spp1315 the book of abstracts 2014 · biological, physical and chemical properties of the bgi. a...

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InternationalSymposiumoftheGermanPriorityProgramme

SPP1315BiogeochemicalInterfacesinSoilon:

BiogeochemicalInterfacesinSoil–TowardsaComprehensiveandMechanisticUnderstanding

ofSoilFunctions

Leipzig,HelmholtzCentreforEnvironmentalResearch–UFZ,“Kubus”,October06–08,2014

BookofAbstracts

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TableofContents:

Programme3OralPresentations10Session1UnravellingBGIstructure:Formation&ArchitectureofBGIs10Session2ExploringBGIs:NewAvenuesfor“Provocative”JointExperimentsandComplementaryCutting‐EdgeTechniques19Session3MicrobialEcologyofBGIs:Soil(Micro‐)Organismsas“Architects”and“Actors”ofBGIs32Session4BGIsinChangingEnvironments:BGIsDynamics&HeterogeneitywithConsequencesforProperties&Processes40Session5QuantitativeUnderstandingofBGIsFunctions:TheoreticalConcepts&ModelstoExplainStructure,Properties&FunctionsofBGIs50Posters60Session1UnravellingBGIstructure:Formation&ArchitectureofBGIs60Session2ExploringBGIs:NewAvenuesfor“Provocative”JointExperimentsandComplementaryCutting‐EdgeTechniques63Session3MicrobialEcologyofBGIs:Soil(Micro‐)Organismsas“Architects”and“Actors”ofBGIs75Session4BGIsinChangingEnvironments:BGIsDynamics&HeterogeneitywithConsequencesforProperties&Processes93Session5QuantitativeUnderstandingofBGIsFunctions:TheoreticalConcepts&ModelstoExplainStructure,Properties&FunctionsofBGIs110ListofParticipants133

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Programme

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PROGRAMMEOFTHESYMPOSIUM06.‐08.OCTOBER2014,LEIPZIGKUBUSATTHEUFZ‐LEIPZIG

MondayMorning,October6th

Schedule Topic PresentingAuthor

8:20‐8:30 OpeningNote KaiUweTotsche

SessionI:UnravellingBGIstructure:Formation&ArchitectureofBGIsChairedby:GeertjeJ.Pronk

8:30‐9:15 FormationofPreferentialFlowandArchitectureofBiogeochemicalInterfaces

inSoilHenryLin

9:15‐9:35 FormationandMaturationofBiogeochemicalInterfacesinSoil

AnjaMiltner

9:35‐9:55 ALightIssue:MicrobialControlsUpontheArchitectureoftheSoil:AtmosphereInterface Invited:KarlRitz

9:55‐10:25 Rest‐CoffeeBreak

Chairedby:JoannaHanzel

10:25‐11:10 RootArchitectsandPlasticPlumbers IainYoung

11:10‐11.30 ContributionofMicrobialBiomasstotheFormationofSoilOrganicMatterandBGI

MatthiasKästner

11:30‐11:50 AnInterdisciplinaryApproachTowardsUnderstandingBiogeochemicalInterface

FormationUsingArtificialSoilsGeertjeJ.Pronk

11:50‐12:10 HotSpotsandHotMoments:EffectofPlantLitterontheFormationofBiogeochemical

InterfacesinSoilMichaelSchloter

12:10‐12:30 SoilParticleWettabilityasaControllingFactorinBiogeochemicalInterfaceFormation Marc‐OliverGöbel

12:30‐13:45 Lunch

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MondayAfternoon,October6th

SessionII:ExploringBGIs:NewAvenuesfor“Provocative”JointExperimentsandComplementaryCutting‐EdgeTechniques

Chairedby:IngridKögel‐Knabner

13:45‐14:30 ImagingBGIs:ASimultaneousLookfromDifferentPerspectivesMayOfferClues Hans‐JörgVogel

14:30‐14:50 PreferentialSequestrationofOrganicMatterinOrgano‐MineralClustersasRevealedby

Nano‐ScaleSecondaryIonMassSpectrometryandIsotopicTracing

KatjaHeister

14:50‐15:10 QuantificationofpH‐DependentSpeciesofOrganicMoleculeswithUV/VISSpectroscopy

andFactorAnalysisThomasRitschel

15:10‐15:30 Multi‐ImagingApproachtoStudytheRoot‐SoilInterface

NicoleRudolph‐Mohr

15:30‐15:50 VisualizationofEnzymeActivitiesatSoil‐RootInterface

BaharsadatRazavidezfuly


Chairedby:SaschaOswald

16:20‐17:05 Revealing(Bio‐)PhysicalStructureandMicrobialColonizationofBGIinSoil:FromQualitativeObservationtoQuantitative

Modelling

ThiloEickhorst

17:05‐17:25 X‐RayPhotoelectronSpectroscopy(XPS)asaVersatileTooltoRelateSurface

ChemicalCompositionandWettingPropertiesSusanneK.Woche

17:25‐17:45 CharacterizationofWetAggregateStabilityofSoilsby1H‐NMRRelaxometry

ChristianBuchmann

17:45‐18:05 HowCanMagneticResonanceImaging(MRI)HelpUnderstandingColloidalParticle

TransportinSoilsEricMichel

18:05‐18:25 RapidFormationofNon‐ExtractableResiduesofSulfonamides:ParamagneticSpinProbingRevealedCovalentBondingofAromatic

AminoGroup

MichaelMatthies

18:25‐18:45 TheInfluenceofExtracellularOxidativeEnzymesontheFormationofNon‐Extractable

AndreasSchäffer

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Residues(NER)of14C‐MetalaxylinSoil

18:45‐19:05 EffectofPhenanthreneandHexadecaneontheReleaseandTransportofMobile

OrganicMatterinArtificialSoil–ATwoLayerColumnStudy

KatharinaReichel

19:05‐20:30 Dinner

20:30‐22:00ac.

PosterSessionI(No.:1‐30)Chairedby:AnjaMiltner

TuesdayMorning,October7th

SessionIII:MicrobialEcologyofBGIs:Soil(Micro‐)Organismsas“Architects”&“Actors”ofBGIs

Chairedby:LukasY.Wick


8:30‐9:15 MicrobialDiversityattheInterface GeorgeA.Kowalchuk

9:15‐9:35 InfluenceofOrganicMatteronMicrobialCommunityStructureandActivityinSoil

Microhabitats

MichaelHemkemeyer

9:35‐9:55 TransportofPhenanthreneinSoilColumnsInfluencetheBacterialCommunityStructure

DoreenBabin

9:55:10:40 SpatialHeterogeneity,Diversity,andEcosystemFunction

JamesProsser


Chairedby:EllenKandeler

11:10‐11:55 Microorganisms:ActiveInhabitantsandArchitectsofBGIsinArtificialSoils

KorneliaSmalla

11:55‐12:15 ReducingDiffusionLimitationShiftstheDominantNitrateReductionMetabolismFromIncompleteDenitrificationtoDissimilatory

NitrateReductiontoAmmonium

LassePedersen

12:15‐12:35 TheSoil‐LitterInterface:AHotSpotforBiogeochemicalInteractions ChristianPoll

12:35‐14:00 Lunch

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TuesdayAfternoon,October7th

SessionIV:BGIsinChangingEnvironments:BGIsDynamics&HeterogeneitywithConsequencesforProperties&Processes

Chairedby:NicoleRudolph‐Mohr

14:00‐14:45 TrophicInterdependenciesShapeSpatialSelf‐OrganizationofMicrobialConsortiaonComplexHydratedSoilSurfaces

DaniOr

14:45‐15:05 BacterialImpactontheWettingPropertiesofSoilMinerals

JanAchtenhagen

15:05‐15:25 Fungal‐MineralInterfaceDuringLeafLitterDecomposition FlaviaPinzari

15:25‐15:45 HowDoestheAdditionofSulphurtoSoilInfluenceChemosynthesisandCarbonFlux? BrianP.Kelleher

15:45‐16:05 UnderstandingRootGrowthInducedChangesinSoil

SonjaSchmidt


Chairedby:JörgBachmann

16:40‐17:25 ActiveMicrobialDispersalinSoils:EffectofSpatialHeterogeneityandVaryingHydration

ConditionsBarthF.Smets

17:25‐17:45 SoilOrganicMatterDecomposition–TheRolesofMicrobialHabitatsandofMicrobial

CommunitiesNaoiseNunan

17:45‐18:05 DroughtImpactonSpatialHeterogeneityofEnzymeActivitiesontheRoot‐SoilInterface

MuhammadSanaullah

18:05‐18:50 TheDynamicsandPropertiesofBiogeochemicalInterfacesinSoil:TheImpact

ofChangingEnvironments

GeorgHaberhauer

18:50‐20:30 Dinner

20:30‐22:00ac.

PosterSessionII(PosterNo.:31‐54)Chairedby:SusanneK.Woche

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WednesdayMorning,October8th

SessionV:QuantitativeUnderstandingofBGIs:TheoreticalConcepts&ModelstoExplainStructure,Properties&FunctionsofBGIs

Chairedby:FriederikeLang


8:30‐9:15 MolecularModelsandSimulationsofSoilOrganicMatter:Structure,Dynamicsand

InteractionswithOtherEntitiesChrisOostenbrink

9:15‐9:35 OrganicFunctionalGroupDensityandStructuralDynamicsofSoilOrganicMatterTakeKeyRoleinCationBridgeFormation

YamunaKunhiMouvenchery

9:35‐9:55 OrganicSorbateInducedCooperativeHydrationofSoilOrganicMatter MichaelBorisover

9:55‐10:15 LinkingPhysicochemicalandStructuralPropertiesofBiogeochemicalInterfacesinSoils

toSequestrationofOrganicPollutantsJaaneKrüger

10:15‐10:35 ModelingSurfaceChemistryofFerrihydrite Invited:JamesKubicki


Chairedby:ThiloStreck

11:00‐11:45 AConceptualApproachtoExperimentalPedology

IngridKögel‐Knabner

11:45‐12:05 DelineationofBiogeochemicalProcessesControllingContaminantFateinanMesoscale

AquiferbyCompound‐SpecificIsotopeAnalyses

MartinElsner

12:05‐12:25 Micro‐ScaleModelingofPesticideDegradationCoupledtoCarbonTurnoverinthe

DetritusphereHolgerPagel

12:25‐12:45 HierarchicalStructureofBiogeochemicalInterfacestoPredicttheTransportofReactive

ChemicalsinSoilThomasRitschel

12:45 AFinalNoteandTheEndoftheSymposium

PatriciaSchmitz‐Möller&KaiUwe

Totsche

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INTERNALMEETINGFORSPP‐MEMBERS

WednesdayAfternoon,October8th


13:30‐13:45 LinkingBGIPropertiestoProcesses:ExemplifiedbySorption,TransformationandBioavailability MichaelSchloter

13:45‐14:00 NanothermalAnalysisofYoungSoils GabrieleE.Schaumann

14:00‐14:15 ComputationalChemistryandAdvancedPhysico‐ChemicalCharacterization:Quantitative

ReconstructionandModellingofBGIs,TheirPropertiesandInteractions

GabrieleE.Schaumann

14:15‐14:30 CombinedExperimentalandModelingStudyonAdsorptionofMCPAHerbicidebyGoethite

DanielTunega

14:30‐14:45 HierarchicalStructureofBiogeochemicalInterfacesinSoiltoPredictTransportofReactive

ChemicalsinSoil

ThomasRitschel

14:45‐15:15 CoffeeBreak

15:15‐15:30 SoilMicrobialEcology:ExploreCommunity'sRoleforBGIsas"ArchitectandActor"‐Elucidate

TransformationofOrganicChemicals

SteffenKolb&MarcusHorn

15:30‐15:45 TheSoil‐LitterInterface:AHotSpotofBiogeochemicalInteractions

ChristianPoll

15:45‐16:00 WormColumnExperiment MarcusHorn

16:00‐16:15 StabilizationofMicrobialBiomassinSoils:ImplicationsforSOMFormation,Xenobiotic

DegradationandResidueFormation

MatthiasKästner

16:15‐16:30 InteractionsofBacteriawithMineralsatBGIsinSoil AnjaMiltner

16:30‐16:45 FinalDiscussion

16:45 TheEnd

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OralPresentationsSession1:UnravellingBGIStructure:Formation&ArchitectureofBGIs

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Session1:UnravellingBGIsStructure:Formation&ArchitectureofBGIsKeynoteTalk

FormationofPreferentialFlowandArchitectureofBiogeochem‐istryinSoilsHenryLinDepartmentofEcosystemScienceandManagement,ThePennsylvaniaStateUniversity,USAPreferential flow(PF) isubiquitousandcontrolsawidevarietyof soilphysical, chemical, andbiologicalprocesses. Thecomplexanddynamicinteractionbetweenpreferentialflowandma‐trixflowresultsindiverseflownetworksembeddedinthemosaicsubsurface.Thepresenceofmacropores in different soils, for instance, often leads to spatial concentrations ofwater andchemicals through theCritical Zone that is poorlydescribedby classical approaches. Thishassignificant implications formodeling andpredicting hydrologic processes and biogeochemicaldynamics.As an example,macroporesoften trigger “hot spots” and “hotmoments”ofbiogeo‐chemical reactions. Interpretations of pointmeasurementswithout knowingmacropores arenowoftenquestioned,becausetheuncertaintyofwhethersoilsolutionisextractedfromstag‐nant or high velocity flowpaths (such asmacropores)makes it difficult to reliably determinemass flux rates.Macropore linings,on theotherhand, could restrict lateralmass transferandreducesorptionandretardation,thusenhancingphysicalandbiochemicalnon‐equilibriumsinfieldsoils.Becausechemicalscarriedbymacroporeflowarenotinintimatecontactwiththesoilmatrix, their binding by soil particles is considerably reduced. Thiswill impact the residencetimeofchemicalsintheCriticalZone.

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Session1:UnravellingBGIsStructure:Formation&ArchitectureofBGIs

FormationandMaturationofBiogeochemicalInterfacesinSoilAnjaMiltner1andKatjaHeister21DepartmentofEnvironmentalBiotechnology,HelmholtzCentreforEnvironmentalResearch–UFZ,Leipzig,Germany2LehrstuhlfürBodenkunde,TechnischeUniversitätMünchen,Freising‐Weihenstephan,GermanySoils are heterogeneous fine‐structured 3‐phase systems and thus are characterised by abun‐dant interfaces.Thesebiogeochemical interfaces(BGI)provideaparticularhabitat forsoilmi‐croorganismsandmostoftheprocessesoccurringinsoils,andarethereforehotspotsfortheseprocesses.AsBGIdevelopovertime,theircharacteristicschange;asaresult,theysupportdif‐ferent typesofprocessesatdifferent times, resulting in temporalvariabilityand thushotmo‐mentsfortheseprocesses.Inordertounderstandandcontrolsoilprocesses,weneedtounder‐standthecharacteristics,theformation,andthematurationofBGI.BGIcontainmineralsaswellasbiologicalandabiotic(chemical)soilcomponents.Thesecomponentsinteractanddeterminebiological,physicalandchemicalpropertiesof theBGI.Aparticular importantcharacteristic istheoccurrenceofconcentrationandenergygradientsatBGI,whichdrivebiologicalactivityaswellaschemicalandphysicalprocesses.BGIaffectmanymicrobially‐drivensoilprocessessuchasSOMformationandturnoverofallkindsoforganiccompounds.BGIcanbefoundatdifferentspatialscalesrangingfromthemoleculartolandscapescaleandcontrolprocessesattemporalscalesrangingfromfemtosecondstomillennia.Themultitudeofsoilconstituentsandthelargerange inscales result inawidevarietyofBGI in soils,whichallneed tobeexaminedandde‐scribed. During formation of BGI, we can distinguish three phases: In the mixing phase, thechemical andgeological constituents aremixedand come into contactwitheachother. In thecolonisationphase,thefirstorganismscolonisethemixedmaterialandstarttheiractivity.Thisfinally results in the interaction phase which is characterised by processes involving two ormoreoftheBGIcomponents.Here,BGIatdifferentscales(frommoleculartohorizonscale)andtheirimpactonselectedsoilprocesseswillbediscussedwithrespecttotheirformation(initialstage)andmaturation(developmentovertime).Particularfocuswillbeontheintra‐andinter‐molecular interactions,onselectedmicrobialactivitiesandonthe influenceofearthwormsontheseactivities.Thecombinationof various techniquesallowedus to identify the functionsofBGI as buffers, accumulators and transformators in soil and thus as important drivers of soilprocesses.

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Session1:UnravellingBGIsStructure:Formation&ArchitectureofBGIsInvitedTalk

ALightIssue:MicrobialControlsUpontheArchitectureoftheSoil‐AtmosphereInterfaceKarlRitz1,2ElenaArmenise1,RobertSimmons1,AminGarbout2,SachaMooney2,CraigSturrock2,SujungAhn3andStefanDoerr31SchoolofEnergy,EnvironmentandAgrifood,CranfieldUniversity,Cranfield,UK2DivisionofAgriculture&EnvironmentalSciences,UniversityofNottingham,SuttonBonington,UK3CollegeofScience,SwanseaUniversity,Swansea,UKThe soil surface is a crucial interface,which connects the atmosphere to thepedosphere.Thenatureandpropertiesofthiszoneplayimportantrolesingoverningmanyaspectsofsoilfunc‐tion,includinghydrologicalprocesses,propensitytoerosion,gasexchange,seedlingemergence,andbioticinteractions.Itiswellrecognisedthat“biologicalsoilcrusts”arecommonandofeco‐logical significance in many natural habitats, particularly in arid and semi‐arid regions, butamoregeneralprevalenceofadistinctsoilsurfacebiotaisbecomingincreasinglyapparent.Par‐ticularlylittleisknownaboutthenature,propertiesandfunctionalsignificanceofthesoilsur‐facebiotainarableandhorticulturalsystems,andlessstillabouttheinteractionsbetweensoilstructureandbiologyinthiszone.Microbialcommunitiesinhabitingthesoilsurfacetendtobedominatedbyphotoautotrophs,drivenbylight,andareverydistinctfromthoseinthesoilma‐trixbelow.“Physicalcrusts”oftendeveloponsoilsviatheactionofraindropsimpactingthesoilsurface, resulting in aggregate breakdownand the re‐organisationof disaggregated soil parti‐cles. These then forma surface layer that is typically lessporous andmore compact than theunderlyingbulksoil.Weconductedalaboratorystudytoinvestigatetherelationshipsbetweenmicrobialcommunitystructureandsoilstructuraldynamicsandhydrologicalpropertiesintwocontrasting‐texturedsoilsusedinhorticulturalproduction.Wemanipulatedthesurfacemicro‐bial communitiesby controlling light, andviaprokaryotic‐ andeukaryotic‐selective inhibitors.Theultra‐fine‐scale spatialand temporaldynamicsof structural seal formationwasvisualisedandquantifiedviaX‐raymicrocomputedtomography.Resultsshowedsignificantvariationsandacomplextopologyoftheextremesurfaceinrelationtotreatment.Theporositybetweendiffer‐ent typesofunderlyingcrusts,and thevolumeof surface‐connectedporesvariedsignificantlybetweenthetwosoiltypes.Fungal‐andphotoautotroph‐dominatedsystemsshowedincreasedporosity, but reduced hydraulic connection, penetrative resistance and structural resilience,than bacterially‐dominated systems. Greater hydrophobicity was manifest in the photoauto‐troph‐dominatedsystems.Theseresultsdemonstrate thesignificantrole thesurfacebiotacanplayinthefunctionalbehaviourofsoilsurfaces,thesubstantivepartplayedbyphotoautotrophsinsuchfunctions,andattendantimplicationsforpotentiallymanagingthenatureofthesoilsur‐face.

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Session1:UnravellingBGIsStructure:Formation&ArchitectureofBGIsKeynoteTalk

RootArchitectsandPlasticPlumbersIainMYoung1,RichardFlavel1,RebeccaHaling2,ChrisGuppy1andMattTighe11Plant,SoilandEnvironmentalSystems,UniversityofNewEngland,Australia2CSIROAgricultureFlagship,Canberra,AustraliaWehaveonlycapturedaglimpseofthemultitudeofprocessesongoingacrossthebiogeochemi‐calandbiophysicalspace insoils. Werecogniseafterdecadesof researchand technologyad‐vancesthatsoilisteemingwithlifeandcontainsthemajorityofbiodiversityontheplanet.Thishasledusintoadecadeofempiricalsciencewherewehavemeasuredandcountedsoil(micro)biologyinanattempttounderstandhowsoilworks.This“biologyofnumbersanddifferences”approachhasprovidedinvaluableinformationaboutthesoilmicrobiology.However,arguablyoverallthisapproachhasfailedtoprovideadeeperunderstandingofsoil.Thekeytoanyunder‐standingofsuchcomplexstructuresandspatio‐temporalprocessesthatdominatemostsoilsys‐tems, lies not in single discipline efforts, but rather in the emergence of integrated cross‐disciplinaryeffortsbyamultitudeofscientists.Habitatgenesisandresilienceinallporousme‐diaarekeyprocessesinallrelevantfunctions.Soil,themostcomplexbiomaterialontheplanet,reliesonanundefinedandunquantifiedbalanceofphysico‐chemical andbiologicalactivity tocreate andmaintaindiversehabitat space, the surfaceareaofwhichactsasadriver formostexchange process in soil: microbe‐mineral; root‐soil; microbe‐microbe; water‐microbe; root‐wateretc.Despitesoilteemingwithmicrobiallife,wenowarebeginningtounderstandthatthephysics of the soil determinesmany of the biological rate processes from nutrient exchange,waterdynamicsandgeneraldiffusionprocesses.Thistalkwillfocusonthesmallvolumeofsoilknownastherhizosphereandpresentdatathatcoverthebiophysicsofsoilecosystems,focus‐inginonwaterrelations,habitatgenesisandhowthebiologyandphysicsofsoilinteracttode‐terminefunction.

