巢湖蓝藻水华形成原因探索及优势种光合假说贾晓会

201131112968—2977ActaEcologicaSinicahttp//．ecologica．cn、-042010-12-162011-04-26*[e-mail]“”1223*45525211．1000482．3004573．1000934．2300615．4300722007、、、。80a10。“”1。。。2、。4、。3。、pH。4。pH。FormationofcyanobacterialbloomsinLakeChaohuandthephotosynthesisofdominantspecieshypothesisJIAXiaohui12SHIDingji23*SHIMianhong4LIRenhui5SONGLirong5FANGHao2YUGongliang5LIXuan2DUGuisen11CollegeofLifeSciencesCapitalNormalUniversityBeijing100048China2CollegeofMarineSources＆EngineeringTianjinUniversityofSciences＆TechnologyTianjin300457China3InstituteofBotanyChineseAcademyofSciencesBeijing100093China4AnhuiCenterofEnvironmentDetectionHefei230061China5InstituteofHydrobiologyChineseAcademyofSciencesWuhan430072ChinaAbstractElucidationofthecausesofcyanobacterialharmfulalgalbloomsCHABsmaybeapreconditionfortheircontrol．WehaveinvestigatedLakeChaohusince2007identifyingphytoplanktonspeciesobservingseasonalvariationindominantspeciesmeasuringprimaryproductivitydetectingchangesinlimnologicalcharacteristicsidentifying“leadingfactors”andthenassayingtheecophysiologyofphotosynthesisinthedominantcyanobacteria．WealsoanalyzedthehistoricaleventsrelatingtoCHABsinthislake．Ourstudiesshowedthatphytoplanktondiversityvariedseasonallyanddominantcyanobacteriarepresentedmorethan74%ofthetotalphytoplanktoncells．Dominantspeciesin2008to2009includedMicrocystisviridisinAprilMayJuneOctoberNovemberandDecemberM．wesenbergiiinJulyandAugustM．aeruginosainSeptemberandAnabaenaflos－aquaeinJanuaryFebruaryandMarch．Bloomswererecordedover100yearsagointhislakeandnoappropriateexplanationshavebeenadvancedfortheircauses．Sincethehttp//．ecologica．cn1930sresearchershavepresentedthefollowingtenhypothesesonbloomformationAtheTN/TPhypothesisBtheinorganicnitrogenhypothesisCthebuoyancyhypothesisDthestoragestrategyhypothesisEthelowlighthypothesisFthehighpH/lowCO2hypothesisGtheelevatedwatertemperaturehypothesisHthetraceelementhypothesisIthezooplanktongrazinghypothesisandJtheevolutionaryadaptationhypothesis．AlthoughthesehypothesesexplainwhycyanobacteriasuccessfullycompeteovereukaryoticalgaeinmostlakesandreservoirstheycannotclarifywhydifferentdominantcyanobacterialspeciesappearinseasonalsuccessioninLakeChaohu．Anewhypothesisisneeded．Basedonourunderstandingwehaveconstructed“thephotosynthesisofdominantspecieshypothesis”asfollows1Bloomsincludevariousspeciesofcyanobacteriaandalgae．Bloominitiationisrelatedtocelldensityandalsotoprimaryproductivity．WecollectedandmeasuredphytoplanktonmonthlyindifferentwaterdepthsatsixpointsinthewesternpartofLakeChaohu．In2008to2009collectedphytoplanktonconsistedof85speciesin5phyla．Bothcelldensityandprimaryproductivitywerehighestduringthesummerandlowestduringwinter．2Duringbloomsdominantspeciesgrewmorequicklyandhadthegreatestbiomassofthephytoplankton．Therewerefourdominantspeciesandtheseconstitutedover74%ofthetotalphytoplanktoncellsindifferentseasons．3Thegrowthofdominantspecieswasaffectedbyenvironmentalfactorswetermedsome“leadingfactors”asthesehadthegreatesteffects．WhenLakeChaohubecameeutrophiclighttemperatureandpHweretheleadingfactors．4Althoughleadingfactorsaffectthegrowthofdominantspeciesphotosynthesisisthemostessentialvariable．Thestudyoftheecophysiologyofphotosynthesismayrevealtherelationshipbetweenleadingfactorsanddominantcyanobacteriaandalsoclarifywhyafewspeciesofcyanobacteriaareabletobedominantduringparticularseasons．WhentemperatureandpHincreasedbetweenspringandsummerthephotosyntheticrateofM．wesenbergiiwasgreaterthanthatofM．viridis．WhentemperatureandpHdecreasedbetweensummerandautumnthiswasfavorabletoM．aeruginosaphotosynthesis．SimilarchangesoccurredbetweenautumnandwinterandM．viridisreplacedM．aeruginosa．AlthoughA．flos－aquaewasabletogrowathighertemperaturesandpHthanM．viridisthisfilamentouscyanobacteriumwasnotabletoadapttohigherlightintensity．Lightintensityappearstobecrucialforthesecyanobacteria．Ourhypothesisisformulatedfromcommonunderstandingwithinthenaturalsciencesquestionsarisingatahigherlevelofintegrationsuchasecologyoragronomyoftenrequiremechanisticansweringatalowerintegrativelevelsuchastheecophysiologyofphotosynthesis．KeyWordscyanobacterialbloomsdominantspeciesecophysiologyofphotosynthesisthephotosynthesisofdominantspecieshypothesisLakeChaohu。、、1。。2。。、。。。80a101/3243546576pH/CO2879810911101。、、、、、。1210a。1064。1969211“”http//．ecologica．cn。。10013。。。“”123414。。、、。15。。。2007。3a、。“”。11Fig．1ThemapofsamplinginWesternAreaofLakeChaohu1．1GPS611N31°39'15．93″E117°18'3．43″、2N31°42'15．25″E117°20'18．98″、3N31°42'28．08″E117°21'44．96″、4N31°41'29．09″E117°23'50．68″、5N31°39'33．35″E117°21'40．85″6N31°35'39．03″E117°20'11．62″。2008420093。1．21．2．116-17。1000—1400。1、3、4、562。250mL00．5m1m1．5m2m1、2。。、、pH、TN、TP。“”18。1．2．2161925#64μm“∞”100mL。《———、》2021。1L1L15mL。24h30mL。。1．2．322-23YY=ni/N×finiiNfii。Y0．02。1．2．424-25BG-11CT25±1℃、80μmol·m－2·s－1。。079231http//．ecologica．cn1．2．526ClarkHansatechLtd．U．K．。2mLDC21015。ORT1。1．2．6a27a。3mL4℃6—14h4000r/min10minA665。Chlaμg/mL=13．9×A665a。1．3ExcelOriginVersion7．5OriginLabSPSS11．5。220084—20093Fig．2Monthlychangesofprimaryproductivity