelossofvegetationincreaseerosionbywindandwater.

Extinction500millionto5-10million,98%extinctionNaturalselection,mostlytobeextinct:Lowpop.DensityFoundinsmallareaSpecializednicheLowreproductiverateHumanAcceleratedExtinctionFood–preyspeciesOrnament–animalskin,ivoryPest–tiger,wolfHabitatalterationQuestion?Whyworry?HumanImpactsonMarineSystems?fewsystemscannowbeconsidered'natural‘-allhavebeenmodified,eventhedeepoceans?humanactivityhaschangedmarinecommunitiesin5majorwaysglobalclimatechangeover-fishingofmarineorganismsinvasionsofexoticspecieschemicalpollutionandeutrophicationlossoralterationsofphysicalhabitatsOver-Fishing?fisheriesexploitationchangesmarineecosystemsmorerapidlyandoverlargescalesthanmostothereffects?leadstochangesin:distributionandabundanceofspeciesbodysize(sizeforreproduction)diversityoforganismsinsystemdynamicsoffoodwebs(lossofpredators)HabitatDamage?commercialfishinggearsareoftenverydestructivetohabitats?loststructureandfeaturescrucialforsupportingfisheryANDothercomponentsoftheecosystem?inmajorregionsoftheworldremoteimageryshowseverymetreofseabedasbeingtrawledmultipletimes?nowseeingdeclinesinrecruitmentofmanyspeciesthatneedhabitatasnurseryareaFig.p.95魚(yú)類(lèi)食物鏈污染Lipcancerofbullhead,insometributariesoftheGreatLakes,mayreach84%EcosystemImpacts?fisheriesoftentargettop-levelpredatorshighfoodandeconomicvalue(e.g.tuna)?thesespeciesoftenhaveenormousimpactontherestoftheecosystemso-called"KEYSTONE"species?historicalremovalfromover-fishingnowimplicatedinmajorecosystemcollapsesincluding;coralreefstropicalseagrassbedskelpforestsaquaculture??SomeProblemstobeSolved

clearingofcoastalvegetationforfishfarms(e.g.mangroves)?pollutionfromfishfarmrunoffinputofdiseasesandnutrients?introductionofnewgeneticstockintowildpopulation?strongdependencyonwild-caughtfishinordertoprovidefoodforaquacultureCulturalEutrophication?nutrientslimitingtoprimaryproducers?excessiveloadingofnutrientsintowaterbodies=culturaleutrophicationhumanandanimalwasterunoffoffertilizersdepositionofnitrogenfromindustrialreleases,carexhaustsanddirectindustrialdischarges?mostcontrolattempts-pointsource?non-pointsourcereleasesimportantamountsNuisanceAlgalBlooms?increasedloadingofnutrientstoestuariesenhancesfrequencyandintensityofnuisancealgalblooms??increasedalgalproductiondoesnottranslatetohighsecondaryproductionplantsusuallytoxicorinediblenofish,consumealgaeFig.5.19mayinvolvetoxicforms,releasetoxicantmortalityofclamsandfishanoxicinbottomwaters,lowDO-'deadzones'onbottomofestuariesNaturalResourceStructuresandprocessesthathumancanusefortheirownpurposesbutnotcreate.Sunlight,metal,scenery,soil.Renewableresources:canbeformedorregeneratedbynaturalprocess.ie.Soil,forest;butnotinexhaustibleNonrenewableresources:fossilfuelandmineral.MineralResourceFormedmillionsofyearsagoQuestionBreak:Whatisit?Include…andCharacteristicinChinaUnevendistributionthroughouttheworldinternationalexchangeDisproportionateshareN.A.5.1%worldpopulation,30%consumptionCostsAssociatedWithResourceExploitationEconomic-monetarycostsnecessarytoexploittheresourceEnergy-energyexpendedexploitingtheresourceEnvironmental-environmentaleffectofresourceexploitation(oftendeferred)Question–