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ContributionofMicrobialBiomasstotheFormationofSoilOr‐ganicMatterandBGIAnjaMiltner1,JanAchtenhagen1,MichaelSchweigert1,Florian‐AlexanderHerbst2,Tho‐masFester1andMatthiasKästner11DepartmentofEnvironmentalBiotechnology,HelmholtzCentreforEnvironmentalResearch‐UFZ,Leipzig,Germany2DepartmentofBiotechnology,ChemistryandEnvironmentalEngineering,AalborgUniversity,Aalborg,DenmarkSoilorganicmatter(SOM)playsanimportantroleinsoils,bothforsoilfertilityandforthesoilcarboncycle.Themolecular imprintof thedirectprecursorsof soilorganicmatterwilldeter‐mine themineralisation, transformationandstabilisationofSOM.Recently, ithasbeenshownthatmicrobialbiomassresiduescontributesignificantlytotheformationofSOM(Simpsonetal.,2007;Miltneretal., 2012).Although livingmicroorganismsonly constituteabout1‐2%of thecarboninsoil,theircontributiontoSOMformationismuchhigherbecauseoftheirrapidturn‐over.AhighcontributionofmicrobialresiduestoSOMcanexplainwhymicrobialbiomoleculesarerelativelystableinsoilandevenaccumulateduringSOMdevelopment,butalsootherchemi‐calandphysicalpropertiesofSOMsuchastheelementalcompositionandthewaterrepellency.Westudiedthefateofmicrobialbiomassresiduesinsoilsbyincubating13C‐labelledmicroor‐ganisms in soil for up to 240 days. Themicroorganismswere selected to represent differenttypes of microorganisms, each with its characteristic cell wall composition and included Es‐cherichia coli (Gramnegative bacterium),Bacillus subtilis (Grampositive bacterium) andLac‐cariabicolor(ectomycorrhizalfungus).Duringincubation,wetracedmineralisation,incorpora‐tionintobiomassasdetectedbyanalysisofbiomarkers(fattyacids,aminoacids,proteins),andtransformationtoSOMofthelabelledcarbon.Wealsovisualisedmicrobialresiduesinsoilsam‐plesbyscanningelectronmicroscopy.Wefoundthatthecarbonfromalltypesofbiomassresi‐dueswaspartlymineralised,partlyincorporatedintomicrobialbiomass,andpartlytransformedintonon‐livingSOM.Thepartitioningbetweenthesethreeprocesses,however,wasslightlydif‐ferent forthedifferentbiomasstypes.Overall treatments,50‐65%ofthemicrobialbiomassCremained in the soil during incubation.However, only a small part remained in themicrobialbiomass,themajoritywastransformedtoSOM.Inparticular,proteinsseemedtoberathersta‐bleinourexperiments.Totalaminoacidcontentsdidnotdeclineduringdegradation,andquiteanumberofB.subtilis‐derivedproteinswereconservedthroughout theexperiment.However,thebiomassresidue‐derivedcarbonwasalso incorporated intootherproteinswhichcouldbeassignedtoawidevarietyofsoilmicroorganisms, indicatingthatmanydifferentsoilmicroor‐ganismsthriveontheresiduesofotherorganisms.Scanningelectronmicrographsshowedalownumberofintactcells,butmainlyfragmentsofabout200‐500nmsize.Similarfragmentswerefound in artificial groundwatermicrocosmswhere theonlypossibleoriginwasmicrobialbio‐mass residues, inparticular cellwall fragments.These results indicate thatmicrobialbiomassresidues,inparticularcellwallfragmentsandproteins,arestabilisedinsoilandcontributesig‐nificantlytoSOMformation.Theextentofthiscontributionisdifficulttoestimateasitdependsontheresiduematerial,onthedegradingorganismsandontheenvironmentalconditions.ReferencesMiltnerA,BombachP,Schmidt‐BrückenB,KästnerM.2012.SOMgenesis‐Microbialbiomassasasignifi‐cantsource.Biogeochemistry111:41‐55.

SimpsonAJ,SimpsonMJ,SmithE,KelleherBP.2007.Microbiallyderivedinputstosoilorganicmatter:Arecurrentestimatestoolow?EnvironSciTechnol41:8070‐8076.

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AnInterdisciplinaryApproachTowardsUnderstandingBiogeo‐chemicalInterfaceFormationUsingArtificialSoilsGeertjeJ.Pronk1,2,DoreenBabin3,FranziskaDitterich4,JuliaGiebler5,KatjaHeister1,MichaelHemkemeyer6,EllenKandeler4,IngridKögel‐Knabner1,2,YamunaKunhiMou‐venchery7,ChristianPoll4,GabrieleE.Schaumann7,MichaelSchloter8,KorneliaSmalla3,AnnelieSteinbach5,ChristophC.Tebbe6,LukasY.Wick5andSusanneK.Woche91LehrstuhlfürBodenkunde,TechnischeUniversitätMünchen,Freising‐Weihenstephan,Germany2InstituteforAdvancedStudy,TechnischeUniversitätMünchen,Garching,Germany3InstituteforEpidemiologyandPathogenDiagnostics,FederalResearchCentreforCultivatedPlants,JuliusKühn‐Institute,Braunschweig,Germany4InstituteofSoilScienceandLandEvaluation,SoilBiologySection,UniversityofHohenheim,Stuttgart,Ger‐many5DepartmentofEnvironmentalMicrobiology,HelmholtzCentreforEnvironmentalResearch‐UFZ,Leipzig,Germany6JohannHeinrichvonThünenInstituteforBiodiversity,Braunschweig,Germany7InstitutfürUmweltwissenschaften,AGUmwelt‐undBodenchemieUniversitätKoblenz‐Landau,Landau,Germany8HelmholtzZentrumMünchen,GermanResearchCenterforEnvironmentalHealth,Neuherberg,Germany9InstituteofSoilScience,LeibnizUniversitätHannover,Hannover,GermanyAninterdisciplinaryapproachwasusedtogainunderstandingoftheformationofbiogeochemi‐cal interfaces in soil.Artificial soilswithdifferentmineral composition and charcoal presenceweredesignedtostudytheestablishmentofmicrobialcommunities,theirfunctionalityandtheresulting development of organic matter (OM). The artificial soils were composed to createasimplifiedsoil‐likematerialwithwell‐definedcompositionandinitialconditionsandcontaineddifferentmixturesof theminerals illite,montmorillonite, ferrihydriteandboehmite,andchar‐coal,andsampledafter3,6,12and18monthsofincubation.Thesampleswerethenanalysedformicrobialabundanceanddiversity, functionalityasdeterminedbyrespirationandenzymeactivity,OMcomposition,physicalstructureandsurfaceproperties.Here,wepresentthe inte‐gratedresultsofthisstudy,focusingonthecombinationofdifferenttechniquestogaininsightintothedevelopmentofbiogeochemicalinterfacesinsoils.Themixturesquicklydevelopedintosoil‐likesystems,andalthoughsurfacepropertiesandorganicmatterdevelopedsimilarlyforallcompositions,charcoalpresenceandmineralcompositiondidhaveacleareffectonthedevel‐opmentofmicrobial communities.The functionalityof themicrobial community,as shownbyenzymeproductionandalkanedegradation,wasatleastpartlycontrolledbythemineralspre‐sent,eitherduetodirectinteractionsofmicrobeswithmineralsurfaces,orduetoacontrolonnutrientavailabilitybysorptiontomineralsurfaces.Overall,theartificialsoilsusedinthisstudyprovidedasuitableapproachtogainamechanisticunderstandingofthemicrobiological,chemi‐cal and physical processes taking place at biogeochemical interfaces in well‐defined soil‐likesystems. This combination of a range of interdisciplinary methods illustrates how microbialcommunitiesinteractedwith,andwereaffectedby,theOM,mineralandcharcoalsurfacespre‐sentintheirhabitats.

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HotspotsandHotMoments:EffectofPlantLitterontheForma‐tionofBiogeochemicalInterfacesinSoilAnnelieSteinbach1,JuliaGiebler1,IrinaTanuwidjaja2,3,NicolasWeithmann2,StefanieSchulz2,FranzBuegger4,AntonisChatzinotas1,GeertjeJ.Pronk3,5,CordulaVogel5,LukasY.Wick1,IngridKögelKnabner3,5,HaukeHarms1andMichaelSchloter21DepartmentEnvironmentalMicrobiology,HelmholtzCentreforEnvironmentalResearch–UFZ,Leipzig,Germany2ResearchUnitEnvironmentalGenomics,HelmholtzCentreMunich,Neuherberg,Germany3ChairofSoilScience,DepartmentEcologyandEcosystemManagement,TechnicalUniversityofMunich,Freising,Germany4InstituteofSoilEcology,HelmholtzCentreMunich,Neuherberg,Germany5InstituteforAdvancedStudy,TechnicalUniversityofMunich,Garching,GermanyPlantlittercreatesalargenumberofnewbiogeochemicalinterfaces(BGIs)insoilandincreasessoilheterogeneity.Asaconsequence,bulksoilhabitats,witharelowinmicrobialactivities,aretransformedintohotspots,withhighlyactivemicrobialcommunitiesafter litter fall.Overtimemicrobialactivitiesdecreasesat thisBGIsasaresultofreducednutrientcontentsandsolublecompoundsoftheplantlitterleachtosoillayersdeeperthanthelitter–soilinterface,changingalsoheretemporallymicrobialcommunitystructureandfunction.Thisconceptofhotspotsandhotmomentshasbeenwidelyproposedinliteraturebutrarelyprovenonthesmallscale,wheremicrobes shape their environment. As plant litter material contains a large number of plantwaxes,alkanedegradingmicrobesareahighlyimportantpartofthelitterdegradingmicrobialcommunities.Thusintheframeofourprojectwefocusedontheeffectsoflitterapplicationontheabundance,diversityandactivityofmicrobialcommunities involvedinalkanedegradationusingthealkanemonooxygenasegenealkBasaproxyintimeandspace.WeperformedseveralmicrocosmexperimentsaddressingquestionsontheroleofthelittermaterialaswellasofthesoiltypefortheformationofcharacteristicBGIsmainlyattheborderoflitterandsoil,butalsoindeepersoillayers.Thereforeweusedsoils,whichwereunderagriculturalusewithdifferentsoiltexture.Inadditionweperformedstudiesusingmixturesofinorganicmaterials,whichformthe soilmatrix,which had been inoculatedwithmicrobes from a “natural soil” togetherwithsterilemanuretostimulatesoil formation(“artificialsoils”)atdifferentmaturationstages.Forthe“natural”soilsourresultsindicateaclearresponsepatternofallinvestigatedbioticandabi‐oticparametersdependingontheappliedlittermaterial,thetypeofsoilused,thetimepointofsamplingandthesoilcompartmentstudied.Asexpectedthedistributionofalkanesofdifferentchainlengthformedasteepgradientfromthelitterlayertothebulksoil.Atthelitter–soilinter‐facethecommunitystructureandabundancepatternsofalkBweredrivenbytheappliedlittertype and its degradation. Surprisingly, thedifferences between thedifferent compartments inonesoilweremorepronouncedthanthedifferencesbetweensimilarcompartmentsinthesoilsstudied. For the “artificial” soils we observed an overall increasing divergence in communitycompositionofalkBharbouringmicrobesduringmaturation,withoutlitterapplication.Theim‐pactofmetaloxidesonalkanedegradingcommunitiesincreasedduringsoilmaturationwhereasthecharcoal impactdecreasedover timeofmaturation.Amongst theclayminerals illite influ‐encedthealkBharbouringbacteriasignificantly,butnotmontmorillonite.Thelitterapplicationinducedstrongcommunityshifts in soils for thosesols thathavebeenmaturated fora longertimeperiodtowardsfunctionalguildstypicalforyoungermaturationstagespointingtoaresil‐ienceof thealkanedegradation function fosteredbyapotential ‘seedbank’ formation.OverallourdataclearlyindicatestheimportanceofplantlitterfortheformationofBGIsinsoil.Theef‐fectsobservedhowevervarystronglyonthesoiltypeandthesoildevelopmentstage.

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SoilParticleWettabilityasaControllingFactorinBiogeochemicalInterfaceFormationMarc‐O.Goebel1,SusanneK.Woche1,PriyaM.Abraham2,GabrieleE.Schaumann2,Ga‐wanJ.H.Muehl3andJörgBachmann11InstituteofSoilScience,LeibnizUniversitätHannover,Hannover,Germany2InstituteforEnvironmentalSciences,UniversitätKoblenz‐Landau,Landau,Germany3InstituteofVegetableandOrnamentalCropsGrosbeeren,GermanyExperimental findingsrevealthatsorptionoforganicmatterorattachmentofbacteriacanen‐hancewaterrepellencyoforiginallywettablemineralparticlesduringthe initialstagesofbio‐geochemicalinterface(BGI)formation.This,inturn,canfeedbackonsubsequentBGIformationas soil particle wettability controls the movement and distribution of water in the soil, andhence,stronglyaffectsthetransportofdissolvedorganicmatter,nutrients,andmicroorganisms.Correspondingprocessesdependonsolid–liquidinteractions,whicharedeterminedbythein‐terfacialfreeenergiesoftheinvolvedphases.Thesolidsurfacefreeenergynotonlydeterminesthewettabilityofparticlesbutisalsoimportantfortheiradhesionproperties.Focusingonboth,theobjectiveofthisstudywastoinvestigatetheeffectofsoilparticleinterfacialpropertieson(i)liquidphasedistributionand(ii)colloidaltransportandinteractionsinporousmedia.Asmin‐eralmatrixweusedquartzsandparticles(63–200μm)ofdifferentwettability.Distributionandconnectivity ofwaterwas visualizedby confocal laser scanningmicroscopy (CLSM) and envi‐ronmentalscanningelectronmicroscopy(ESEM).Transportandretentionofcolloidswasstud‐ied by analyzing the breakthrough behavior of 1 μm carboxylatedmicrospheres in saturatedsandcolumnsatdifferentionicstrengths.Interactionfreeenergiesapproximatedfromzeta(ζ)‐potentialandcontactangledatawereusedtoexplainthecolloidretentionbehavior.AsrevealedbyCLSM,reducedparticlewettabilityleadstoadecreaseinwettedareaandwaterphasecon‐nectivity.Theeffectofwettabilitydecreasedwith increasingwatercontentandwasno longersignificantwithrespectto liquidphasespatialdistributionatwatercontents>30vol‐%.ESEMcondensationexperimentscorroboratethesefindings,showingthatonwaterrepellentparticleswater condensed as small drops, whereas it condensed uniformly on wettable particles. Theliquidmenisciformedbetweenwaterrepellentparticleshadsmallercross‐sectionalareasthaninthewettablematrix,illustratingthatwaterconnectivitybetweenparticlescanbeconsidera‐bly reduced. The breakthrough experiments revealed that colloids were more effectively re‐tainedinwaterrepellentthaninwettablesand.Thelargedepositionratesfoundforwaterre‐pellentsandcouldprimarilybeexplainedbyaverysmallelectron‐donorcomponentofsurfacefreeenergy, leadingtostronglyattractiveacid–base interactionsatsmallseparationdistances.Inaddition, increasing ionicstrengthreducedtherepulsiveelectrostatic interactionsandgeneallyincreasedcolloiddepositionwiththeeffectbeingmorepronouncedagainforthewaterre‐pellent sand. However, the calculated values of interaction free energy should be consideredonlyasanapproximationbecausenanoscalesurfacechemicalheterogeneityandroughness,asrevealedbyatomicforcemicroscopy,canpotentiallybiasthedeterminationoftheactualinter‐actionenergyconditions.Overall,ourfindingsdemonstratetheintrinsicrelationshipbetweenaparticle’swettability(i.e., itsaffinityforwater)anditsabilitytointeractwithcolloidsandem‐phasize therelevanceofparticlewettabilityasa controlling factor forboth liquiddistributionandadhesionphenomenainporousmedia.

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Session2:ExploringBGIs:NewAvenuesfor“Provocative”JointExperiments&ComplementaryCutting‐EdgeTechniques,incl.Spectroscopy,(Spectro)Microscopy&Tomography

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Session2:ExploringBGIs:NewAvenuesfor“Provocative”JointExperiments&ComplementaryCutting‐EdgeTechniques,incl.Spectroscopy,(Spectro‐)Microscopy&TomographyKeynoteTalk

ImagingBGIs:ASimultaneousLookfromDifferentPerspectivesMayOfferCluesHans‐JörgVogelHelmholtzCentreforEnvironmentalResearch‐UFZ,HalleMostof soil functionsdependonbiological, chemical andphysicsprocesseswithin a complexarchitectureofporesandsolidmaterials.Thisistruefortherecyclingofnutrientsandthestor‐ageofcarbon,thefiltrationofgroundwaterandforqualityofsoilsashabitatforamultitudeoforganisms.Thenotionofbiogeochemicalinterfaces(BGIs)isthoughttoincludethelocal,micro‐scopic conditionswherebiological actorsmeet theirphysicochemical environment andwherereactionsarecontrolledbytheaccessibilityofrequiredingredientsandespeciallybytheavail‐ability of water and oxygen. The fundamental difficulty for a profound understanding of soilprocessesandtheirinteractionisthefactthatsoilsareopaqueand,thus,thedetailedsoilarchi‐tectureandthedirectobservationofongoingprocessesishardlypossible.Today,newtoolsareavailable to make soil transparent and to characterize soil architecture with minimal distur‐banceandinfullthreedimensions.EspeciallyX‐raytomographyisasuitabletooltoquantifythespatialstructureofporesandsolidatresolutionsrangingfromthesub‐micronscaletothescaleofsoilhorizons.Besidesthephysicalstructureofporesandsolidwhichdeterminestheflowofwater,oxygen,solutesandparticlesalsothebiochemicalstructureisofcentralimportance.This,however,cannotbevisualizedbyX‐raytomographyandistypicallyobtainedonlyafterdestruc‐tivesampling.Inthispresentationwediscussanavenuetowardsamorecompletevisualizationandquantificationofthesoils’functionalarchitecture.ItisbasedonX‐raytomographyatvari‐ousspatialresolutionstoarriveataexhaustivepictureofthesoilporestructure,i.e.transportpathways. Thebiochemical structure canbe obtained from chemicalmapping of impregnatedcross‐sectionasprovidedbynewtechniquesasSEM‐EDXorNanoSIMS.Thechallengeistopro‐jecttheresultsbacktothethreedimensionalrealityandtoconnectthespatialscalesfromsubmicronstosoilhorizons.

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Session2:ExploringBGIs:NewAvenuesfor“Provocative”JointExperiments&ComplementaryCutting‐EdgeTechniques,incl.Spectroscopy,(Spectro‐)Microscopy&Tomography

PreferentialSequestrationofOrganicMatterinOrgano‐MineralClustersasRevealedbyNano‐ScaleSecondaryIonMassSpec‐trometryandIsotopicTracingCordulaVogel1,KatjaHeister1,CarstenW.Mueller1,CarmenHöschen1,F.Buegger2,Ste‐fanieSchulz3,MichaelSchloter3andIngridKögel‐Knabner1,41LehrstuhlfürBodenkunde,TechnischeUniversitätMünchen,Freising‐Weihenstephan,Germany2InstituteofSoilEcology,HelmholtzZentrumMünchen,Neuherberg,Germany3ResearchUnitofEnvironmentalGenomics,HelmholtzZentrumMünchen,Neuherberg,Germany4InstituteforAdvancedStudy,TechnischeUniversitätMünchen,Garching,GermanyTheassociationoforganicmatter (OM)withmineralparticles isonemajormechanism insoilOM sequestration. The contacting different organic, inorganic and biological components ofasoildefinethesoil’sbiogeochemical interface,which isanactivehotspotof fundamentalsoilprocesses.Bycombiningnano‐scalesecondary ionmassspectrometry(NanoSIMS)withstableisotopetracing,itispossibletostudytheformationandspatialheterogeneityoforgano‐mineralassociationsandtovisualizethearchitectureofthebiogeochemicalinterfaceofsoilatarelevantscale.Here,we follow the formation of organo‐mineral associations over timeby imaging thecomplex interaction between soil mineral surfaces and decomposed organic compounds anddemonstratetheheterogeneouscompositionandthedevelopmentofbiogeochemicalinterfacesinsoil.Weincubatedatopsoil(sieved<2mm,AphorizonofaLuvisol)with13Cand15Nlabelledlitter material under controlled laboratory conditions. Samples were taken 2 hours after thestartoftheincubationandafter1,7,21and42days.Paralleltothedeterminationofmicrobialbiomass13C,salt‐extractableorganiccarbon13Candtheisotopiccompositionofbulksoilandsoilfractions (obtained by a combined density and particle size fractionation) using isotope ratiomassspectrometry,thespatialdistributionofOMwasinvestigatedbyNanoSIMSanalysisoftheclay‐sizedfraction.ByquantificationofexposedareasvisiblebyNanoSIMS,weshowthatonlyup to19%of themineral surfaces are coveredbyOM,whereasmostmineral surfacesdonotshowanyOMcoverage.Ourstudydemonstrates thatmineralparticles inclusteredstructureswithroughsurfacesexhibitthepreferentialbindingspotsforOM.ComparisonoftheOM‐coatedareasrevealedbythe2DNanoSIMSimagingandN2adsorptiongivesevidencethatmineralpar‐ticleswithahigh specific surfaceareaare coveredbyOM in these clusters.Consequently,weidentifydistinctivemicro‐scalespotsenrichedin13Cand15NandapreferentialbindingofOMtoroughsurfacesofmineralclustersasahighlyactivedomaininsoil.ReferenceVogelC,MuellerCW,HöschenC,BueggerF,HeisterK,SchulzS,SchloterM,Kögel‐KnabnerI.2014.Submi‐cronstructuresprovidepreferentialspotsforcarbonandnitrogensequestrationinsoils.Nat.Commun.5:2947.doi10.1038/ncomms3947.

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QuantificationofpH‐DependentSpeciesofOrganicMoleculeswithUV/VISSpectroscopyandFactorAnalysisThomasRitschelandKaiUweTotscheInstituteofGeosciences,FriedrichSchillerUniversityofJena,Jena,GermanySpectroscopicmethodsareamongthemostcommontechniquesinnaturalsciences.Thespectrameasured forexamplewithUV/VISor fluorescencespectroscopycontain informationonelec‐tronconfigurationoftheatomsandmoleculesinthesample.Sincemanyelectrontransitionsarecoveredbyasinglemeasurement,itisdifficulttoquantifytheeffectofsinglefunctionalgroups.Eveninsinglecomponentsystems,multiplespeciescanbepresentduetodifferentprotonation,complexation or dimerisation. Factor analysis of organic compounds showed, that the shift ofspectraatdifferentpHvaluesiscausedbythesuperimpositionofspecieswithdifferentproto‐nation.We thereforemade the attempt to reconstruct the underlying spectral contribution ofthesespeciesexemplifiedbyorganicmodelcompounds.Wefocusedoncarboxylicgroups,whichareeasilyaffectedbypHandshowstronglightabsorptionintheUVrangeduetotheπ‐electronsystem, and thephenolic groups,whichdeprotonate in alkaline solutions. Specifically, vanillicacidassurrogateforlignin,salicylicacidascommonrootexudateandMCPAasmodelherbicidewereinvestigated.Theevaluationwasdonebyfactoranalysiswithanon‐negativityconstraint(positivematrixfactorisation,KimandPark,2008).Weadaptedthealgorithmtoincludefixedbackground species andoptionally unimodal spectra.This allowedus to quantitatively recon‐structspeciesdistributionfromUV/VISabsorptionandtodistinguishbetweenthecontributionofcarboxylicandphenolicgroups.ThisoffersthepossibilitytoquantifyorganiccolumneffluentconcentrationsinnearlyrealtimeandtotrackthepHvaluewithoutdirectlymeasuringit.ReferenceKimH,ParkH.2008.NonnegativeMatrixFactorizationBasedonAlternatingNonnegativityConstrainedLeastSquaresandActiveSetMethod.SIAMJ.MatrixAnal.Appl.30(2):713‐730.

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Multi‐ImagingApproachtoStudytheRoot–SoilInterfaceNicoleRudolph‐Mohr1,PaulVontobel2andSaschaE.Oswald11InstituteforEnvironmentalandEarthScience,UniversityofPotsdam,Potsdam,Germany2PaulScherrerInstitute,Villigen,SwitzerlandDynamicprocessesoccurringatthesoil‐rootinterfacecruciallyinfluencesoilphysical,chemical,andbiologicalpropertiesatlocalscalearoundtherootsthataretechnicallychallengingtocap‐ture in situ. Combining fluorescence andneutron imaging,wedeveloped and validated a newmulti‐imaging approach capable of simultaneously quantifying H2O‐, O2‐, and pH‐distributionaroundlivingplantroots.Theinterrelatedpatternsofrootgrowthanddistributioninsoil,rootrespiration,rootexudation,androotwateruptakecanbestudiednon‐destructivelyathightem‐poralandspatialresolution.Fluorescencesensor foilswereattachedat the inner‐sidesof thinboron‐lessglass‐containerswhereoneLupinusalbusplantwasgrownineachcontainer.Onday11and25,wewettedthecontainersfromthebottom,andsubsequentlytooktimeseriesoffluo‐rescenceandneutronimagesduringdayandnightcycles.Theneutronradiographsmadeitpos‐sibletovisualizeandquantifytherootsysteminassociationwiththeobservedpHandoxygenpatterns.Theolderpartoftherootsystemwithhigherrootlengthdensitywasassociatedwithfastdecreaseofwatercontentandrapidchangeinoxygenconcentration.pHvaluesaroundtheroots located inareaswith lowsoilwatercontentwassignificantly lower than therestof therootsystem.Theresultssuggestthatthecombinedimagingsetupisabletomapimportantbio‐geochemicalparametersaround livingplantswithahighspatial resolutionsufficient to relatepatternsoftheobservedbiogeochemicalparameterstotherootsystem.

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VisualizationofEnzymeActivityatSoil‐RootInterfaceBaharsadatRazavidezfuly1,MuhammadSanaUllah1,EvgeniaBlagodatskaya2andYakovKuzyakov11DepartmentofAgriculturalSoilScience,UniversityofGöttingen,Göttingen,Germany

2DepartmentofSoilScienceofTemperateEcosystems,UniversityofGöttingen,Göttingen,Germany

Extracellularenzymesareimportantduetotheirroleindecompositionofmanybiologicalmac‐romoleculesabundantinsoilsuchascellulose,hemicellulosesandproteins.Enzymeactivityiscommonly described by the Michaelis–Menten relationship, which is a saturating function ofsubstrateconcentration(Allisonetal.,2010;Chenetal.,2012).Nonethelessalackofspatiallyexplicitmethodsforthedeterminationofthedistributionofenzymeactivityintherhizospherehasbeenemphasizedseveraltimes.Recently,zymographywasintroducedasanewtechniqueinsitutovisualizeenzymeactivityinsoil.Anunderestimationofenzymesactivitycouldoccurbythistechnique,asitisbasedondiffusionofenzymesthroughthe1mmgelplate.Here,wefur‐therdevelopedsoilzymographymethodtoobtainabetterknowledgeonenzymeactivityatsoil‐rootinterfacewithahigherresolution.WegrewMaizeinrhizoboxes(12.3×12.5×2.3cm)for14daysunderoptimumconditions.Weappliedbasiczymographytoobtainfingerprintofenzymesactivityinundisturbedsoil‐plantsystem.Then,wegentlydugoutplantwiththerootswhiletherhizosphericsoilwasstillattachedtotheroots.Wevisualizedtheactivityofthreeenzymesin‐volved in C, P andN cycling (β‐glucosidase, phosphatase and leucine amino peptidase) usingzymographymethodwith smallmodifications.Wedid not use gel plate and directly attachedamembrane saturatedwith substrate to theplant root.Thereafter,wealso carefully sampledthe rhizosphere soil attached to the roots and the bulk soil and determined the Michaelis–Menten kinetics [maximal rate of activity (V

max) and half‐saturation constant (K

m)] by fluoro‐

genicallylabeledsubstratesmethod.Ourresultsofzymographymethodshowedgreateractivityofphosphatasethanβ‐glucosidasebothinveryvicinityofplantrootsandintherhizospheresoil.We also found that the activity of leucine amino peptidasewas the lowest. These differenceswerealsoconfirmedwithfluorogenicallylabeledsubstratesmethodwhichenabledustodistin‐guish differences in enzymes kinetics between microbial communities of rhizoplane, rhizo‐sphereandbulksoil.Thus,thecombinationofzymographywithenzymeskineticsispromisingfordetermining the spatial distributionof enzymeactivity in the rhizosphere as a functionofdistancefromroot.

ReferencesAllisonSD,WallensteinMD,BradfordMA.2010.Soil‐carbonresponsetowarmingdependentonmicrobialphysiology.Nat.Geosci.3:336–340.

ChenR,BlagodatskayaE,SenbayramM,BlagodatskyS,MyachinaO,DittertK,KuzyakovY.2012.Decom‐positionofbiogasresiduesinsoilandtheireffectsonmicrobialgrowthkineticsandenzymeactivities.BiomassBioenergy45:221–229

SpohnM,KuzyakovY.2013.Phosphorusmineralizationcanbedrivenbymicrobialneedforcarbon.SoilBiol.Biochem.61:69‐75.

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Session2:ExploringBGIs:NewAvenuesfor“Provocative”JointExperiments&ComplementaryCutting‐EdgeTechniques,incl.Spectroscopy,(Spectro‐)Microscopy&TomographyKeynoteTalk

Revealing(Bio‐)PhysicalStructureandMicrobialColonizationofBGI inSoil:FromQualitativeObservationtoQuantitativeModel‐lingThiloEickhorstSoilMicrobialEcology,UniversityofBremen,Bremen,GermanyBiogeochemicalinterfaces(BGI)areformedasaresultofthecomplexstructureandcompositionofsolid,liquid,andgaseouscompoundsinsoils.Theyareinfluencingvarioussoilprocessesandfunctionsbeingrelevantforsoilecosystemservicessuchasnutrientcycling,wateravailability,andclimateregulation.Avarietyofadvancedmicroscopic,spectroscopic,andtomographictech‐niqueshavebeenintroducedinrecentyearstounravelphysico‐chemicalpropertiesandmecha‐nismsofBGIonthemicro‐andeventhenanometerscale.Microorganismsareofgreat impor‐tanceforawiderangeofprocessesinsoilsaswellandthereforeinteractwithBGIandthere‐sultinggradients.TheirphysiologyisregulatedbytheenvironmentalconditionsonthescaleofmicrobialhabitatswhicharemainlythefeaturesofBGI.ThemicrobialcolonizationofBGIinsoilis hence of great importancewhen studying processes on this particular scale. A set of tech‐niqueshasbeendeveloped recently to study the colonization anddistributionofmicroorgan‐isms in theundisturbedsoilmatrixandthus in theirmicrobialhabitat insitu.This isdonevia16S rRNA targeted fluorescence in situ hybridization (FISH) combinedwithmicropedologicalresinimpregnation.Theimpregnationofthefragilesoilstructureisagoodwaytopreservetheinsituarrangementsofsoilcompoundsformingthephysicalstructureofthesoilmatrixinclud‐ing theporespacebeingrelevant for thesupportwithwaterandair. Thepreparationofhighqualitypolishedblocksandthinsectionsoftheseresinimpregnatedsamplesenablesadetailedanalysisofthespatialinformationonthelevelofmicrobialhabitatsinsoil.Acorrelativemicro‐scopic approach of the aforementioned techniques allows the characterization of BGI and theresultingphysico‐chemicallivingconditionsaswellastheidentificationandlocalizationofsoilmicroorganisms on themicroscale. This gives qualitative insights of the features inmicrobialhabitatsandrelatedinterfaces(soil‐rootinterfacesandBGIe.g.)whichareofgreatimportanceforthestudyofthemicrobialecologyofmicrobesinsoil.SincethevariousprocessesofBGIhavearelevanceonthelargescaleandviceversaupscalingisofgreatimportancefortheinvestiga‐tionoftheirinfluenceonecosystemfunctioning.Furthermorespatialmodellingbasedontheseobservations is required to understand and predict the effects of changing physico‐chemicalconditions.Accuratequantitativedataarethereforerequiredwhichcanberetrievedfromcor‐relativemicroscopic/spectroscopicanalysisdirectlyorgeneratedbystatisticalanalysisofindi‐vidual spatial data or spatial extrapolation. Examples for these approacheswill be presentedbasedonapplicationsinpaddysoilsystems.Theinfluenceofphysicalstructuredynamicsasitoccurs under submerged paddy soilmanagement due to the cycles of flooding and drying onbiogeochemical features and microbial dynamics will be shown. Spatio‐temporal effects andtheirconsequencesforgreenhousegasemissionandironoxidationwillbehighlighted.Basedonmicrocosmapproachesexamplesforreliablequantitativedataacquisitionofmicrobialdistribu‐tioninthesoilmatrixandthesoil‐rootinterfacewillbedemonstrated.

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X‐RayPhotoelectronSpectroscopy(XPS)asaVersatileTooltoRe‐lateSurfaceChemicalCompositionandWettingPropertiesSusanneK.Woche1,Marc‐OliverGoebel1,DanielTunega2,RolandŠolc2,GeorgGuggen‐berger1andJörgBachmann11InstituteofSoilScience,LeibnizUniverstätHannover,Germany2InstituteofSoilResearch,UniversityofNaturalResourcesandLifeSciencesVienna,AustriaAs particlewettingproperties (in termsof contact angle CA) are determinedby the chemicalcompositionofonlythefirstnm(CA_interphase,(FergusonandWhitesides,1992))asurfacespe‐cificchemicalanalysisisneededtorelateCAtochemicalcomposition.Here,Xrayphotoelectronspectroscopy(XPS)offersfascinatingpossibilities.BombardmentofthesurfacewithXraysre‐sultsintheemissionofphotoelectronswithanelement‐specificbindingenergy.Themaximumanalysis depth of about 10 nm is considerably smaller than that of common surface analysistechniqueslikeEDXandATR‐FTIR(about1μm)andclosetotheCA_interphase.RelatingCAandsurfacechemicalcompositionsofarindicatedthesurfaceO/Cratioasageneralparameter(CAincreaseswithdecreasingO/Cratio).KnowingtheanalysisdepthandassumingthatBGImainlyconsistoforganicmaterial,detectionofelementslikeSiandAlshouldbeascribabletotheun‐derlyingmineral,thusindicatingeitheraBGIthickness<10nmoranincompletecoverage.Eval‐uation of thesepeaksprobably could allowa furtherBGI characterizationwith respect toCA,especiallyincaseswherethecarbonconcentrationcannotbeuseddueto“adventitiouscarbon”(carbon components sorbed to the surface from the ambient air). As natural BGI consist ofawidevarietyofcompoundsthatarealmostimpossibletoidentifyinfull,inafirststepdefinedmodelsystemswerehelpfultotesttheusefulnessofnon‐BGIelementsthatusuallyarenotcon‐nectedwith CA. Glass slides (“model surface”)were coatedwith defined organic components(“modelBGI”)byexposure toorganosilanes(dichlorodimethylsilaneDCDMS,dimethyldiethox‐ysilaneDMDES,octadecyltrichlorosilaneOTS,aminopropyltriethoxysilaneAPTES)ofvaryingCchainlength(DCDMS,DMDES:C1;APTES:C3;OTS:C18)andpolarity(DCDMS,DMDES,OTS:nonpolar;APTES:partly‐polar).XPSsurveyspectrawererecorded,CAwasdetermined,andbasedonenergeticconsiderationssurfacestructureandCAmodeled.CAoftheDCDMS,OTS,andAPT‐ES slidewere found to be related to chain length andpolaritywithmodeling resulting in thesametrend(i.e.,CA_OTS>CA_DCDMS>CA_APTES).OnlyDMDESthatintheoryshoulddisplaythesameCAasDCDMS,wasfoundtoshowaconsiderablysmallerCA.Probablyatleastinpartduetoadventitiouscarbon,surfaceCconcentrationexhibitednodefinedrelationwithCA,butallslidesshowedadistinctNapeakfromtheunderlyingglass.RelatingCAandNacontentdepictedsurprisingresults.Notonlyacorrelationcouldbefound(i.e.,CAincreasedwithdecreasingNacontent),but theDMDESslide indeedshowedahigherNacontent thantheDCDMSslide.Thisindicates thatuseofnon‐BGIelementsmaybeanadditionalmeanstochemicallycharacterizeparticlewettingpropertieswhichissupportedbyrespectivefirstattemptswithnaturalsoilma‐terialfromasoilchronosequencewheretheAlconcentrationwasfoundtoberelatedtoCA.ReferencesFergusonGS,WhitesidesGM.1992.In:ModernApproachestoWettabiltyTheoryandApplications,SchraderME,LoebG(eds),PlenumPress,NewYork,1992.

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CharacterizationofWetAggregateStabilityofSoilsby1H‐NMRRelaxometryChristianBuchmann,MaximilianMeyerandGabrieleE.SchaumannInstituteforEnvironmentalSciences,EnvironmentalandSoilChemistry,UniversitätKoblenz‐Landau,Landau,GermanyFor theassessmentofsoil structuralstabilityagainsthydraulicstress,wet‐sievingorconstantheadpermeabilitytestsaretypicallyusedbutratherlimitedintheirintrinsicinformationvalue.Themultipleapplicationsof several tests is theonlypossibility toassess importantprocessesandmechanismsduringsoilaggregatebreakdown,e.g.theinfluencesofsoilfragmentreleaseordifferentialswellingontheporoussystemsofsoilsorsoilaggregatecolumns.Consequently,thedevelopmentofnew techniques for a faster andmoredetailedwet‐aggregate stability assess‐ment is required. 1H nuclearmagnetic resonance relaxometry (1H‐NMR)might provide theserequirementsasithasalreadybeensuccessfullyappliedonsoils.Weevaluatedthepotentialof1H‐NMRfortheassessmentofwet‐aggregatestabilityofsoils,withmoredetailedinformationonoccurringmechanismsat the same time.Therefore,weconductedsinglewet‐sievingandcon‐stant headpermeability tests onuntreated and 1%polyacrylic acid‐treated soil aggregates ofdifferenttexturesandorganicmattercontents,subsequentlymeasuredby1H‐NMRrelaxometryafter percolation. The stability of the soil aggregatesweremainly depending on their organicmattercontentsandthetypeofaggregatestabilization,wherebyadditionaleffectsofclayswell‐ingon themeasuredwet‐aggregate stabilitywere identifiedby the transverse relaxation time(T2)distributions.Regressionanalysesshowedthatonlythepercentageofwater‐stableaggre‐gatescouldbedeterminedaccuratelyfrompercolatedsoilaggregatecolumnsby1H‐NMRmeas‐urements.1H‐NMRseemsapromisingtechniqueforwet‐aggregatestabilitymeasurementsbutshouldbefurtherdevelopedfornon‐percolatedaggregatecolumnsandrealsoilsamples.

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HowCanMagneticResonanceImaging(MRI)HelpUnderstandingColloidalParticleTransportinSoilsAlizéeLehoux1,2,3,EricMichel1,2,PamélaFaure3,DenisCourtier‐Murias3,FrancoisLafo‐lie1,2andPhilippeCoussot31INRA,UMR1114EMMAH,Avignon,France2UAPV,UMR1114EMMAH,Avignon,France3CNRSENPCIFSTTAR,UMR8205LaboratoireNavier,Champs‐surMarne,FranceThecapabilitytopredictthefateofcolloidalparticlesinthesubsoilisofparamountimportancefor scientists, engineers or policy‐makers, as such particles can carry adsorbed pollutant to‐wards the groundwater or be themselves pollutants. Currentmodels often fail to predict ob‐servedcolloid fate, indicatingtheneed forabetterunderstandingof theprocessescontrollingcolloidattachment,detachmentand transport in the soil.Mostof theseprocesses canonlybestudied indirectly(e.g.usingparticlebreakthroughcurve(concentrationasa functionof time)recordedduringsimulatedrainfalls).Forthisreason,thesoilcanbeconsideredasa“blackbox”system. Imagingtechniques(X‐raytomography,MRI)have increasinglybeenusedtoopentheblackboxandstudywatermovementinsoilcores,buttheyhaveseldombeenappliedtoinves‐tigatethefateofcolloidalparticlesinsoils.Withtheaimofgaininginternalinformationontheirtransport,weinjectedapulseofsuperparamagneticnanoparticules(longitudinalrelaxation70s‐1mM‐1)insaturatedsandcolumnsandrecorded:(i)theireffectonprotonMRIsignal(doublespinechosequence,acquisitionduration70s)asafunctionofthecoredepth(150mm,resolu‐tion1.6mm)andtimeand(ii)theparticlebreakthroughcurvesatthecolumnoutlet.Thenano‐particuleswereeithernegatively(np‐)orpositively(np+)charged.Wefoundthat,asexpectedinnegativelychargedquartzsand,np‐particleswereentirelyrecoveredatthecolumnoutlet,whilenp+particleswerecompletelyretained.Forbothparticles,MRIrecordingspermittedtofollowparticlepulsedisplacementinthecolumns,providingotherwiseinaccessibleinformationontheretentiondynamicsandlocusofnp+particles.Interestingly,wefoundthatbothsuspendedandadsorbednanoparticulescontributedtotheMRIsignal.Forthisreason,webuilttwocalibrationsrelationshipsbetweentheMRIsignalofsuspended(respectivelyadsorbed)particlesandtheirconcentrationinporewater(respectivelyonthesolidphase).WethencomparedtherecordedMRIsignalwiththesignalcomputedfromthesecalibrationsandtheoutputsofacolloidtrans‐portmodelbasedonakineticreversibleparticledepositionontosandgrains.Inthiscontribu‐tionwewilldiscusshowthe largespatiallyandtimeresolved internaldatayieldedbyMRI(i)featuresthistechniqueasacuttingedgetooltotestcolloidtransportmodelstotheirverylimitsand (ii) provides anunmatched situation tounderstand “why” and “where”particle retentionoccurs.AcknowledgementOneofus(AL)benefitedofaPhDgrantfundedbyIFSTTARandINRA

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RapidFormationofNon‐ExtractableResiduesofSulfonamides:ParamagneticSpinProbingRevealedCovalentBondingofAro‐maticAminoGroupMichaelMatthies1,TanjaMüller1,OlgaAlexandrova1,JörgKlasmeier1,Hans‐JürgenSteinhoff2andKalmanHideg31InstituteofEnvironmentalSystemsResearch,UniversityOsnabrück,Osnabrück,Austria2DepartmentofPhysics,UniversityOsnabrück,Osnabrück,Austria3DepartmentofOrganicandMedicinalChemistry,UniversityofPécs,Pécs,HungarySulfonamideantimicrobial agents comprisean important classofhumanandveterinaryphar‐maceuticals,whichareappliedtosoilviasludgeormanureamendment.Soilincubationexperi‐mentswithsulfadiazine(SDZ)showedarapidformationofnonextractableresidues(NER)(För‐steretal.,2009),whichisattributedtothenucleophilicadditionreactionofthearomaticaminogroup toquinones of soil organicmatter (SOM) (Gulkowskaetal.,2014).Mülleretal. (2010)observedaninstantaneouslossofextractabilityofSDZonatimescaleofminutesaswellaski‐neticallydeterminedsequestrationandNERformationover24hintwodifferentsoilswithandwithoutmanure, for air‐driedand formoist soils.Wepresent anewapproachof using stableparamagneticelectronspinprobes to investigate therapid interactionofaminogroupsofsul‐fonamidesandotherxenobioticswithSOM.WeusedthenitroxidespinlabelsTEMPO(2,2,6,6‐Tetramethylpiperidin‐1‐oxyl), amino‐TEMPO (4‐amino‐2,2,6,6‐Tetramethylpiperidin‐1‐oxyl)and anilino‐NO(2,5,5‐Trimethyl‐2‐(3‐aminophenyl)pyrrolidin‐1‐oxyl), which differ in their hy‐drophobicity and reactivity to SOM. A significant broadening of the ESR‐signals of anilino‐NOincubatedwithluvisolsoil fromMerzenhausenindicatedastrongrestrictionofthereorienta‐tionalmotionof thespinprobe,whichcouldnotbeobservedwith theother twospinprobes.ThesamesignalscouldbedetectedwithLeonarditehumicacid,whichsuggestastrongbondingtosoilhumicsubstances,i.e.covalentbonding.Sequentialdesorptionfromincubatedsoilusingultrafiltrationrevealedanalmostexponentialdecreaseofthepercentageofallthreespinprobesremaininginthesoil.ThefractionsofTEMPOandamino‐TEMPOalmostcompletelydiminishedwith increasing volume of percolate, whereas those of anilino‐NO approximated a stationarylevelof6%remaininginsoil.Weconcludethatlargefractionsofallthreespinprobesareweak‐lyboundtosoilwithlowbindingenergy,becausetheycanbeextractedbyanexcessofwater.Foranilino‐NO,resultsindicateanadditionalfractiontobeirreversiblyboundtosoil.Thisfind‐ing supports the conclusion from theESR‐spectroscopicanalysisof the interactionof the spinprobeswithSOMandLeonarditehumicacid.Ourworkclearlydemonstrates for the first timethebenefitofusingspinprobestoinvestigatetheinteractionoffunctionalaminogroupsofxe‐nobioticswithnaturalsoil.ReferencesFörsterM,LaabsV,LamshöftM,GroenewegJ,ZühlkeS,SpitellerM,KraussM,KaupenjohannM,AmelungW.2009.Sequestrationofmanure‐appliedsulfadiazineresiduesinsoils.EnvironSciTechnol43:1824‐1830.

GulkowskaA,ThalmannB,HollenderJ,KrausM.2014.Nonextractableresidueformationofsulfonamideantimicrobials:Newinsightfromsoilincubationexperiments.Chemosphere107:366‐372.

MüllerT,RosendahlI,FocksA,SiemensJ,KlasmeierJ,MatthiesM.2013.Short‐termextractabilityofsul‐fadiazineafterapplicationtosoils.EnvironPollut172:180‐185.

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TheInfluenceofExtracellularOxidativeEnzymesontheForma‐tionofNon‐ExtractableResidues(NER)of14C‐MetalaxylinSoilAndreasSchaeffer1,JensBotterweck1,BurkhardSchmidt1,RoschniKalatoor2andJanSchwarzbauer21InstituteforEnvironmentalBiologyandChemodynamics(UBC),InstituteBiologyV,RWTHAachen,Aachen,Germany2InstituteofGeologyandGeochemistryofPetroleumandCoal,RWTHAachenUniversity,Aachen,GermanyThe influence of extracellular phenoloxidases and peroxidases on the formation of nonex‐tractable residues (NER) of the systemic fungicide metalaxyl (N‐(methoxyacetyl)‐N‐(2,6‐xylyl)‐DL‐alaninate) in soilwas examined in a time course studyover90days.Metalaxylwasincubatedas(ring‐U‐14C)labeledradioactivecompoundinanEutriccambisolsoilfromUl‐tuna, Sweden. To prove that xenobiotics likemetalaxyl are incorporated and/or bound to or‐gano‐clay complexes by oxidative enzymatic coupling reactions, different sterilization tech‐niqueswereestablishedresultingin(A)sampleswithneithermicrobialactivitiesnorextracellu‐lar phenoloxidase and peroxidase activities; (B) samples without microbial activities but re‐mainingactivitiesof theseenzymes. Incubation insuchsterilizedsampleswascomparedwithnativesoilsamples(C).Thefateandbehaviorofthefungicidewasstudiedwithinthebulksam‐plesandtheirparticlesizefractions.NERwerelocatedmainlyinthesiltfractionofthesoilandincreasedinthecourseoftimereachingafinalamountofaround25%in(C),about10%in(B)and about 5 % in (A) of applied radioactivity after 92 days of incubation. Amounts of NERformedwerecloselycorrelatedtomicrobialactivities,organicmattercontentandextracellularphenoloxidase and peroxidase activities. The analysis of the bound residues showed that theparentsubstanceanditsmaintransformationproduct,metalaxylacid,weremainlyboundtothehumicmatterfractionsbyesterandamidelinkages,exceptthecompoundsboundtothehuminefraction,whichwerestrongerboundtothematrix,e.g.byetherorcarbon‐carbonlinkages.Fi‐nally14C‐metalaxylwas incubated insterilizedsoilafteradditionofalginate immobilized lac‐caseleadingtoincreasedamountsofNERwithininthesoilsamples,provingthatimmobilizedoxidativeenzymescontributetotheformationofxenobioticNER.

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Effect of Phenanthrene and Hexadecane on the Release andTransportofMobileOrganicMatterinArtificialSoil‐ATwoLayerColumnStudyKatharina Reichel1, Doreen Babin2, Irina Tanuwidjaja 3, Marc‐Oliver Göbel4, Armin H.Meyer5,KorneliaSmalla2,MichaelSchloter3andKaiUweTotsche11InstituteforGeoscience,ChairofHydrogeology,FriedrichSchillerUniversityofJena,Germany2InstituteforEpidemiologyandPathogenDiagnostics,JuliusKühnInstitut,Braunschweig,Germany3ResearchUnitofEnvironmentalGenomics,HelmholtzZentrumMunich,Germany4InstituteforSoilScience,LeibnizUniversityofHannover,Germany5InstituteforGroundwaterEcology,HelmholtzZentrumMunich,GermanyBiogeochemicalinterfaces(BGIs)insoilsare“hotspots”ofmicrobialcommunitiesandturnoveroforganicsubstances.Wehypothesizethatthemodelcompoundsandadditionalcarbonsourcesphenanthrene(PHE)andhexadecane(HEX)influencemicrobialcommunities,whichinturnmayaffect thereleaseofmobileorganicmatter(MOM), includingbiocolloids,andthepropertiesofBGIs inpristine soils.Weexplored the releaseof PHEandHEXusinganewexperimental ap‐proach employing two‐layer columns (10x12 cm) filledwith an artificialmineral soilmixture(quartz, illite,goethite). In thisset‐up, the lower layer, furthercalled“reception layer” (RL,10cm),containedthemineralsoilmaterialandtheupperlayer(2cm)servedassourcelayer(SL)andconsistedofthemineralmixture,sterilemanure(asOMsource)andmicrobialcommunityextractedfromaLuvisol(Scheyern,Germany).SLwasspikedwithPHEorHEX(2.0mgg‐1)and,to identify theactivemicrobialdegraders, two columnswereadditionally spikedwith labeled13C‐PHEor13C‐HEX(2.0mgg‐1).Un‐spikedcolumnsservedascontrols.Ingeneral,fivedifferentvariationsofSL‐spikingwereruninparallelwithtworeplicatespertreatment.Theexperimentwas carried out under unsaturated flow conditions. All columnswere irrigatedwith artificialrainwater foraround35days(d)(0.5porevolumeday‐1)withseveral flowinterrupts(FI)ofdifferentdurations (1‐30d) to allowreactionson solidphases.Physicochemical andchemicalparameters (pH,EC, turbidity,TOC/DOC,anions/cations,PHE,HEXand theirmetabolites)andmicrobial community compositionwere analysed in effluent samples. After the transport ex‐periment, columnswere sliced into 1 cm thick layers andmicrobial community composition,morphologyandtopographyofsolidphasesandcontactangleweredeterminedalongthecol‐umns depths. The release of MOM from the columns was in general controlled by non‐equilibrium. Themaximum release of organic carbon (after 0.7‐0.9 pore volumes) is delayedwhichiscausedbylongerflowpaththroughthecolumns.PHEandHEXhadnoeffectonMOMrelease.Turbidityandhydrodynamicdiameter,twoparametersthatrelatetosuspendedparti‐clesandcolloids,wereunaffectedinallthetreatedcolumns.Inalleffluentfractions,diverseandheterogeneousbacterialcommunitieswerefound.Thisprovestheassumptionthatmicroorgan‐isms aremobile in the studied artificial soil and under designed flow conditions. Denaturinggradient gel electrophoresis (DGGE) results showedhigh similarities inbacterial communitiesassociated with the immobile solid phase among different depth layers and treatments. FewbacterialpopulationsinDGGEfingerprintsweredependedonthedistancetoSLinPHE‐spikedcolumns.

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Session3:MicrobialEcologyofBGIs:Soil(Micro‐)Organismsas“Architects”&“Actors”ofBGIs

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Session3:MicrobialEcologyofBGIs:Soil(Micro‐)Organismsas“Architects”and“Actors”ofBGIsKeynoteTalk

MicrobialDiversityAttheInterfaceGeorgeA.Kowalchuk1,2,31InstituteofEnvironmentalBiology,UtrechtUniversity,Utrecht,TheNetherlands2NetherlandsInstituteofEcology(NIOO‐KNAW),Wageningen,TheNetherlands3DepartmentofEcologicalScience,VrijeUniversiteit,Amsterdam,TheNetherlandsSoil‐bornemicrobial diversity is vast and still rather poorlyunderstood.Molecular, andmorerecentlyhigh‐throughputsequencing,approacheshavefacilitatednumeroussurveysofthisdi‐versity,providinguswithanewfoundappreciationforsoil‐bornemicrobialdiversityandreveal‐inginsightintosomebroadenvironmentaldriversofsoil‐bornemicrobialcommunitystructure.However,westillhavearathercrudeunderstandingoftheforcesthatdrivepatternsofmicro‐bialdiversityinsoilenvironmentsandthebiogeochemicalinterfacestheycontain.Thescaleatwhichmicrobesinteractwiththeirstructuredsoilenvironment,andtheorganismswithwhichtheysharethesehabitats,israrelytakenintoaccountinstudiesofmicrobialdiversity.Thisfail‐uretotakethephysicalstructureofsoilintoaccounthampersourabilitytodetectmeaningfulinteractions and insights intomicrobial lifestyles and activities in soil. To tackle these limita‐tions,wehaveadoptedtwogeneralapproaches:(a)fine‐scalesamplinganddeepinterrogationofpatternsofmicrobialdiversity,and(b)laboratoryexperimentsusingartificialsoilsystemstotracktheimpactoffine‐scalesoilstructureonpatternsofbacterialinteractionsandthemainte‐nanceofbiodiversity.Usingfine‐scalesampling,weexaminethemicro‐scalepatternsofmicro‐bialdiversityofindividualsoilgrainsandrootsurfacesviahigh‐throughputtagpyro‐sequencingapproaches.Tocomplementthis insituapproach,wealsotrackmicrobialdiversitypatternsinartificial soil‐like systems in response to manipulations of soil structure and moisture, andthereforeconnectivity.Combiningoursurvey‐basedandexperimentalapproacheshasallowedustoadoptamoremicrobe‐centricpointofviewinourexaminationofsoil‐bornemicrobialdi‐versity,facilitatingabetterunderstandingofthedriversofmicrobialcomposition,diversityandfunction.

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Session3:MicrobialEcologyofBGIs:Soil(Micro‐)Organismsas“Architects”and“Actors”ofBGIs

InfluenceofOrganicMatteronMicrobialCommunityStructureandActivityinSoilMicrohabitatsMichaelHemkemeyer1,TobiasSchlinsog1,BentT.Christensen2,RainerMartens1andChristophC.Tebbe11ThünenInstituteofBiodiversity,Braunschweig,Germany2DepartmentofAgroecology,AarhusUniversity,Foulum,DenmarkDifferently sized soil particle fractions (PSF)differ inmineral composition and in soil organicmatter(SOM)contentandcomposition.PSFtherebyprovidemicrohabitatsassociatedwithdis‐tinctsurfaceproperties.Previousstudiesdemonstratethatthedifferentmicrohabitatsmayse‐lectforstructurallydistinctmicrobialcommunities(Neumannetal.,2013),andthatdifferencesinSOM,generatedbycontrastinglong‐termfertilisation,mayinfluencethemicrobialcommunityinvolved indegradationoforganicpollutants(Neumannetal.,2014).Thisstudyexamines theimpact of SOM accumulated in individual PSF on the structure and function of themicrobialcommunities,usingphenolmineralisationasanindicatoroffunction.Soilwasfromunfertilised,mineral fertilised and animalmanured treatments in the Askov Long‐Term Field Experiment(Denmark),whichhasnowbeencontinuedfor120years.ThetreatmentshavesimilarparticlesizedistributionandpHbutdiffer in SOMcontents. Soil sampleswere separated into a sand‐sizedfraction(63–2000μm)containingalsoparticulateorganicmatter(POM),coarsesilt(20–63μm),finesilt(2–20μm),andclay(<2μm)bymildsonication,wetsievingandcentrifugation.DNA was extracted from bulk soil and from PSF. Microbial populations were determined byquantitativePCR(qPCR)ofsmallsubunit(SSU)rRNAgenes.Thesamegeneswereusedforge‐netic profiling using terminal restriction fragment lengthpolymorphism (T‐RFLP). To investi‐gatethemineralisationofphenol,thePSFwereincubatedwithsterilequartzforbetteraeration,especiallyofthefinerfractions.Themineralisationofadded14C‐phenolwasmonitoredbyquan‐tificationofliberated14CO2trappedinNaOH.Thedistributionof14C‐phenolwithinthesoilwasexaminedinadsorptionstudiesandsubsequentfractionation.Bulksoilcontained2.4–3.9·1010genecopiesg‐1soilofbacteria,0.5–1.3·109ofarchaea,and5.5–9.0·108offungi.Generally,micro‐bial abundancewas negatively correlatedwith particle size andwas highest inmanured soil.Communitiesofallthreemicrobialdomainsrespondedtoparticlesizeandfertilisationregime,buttodifferentdegrees:BacterialcommunitieswerepredominantlydeterminedbyPSF,whilethefertilisationregimewasthemaindriverforarchaea.Bothfactorswereequallyimportantforfungi. Phenol mineralisation correlated positively with microbial abundances, except for thesand‐sized fraction, suggesting an impactbyPOM.Highestmineralisation rateswere found inthemanuredsoil.Thiswasrelatedtophenoladsorptionbeingsmallestinthemanuredsoilandthusleavingmorephenolbioavailable.OurstudyshowsthatSOMaccumulatedunderdifferentfertiliserregimesleadstomicrohabitatsthatsupportstructurallyandfunctionallydifferentsoilmicrobialcommunities.ReferencesNeumannD,HeuerA,HemkemeyerM,MartensR,TebbeCC.2013.Responseofmicrobialcommunitiestolong‐termfertilizationdependsontheirmicrohabitat.FEMSMicrobiolEcol86:71–84.

NeumannD,HeuerA,HemkemeyerM,MartensR,TebbeCC.2014.Importanceofsoilorganicmatterforthediversityofmicroorganismsinvolvedinthedegradationoforganicpollutants.ISMEJ8:1289–1300.

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TransportofPhenanthreneinSoilColumnsInfluencedtheBacte‐rialCommunityStructureDoreen Babin1,2, Katharina Reichel2, Vitali Maffenbeier1, Guo‐Chun Ding3, Kai UweTotsche2andKorneliaSmalla11InstituteofEpidemiologyandPathogenDiagnostics,JuliusKühn‐Institut,Braunschweig,Germany2InstituteforGeosciences,ChairofHydrogeology,Friedrich‐Schiller‐UniversitätJena,Germany3CollegeofResourcesandEnvironmentalSciences,ChinaAgriculturalUniversity,Beijing,ChinaMobileorganicmatter(MOM)insoilprovidesnutrientsformicrobesresidingdistantlyfromtheorganic‐richtoplayer.Furthermore,MOMcontainsbiocolloidswhichfacilitatesthepropagationofbacteriawithinthesoilprofile.OrganicpollutantsareoftenassociatedwithMOMwhichcon‐trolstheirenvironmentalfateandrelease.Inthisstudy,weinvestigatedwhetherthetransportof phenanthrene used as model compound for organic pollutants affects the composition ofMOMandthesoilbacterialcommunitystructure.Therefore,weconductedatwo‐layercolumntransportstudyunderunsaturatedconditions.Columns(10x12cm)were filledwithpristineLuvisolsoil.Theupper2cmofcolumnscontainedLuvisol(0.2mgg‐1)eitherunspiked(control)or phenanthrene‐spiked. Each treatment consisted of two replicates. Columns were irrigatedwithartificial rainwater (1‐1.5porevolumeday‐1) foronemonthwith several flow interrup‐tions(FIs)ofvarieddurationtoallowreactionsatbiogeochemicalinterfaces.Aftertheendoftheflow period, columns were sliced into several layers (source, interface, recipient) to obtainadepthprofile.Thebacterial community compositionwas studiedbydenaturinggradient gelelectrophoresis(DGGE)andpyrosequencingof16SrRNAgenesamplifiedfromtotalcommunityDNAwhichwasextractedfromeffluentandsoilslices.Furthermore, thepresenceofgenes in‐volved in the degradation of phenanthrene and physico‐chemical parameters (pH, TOC/DOC,phenanthrene etc.) were determined. By DGGE, a changing bacterial community compositionwasfoundineffluentsamplesovertheflowperiod.TOC/DOCandthenumberofbacterial16SrRNAgene copies in effluent samples showed similar trends suggesting a rate‐limited releasebutonlyasmall impactofspikedphenanthrenewasobserved.Bacterial communitiesshowedahighhomogeneitywithinthesoilprofile.ThemainrespondertophenanthrenewasaffiliatedtoGeothrixfermentansbelongingtotheAcidobacteriaphylum.Theeffectofphenanthreneonthebacterialcommunitystructureandtheabundanceofgenesinvolvedintheaerobicdegradationof phenanthrene decreased to the recipient layer. Highest phenanthrene concentrationswerefoundintheinterfacelayerindicatingaslowtransportofphenanthrenetodeepersoillayers.Inconclusion,thisstudysuggestsanimpactofphenanthreneonqualityandquantityofMOMre‐sultinginchangesofthesoilbacterialcommunities.

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SpatialHeterogeneity,DiversityandEcosystemFunctionJamesI.ProsserInstituteofBiologicalandEnvironmentalSciences,UniversityofAberdeen,Aberdeen,UKSoilmicrobialecologyhasbeendominatedduringthepast25yearsbystudiesofthediversityofsoilmicroorganisms,particularlybacteriaandarchaea.Thisinterestresultedfromtheapplica‐tion ofmolecular techniques that provided evidence for diversity of 16S rRNAand functionalgenesthatmuchhigherthanexpectedandthehighrelativeabundanceoforganismsthatwerepreviouslyunknownorconsideredtoberareinsoil.Thishighdiversityraisedtwofundamentalquestions:whyissequencediversitysohighandwhataretheconsequencesforsuchhighdiver‐sityonecosystemfunction.Thesecondquestionhasreceivedmostattentionandthemajorityofstudiescharacterisesequencesinnucleicacidsextractedfrom1–10gsoil.Althoughdiversityisstudiedat thisscale,manyof themechanisms thought to influenceboth theoriginandconse‐quencesofdiversityarebelievedtooperateatmuchsmallerscales.Consequentlythemajorityof studies arenotmechanisticallybasedandmuchof the “noise”obtained indiversitydata isblamedonlackofconsiderationofsmall‐scaleheterogeneityandexcusedbyinabilitytomeas‐uresmall‐scalediversity.Thispresentationwillexplorethedangersof ignoringheterogeneity,ways in which small‐scale mechanisms can generate predictions that can be tested at largerscalesandwaysinwhichmoleculardatacangiveinformationontheconsequenceofheteroge‐neity.

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Microorganisms:ActiveInhabitantsandArchitectsofBGIsinArti‐ficialSoilsKorneliaSmalla1,DoreenBabin1,Guo‐ChunDing2,CordulaVogel3,GeertjeJ.Pronk3,4,KatjaHeister3,IngridKögel‐Knabner3,4,andMichaelSchloter51InstituteofEpidemiologyandPathogenDiagnostics,JuliusKühn‐Institut,Braunschweig,Germany2CollegeofResourcesandEnvironmentalSciences,ChinaAgriculturalUniversity,Beijing,China3LehrstuhlfürBodenkunde,TechnischeUniversitätMünchen,Freising‐Weihenstephan,Germany4InstituteforAdvancedStudy,TechnischeUniversitätMünchen,Garching,Germany5ResearchUnitforEnvironmentalGenomics,HelmholtzZentrumMünchen,GermanResearchCen‐terforEnvironmentalHealth,Neuherberg,GermanySoilsbelongtothemostcomplexmaterialsonearth.Constituentsofdifferentoriginareinclosecontactand interactwitheachother.Thepresenceofvariousmicrositesgoesalongwithadi‐verse soilmicrobiota.Theadvent of newmolecular techniques inmicrobial ecologyopensupnewways toexplore themicrobialdiversity insoil.TotalcommunityDNA‐basedanalysiswasemployed to disentanglemicrobial community composition and responders to spikes in long‐termmaturedartificialsoils.ThejointSPP1315experimentusingartificiallycomposedsoillikemixtureswasestablishedtoelucidatetheformationofbiogeochemicalinterfaces.ArtificialsoilswerecomposedbyaddingthemicrobialfractionfromanaturalLuvisolasinoculumtofoursoilcompositionsdiffering in the typeofclaymineral (illite,montmorillonite)and thepresenceofcharcoalor ferrihydrite.Aftermore than twoyearsof incubation, soilswerespikedwithphe‐nanthreneand/orplantlitter.TotalcommunityDNA(TC‐DNA)wasextracteddirectlyfromsoilsamples taken0,7,21and63daysafter spiking.Themicrobial communitieswerestudiedbyDGGEand454pyrosequencingof16SrRNAgenesamplifiedfromTC‐DNA.Thecombinationofbothcultivation‐independenttechniquesprovidedinsights intothemicrobialcommunitycom‐position,temporalchangesandallowedassumptionsonmineral‐microbialinteractions.Weob‐servedthatthetypeofclaymineralwasthemainfactorshapingthebacterialcommunitycom‐position over a long‐term incubation. Actinobacteria, Bacteriodetes, and Alphaproteobacteriawere more abundant in soils containing illite whereas montmorillonite‐soils exhibited moreGammaproteobacteriaandFirmicutes.Influencesofferrihydriteorcharcoalwereseenonlowertaxonomiclevels.Wecouldshowthatthebacterialcommunitiesestablishedinmaturedartificialsoilschanged inresponse tophenanthrenespikingand thatmorepronouncedshiftswereob‐servedinmontmorillonite‐soilscomparedtootherartificialsoilswithbothmethods.Highnum‐bersofsequencesaffiliatedtothegenusKocuriawerefoundinartificialsoilscomposedsolelyofmontmorillonite,whereasArthrobacterwasenrichedinallotherphenanthrene‐spikedsoils.Inaddition,severallitter‐responderswereidentified(e.g.Adhaeribacter,Devosia,andLuteimonas).Thepresentstudyshowedthelong‐termdrivinginfluenceofthesoilmineralcompositionandcharcoal on microbial community composition. To conclude, the analysis of 16S rRNA genefragmentsamplifiedfromtotalcommunityDNAprovidedinsightsintothebacterialcommunitycompositionestablished in artificial soils andpotentially contributing to the formationofbio‐geochemical interfaces and to disentangle responders to the phenanthrene and litter spikewhich might have potential degradative functions. However, 16S rRNA gene‐based methodsemployedprovideonlyarathercourseviewofthestructuralandfunctionaldiversityandfailtogain informationon the activebacterial fraction and itsmobile genepool, on spatial arrange‐ments and synergisticor antagonistic interactions.However, the informationgainedondomi‐nantbacterialOTUsdwellinginartificialsoilsandrespondingtothespikescannowbeusedtodevelopofprobesforadvancedmicroscopyanalysisatthemicro‐scale.

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ReducingDiffusionLimitationShiftstheDominantNitrateReduc‐tionMetabolismFromIncompleteDenitrificationtoDissimilatoryNitrateReductiontoAmmoniumLasseL.Pedersen,ArnaudDechesneandBarthF.SmetsDepartmentofEnvironmentalEngineering,TechnicalUniversityofDenmark,Kgs.Lyngby,DenmarkMicronichesareμmtommsubdomainswhereadiffusionlimitedexchangewiththe“bulk”sys‐temleadstoadifferentbiogeochemistry,andthustoawidearrayofreactiveinterfaceswherevarioustypesofmicrobialmetabolismcantakeplace.Examplesofmicroniches,cracksinsandgrains andpores inorganic remains in soil and in lakeandmarine sediments; theyvaryovertimeandmaybeshortlived.Asafractionofthewholethevolumeinmicronichesinsoilmaybesmall,butthesurfacearealarge‐andsincereactivecompoundsandmicrobesoftenareboundto thesesurfaces it is important toconsiderspatialdistribution,chemicalgradientsandtrans‐portprocesses,duetotheeffecttheyhaveonbiochemicalreactionsandreactionrates.SoilisakeycompartmentfortheglobalNitrogencycle,withbacteriaplayingamajorrolebothinnitrifi‐cationanddenitrification.Thiscycleisoftenconsideredatalargescale,butitistheconditionsexperienced‘locally’bythebacteriathatsetwhattypeofmetabolismcantakeplace.Thesecon‐ditions,andespeciallytheredoxconditions,arelikelycontrolledbydiffusiveprocesses.Inthisstudyweinvestigatehowmodulatingdiffusionlimitationimpactsonbiologicalnitratereductioninasoilsystem.Tothisend,wehaveconstructedanarrayofcolumns,all fedasolutionofni‐trateandcontainingthesameamountoflitter‐richsoilencasedinalginate–butvaryinginhowthesoilaggregatesarespatiallydistributedandintheamountofpotentiallyreactivesoilaggre‐gate surface. The effluent was analyzed for nitrate‐, nitrite‐, ammonium‐, nitrous oxide‐, andTOC‐concentration,pHandamountofmicroorganisms. Inaddition,at theendof theafter theexperimentthecolumnswereanalyzedusingqPCRtargetedatnirandnos,keygenesinthede‐nitrificationpathways.The results show that going fromahigh level ofdiffusive limitation toa lowlevelshifts thesystemfromincompletedenitrificationwithproductionofnitriteandni‐trous oxide to dissimilatory nitrate reduction to ammonium, DNRA. Diffusion limitation thusimpactsstronglyNitrogenbiogeochemicalpathwaysinthissystemrichinorganiccarbon.Thishighlights the importance ofmicroniches in soil functioning and in the global biogeochemicalcycle.

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TheSoil‐LitterInterface:AHotSpotforBiogeochemicalInterac‐tionsChristianPoll1,HolgerPagel2,FranziskaDitterich1,ThiloStreck2andEllenKandeler11InstituteofSoilScienceandLandEvaluation,SoilBiology,UniversityofHohenheim,Stuttgart,Germany2InstituteofSoilScienceandLandEvaluation,Biogeophysics,UniversityofHohenheim,Stuttgart,GermanyThesoil‐litter interface isan importantbiogeochemical interfacewherecarbonentersthesoil.Whereasmoststudies focusedon the flowof litterC into thesoiland itsmicrobialutilisation,much less attentionwasdrawn topossible consequencesofC transporton soil processesnotdirectlyconnected to litterC turnover.This talkwillprovideanoverviewofourexperiments,which focused on microbial‐physicochemical interactions during coupled soil organic matterdecompositionanddegradationofMCPA(2‐Methyl‐4‐chlorophenoxyaceticacid)atthesoil‐litterinterface.WeusedtheherbicideMCPAasamodelcompoundfororganicchemicalsandstudiedmicrobialMCPAdegradation,abundanceofmicrobialdegradersandadsorption,desorptionandtransportofMCPA.Inafirstexperiment,transportoflittercompoundswasidentifiedasimpor‐tantprocess,whichregulatestheactivityoftheMCPAdegradingcommunityresultinginaccel‐eratedMCPAdegradationat the soil‐litter interface (Polletal., 2010). Increasedbacterial andfungal MCPA degradation might be hierarchically regulated: (1) At the cellular level by co‐substrate availability and activity of unspecific enzymes (e.g. laccases), (2) at the communitylevelbytheecologyofdifferentdegraderpopulationsand(3)atthemicrohabitatlevelbyinter‐actionbetweenMCPAdegradersandorgano‐mineralsurfacesaswellastransportprocesses.Inaseriesofexperiments,wetesteddifferentregulationmechanisms.WhereaspreliminaryresultsindicatethatonlysmallamountsofMCPA‐CwereincorporatedintothefungalbiomassandthatcommerciallyavailablefungallaccasesdidnotincreaseMCPAdegradation,wewereabletode‐tectdifferencesbetweentheecologyofspecificdegraderpopulations(Ditterichetal.,2013).WecouldalsoshowthatMCPA‐Cwasincorporatedbymicroorganismsandstabilizedinsoilasbio‐genicresidues.Inabatchexperiment,wefoundthattheobservedsmall‐scalemechanismsatthesoil‐litterinterfacewererelevantatalargerscaledependingontheamountofaddedMCPAandlitter(Salehetal.,inprep.).Finally,wedevelopedandappliedamechanisticmodel,whichinte‐gratesbiologicalandphysicalprocessestoimproveourunderstandingofthemicrobialregula‐tionofMCPAdegradationatthesoil‐litterinterface(Pageletal.,2014).ReferencesDitterichF,PollC,PagelH,BabinD,SmallaK,HornM,StreckT,KandelerE.2013.SuccessionofbacterialandfungalMCPAdegradersatthesoil‐litterinterface.FEMSMicrobiolEcol86:85‐100.

PagelH, Ingwersen J, Poll C,KandelerE, StreckT. 2014.Micro‐scalemodelingof pesticidedegradationcoupledtocarbonturnoverinthedetritusphere‐Modeldescriptionandsensitivityanalysis.Biogeoche‐mistry117:185‐204.

PollC,PagelH,Devers‐LamraniM,Martin‐LaurentF,IngwersenJ,StreckT,Kandeler.2010.RegulationofbacterialandfungalMCPAdegradationatthesoil‐litterinterface.SoilBiolBiochem42:1879‐1887.

SalehO,PagelH,EnowashuE,Devers‐LamraniM,Martin‐LaurentF, StreckT,KandelerE,PollC.2014.Evidencefortheimportanceoflitterasco‐substrateforMCPAdissipationinanagriculturalsoil.inprep‐aration.

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Session4:BGIsinChangingEnvironments:BGIsDynamics&HeterogeneitywithConsequencesforProperties&Processes

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Topic4:BGIsinChangingEnvironments:BGIsDynamics&HeterogeneitywithConsequencesforProperties&ProcessesKeynoteTalk

TrophicInterdependenciesShapeSpatialSelf‐OrganizationofMi‐crobialConsortiaonComplexHydratedSoilSurfacesDaniOrDepartmentofEnvironmentalSystemsScience,ETHZurich,SwitzerlandMicrobiallifeinsoiloccurswithinfragmentedporespacesandaquatichabitatswheremotilityisrestricted to thin liquid filmscapableof supportingmotion, and for relatively shorthydrationwindows(immediatelyfollowingwettingevents).Thelimitedrangesofself‐dispersion,andthephysical confinement, enforce spatial association among trophically interdepended microbialspecieswithdifferentandcompetingresourcerequirements.Thespatialorganizationandfunc‐tional patterns of such complex diffusion‐controlled communities remain unclear. We reportamechanisticmodeling study ofmultispeciesmicrobial communities grown on hydrated soilsurfaces.Modelresultsshowhowtrophicdependenciesandcell‐level local interactionswithinpatchydiffusionfieldsleadtonichepartitioningandpromotespatialself‐organizationofmotilemicrobial cells.The spontaneously formingpatternsof segregatedyet coexisting specieswereshowntoberobusttospatialheterogeneitiesandtemporalperturbations(hydrationdynamics),andrespondedprimarilytothetypeoftrophicdependenciesandboundaryconditions(nutrientfluxesatboundaries).Thespatiallyself‐organizedconsortiaformecologicaltemplatesthatop‐timizenutrientutilization(andpotentiallyotherfunctions),thesepatternscouldformthebasisfor subsequent sessile andEPS‐embeddedmicrobial colonies formingonnewly inhabited soilsurfaces.The limited spatial rangeofmicrobial displacementon surfacesdefines ahydration‐dependentseparationdistancefortheactivationofspatialself‐organization(i.e.,memberssepa‐ratedbeyondthisdistancecannot“join”theconsortium).Thestudyprovidesnewinsightsintopotentialmechanismsbywhichdifferencesinnutrientaffinitiesamongmicrobialspeciescouldgiverisetospatialorderinanextremelyheterogeneousandcomplexsoilmicrobialworld.

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BacterialImpactontheWettingPropertiesofSoilMineralsJanAchtenhagen1,Marc‐OliverGöbel2,AnjaMiltner1,SusanneK.Woche2andMatthiasKästner11DepartmentofEnvironmentalBiotechnology,Helmholtz‐CentreforEnvironmentalResearch‐UFZ,Leipzig,Germany2InstituteofSoilScience,LeibnitzUniversitätHannover,Hannover,GermanySoil water repellency (SWR) is a widely observed phenomenon with severe impacts like in‐creased erosion, inhibited plant growth and surface runoff. Nevertheless, a physicochemicalframeworktoexplaintheoccurrencesandoriginofSWRisstillamajorfieldofresearch.Recentstudies have shown that microbial biomass residues, in particular cell fragments, contributesignificantlytotheformationofsoilorganicmatter(SOM)andarethereforeimportantbiogeo‐chemicalinterfaces.Itwasalsoshownthatosmoticstressincreasesthehydrophobicityofbacte‐rialcellsurfaces.IfmicroorganismsareanimportantsourceofSOM,theattachmentofcellsandtheirresiduesonmineralgrainsshoulddecreasewettabilityofmineralswhiletheeffectshouldbe more pronounced in case of osmotic stress. Cultures of Pseudomonas putida, either un‐stressedorexposedtoosmoticstress,andcellfragmentsweremixedwithmineralsandtheim‐pactonsurfacewettingpropertieswasinvestigatedbydeterminingthesolid‐watercontactan‐gle. Scanning electronmicroscopywas used for visualization of structures in the sub‐μm sizerangeandenvironmentalscanningelectronmicroscopywasusedtodeterminethemicro‐scalewettability.Attachmentofbacteriatoquartzsurfacesresultedinasignificantincreaseinhydro‐phobicityof thesurfaces (contactangle increasebyup to90°), inparticular forstressedcells,evenifthesurfacecoveragebybacterialbiomasswasverylow(<5%).Cellfragmentsandcyto‐solaswellwerefoundtodecreasewettabilitysignificantly(contactanglesofupto100°).ThesefindingsmayexplainvariousphenomenarelatedtoSWR,likecriticalsoilwatercontentandmaybeoneimportantparameterfortheformationofSWRafterirrigationwithtreatedsewageefflu‐ents.TheresultsalsosupportthehypothesisofamicrobialoriginofSWR, inwhichmacromo‐lecular biological structuresmay have a greater impact than specific classes of organic com‐pounds.

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Fungal‐MineralInterfaceDuringLeafLitterDecompositionFlaviaPinzari1,LoredanaCanfora1,MelaniaMigliore1,andRosarioNapoli11ConsiglioperlaRicercaelasperimentazioneinAgricoltura,CentrodiRicercaperlostudiodellerelazionitrapiantaesuolo,Rome,ItalyForsomeauthors,thedecompositionofcelluloseandotherorganiccompoundsinsoil isposi‐tivelycorrelatedtotheconcentrationofmacronutrients,suchasNandP.SeveralstudiesonleaflitterdecompositiondemonstratedthatthecontentofNandPcandefinethedecomposabilityoftheorganicsubstrate(Melilloetal.,1982).ButtheeffectofothernutrientssuchasMn,K,Caandmicronutrients (Mo, Cu, Zn, Fe) seemed equally essential on the rate of decomposition. PerezandJeffries(1992)forexamplefoundthatMnactsasanactivatoroffungalenzymessuchasMn‐peroxidasethatworkinthebreakdownof lignin.Alongthecomplexprocessofdegradationoftheorganicsubstanceinthesoil,theelementspresentinlimitingquantitiescaninducecompeti‐tionbetweendecomposersandresultrapidlyimmobilizedinthebiomassofthesame,withtheconsequentincreaseoftheirconcentrationinthelitter.TiunovandScheu(2005)showedhowdecompositionprocessesatthelevelofthesoilandlitterareoftendrivenbyfungi,whosefunc‐tionaldiversitymaybedeterminantataspatialscaleinwhichfungalhyphaeinteractwitheachotherandwithbothmineralandorganiccompounds.Thesemicrositescanbecharacterisedbydifferentconcentrationsofmicroelementsasaconsequenceof fungalabilitytodissolveorde‐positsomemineralcompounds.Salamancaetal.(1998)andBrionesandIneson(1996)showedanet transferofnutrients suchaspotassium (K), calcium (Ca) andmagnesium (Mg)betweendifferent litters. The translocation of nutrients and the leaching activity or hyphae allows thepioneersfungitoovercomethelimitationsofferedbyapoorsubstrate.Actuallyinmostnaturalhabitats the spatial distribution of organic particles andminerals is patchy. In this studyweuseda combinationof experimental techniques to compare fungal communitiesdeveloping intwoleaf litterenvironments,characterisedbythesamerocksubstrate(volcanicsoil),butwithdifferent forestcoverage(Quercusspp.andFagussylvaticaL.).Thedatahereshowedarerele‐vant to the changes in elemental composition of leaf litter after fungal development and toa comparisonof the fungal communities in the two systems.DecomposingQuercusandFagusleaveswereanalysedwithavariablepressureSEMinstrument(EVO50,Carl‐ZeissElectronMi‐croscopyGroup)equippedwithadetectorforelectronbackscattereddiffraction(BSD).Mostofthe fungal structures documented on leaf litter proved to be capable of concentrating severalimportantbiogenicmicroelements(N,P,S,K,MgandCa), thatareata lowerconcentrationorabsentinthebackgroundsubstratebeforefungalcolonisation.Moreoveritwasdocumentedtheformationofoxalatesdirectlyonleafsurfacesasaresultoftheactivetranslocationofcalciumbythe fungalmycelium.The comparedecosystems, although sharing several important variables(macroclimate,exposition,soilparentalmaterial)showedtosupportdifferentfungalcommuni‐tiesthathavespecificdecompositionabilitiestowardsboththeorganicandmineralsubstrate.ReferencesBrionesMJI,InesonP.1996.Decompositionofeucalyptusleavesinlittermixtures.SoilBiol.Biochem.28:1381‐1388.

MelilloJM,AberJD,MuratoreJF.1982.Nitrogenandlignincontrolofhardwoodleaflitterdecompositiondynamics.Ecology63:621‐626.

PerezJ,JeffriesTW.1992.RolesofmanganeseandorganicacidchelatorsinregulatinglignindegradationandbiosynthesisofperoxidasesbyPhanerochaetechrysosporium.AppEnviron.Microbiol.58:2402‐2409.

SalamancaEF,KanekoN,KatagiriS.1998.EffectsofleaflittermixturesonthedecompositionofQuercusserrataandPinusdensiflorausingfieldandlaboratorymicrocosmmethods.Ecol.Eng.10:53‐73.

TiunovAV,ScheuS.2005.Facilitativeinteractionsratherthanresourcepartitioningdrivediversity‐functioningrelationshipsinlaboratoryfungalcommunities.Ecol.Lett.8:618‐625.

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HowDoestheAdditionofSulphurtoSoilInfluenceChemosynthe‐sisandCarbonFlux?KrisM.Hart1,AnnaN.Kulakova2,ChristopherC.R.Allen2,AndreJ.Simpson3,SethF.Op‐penheimer4,HussainMasoom3,DenisCourtier‐Murias3,RonaldSoong3,LeonidA.Kula‐kov2,PaulF.Flanagan2,BrianT.Murphy1andBrianP.Kelleher11SchoolofChemicalSciences,DublinCityUniversity,Glasnevin,Ireland2TheSchoolofBiologicalSciences,Queen’sUniversityBelfast,MedicalBiologyCentre,Belfast,N.Ireland3DepartmentofChemistry,DivisionofPhysicalandEnvironmentalScience,UniversityofTorontoatScarborough,Toronto,Ontario,Canada4DepartmentofMathematicsandStatistics,ShackoulsHonorsCollege,MississippiStateUniversity,MississippiState,USAThe sequestration of CO2 in soil represents a potential solution to rising atmospheric carbonconcentrationsandloweringagriculturalproductivity(King,2010).Themicrobialcontributiontosoilorganicmatter(SOM)hasrecentlybeenshowntobemuchlargerthanpreviouslythoughtand thus its role in the carboncyclemayalsobeunderestimated (Simpsonetal., 2007).Bothphotoautotrophicandchemoautotrophic soilmicroorganismscan fixCO2 throughavarietyofassimilatorypathways (Yuanetal., 2012). Chemoautotrophs canworkwithout sunlight as anenergysourceandgleanenergythroughtheoxidationofreducedelementssuchassulphur.Re‐centlyweshowedthatbyaddinganelectrondonor,inthiscaseS2O32−toasoilslurry,therewasan order ofmagnitude increase in the uptake of CO2 by chemoautotrophs (Hart etal., 2013).Whatthenhappenswhensulphurisaddedtosoilasisdonecommonlyinagriculture?Hereweshowthatovera12weekperiod,theadditionofsulphurtosoilresultsinaninitialsurgeinpro‐duction of CO2 throughmicrobial respiration/degradation and this is followed by an order ofmagnitudeincreaseinthesequestrationofcarbonfromtheatmosphereaselementalsulphurisoxidisedtosulphate.StableisotopeProbing(SIP)showsthatThiobacillusspp(achemoautotro‐phicbacterium) takeadvantageof thereducedconditions tobecomethedominantgroup thatconsumes 13CO2 and uses the carbon for cellular growth. Through nuclearmagnetic spectros‐copy (NMR)we candiscern thedirect incorporationof atmospheric carbon, facilitatedby theoxidationofsulphur,intosoilcarbohydrate,proteinandaliphaticcompoundsanddifferentiatethesefromexistingbiomass.ReferencesHartKM,KulakovaAN,AllenCCR,SimpsonAJ,OppenheimerAF,MasoomH,Courtier‐MuriasD,SoongR,L.KulakovA, Flanagan PV,MurphyBT, Kelleher BP. 2013. Tracking the fate ofmicrobially sequesteredcarbondioxideinsoilorganicmatter.EnvironSciTechnol47:5128‐5137.

KingGM.2010.Enhancingsoil carbonstorage forcarbonremediation:potentialcontributionsandcon‐straintsbymicrobes.TrendsMicrobiol19:75‐84.

SimpsonA,SimpsonMJ,SmithE,KelleherBP.2007.Microbiallyderivedinputstosoilorganicmatter:Arecurrentestimatestoolow?EnvironSciTechnol41:8070‐8076.

YuanH,GeT,ChenC,O’DonnellAG,Wu J.2012.Microbialautotrophyplaysasignificantrole in these‐questrationofsoilcarbon.ApplEnvironMicrobiol78:2328‐2836.

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UnderstandingRootGrowthInducedChangesinSoilSonjaSchmidt1,GlynBengough2,3andPaulHallett41AbertayUniversity,TheSIMBIOSCentre,Dundee,UK2TheJamesHuttonInstitute,Invergowrie,Dundee,UK3TheUniversityofDundee,GeotechnicalEngineering,Dundee,UK4TheUniversityofAberdeen,SchoolofBiologicalSciences,Aberdeen,UKWithincreasingdemandforfoodandvariablewaterregimesduetoclimatechange,itisimpor‐tant to get a better understanding the processes involved in roots growing through soil. It isknown that roots change their environment during growth and changes in soil structurewillaffectwaterandnutrientavailabilitiesforplantsbutlittleisknownhowsoilstructuralproper‐tieschangeovertime.Moredetailedinformationonthemechanismsinvolvedofrootspushingthroughsoilwillhelpustomodelrootgrowthandwaterandnutrientuptakebyplants.Theaimofthisstudywastoobtaindataonsoilstructureintherhizosphereandattherootsoilinterfaceduringrootgrowthofyoungmaizeseedlingsaswellasdataonfailuremechanismsofsoilunderpressure.3Dvolumetricimagesofgrowingmaizerootsweretakenoveraperiodofsix.Soilwascompacted to twodifferent levels (50kPaand200kPa)andwetted to twomatricpotentials (‐10kPaand‐100kPa).2Dcrosssectionsofdifferentpositionsalongtherootswereanalysedforchangesinporosity,poreconnectivityandroot‐soilcontactfordifferenttimesteps.Particleim‐agevelocimetry(PIV)wasusedtoquantifyparticlemovementduringtherootgrowth.Soilphys‐icalcharacteristicsweredeterminedusingacrackpropagation–notchedbendtestandacom‐pression test. Soil structural changeswereobservedduring root growth.Root‐soil contact in‐creasedwithtimewhereasporositydecreasedincloseproximitytotheroot.Soildeformedra‐diallyandsomeaggregatesweredestructedduringrootgrowthwhileotherswerepushedintotheporespace.Soilmechanicalbehaviourwassignificantlyaffectedbycompactionbutnotbythewatercontent.Thesedataonthechangesinsoilstructurewillhelpustopredictwaterandnutrientavailabilityforplants.

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Session4:BGIsinChangingEnvironments:BGIsDynamics&HeterogeneitywithConsequencesforProperties&ProcessesKeynoteTalk

ActiveMicrobialDispersalinSoils:EffectofSpatialHeterogeneityandVaryingHydrationConditionsBarthF.SmetsDepartmentofEnvironmentalEngineering,TechnicalUniversityofDenmark,Lyngby,DenmarkThoughweoftenconsidermicrobesinsoilasattachedontosoilinterfaces,thefactthattheycandisperseshouldnotbeoverlooked. Indeed, theabilityofmicrobes tobespatiallydynamichaswiderangingconsequencesformicrobialecology(e.g.geneflowinmicrobialcommunities)andfortheprovisionofthekeysoilservices(e.g.degradationofxenobiotics).However,ourcurrentknowledgeofspatialorganizationandspatialdynamicsofmicrobesinsoilatthemicroscaleislimited.Whilepassivedispersalviawaterfloworsoilbiotaisamajordispersalroute, it is im‐portanttoevaluatethecontributionofactivedispersaltomicrobialspatialdynamics.Inbacte‐ria, active dispersal, termed motility, is enabled by diverse appendages and, in the case ofswarmingmotility,bythesecretionofsurfaceactivebiomolecules.Itisuncleartowhichdegreedifferenttypesofmotilitycantakeplaceinthesoilpores,ahabitatcharacterizedbyacomplex3Dgeometryandvariablehydration. Toaddressthesequestions,wehavetakenadvantageofthePorousSurfaceModel(PSM)auniqueexperimentalplatformthatallowsdirectmonitoringofmicrobialmotion under controlledmatric potential. Using gfp‐tagged Pseudomonas strainsandisogenicmutantswithvariousabilitiestoexpressvarioustypesofmotility,wehaveaimedtoquantify thephysical barriers of bacterialmotility.Our results demonstratehowhydrationandsubstratumtopographycontrolbacterialmotilityunderunsaturatedconditions.Thesefind‐ingscanformthebasisofimprovedbiodegradationmodelsthatincludemicrobialdispersalpro‐cesses.

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SoilOrganicMatterDecomposition–TheRolesofMicrobialHabi‐tatsandofMicrobialCommunitiesSabrinaJuarez,NaoiseNunan,ValériePouteau,ThomasLerchandClaireChenuInstituteofEcologyandEnvironmentalSciences–Paris,ThivervalGrignon,FranceSoilmicrobialcommunitiesliveinacomplexthree‐dimensionalframeworkinwhicharangeofmicrobialnicheswithavarietyofpropertiesexists.TheimportanceofthesehabitatpropertiesrelativetotheintrinsicpropertiesofmicrobialcommunitiesintheregulationofSOMdecompo‐sitionandsoCO2emissionsisstillunclear.SomestudiessuggestthatabioticprocessesdominateSOMdecomposition,mainlythroughphysicalmechanisms(i.e.occlusionwithinaggregates,ad‐sorptionontominerals)thatlimittheaccessdecomposershavetoorganicsubstrates.MicrobialhabitatpropertiesarethereforelikelytoprofoundlyaffectmicrobialdecompositionofSOM.Incontrast, others studies have concluded that soilmicrobial communities acting as catalysts ofbiogeochemicalcyclesbyconvertingorganicmaterial to inorganicsubstancesplayadominantrole in SOMdecomposition.Most studies on the relationship betweenmicrobial diversity andSOMdecomposition indicate that the lack of relationship between the two is due to a certainfunctionalredundancythatexistswithinmicrobialcommunities.However,theexperimentsonwhichthisconclusionisbasedgenerallyappeartocontainthesamedominantmicrobialspeciesandthereforethesamedominantactivespecies.Inordertodeterminewhichofmicrobialhabi‐tat properties or intrinsicmicrobial community properties is the dominant regulator of SOMdecomposition, we sterilised samples from 6 soils, cross‐inoculated them with communitiesoriginatingfromeachofthe6soilsandmeasuredCmineralisationintheinoculatedsoilsduringanincubationthat lastedforaperiodofXXXdays.The6soilsvariedintexture,pH,OMstatusandcontaineddifferentmicrobialcommunities(verifiedbyt‐RFLP),meaningthattherewere36treatments (6 soils x6 communities)whichcontaineda rangeofdifferenthabitat xmicrobialcommunitycombinations.Thecumulativerespirationcurveswerefittedwithtwo‐compartmentfirstordermodel,andtheparameterswereanalysedtodeterminewhataffectedtheCO2emis‐sions.MicrobialhabitatpropertiesweremorecloselyrelatedtoSOMdecomposition.Neverthe‐less,themineralisationrateofthenativepool(βparameter)wasaffectedbythestructureofthemicrobialcommunities.

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DroughtImpactonSpatialHeterogeneityofEnzymeActivitiesontheRoot‐SoilInterfaceMuhammadSanaullah1,2,BaharSadatRazavi1,EvgeniaBlagodatskaya1andYakovKuzyakov11GeorgAugustUniversityofGöttingen,Göttingen,Germany2InstituteofSoilandEnvironmentalSciences,UniversityofAgriculture,Faisalabad,PakistanRhizosphereisoneofthemostimportanthotspotsinsoilwithverytightbioticandabioticin‐teractions, thespatialstructureofwhichdefines thecomplexityandheterogeneityofroot‐soilinterface.Wemodified insitusoilzymographyanduseditforidentificationandlocalizationofhotspots of β‐glucosidase activity in the rhizosphere of maize depending on soil drying‐rewetting.Underdroughtstress(30%offieldcapacity),zymographicimagesshowedveryhigh‐lightedspotsofβ‐glucosidaseactivityalongroots.Thezymographicsignalswereespeciallyhighat root tips andweremuch stronger for activity of β‐glucosidaseunderdrought as comparedwith optimalmoisture (70% of field capacity). This distribution of enzyme activity was con‐firmedby fluorogenically labelledsubstratesapplieddirectly to therootexudatesof thesamemaizeplant,sampledwithin1hourafterzymography.Theactivityofβ‐glucosidasebyrootas‐sociatedmicroorganismsinrootexudateswassignificantlyhigherbydroughtstressedplantsascomparedwithoptimalmoisture.Incontrast,theβ‐glucosidaseactivityindestructivelysampledrhizospheresoilwaslowerunderdroughtstresscomparedwithoptimalmoisture.Furthermore,droughtstressdidnotaffectedβ‐glucosidaseactivityinbulksoil,awayfromrhizosphere.Con‐sequently, we conclude that higher release ofmucilage by roots under drought had strongerimpact on β‐glucosidase activity in the rhizosphere. Remoistening of these drought‐stressedplantseliminatedthedifferencesinfingerprintsofβ‐glucosidaseactivityduetodroughtstress.Thus,thezymographyrevealedplant‐mediatedmechanismsacceleratingβ‐glucosidaseactivityunderdroughtattheroot‐soil interface.So,couplingofzymographyandenzymeassaysintherhizosphereandnon‐rhizospheresoilenablesprecisemappingthechangesintwo‐dimensionaldistributionofenzymeactivitiesduetoclimatechangewithindynamicsoilinterfaces.

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Session4:BGIsinChangingEnvironments:BGIsDynamics&HeterogeneitywithConsequencesforProperties&ProcessesKeynoteTalk

TheDynamicsandPropertiesofBiogeochemicalInterfacesinSoil:TheImpactofaChangingEnvironmentGeorgHaberhauer,MartinH.Gerzabek,DanielTunega,GeorgJ.Lair,andFranzZehetnerInstituteofSoilResearch,DepartmentforForestandSoilSciences,UniversityofNaturalResourcesandLifeSciences,Vienna,AustriaManyofthesoilfunctions–suchasthefilterandbufferfunctionforprovidingcleanwaterorthesourceofrawmaterial–arecloselyrelatedtothebio‐geochemicalcharacteristicsofsoils.Manyofthesoilpropertiesrelatingtosoil functionalitydependnotonlyonbulkcompositionbutoncompositionalandstructuralfeaturesofthebiogeochemicalinterfaces(BGIs). Propertiessuchashydrophobicityofsurfaces,reactivitywithrespecttointeractionwithinorganicandorganicpollutantsvary in timedue toweatheringprocessesand theanthropogenic impactonsoils.AchronologicalframeworkforfluvialdepositsalongasoilsequenceattheDanubeRivernearVi‐enna,Austria,a longtermexperimentusingdifferent treatmentmethodsandanexperimentalstudyexposingsoiltodifferentclimateconditionsconfirmthatchangesintheenvironmentdohavean impactonsoilorganicmatter(SOM)dynamicsand itssorptionproperties fororganicandinorganiccompounds.There is increasingevidencethatthebehaviourofpollutantsat themicro‐or larger scales isdrivenby their interactionsatnanoscale. Usingadvanced computa‐tionalmolecularmodellingmethods tomodel such biogeochemical interfaces in soil is a newfieldinsoilscienceandcanyielddeeperunderstandingofcrucialmolecularinteractionswithinBGIs.Stilloneofthechallengesisbridgingandlinkingmolecularandhigher(e.g.microscopic)scalesof complexandheterogeneousBGIs systems investigatedbymolecular simulationsandexperimentaltechniques.Currentspatialandtemporalscalesinmolecularmodelling,whicharemanageableinarealisticcomputationaltime,areuptotenthsofnanometersandmicroseconds.Molecularsimulationmethodsarehelpfulinexploringbasicmechanismsandelementarysteps,whichcannotbeinvestigatedexperimentallyatpresent.Withinthispresentationseveralexam‐plesandresultsofmodellingexperimentsrelatingtoBGIsandcertainenvironmentalconditionswillbeshown.Thesemodelsincludetheinteractionsoforganicmoleculeswithsoilcomponents(soilminerals, SOM), the role ofwater and cationbridges in SOMstabilization, hydration andwettability of SOM and wettability of mineral and organo‐mineral surfaces. Further develop‐mentstolinkthesetheoreticalmodelstoexperimentalstudiestoinvestigateBGIsinresponsetoenvironmentalchangeswillbediscussed.

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Session5:QuantitativeUnderstandingofBGIsFunctions:TheoreticalConcepts&ModelstoExplainStructure,Properties&FunctionsofBGIs

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Topic5:QuantitativeUnderstandingofBGIs:TheoreticalConcepts&ModelstoExplainStructure,Properties&FunctionsofBGIsKeynoteTalk

MolecularModelsandSimulationsofSoilOrganicMatter:Struc‐ture,DynamicsandInteractionsWithOtherEntitiesChrisOostenbrinkInstituteofMolecularModelingandSimulation,UniversityofNaturalResourcesandLifeSciences,Vienna,Austria Moleculardynamicssimulationsgiveinsightintomolecularprocessesataresolutionthatisof‐teninaccessiblebyexperiments.Thestructureand(thermo)dynamicsofsmallmoleculesinter‐actingwithvariousmediaarecommonlystudiedbycomputersimulationsinmaterialsciencesand biomolecular sciences. However, extensivemolecular simulations of soil constituents arehampered by ill‐definedmolecular systems and restrictions in the description of the relevantinteractions.Here,wepresentalibraryofbuildingblocksforclassicalmolecularsimulationsofsoilorganicmatter.Anapproach toestablishcondensedphase,amorphicsystemswillbepre‐sented,whichcansubsequentlybeusedforextensive insilicoexperiments,e.g.addressingthestructureofthesystems,thetheirthermodynamicstabilityortheadsorptionofsmallmolecularpollutants.Wewill demonstrate the need for extensive sampling of the conformational spaceandsuggestapplicationsofmodernsimulationmethodstosoilcomponents.

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Topic5:QuantitativeUnderstandingofBGIs:TheoreticalConcepts&ModelstoExplainStructure,Properties&FunctionsofBGIs

OrganicFunctionalGroupDensityandStructuralDynamicsofSoilOrganicMatterTakeKeyRoleinCationBridgeFormationYamunaKunhiMouvenchery1,2andGabrieleEllenSchaumann21Departmentofchemistry,N.S.S.College,Manjeri,Kerala,India2Departmentofsoilandenvironmentalchemistry,InstituteofEnvironmentalSciences,UniversityofKoblenz‐Landau,Landau,GermanyCationsandwatermoleculescross‐linksoilorganicmatter(SOM)segmentsandwiththis,formcation bridges (CaB) and water molecule bridges (WaMB), respectively. The spatial distancebetweentheOMfunctionalgroupsaswellasthecationsizeisdeterminantfortheformationofCaB (KunhiMouvenchery etal., 2013). Thus small cationswill not be able to cross‐link overlargedistances.ItishypothesisedthatwatermoleculescanassistmultivalentcationstobridgelargedistancesbetweenOMmolecules,eitherashydrationwaterorasbridgingagentsbetweencationsandOMmolecules,viaCaB‐WaMBassociations(Schaumannetal.,2013).Astronglyheldhydration sphere of cationsmay result in cross‐links bridging larger distances than the barecationsdo.Thiswill form innerspherecomplexes.LargerCaB‐WaMBassociationsmaybridgeevenlargerdistancesbyinvolvingmorewatermoleculesbetweenthehydratedcationandor‐ganicfunctionalgroups.Inordertoverifythishypothesis,experimentswereconductedwiththeaimofinducingCaB,ontwodifferentSOMmaterials.Sampleswereselectedbasedontheeffec‐tive exchange capacity (CEC), under the assumption that sample with higher CEC representsSOMrichinactivefunctionalgroups.LowCECsamplespossesslowfunctionalgroupdensityandhencethespatialdistancebetweenadjacentfunctionalgroupswillbelarge.ApeatofCEC=123mmolckg‐1andaforestSOMofCEC=303mmolckg‐1wereselected.Afterremovaloftheorigi‐nallypresentcations,samplesweretreatedwithbivalentcations(Mg2+,Ca2+andBa2+) invari‐ableconcentrationsandWaMBtransitiontemperature(T*;Schaumannetal.,2013)wasmeas‐uredatdefinite intervals.T*,measuredbydifferentialscanningcalorimetry(DSC),reflects thechangeinmatrixrigidityduetodisruptionofWaMBatT*.ThehigherT*,themorestablearetheWaMBandthemorerigidisthematrixheldtogetherbyWaMB.Cationtreatmentdidnotcausesignificantchangeinmatrixrigidityinpeat,butinducedstrongagingeffects.Fortheforestsoil,Mg2+formedweakerinteractionswithintheSOMthanCa2+andBa2+,asrevealedbychangeinT*values after cation treatment. After aging for eightweeksmatrix rigiditywas enhanced in allsamples, indicating strengthening of the existing interactions or the formation of new CaBand/orWaMBinteractions.ThefinalmatrixofMg2+‐treatedsampleswasevenmorerigidthanthat of Ca2+ andBa2+. This canbe easily explained as: initially less rigidMg2+‐treated samplesunderwenthigherdegreeofstructuralreorganisationduringagingthanintheothertwo,morerigidset.ItcouldbethatreorganisationofSOMsegmentsandwatermoleculesoccurredsuchawaythatMg2+wasabletoformcross‐linksintheformofCaB‐WaMBassociations.Thiscumula‐tivestudythusrevealtherelevanceofSOMqualityandtheroleofwatermoleculesinCaBfor‐mation,andtheroleofCaBinteractionsinsoilagingprocess.ReferencesKunhiMouvencheryY,JägerA,AquinoAJA,TunegaD,DiehlD,BertmerM,SchaumannGE.2013.Restruc‐turingofaPeatinInteractionwithMultivalentCations:EffectofCationTypeandAgingTime.PLoSONE.8(6):1‐11.

SchaumannGE,Gildemeister,D,KunhiMouvencheryY,SpielvogelS,DiehlD.etal.2013.Interactionsbe‐tweencationsandwatermoleculebridgesinsoilorganicmatter.J.Soil.Sediment.13,1579‐1588.

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OrganicSorbate‐InducedCooperativeHydrationofSoilOrganicMatterMikhailBorisoverInstituteofSoil,WaterandEnvironmentalSciences,TheVolcaniCenter,AgriculturalResearchOrganization,BetDagan,IsraelHydrationiswellexpectedtoaffectpropertiesandfunctionsofsoilorganicmatter(SOM)whichistheimportantcomponentofbiogeochemicalinterfacesinsoil.ThebetterunderstandingoftheSOMhydrationatthemicro‐environmentscalemaybereachedbyexaminingtheinterplaybe‐tweenwaterandorganicmoleculessorbingbySOM.Therefore, theaimof thispresentation istwo‐fold.Thefirstgoalistoattracttheattentiontothesignificanceandcomplexityofwaterpar‐ticipation insorption interactionsoforganiccompoundswithSOM,and,specifically, totheco‐operativecharacterofthisparticipation.ThesecondgoalistodiscusshowthecomplexityoftheSOMassemblagecouldberesponsibleforthecooperativeSOMhydrationinducedbysomeor‐ganic sorbates. The analysis is based on sorption data accumulated for various organic com‐poundsonmodelSOMsorbentsatvariablewatercontentsandactivities(BorisoverandGraber,2002;Graberetal.,2007;Borisoveretal.,2011;Borisover,2013).Themajorpointsarethat(a)multipleorganic compounds interactingwithSOMdrivewatermolecules into theSOMphase,and (b) severalmolecules ofwatermay have to participate cooperatively in this organic sor‐bate‐induced SOM hydration. The organic sorbate‐induced cooperative SOM hydration is ex‐pected for verymanyorganic compounds containingN, S,O atoms (in contrast to sorptionofrather „lesspolar“organicmoleculeswhichpushwater out of theSOMphase).DrivingwatermoleculesintoSOM(i.e.,theorganicmolecule‐watercollaborationinsorption)maybelinkedtothenecessity of solvating the SOMsurfaces exposed/deformeddue to the interactionwith anorganicsorbate.However,itismuchlessclearwhyseveralmoleculesofwaterhavetopartici‐pate cooperatively in this process. Therefore, this raises questions on the SOM „architecture“.Thehypothesesonthehydration‐inducedlocalSOMconformationalchangesthatcouldenhancethe uptake of followingwatermolecules and/or on the enhancedwater‐water interactions inaSOMphasecouldbesuggestedaspossiblemechanismsforthecooperativeSOMhydrationbutthe proofs for these interpretations are needed, yet. It appears that organic sorbate‐inducedhydrationofSOMmayoccureveninfullywetSOMthuscallingforconsideringsoil/SOMsorp‐tionreactionsoforganicmoleculesfromwaterasoccurringwithaco‐sorptionofseveralwatermolecules.However, a directmonitoringof a co‐participation ofwater andorganicmoleculessorbingonSOMsorbentsfromtheliquidphasewouldbeveryusefulinordertomakeafurtheradvanceintheconception.ReferencesBorisoverM,GraberER.2002.Simplifiedlinksolvationmodel(LSM)forsorptioninnaturalorganicmat‐ter.Langmuir18:4775‐4782.

BorisoverM,SelaM,ChefetzB.2011.Enhancementeffectofwaterassociatedwithnaturalorganicmatter(NOM)onorganic compound ‐NOM interactions:A case studywith carbamazepine.Chemosphere82:1454‐1460.

BorisoverM.2013.The effect of organic sorbatesonwater associatedwith environmentally importantsorbents:estimatingandtheLFERanalysis.Adsorption19:241‐250.

GraberER,TsechanskyL,BorisoverM.2007.Hydration‐assistedsorptionofaprobeorganiccompoundatdifferentpeathydrationlevels:thelinksolvationmodel.EnvironSciTechnol41:547‐554.

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LinkingPhysicochemicalandStructuralPropertiesofBiogeo‐chemicalInterfacesinSoilstoSequestrationofOrganicPollutantsJaaneKrüger1,JanSiemens2,MartinKaupenjohann3andFriederikeLang11ChairofSoilEcology,UniversityofFreiburg,Freiburg,Germany2InstituteofCropScienceandResourceConservation,UniversityofBonn,Bonn,Germany3DepartmentofSoilScience,TUBerlin,Berlin,GermanyPhysicochemicalandstericpropertiesoforganicchemicalsontheonehandandphysicochemi‐cal surface properties and structural properties of the sorbent on the other hand determinesorptive interactions at biogeochemical interfaces, thereby controlling the mobility and (bio‐)degradation of these substances.Our aim is to test the hypotheses (1) that the sorption anddistributionoforganicchemicalsatbiogeochemicalinterfacesiseitherdeterminedbythemole‐cules’ hydrophobic R‐groups (“R‐determined” chemicals) or its functional groups (“F‐determined”chemicals)and(2)thattheretentionoforganicchemicalsbymineral‐organicasso‐ciations is determined bymicrodiffusion processes.We studied the sorption of PhenanthreneandBisphenolA(R‐determined‐chemicals)andMCPAandBentazone(F‐determined‐chemicals)onpureminerals,onbiofilmmodelsubstances(polygalacturonicacid),andonmineral‐organicmixtures by isothermal titration calorimetry (ITC) in combinationwithmacroscopic sorptionexperiments. According to our hypothesis the thermodynamic characterisation indicated thatthe interaction of “R‐determined” chemicals on pure minerals is an entropy‐driven processwhile the reaction of “F‐determined”‐chemicals is enthalpy‐driven. In a second approach westudiedsorptionofMCPAandPhenanthrenetoartificialmineral‐organicmicro‐aggregates.Themicro‐aggregateswere synthesized in batch experiments by shakingminerals (kaolinite, goe‐thite, quartz) in combination with differently processed particulate organic matter (POM) in0.01MKClatpH4.DifferentlyprocessedPOMwasderivedfromOiandOahorizonsofapodzol.Allprimarymaterialsaswellas the formedmineral‐organicaggregateswerecharacterizedbySEM,andanalyticalcentrifugation.AdditionalthePOMwascharacterizedbyFTIRandCandNconcentrationsweredetermined.Aggregateswerecharacterizedbyultrasoundapplicationanddensityfractionation.Diffusionintomicro‐aggregateswasaddressedinbatchexperimentswith14C‐labeled MCPA and Phenanthrene in 0.1 M KCl at pH 4. Density fractionation of the min‐eral/organicmixturesshowedthat59to93%oftheorganicCwasassociatedtominerals.Re‐sults fromsorptionkineticsshowed, thataggregationdecreases theretentionofpolarorganiccompounds(MCPA)byreducingtheaccessibilityofpolarsorptionsites.Diffusionbecomesthegoverningprocess for the retention of polar organic compounds.No significantdifferencebe‐tweensorptionkineticsofPhenanthrenetodifferentPOMandmicro‐aggregateswasfound,in‐dicatingthathighaffinityofPhenanthrenetoorganicmatterdominatestheretentionprocess.

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Topic5:QuantitativeUnderstandingofBGIs:TheoreticalConcepts&ModelstoExplainStructure,Properties&FunctionsofBGIsInvitedTalk

ModelingSurfaceChemistryofFerrihydriteJamesD.KubickiDepartmentofGeosciences,ThePennsylvaniaStateUniversity,USAFerrihydriteisacriticalsubstrateforadsorptionofspeciessuchassoilorganicmatterandnu‐trientsintheenvironment(BrownandCalas,2012).Thenanoparticulatenatureofferrihydriteis inherentto its formation,andhence ithasbeencalleda“nano‐mineral”(HochellaandMad‐den, 2005). The nano‐scale size and unusual composition of ferrihydrite hasmade structuraldeterminationofthisphaseproblematic.Micheletal.(2007)haveproposedanatomicstructureforferrihydrite,butthismodelhasbeencontroversial(RancourtandMeunier,2008;Manceau,2011).RecentworkhasshownthattheMicheletal.(2007)modelstructuremaybereasonablyaccurate despite some deficiencies (Maillot et al., 2011; Pinney et al., 2009; Hiemstra, 2012).Thisworkutilizesdensityfunctionaltheory(DFT)calculationstomodelthestructureofferrihy‐dritenanoparticlesandthesurfacechargingandadsorptionbehaviorbasedontheMicheletal.(2007)modelasrefinedinHiemstra(2013).Periodicprojector‐augmentedplanewavecalcula‐tionswereperformedwiththeViennaAb‐initioSimulationPackage(VASP;KresseandFurtmul‐ler,1996)onanapproximately1.6nmdiameternanoparticle(Fe38O112H110).Afterenergymini‐mizationofthesurfaceHandOatoms,surfaceswereextractedtomodeltheinteractionoftheFe‐OHandFe‐OH2groupswithH2O.Chargingenergieswerecalculatedinordertobegintomod‐el theatomisticdetailsof ferrihydritesurfacechemistry.Themodelwillbeused toassess thepossibleconfigurationsofadsorbedhumicacidsandphosphateonvarioussurfaces.ReferencesBrownGE Jr, Calas G. 2012.Mineral‐aqueous solution interfaces and their impact on the environment.GeochemPerspectives1:483‐742.

HiemstraT.2013.Surfaceandmineralstructureofferrihydrite.GeochimCosmochimAc105:316‐325.HochellaMF,MaddenAS.2005.Earth’snano‐compartmentfortoxicmetals.Elements1:199‐203.Kresse G, Furthmuller J. 1996. Efficient iterative schemes for ab initio total‐energy calculations usingaplane‐wavebasisset.PhysRevB54:11169‐11186.

MaillotF,MorinG,WangY,BonninD,IldefonseP,ChaneacC,CalasG.,2011.Newinsightintothestructureofnanocrystallineferrihydrite:EXAFSevidencefortetrahedrallycoordinatediron(III).GeochimCosmo‐chimAc75:2708‐2720.

ManceauA.2011.Criticalevaluationoftherevisedakdalaitemodelforferrihydrite.AmMineral96:521‐533.

MichelFM,EhmL,AntaoSM,LeePL,ChupasPJ,LiuG,StronginDR,SchoonenMAA,PhillipsBL,PariseJB.2007.Thestructureofferrihydrite,ananocrystallinematerial.Science316:1726‐1729.

PinneyN,KubickiJD,MiddlemissDS,GreyCP,MorganD.2009.Densityfunctionaltheorystudyofferrihy‐driteandrelatedfe‐oxyhydroxides.ChemMater21:5727‐5742.

RancourtDG,MeunierJF.2008.Constraintsonstructuralmodelsofferrihydriteasananocrystallinema‐terial.AmMineral93:1412‐1417.

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Topic5:QuantitativeUnderstandingofBGIs:TheoreticalConcepts&ModelstoExplainStructure,Properties&FunctionsofBGIsKeynoteTalk

AConceptualApproachtoExperimentalPedologyIngridKögel‐Knabner1,2,KatjaHeister1andGeertjeJohannaPronk11ChairofSoilScience,TechnischeUniversitätMünchen,Freising‐Weihenstephan,Germany2TUMInstituteofAdvancedStudy,Garching,GermanyUnderstandingtheprocessofhowaggregatesareformed,stabilizedandturnoverwillhelpustounderstand and predict the retention and movement of gases, water and solutes in soil; thegrowth,vigourandproductivityofplants;andtheactivity,growthandmovementofsoilorgan‐isms.Thesequestionsarevital formanycurrentagronomicandenvironmental issues.Beyondallourqualitativeknowledgeonsoilformation,wearefarfrombeingabletoquantifythecom‐plexprocessesofsoilstructuredevelopment,whichhavedifferentspacescalesandtimescalesdependingonsoiltype,textureandmanagement.AcoordinatedexperimentwithinthePP1315“Biogeochemical interfaces in soils”was set up to investigate the formation of soil structuresundercontrolledconditionsandwithdefinedparentmineralandorganicstartingmaterials. Itwasconsideredthatsoilasafunctioningcomplexnaturalbodywithuniquecharacteristicsandemergent behaviours cannot be deduced from an isolated investigation of its constituents orsingleprocesses,butonlybyconsideringtheinterplayofcomponentsandprocessesduringsoilformation.Theexperimentrevealedthatitispossibletoproducesoilaggregatesinthelabora‐tory(Pronketal.,2012,2013).Theexperimentshowedthattheessentialingredientstoproduceanemergentaggregatedsoilmaterialareaparentmineralmaterialcomposedofphyllosilicatesand/orironoxides,anorganicsubstrateandaheterotrophicmicrobialcommunity.Aseriesofartificialsoilsofeightdifferentcompositionswasproducedinthissimplesystemthatexcludedtheinfluencesofenvironmentalconditions,soilfauna,orrootsonaggregateformation,nordidittakeplaceinsitu,butnever‐the‐lessintensiveaggregateformationtookplace.Suchexperimentsprovideanewmeans tounderstandsoil formationundercontrolledconditionsandwithcon‐trolledparentmaterials.ReferencesPronkGJ,HeisterK,DingG‐C,SmallaK,Kögel‐KnabnerI.2012.Developmentofbiogeochemicalinterfacesin an artificial soil incubation experiment; aggregation and formation of organo‐mineral associations.Geoderma189‐190:585‐594.

PronkGJ,HeisterK,Kögel‐KnabnerI.2013.Isturnoveranddevelopmentoforganicmattercontrolledbymineralcomposition?SoilBiolBiochem67:235‐244.

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DelineationofBiogeochemicalProcessesControllingContami‐nantFateinanMesoscaleAquiferbyCompound‐SpecificIsotopeAnalysesShiranQiu1,DominikEckert2,HeideBensch1,MichaelMaier1,ArminMeyer1,RamonaBrejcha1,MartinaHöche1,OlafCirpka2andMartinElsner11InstituteofGroundwaterEcology,HelmholtzZentrumMünchen,Neuherberg,Germany2CenterforAppliedGeoscience,UniversityofTübingen,Tübingen,GermanyForacomprehensiveunderstandingof the fateoforganiccontaminants in thesubsurface it isimportant to identify thedominant interactions (sorption,dispersionanddegradation)occur‐ringatbiogeochemical interfaces.Accordingtotheirchemicalstructures(conformity,heteroa‐toms,OHand,COOH‐groups)andtheirbioavailability,organicmicropollutants, liketheherbi‐cide diclobenil, itsmetabolite BAM or pharmaceuticals such as ipubrofen and diclofenac, areexpectedtobehavedifferentlyinenvironmentsubsurfaces.Withcurrentmethodsinsightsaboutthe controllingprocesses are limited.Within this studyweaimed to exploreunder controlledconditions(closedmass‐balance,useofaconservativetracerinanaquifermesocosm)whetherthe analysis of naturally occurring isotope ratios in organic contaminants (compound‐specificisotopeanalysis)cangiveinformationaboutmolecularinteractionsinnature.Inapulseexperi‐mentwe injected the aromatichydrocarbon toluene togetherwithD2Oas conservative tracerintoamesoscaleaquiferfilledwithnaturalsediment(Qiuetal.,2013)(Figure1).Breakthroughcurvesofconcentrations(Fig.1a)aswellas13C/12Cratiosintoluene(Fig.1b)demonstratedin‐deedtheinfluenceofboth,sorptionandbiodegradation,andcouldbemodelledbyapplicationofanoptimized reactive transportmodel (Eckertetal., 2013). Inparticular, isotope trendsevendemonstratedthatdegradationunderwentMichaelis‐Mentenkinetics.Inongoingworkweeval‐uateisotopefractionationofherbicidesandpharmaceuticainsimilarexperimentswiththeaimtoinvestigatetheinfluenceofheteroatomsandfunctionalgroupsonsorptionanddegradationatbiogeochemicalinterfaces.

Figure1.a)MeasuredandmodeledconcentrationsofD2O(greendotsandline)andtoluene(blackcrossesandblackline).b)Experimentalandsimulatedcarbonisotopetrendsresultingfromvariousfractionationprocesses.Linesshowmodelediso‐topedatafittedtoexperimentaldata.

ReferencesEckertD,QiuS,ElsnerM,CirpkaOA.2013.Model complexityneededforquantitativeanalysisofhighresolutionisotopeandconcentration data from a toluene‐pulse experiment. EnvironSciTechnol47:6900‐6907.Qiu S, Eckert D, Cirpka OA, Huenniger M, Knappett P,Maloszewski P, Meckenstock RU, Griebler C, Elsner M. 2013.Direct experimental evidence of nonfirst‐order degradationkinetics and sorption – Induced isotopic fractionation inamesoscale aquifer: 13C/12C analysis of a transient toluenepulse.EnvironSciTechnol47:6892‐6899.

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Micro‐ScaleModelingofPesticideDegradationCoupledtoCarbonTurnoverintheDetritusphereHolgerPagel1,ChristianPoll2,JoachimIngwersen1,FranziskaDitterich2,AureliaGebala2,EllenKandeler2andThiloStreck11InstituteofSoilScienceandLandEvaluation,SectionofBiogeophysics,UniversityofHohenheim,Stuttgart,Germany2InstituteofSoilScienceandLandEvaluation,SectionofSoilBiology,UniversityofHohenheim,Stuttgart,GermanyThedetritusphere(soilclosetothesoil‐litterinterface)ischaracterizedbyahighavailabilityoflitter‐derivedorganicsubstratesstimulatingmicrobialgrowthandactivity.Itisahotspotofcar‐bon(C)turnoveranddegradationofpesticides.Toimproveourunderstandingoftheregulationmechanisms, which are responsible for stimulated degradation of the herbicide MCPA (2‐Methyl‐4‐chlorophenoxyacetic acid) at the soil‐litter interface, we applied the recently devel‐opedPECCADmodel(PEsticidedegradationCoupledtoCArbonturnoverintheDetritusphere;Pageletal.,2014)tothedataofadetailedmicrocosmexperiment.Weprepared14C‐MCPA(50mgkg‐1)amendedsoilcoresandsetupthreeexperimentaltreatments:1)maizelitter(control),2)MCPAand3)MCPA+maizelitter.Thelitterwasplacedontopofthesoilcoresandthemicro‐cosmswereincubatedat20°Cfor23days.Thesoilcoresweresampledatfivedatesandsam‐pleswereobtainedfromin7layersdownto1mmthickness.WeanalyzedMCPAanddifferentCpools(soilandCO2)fortotalconcentrationaswellasisotopiccomposition(13C,14C).Wemeas‐uredthreemolecularmarkers(tfdAgenes,16SrRNAgenesandfungalITSfragments)toestimatetheabundanceofbacterialMCPAdegraders,totalbacteriaandfungiinsoil.ThePECCADmodelwas calibrated using these data by means of a multi‐objective Pareto analysis. In the detri‐tusphere,weobserved increasedconcentrationsofdissolvedorganicC (DOC)andaccelerateddegradation of MCPA. Litter stimulated the microbial community as reflected by increasedabundancesofmolecularmarkergenes.FungalITSfragmentsshowedthestrongestresponsetolitter‐Cinputindicatingthatfungibenefitedmostfromadditionalsubstratesupply.ThePECCADmodelcouldmatchobserveddynamicsofMCPA,DOCandmicrobialbiomassCatthesoil‐litterinterface.AlthoughthestrongincreaseoffungalITSfragmentsinthedetrituspherewasunder‐estimatedbyPECCAD,themodelreflectedthestrongresponseoffungitolitter‐Cinput.PECCADsimulations indicate that fungalactivityandgrowthwasspecificallystimulatedby lowqualityDOC,whereasbacterialMCPAdegradersbenefitedfromhighqualityDOCinadditiontoMCPA.MCPAdegradationoccurredpredominantlyviaco‐metabolictransformationbyfungiaccordingtotheparameterizedPECCADmodel.AmongthemicrobialpopulationsbacterialMCPAdegrad‐ersthenincorporatedbyfarthemostMCPA‐C,primarilybecausetheytookuphighqualityDOCproducedbyco‐metabolictransformationofMCPAandtoamuchlesserextendalsoduetodi‐rectuptakeofMCPAforgrowth.Mathematicalmodelingcombinedwithexperimentalworkpro‐videdcomprehensiveinsightintocoupledCandMCPAdynamicsatthesoil‐litterinterface.Ourstudydemonstratesthatknowledgeaboutthemicro‐scaledynamicsofhotspotsinsoilisveryimportant tounderstand fundamental soil functions, suchasdecompositionof organicmatteranddegradationofpesticides.ReferencesPagelH, Ingwersen J, Poll C,KandelerE, StreckT. 2014.Micro‐scalemodelingof pesticidedegradationcoupled to carbon turnover in the detritusphere: model description and sensitivity analysis. Biogeo‐chemistry117:185‐204.

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HierarchicalStructureofBiogeochemicalInterfacestoPredicttheTransportofReactiveChemicalsinSoilThomasRitschel1, JannisTzavaras2,Marc‐OliverGöbel3, SusanneK.Woche3,KatharinaReichel1, John Maximilian Köhne2, Hans‐Jörg Vogel2, Jörg Bachmann3 and Kai UweTotsche11InstituteofGeosciences,FriedrichSchillerUniversity,Jena,Germany2DepartmentofSoilPhysics,HelmholtzCentreforEnvironmentalResearchGmbH(UFZ),Halle,Germany3InstituteofSoilScience,GottfriedWilhelmLeibnizUniversity,Hannover,GermanyThereactivetransportandtransformationoforganicchemicals(OC)insoilsimpactsoilecologi‐calandfilterfunctions.AquantitativeunderstandingoftheprocessesandratesthatcontrolthedistributionandpersistenceofOCisamandatoryprerequisiteforthepredictionoftheirfateinsoils.Yet,"predictivemodels"toalargeextentrelyonparametersthathavebeenobtainedfrom"fitting"procedureswithnopredictivecapabilities.Therefore,adesirenotonlyinfundamentalsoilsciencewouldbetohaveastrategythatallowsforindependentquantitativereconstructionof properties. Our joint experiment on “Hierarchical structure of biogeochemical interfaces insoiltopredictthetransportofreactivechemicalsinsoil”contributestothisambitiousgoal.Re‐sults from pore scale model simulations suggest that highly irregular spatial distributions ofreactivesitesmaystronglyaffect themacroscopic flowand transportpatternsofOC, i.e. theirbreakthroughbehavior.Innaturalsoils,aspatiallyheterogeneousdistributionofreactiveinter‐facescanbeexpectedtobemorelikelythanahomogeneousdistribution.Anotherissuethatwillbeaddressedistheavailability/accessibilityofreactivesurfacesformobilereactivesubstances.EventhoughsomeOChaveahighsorptionaffinitytomineralsurfaces,innaturalporousmedia,thesesurfacescanbelocatedinsideaggregates,atgrain‐graincontacts,orindomainswhichdonotparticipateinwaterflow.Aquantificationoftheavailablesurfaceisthereforeacrucialstep.Tostudythedecisivestructuralpropertiesofaporousmediumanditsconstituentsandtogetamechanisticunderstandingofsolutetransport,welaunchedajointcolumnexperimenttoin‐dependently predict the reactive transport of target compounds.We started our experimentswithawell‐definedSPPartificialsoil.Theresultswereencouragingregardingtheconservativetransport,butstructuraldiversityandhierarchy in theporenetworkwerenotcoveredbytheapproach.Therefore,wedevelopedanewartificialstructure.Asareference,twocolumnsweresetupwithsphericalborosilicateglassbeads(diameter:3mm).Tocreateadistincthierarchyintheporesizedistribution,theseglassbeadsweremixedwithporousglassbeadswithaninnerporosityofabout60µmandfilledinanothertwocolumns.Theseporousglassbeadsserveasamodelaggregateembeddedinamatrixoflargerpores.Foranygivensoilcolumn,thestartingpoint is thequantificationof theporestructureof freshlypackedcolumnsforporesizes>0.1mmusingmicro‐computedtomography(μ‐CT)followedbyimageanalysis(groupofVogel,Hal‐le).The3Dstructureisthenevaluatedwiththeporenetworkmodel(PNM)togeteffectivecon‐tinuumscaleparameters(i.e.dispersivity).Thisallowsforthepredictionofaconservativetrac‐erbreakthroughwithoutusinganyfittedparameters.ThecolumnsarethentransferredtoJenafor experiments, run in both closed and open flowmode, for investigating chemical fate andtransportdynamicsatvariablesaturated flowconditions(groupofTotsche, Jena).ThesolutesunderstudyincludeNaClasconservativetracerandMCPAandvanillicacidasreactivechemi‐cals.AfterthehierarchyintheporespacecanberepresentedbythePNMinawaythatsuccess‐fullypredictsconservativetransport,wewillcoatpartoftheporousmediumwithreactivemin‐erals(e.g.goethite).Inthiswayweaimatcreatinga3Dmapofreactivityspotsinthesoilcol‐umn,superimposedonitsphysicalporesystemgeometry.Ifthiscanbeachieved,thetransportandbreakthroughbehaviorofreactivechemicalscanbepredictedwithoutanycontinuumscaleparameterfitting.

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PosterPresentations

Session1:UnravellingBGIStructure:Formation&ArchitectureofBGIs

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Session1:UnravellingBGIsStructure:Formation&ArchitectureofBGIsPosterNo.1

DissolvedOrganicCarbonasaGoodToolforPredictingSourcesofLabileCarboninSoilSurfaceHorizonsŠárkaCepáková1,2andJanFrouz1,31InstituteofsoilbiologyBCASCR,NaSádkách7,ČeskéBudějovice,CzechRepublic2DepartmentofEcosystemBiology,UniversityofSouthBohemiainČeskéBudějovice,ČeskéBudějovice,CzechRepublic3InstituteforEnvironmentalStudies,CharlesUniversityinPrague,Prague,CzechRepublicLitterandrhisodeponiesareakeyorganicCinputintosoil.Newly,importantroleinsoilorganicmatter(SOM)isattributednotonlytoaromaticandaliphatic(recalcitrant)fractionsbutalsotoeasilyextractableorganiccompounds.Thus,dissolvedorganiccarbonmayplayimportantrolealsoinSOMstabilization.Theobjectiveofthisstudywastoassessseasonalvariabilityincontri‐butionof aboveground litter inputand root related input todissolvedorganic carbon.Weex‐ploredhowthesepatternsdifferbetweenplantationsofdifferenttreespecies.Westudiedfourtree species sites includingone conifer (Pinus sylvestris) and threebroadleaf species (Quercusrobur,AlnusglutinosaandSalixcaprea)atonelargeplantexperimentareainpost‐miningsitesnearSokolov,CzechRepublic.SoilwassampledfromOeandAhorizonseverytwomonths. Inaddition,we sample fresh litter and established sand filled ingrow cores that allow samplingrootswithassociatedrootexudates.Dissolvedorganicmatterwasextractedonthebasisof itsavailability: HWC (HotWater Carbon) andWSC (Water Soluble Carbon) extractions. Both ex‐tractsweredeterminedonTOC(TotalOrganicCarbon)andTN(TotalNitrogen)analyzer,SUVA(SpecificUVAbsorbance)measurementandNMRspectroscopy.Resultsshowtwopeaksoftheincreaseinlabilecomponentsavailability.ThefirstonewasinJuneandthesecondonewasinDecember.ThesepeakswereseparatedbythedeclineinOctober.Weexpect,thefirstpeakcor‐respondswith root derivedmaterial and the second onewith leaves input. This patternwasmore pronounced in broadleaf with seasonal litter fall and less in conifer. Sites with well‐developedOelayerhadthistrendmoreapparentinOelayer,theothersinAlayer.WeconsiderHWCandWSCaregoodindicatorsrespondingtochangesinthecarboninputduringseasons.

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Session1:UnravellingBGIsStructure:Formation&ArchitectureofBGIsPosterNo.2

InvestigationoftheDegradationof13C‐LabeledFungalBiomassinSoil‐FateofCarboninaSoilBioreactorSystemMichaelSchweigert1,ThomasFester1,AnjaMiltner2andMatthiasKaestner21DepartmentofEnvironmentalMicrobiology,HelmholtzCentreforEnvironmentalResearch‐UFZ,Leipzig,Germany2DepartmentofEnvironmentalBiotechnology,HelmholtzCentreforEnvironmentalResearch‐UFZ,Leipzig,GermanyNutrientbalancesanddegradationprocessesinborealforestsaremainlyinfluencedbyinterac‐tions of plant roots and ectomycorrhizal fungi. Plants benefit from nitrogen compounds pro‐vided by their symbiotic interaction partner. In return ectomycorrhiza are provided by largeamountsofcarbonfromtheplantswhichisusedforthesynthesisofhyphalnetworksinsoilandformetabolicactivityfornutrientuptake.Thereforeectomycorrhizalfungiplayamajorroleinecosystems of boreal forests and are consequently an important sink for carbon by buildinglargeamountofmycelia.Recently,ithasbeenshownthatmicrobialbiomassresiduescontributesignificantlytosoilorganicmatterformation.Thissuggeststhatalsoresiduesofectomycorrhizalfungimaybeanimportantsourceforsoilorganicmatterformationinforestsoilswherethesefungiareabundant.However,thefateofectomycorrhizalbiomassresiduesinsoilsisunknown.Wethereforeinvestigatedthefateofectomycorrhizalbiomassinsoilinasoilbioreactorsystemtoquantifythecontributionofthismaterialtosoilorganicmatterformation.Asamodelorgan‐ism,weselectedLaccariabicolor,whichwaslabelledbygrowingthefunguson13Cglucose.Thestableisotope‐labeledbiomasswasthenhomogenizedandincubatedinapodzolfromatypicalforest site in Central Germany. The fate of the labeled biomass was traced by analyzing theamountof13Cmineralizedandtheamountremaininginthesoil.Thefungalbiomasscarbonwasmineralizedratherrapidlyduringthefirst50days.Thenthemineralizationratesloweddown,butmineralizationcontinueduntil theendof theexperiment,whenapproximately40%ofthe13Cwasmineralizedand60%remained insoil. Inaddition,weanalyzedbiomoleculessuchasfattyacidstotracetheincorporationoftheL.bicolor‐derivedbiomasscarbonintoothermicro‐organismsandtoidentifypotentialprimaryconsumersoffungalbiomass.Bytheseanalyses,wefound a significant incorporation of L. bicolor‐derived carbon into awide variety of differentbacterial taxa, indicatingtherelevanceof fungalbiomassresidues forsoilbacteriaasacarbonsource.Inalaterphaseoftheexperiment,wewillalsotracethefateofsoilorganiccarbonintothefungalbiomassandtheplantpartner(Piceaabies).Theseresultswillprovideacomprehen‐siveviewoftheroleofectomycorrhizalfungiandtheirresiduesonsoilcarboncycling.

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Session2:ExploringBGIs:NewAvenuesfor“Provocative”JointExperiments&ComplementaryCutting‐EdgeTechniques,incl.Spectroscopy,(Spectro)Microscopy&Tomography

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Session2:ExploringBGIs:NewAvenuesfor“Provocative”JointExperiments&ComplementaryCutting‐EdgeTechniques,incl.Spectroscopy,(Spectro‐)Microscopy&TomographyPosterNo.3

InsituAnalysisofPoreScaleProcessesatBiogeochemicalInter‐facesinModelSystems

ChristianMetz,NataliaP.Ivleva,ReinhardNiessnerandThomasBaumannInstituteofHydrochemistry,TechnischeUniversitätMünchen,Munich,GermanyBiogeochemicalinterfaces(BGI)insoilcontrolthefateoforganicchemicalsandthefunctioningof soil asa filter toprotectgroundwater resources.Biogeochemical interfacesare transient inspace and time, thus rendering batch tests under equilibrium conditions andwithout spatialrestrictions inadequate topredict theoverallbehavior. Instead, theconcentrationgradientsoforganicchemicalshavetobemeasuredandthespatialandtemporaldynamicsoftheBGIthem‐selveshavetobemonitored.ProcessesatBGIcanbevisualizedandquantifiedusingmicroflu‐idicstructuresmimickingtheporetopologyof thesoil, socalledmicromodels. IncombinationwithRamanmicrospectroscopychemical informationcanbe retrieved fromamicromodelex‐perimentwithaspatialresolutionontheorderof1μm²andatemporalresolutioninthesec‐onds‐range.Toincreasethesensitivity,silvernanoparticleshavebeenaddedtothewaterphaseflowingthroughthemicromodeltomakeuseoftheamplifyingsurface‐enhancedRamaneffect.Currently chemical gradients of moderately lipophilic substances have been acquired withalimitofdetectionof10‐8mol/L.Challengestoovercomeincludetheinteractionsbetweensil‐vernanoparticlesandtargetanalyteswhichmightalterthemasstransferrates,andthesettlingofnanoparticlesinthechannel.Ashighresolutionacquisitioncomeswithalimitedfield‐of‐view(FoV)and,e.g.,thegrowthofabiofilmoutsideoftheFoValterstheflowpattern,theflowveloc‐ity has to bemonitored using fluorescent latex beads and single particle tracking. For a fastmeasurementofwell‐definedvariables,likethepH‐valueortheoxygenconcentration,thinfilmpolymerswithencapsulatedsensordyesarechosen.When lookingatmicrobialgrowth inpo‐rousmedia,notonlythedevelopmentofabiofilmchangestheflowpathsandtheaccessibilitytothemicrobes,butalsothedevelopmentoflocallyconfinedgasbubbles,aswithP.denitrificans.Here,thegrowthrateiscorrelatedwithbacterialactivityandtheresultsindicatedifferentbac‐terialdensitiesinporebodiesandporethroats.Imagingresultsattheinterfaceandthedevel‐opmentoftheconcentrationgradientsuggest,thattheinterfaceishighlydynamicinthebegin‐ning.Marangoniconvectionwithvelocitiesintheupperμm/srangeisreachingseveraldozensofμmfromtheinterfaceintothesolution.Adiffusioncontrolledmasstransferisestablishedatalaterstageonly.Thisobservationmightexplainpartofthefirstflushphenomenon.

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AgingDynamicsofSoilOrganicMatter–Implicationsfrom1HSol‐id‐StateNMRonSequestrationofPollutantsandIonsAlexJäger1,MarkoBertmer1andGabrieleE.Schaumann21InstitutfürExperimentalphysikII,UniversitätLeipzig,Leipzig,Germany2InstitutfürUmweltwissenschaften,UniversitätKoblenz‐Landau,Landau,GermanyPhysicalentrapmentandreleaseofchemicalsinsoilorganicmatter(SOM)isstronglydependingonthemobilityoforganicmattersegmentsinthesupramolecularSOMstructure.Thesegmentmobilitydependssignificantlyonthewatercontentandshowspatternsofapolymeragingdy‐namics, i.e.,a lineardecreaseinmolecularmobilityona logarithmictimescale1. Inthisstudy,wepresentexperimentalresultsofanagingexperimentonsamplesinhermeticallysealedcon‐tainersthathadbeentriggeredbyaheating/coolingeventof30minutesat110°Ctodisturbthesystemandfollowtheregenerationwhichwerefertoasphysicalaging.Twosoilsamples,asaprichistosolwithhighorganicmattercontentandagleyicpodsolwithloworganicmattercontent,wereinvestigated.By1Hsolid‐statenuclearmagneticresonance(NMR),wetracedthechangesinmobilitymakinguseofawidelinedecompositionscheme2.Viadifferentialscanningcalorimetry(DSC)weobservedchanges in thematrixrigidity,expressing inastep‐like transi‐tion temperature, that shifts during the aging process. Both methods observe effects withinatimespanofalmostoneyear.Possibleimplicationsontheimmobilizationoforganicchemicalsin terms of a sequestration into nanovoids generated by a stable water molecule bridges(WaMB)networkwillbediscussed.AlsotheinfluenceoflongchainaliphaticsandSOMsegmentswithhigherdegreesofmotionalfreedomonthemobilizationeffectsaretakenintoaccountasanalternative viewon SOMdynamics. On the basis of these findingswe offer predictions to theenvironmentalfateoforganicpollutantssuchasphenolornaphthaleneandprevalentionssuchasNa+,Ca2+,andAl3+.References:JägerA,SchwarzJ,MouvencheryYK,SchaumannGE,BertmerM.Physicallongtermregenerationdynam‐icsofsoilorganicmatterasfollowedby1Hsolid‐stateNMRmethods.tobesubmitted.

JägerA,BertmerM,SchaumannGE.2011.OptimizedNMRspectroscopic strategy tocharacterizewaterdynamicsinsoilsamples.OrgGeochem42:917‐925.

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ImagingandModelingofPoreScaleProcessesinSoilAggregateUsingX–RayComputedTomographyandLatticeBoltzmannSolverFaisalKhan,FriederEnzmannandMichaelKerstenInstituteforGeosciences,JohannesGutenberg‐UniversityMainz,GermanyPorescalemodelingisthefundamentalapproachformodelingsingleormultiphaseflowinpo‐rousmedia,whichisofgreatimportancetovadosezoneflowandtransportofinterest,e.g.,forcontaminant remediation. This approach provides a way for the parameterization of macro–scaleconstitutiveparameters, i.e.porosityandpermeability,whichineffectgoverntheoverallperformanceofmany flowand transportmodels.Pore scalemodeling is a challenging task ina complex and tortuous nature of the pore structures that requires high‐resolution imagingtechniquesforobtainingtheintegraldescriptionoftheporegeometries,andefficientandrobustnumericalmethodsofhandlingthecomplexgeometries.TheadventofX–raymicrotomography(µCT)hasmade itpossible toobtain three‐dimensional imagesofsoilaggregatedowntosub‐micron resolutionwhichallows for the characterizationof thepore space structure. In recentyears,thenumericallatticeBoltzmannequationapproachformodelingoffluidflowandtrans‐porthasreceivedincreasedattentionbecauseofitssimpleformulationandapplicationsincom‐plexgeometries.ThelatticeBoltzmannmethodfollowssimpleandlocalupdaterulesbasedonthemotionandcollisionofparticlesonacubiclattice(voxels)withinadigitalµCTimagetoap‐proximate Navier Stokes equation for the fluid flow simulation. Recent advancement in com‐puter technology introducinghighperformanceparallel computing anddevelopmentof easy–to–usegraphicaluser interfacesoftware,aswellaseffectivevisualizationofgeneratedresultsfromthosesimulations,enablesimulationof thecomplexdynamics (velocityvector field)andparticletransportprocesses(solute/colloidtracking)ataporescalelevel.Themainfocusofthisstudyisthequantitativedescriptionofimmiscibleair‐waterphasesbycapillarypressure–wa‐tersaturation–hydraulicconductivityrelationshipsforboththedrainageandimbibitionproc‐essina3Dunsaturatedsoilimageobtainedbysynchrotron–basedµCT.Thehystereticeffectsofboth capillary pressure and hydraulic conductivity were investigated by the combination ofa pore–morphology based approach and the latticeBoltzmann solver, respectively.Moreover,the transport of a biogenic colloid like Escherichia coli as pathogens indicator organismwasstudied.Asaresult,thedirectinfluencesofporesizedistributioninrelationtothecolloidalsizesandpressuregradientsontheirtransportandbreakthroughcurvesareanalyzed.

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SpatiotemporalProcessMonitoringofConservativeandReactiveTracerTransportinaSyntheticSoilColumnJohannesKulenkampff1,MadeleineStoll1,2,FriederEnzmann2,MarionGründig1,Alexan‐derMansel1andJohannaLippmann‐Pipke11InstituteofResourceEcology,HZDRResearchSiteLeipzig,Germany2InstituteforGeosciences,JohannesGutenberg‐University,Mainz,GermanyTransportandretardationofchemicalspeciesinsoilsasobservedbyinput‐outputapproachesarecommonlyinterpretedbyprocesssimulationsandbreak‐throughcurve(BTC)fitting.Posi‐tronemission tomography(PET)providesadirectquantitativespatiotemporal (4D)visualiza‐tionmethodforthepropagationofcompoundslabelledwithaPET‐traceratintermediatereso‐lutionandmolecularsensitivity(Kulenkampffetal.,2013). In the frameworkofSPP1315,weconductedtransportexperimentsonanartificialsoilcolumnwithbothreactiveandconserva‐tivetracers,whichweremonitoredwithsequentialPETimaging.Thesoilcolumnused(l:94.5mm, d: 40mm; composition: 94% sand, 5% illite, 1% goethite; porosity: 29%)was preparedunderCO2‐atmosphereandstructurallycharacterizedbyμCTimagingaswidelyhomogeneous.For the conservative tracer experiment, 5 mL 0.001 M NaNO3 + 0.01 M [18F]KF was flownthroughtheequilibratedcolumn.Forthereactivespeciesexperiment,64CuwasproducedattheLeipzigcyclotronbythenuclearreaction64Ni(p,n)64Cuandseparationbyionexchange.5mLof0.0008M[64Cu]Cu(MCPA)2wasproducedfrom2mL64Cu2+in0.1MHNO3,1mgCu(NO3)2·3H2Oand2mgMCPAinsyntheticporewater.The labeledsolutionwasadjustedtopH5andflownthroughthecolumn,whichhadnoformercontactwithMCPAandhadbeenpreconditionedfor4dayswithsyntheticporewateratpH5.Inbothexperimentstheflowratewas0.1ml/min.Intheconservativeexperiment,thebreak‐throughoccurredafter140min,and–inspiteofthehomo‐geneouspackingofthecolumn–thetracerpropagationobservedwithPETshowedapreferen‐tialflowfieldtowardstherimofthesample.Thereactive[64Cu]Cu(MCPA)2pulsewasstronglyretardedwithabreak‐throughoftheactivityafter66h.Fig.1showsasnapshotofbothexperi‐mentsafter110min.Preferentialandsuperficialtransport,commonlyignoredin input‐outputapproaches, controls theeffectivevolumeandreactive internalsurfacearea,and thus impactsinterpretationandinversenumericalmodellingofBTCs.Sucheffectscanbeassessedandquan‐tifiedwithPETprocesstomography,especiallywhentheporestructureisheterogeneouslyal‐teredbymicrobialactivity.

Fig.1:Conservativeandreactivetransportinanartificialsoilcolumn(seetext).ReferenceKulenkampff J, Gründig M, Korn N, Zakhnini A, Barth T, Lippmann‐Pipke J. 2013. Application of high‐resolutionpositron‐emission‐tomographyforquantitativespatiotemporalprocessmonitoringindensematerial.http://www.isipt.org/world‐congress/7/902.html.

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Session2:ExploringBGIs:NewAvenuesfor“Provocative”JointExperiments&ComplementaryCutting‐EdgeTechniques,incl.Spectroscopy,(Spectro‐)Microscopy&TomographyPosterNo.715N/14NIsotopeAnalysisIndicatesDeprotonationofGlyphosateinOxidativeDegradationatMnO2SurfacesEmmanuelMogusu1,BenjaminWolbert2,DorotheaKujawinski2,MaikJochmann2andMartinElsner11InstituteofGroundwaterEcology,HelmholtzZentrumMünchen,Neuherberg,Germany2InstrumentalAnalyticalChemistry,UniversityofDuisburg‐Essen,Essen,GermanyGlyphosate(N‐(phosphonomethyl)glycine), themostwidelyusedherbicideworldwide, isbio‐degradable. The main metabolite AMPA (aminomethylphosphonic acid) has been frequentlydetectedinsoilandwater(Helanderetal.,2012;Borggaardetal.,2008).Thespeciationofgly‐phosatedirectlyinfluencesitsinteractionswithmineralsurfacesthatcontributetoitsdegrada‐tion in theenvironment.We(i)developedanitrogenstable isotopemethod to investigate theinteractionofglyphosatewithmineralsurfacesand(ii)usedthemethodtoinvestigatenitrogenisotopefractionationduringtransformationofglyphosateatManganesedioxide(MnO2)surfaces(BarretandMcBrideetal.,2005).GlyphosatewasdegradedbyMnO2asevidencedbytheforma‐tionofbothAMPAandsarcosineastransformationproductswithin10hoursoftheexperiment.15N/14N ratios in glyphosate, AMPA and sarcosine were measured by gas chromatography‐isotope ratiomass spectrometry (GC‐IRMS) (Elsneretal., 2012) after derivatizationwith iso‐propyl chloroformate and trimethyl silyldiazomethane (Mogusuetal., inprep.).Nitrogen iso‐tope fractionation during abiotic degradation of glyphosate at themanganese dioxide (MnO2)surfacewasashighas‐17‰±0.5‰.Asimilarfractionationof‐20‰wasreportedforequilib‐rium nitrogen isotope effects (EIE) between [‐N+H2‐] (protonated) versus [–NH‐] (non‐protonated)aminogroups(Hofstetteretal.,2011).Thisresultsuggeststhattheabioticbreak‐downof glyphosatewithMnO2 involves theequilibriumdeprotonationof theamino groupasinitialstepthatmakesitpossibleforthephosphategrouptoattachtotheMnO2surface.ReferencesHelanderM,SaloniemiI,SaikkonenK.2012.Glyphosateinnorthernecosystems.TrendPlantSci17:569‐574.

BorggaardKO,GimsingAL.2008.Fateofglyphosateinsoilandthepossibilityofleachingtogroundandsurfacewaters.PestManagSci64:441–456.

Barrett KA, McBride MB. 2005. Oxidative degradation of glyphosate and Aminomethylphosphonate bymanganeseOxide.EnvironSciTechnol39:9222‐9228.

ElsnerM, JochmannMA, Hofstetter TB, Hunkeler D, Bernstein A, Schmidt TC, Schimmelmann A. 2012.Current challenges in compound‐specific stable isotope analyses of environmental organic contami‐nants.AnalBioanalChem403:2471‐2491.

MogusuE,JochmannMA,ElsnerM.2014Compound‐specificnitrogenisotopeanalysisofglyphosateandAMPAbyderivatizationgaschromatography‐isotoperatiomassspectrometry(GC‐IRMS).inpreparation.Skapeli‐LiatiM,TurgeonA,GarrAN,ArnoldWA,CramerCJ,HofstetterBT.2011.pH‐dependentequilib‐riumisotopefractionationassociatedwiththecompoundspecificnitrogenandcarbonisotopeanalysesofsubstitutedanilinesbySPME‐GC/IRMS.AnalChem83:1641‐1648.

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MappingSoilCarbonDistributioninIntactSoilsUsingaCombinationofHyperspectralandX‐RayFluorescenceImagingTechniquesSharonM.O’Rourke1,2,AlexanderB.McBratney2andNicholasM.Holden1

1UCDSchoolofBiosystemsEngineering,UniversityCollegeDublin,Belfield,Ireland2USydFacultyofAgriculture&Environment,TheUniversityofSydney,Australia

Thelinkbetweenthesmall(<mm)scalespatialorganisationofsoilcarbon(C)andthelong‐termsecurity of the abiotic C store is poorly understood.Deep soil is assumed to be a C reservoirhowever the vertical distribution of C remains unknown (Schmidt et al., 2011). Part of theproblem is that conventional soil sampling and C analysis of macro samples, collected atstandard10cmdepthsorsimilarcharacteristicsoilhorizonintervals,missmuchoftheinherentsoilvariability.Intermsofsoilimaging,thereisaknowledgegapatthesoilprofilescale(LorenzandLal,2005),thusfailingtoadequatelylinkwhatisknownaboutsoilCatthesub‐millimetertolandscapescales.TheaimofthisresearchistodevelopatooltomapsoilCatthemicroaggregatescale within intact soil cores 1 m long. The technology employed is laboratory basedhyperspectralimaging.Duetotheheterogeneouscompositionofsoil,referencingspectraldatawith C values determined for macro samples may not be optimal. Therefore a secondtechnology, X‐ray fluorescence (XRF) core scanning, whichmeasures the elemental profile ata similar pixel scale as hyperspectral imaging, is being investigated to determine if candidateindicators for theestimationofsoilCcanbe identified.Datawassampledat10,1and0.1cmresolutionsfromhyperspectral imagesandXRFprofiles,respectively.Multiplecorrelationwasperformed to identify candidate indicators of C fromelemental profiles. Partial Least Squaresregression was employed to build predictionmodels to estimate C, first from conventionallymeasured soil C values and then using indicators of C from XRF. Preliminary results of thismethoddevelopmentwillbediscussed.ReferencesLorenzK,LalR.2005.Thedepthdistributionofsoilorganiccarboninrelationtolanduseandmanage‐mentandthepotentialofcarbonsequestrationinsubsoilhorizons.AdvAgron88:35‐66.

SchmidtMWI, TornMS, Abiven S, Dittmar T, Guggenberger G, Janssens IA, KleberM, Kögel‐Knabner I,Lehmann J, Manning DAC, Nannipieri P, Rasse DP,Weiner S, Trumbore SE. 2011. Persistence of soilorganicmatterasanecosystemproperty.Nature478:49‐586.

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NumericalandExperimentalInvestigationofBreakthroughFea‐turesAppearinginClosed‐FlowTransportExperimentsThomasRitschelandKaiUweTotscheInstituteofgeosciences,FriedrichSchillerUniversityJena,Jena,GermanyThe investigation of solute transportwith column outflow experiments can be carried out inaclosedflowmodebyrecirculationofeffluentsolutiontothesolutionsupplyvesselthatfeedsthe column inflow.While theexperimental effort is rather similar to classical approachesandthepossibility to study liquid solid interactions aswell as structural properties of theporousmediumremainsintact,theclosed‐flowmodeeliminatesdisadvantagesarisingfromopen‐flowapproaches.Asanexample,thefeedbackduringequilibrationwiththesolidphaseismaintainedlike inbatchexperiments.Furthermore, thebreakthroughexhibitsanoscillationofconcentra‐tion in theeffluentand thesolution supplyvesselunderdefinedboundaryconditions, i.e. lowvolumeofthesolutionsupplyvessel.Sinceeachoscillationrepresentsonecyclingoftracersolu‐tionthroughtheporousmedium,interactionprocessesimprintonthewholedatarangeofthebreakthrough.Asaconsequence, thebreakthroughshowsadditionalcharacteristicandindica‐tivefeaturesthatpermitfurtherinterpretationofinvolvedprocessesandgivesintrinsiccontroloverboundary conditions.Anumerical simulationof closed flowexperiments isbasedon thecouplingofatransportequationwiththepartialdifferentialequationthatdescribesthecourseof concentration in the solution supply vessel. This is especially interesting since the columninfluent is short‐circuited to the effluent via themixingprocess in the solution supply vessel,resultinginadynamicboundaryatthecolumninflow.Wepresentwaysofimplementationinanimpliciteulerscheme.Furthermore,weconductedasetofexperimentstoverifythisnumericalmodel.Weshowthatasingletracerbreakthroughcanbeusedtodeterminethedispersion,theexactappliedpumpingrateand,dependingonthetracer,thewatercontentortheretardation.Inaddition,thekineticsinvolvedinliquidsolidinteractioncanbeobserveddirectly.

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Non‐InvasiveImagingTechniquestoStudyO2/pHMicro‐PatternsandPesticideDegradationatLupineRootsNicoleRudolph‐Mohr1,SebastianZuehlke2,SebastianGottfried2,SaschaE.Oswald1andMichaelSpiteller21InstituteofGeosciencesEnvironmentalandEarthScience,UniversityofPotsdam,Potsdam,Germany2InstituteofEnvironmentalResearch(INFU)ofthefacultyofchemistryandchemicalbiology,TechnicalUniversityofDortmund,Dortmund,GermanyThesoil‐rootinterfaceisahighlyheterogeneoussystem,e.g.intermsofO2andpHdistribution.Thedestructivecharacterofconventionalmethodsdisturbsthenaturalconditionsofthosebio‐geochemical gradients. Therefore, experiments aiming to control these influences and studypesticidekineticsundergivenO2andpHconditionssufferfromalargeuncertaintyofthe“real”O2/pHatacertainposition.Ourapproachwith twodifferent imagingtechniqueswillexaminethesoil–rootinterfaceaswellasthedissipationoftheappliedpesticideathighspatialresolu‐tion.Homogenoussoilwasbatchedin150x150x15mmglasscontainersequippedwithpH/O2sensitivefoils,wettedto60%watercontentandasproutedseedofLupinusalbuswascentrallyappliedtoeachcontainer.Theplantsweregrownfor25dayswithadailyphotoperiodof14h.Afteragrowingperiodof7days,thesampleswereimagedonceadaytocaptureoxygenconcen‐trationandpHdistribution.2daysafterthelastpH/O2imagingthecontainerswereopenedandlyophilizedandthesurfacerootswereharvestedformatrix‐assistedlaserdesorption/ionizationimagingmassspectrometry(MALDI‐IMS).TheobtainedoutcomesshowdirectlythatthepHhasaninfluenceonenantioselectivedissipationoftheacetanilidefungizidemetalaxyl.Inareaswithhigh pH from an applied racemic mixture, the R‐enantiomer dissipates faster than the S‐enantiomer.Moreover,wefoundsignificantlyreducedoxygenvaluesinthebulksoilandvicinityofmetalaxyl treated roots compared to control plant roots. The combination of (MALDI‐IMS)andfluorescenceimagingindicatedtheoxygen‐dependentdegradationofmetalaxylattherootsurface.Theresultspresentedhereunderlinethegreatpotentialofcombiningdifferentimagingmethodstoexaminethesoil–rootinterfacesaswellasthedissipationoforganicpollutantsinsmallsoilcompartments.

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DoMicroScaleEffectsConstraintheQuantificationofSoilOrganicMatterbyNanoSIMS?ChristianSchurig1,ThomasSchrank1,CarstenW.Müller1,CarmenHöschen1,LydiaPohl2,KaiU.Totsche2andIngridKögel‐Knabner11LehrstuhlfürBodenkunde,TechnischeUniversitätMünchen,Freising‐Weihenstephan,Germany2LehrstuhlHydrogeologie,InstitutfürGeowissenschaften,Friedrich‐Schiller‐UniversitätJena,Jena,GermanySoilsarehighlyheterogeneousstructuresinwhichbothorganicandinorganicaswellaslivingandnon‐livingbuildingblocksareinteractingtoformbiogeochemicalinterfaces(BGI;Totscheetal.,2010).Whileprocesses at these interfaces areoccurringat themicro‐or submicron‐scale,theyarereasonedtoinfluencethebehaviourofsoilsattheglobalscale,forexampleassoilsbe‐ing carbonsinks (e.g. SchulzeandFreibauer,2005;Totscheetal.,2010;Schmidtetal., 2011).Consequently,analyticalmethodologieswithahighresolutionarerequiredinordertoinvesti‐gate these processeswith the final goal tomechanistically understandBGI formation. Amongspectroscopicmethodologiesnanoscalesecondaryionmassspectroscopy(NanoSIMS)isarela‐tively young technique and has only been used for soil science during the last decade (e.g.Herrmann etal., 2007;Mueller etal., 2012; Vogel etal., 2014). AlthoughNanoSIMSmeasure‐mentsweredemonstratedtomatchbulkscalemeasurements(GC‐IRMS)regardingtheisotopicenrichmentofsoilsamples(Vogeletal.,2014),theinfluenceofvariousmatricesonthedetectionofsoilorganicmatteradsorbedatmineralshasnotbeeninvestigated.Withthepresentstudyweperformedsorptionexperimentsofdissolvedorganicmatteronmodelminerals,suchasBoeh‐miteandIllite.WemeasuredadsorptionbyconventionalbulkscalemethodsandcomparedthedatawithNanoSIMSmeasurements.Withthedataobtainedweaimtodevelopscalingfactorstobothcomparedbulkscaletosubmicronscalemeasurementsandtoscaleorganicmattermeas‐urementsatvariousmineralswithinanindividualNanoSIMSmeasurement.ReferencesTotsche KU, Rennert T, GerzabekMH, Kögel‐Knabner I, Smalla K, SpitellerM, Vogel H‐J. 2010. Biogeo‐chemicalinterfacesinsoil:Theinterdisciplinarychallengeforsoilscience.JPlantNutrSoilSci173:88‐99.

SchulzeED,FreibauerA.2005.EnvironmentalScience:Carbonunlockedfromsoils.Nature437:205‐206.SchmidtMWI, TornMS, Abiven S, Dittmar T, Guggenberger G, Janssens IA, KleberM, Kögel‐Knabner I,LehmannJ,ManningDAC,NannipieriP,RasseDP,WeinerS,TrumboreSE.2011.Persistenceofsoilor‐ganicmatterasanecosystemproperty.Nature478:49‐56.

HerrmannAM, Clode PL, Fletcher IR, NunanN, Stockdale EA, O'Donnel AG,MurphyDV. 2007. A novelmethodforthestudyofthebiophysicalinterfaceinsoilsusingnanoscalesecondaryionmassspectrome‐try.RapidCommunMassSpectrom21:29‐34.

MuellerCW,KölblA,HoeschenC,HillionF,HeisterK,HerrmannAM,Kögel‐KnabnerI.2012.Submicronscale imagingof soilorganicmatterdynamicsusingNanoSIMS ‐Fromsingleparticles to intactaggre‐gates.OrgGeochem42:1476‐1488.

VogelC,MuellerCW,HöschenC,BueggerF,HeisterK,SchulzS,SchloterM,Kögel‐KnabnerI.2014.Submi‐cronstructuresprovidepreferentialspots forcarbonandnitrogensequestration insoils.NatureCom‐munications5:2947.

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BiogeochemicalImprovementsofHighlyPermeableSoilsbyWa‐terRetentionMembranesInstalledBelowthePlantRootZoneAlvinJ.M.SmuckerandAndreyGuberDepartmentofPlant,SoilandMicrobialSciences,MichiganStateUniversity,EastLansing,Michigan,USAHighlypermeablesoils containing little carbonrequirenewenvironmentally sustainable long‐termtechnologiesthat improvetheirretentionofwaterandnutrients in therootzone.Anewsubsurfacewater retention technology (SWRT)membrane configuration, installed at strategicsoildepths,hasbeendesignedtocaptureandretaintwiceasmuchvolumetricwatercontentinplantrootzonesinamannerthatpromoteslargeincreasesintheaboveandbelowgroundbio‐mass growthwhile reducing deep leaching losses of agricultural chemicals into groundwater.MultipleecosystemservicesoftheseSWRTmembranesincludeimprovedsoilcarbonsequestra‐tion,formationofnewstablesoilaggregates,increasedwateruseefficiency,reducedrootturn‐overand increasedshoot to root ratiosamonghorticulturalandrowcroppingsystems.Theseandadditionalhydropedologicalrhizosphereopportunitiestoconvertmorethan3billionhec‐taresofsandysoilsintosustainableagriculturalproductionsystemstofeedtheworld’sgrowingpopulation,withlesswater,willbepresented.

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InfluenceofAnaerobicDigestatesDerivedfromVariousInputSubstratesontheWettingBehaviorofSoilsAffectedbyFunc‐tionalGroupsofTheirOrganicMaterialAmreiVoelkner1,RuthH.Ellerbrock2,DörtheHolthusen1,SusanneOhl3,EberhardHar‐tung3andRainerHorn11InstituteofPlantNutritionandSoilScience,UniversityofKiel,Kiel,Germany2InstituteofSoilLandscapeResearch,LeibnitzCentreforAgriculturalLandscapeResearch,Müncheberg,Germany3InstituteofAgriculturalEngineering,UniversityofKiel,Kiel,GermanyAnaerobic digestates, as a by‐product of biogas production, are used as organic fertilizers onarablefieldsduetotheirhighamountsofnutrients.Itisgenerallyestimatedthatthedigestatesofdifferentcropscaninteractwiththesoilparticlesandinfluencesthesoilstructure.Withtheapplicationofdigestates,solublemonovalentsalts,polysaccharides,humicsubstancesandfattyacidscanbetransferredtothesoilmatrixandsurroundmineralparticlesascoatings.Thecon‐sequence of the organic amendment canbe the degradation of soil functions provokedby in‐creasedwaterrepellency(Aryeetal.,2011).Hence,diminishedwettabilityofthesoilcanresultina reducedwater infiltrationwhich indeedpreservesstableaggregatesbutcanneverthelessledtohigherriskofsoilerosionandpreferentialflow.Forourresearchwechosedisturbedsoilsamples from the A‐horizon of two differently textured soils (loamy and sandy soilmaterial)fromarablelandandapplied30m³ha‐1and90m³ha‐1ofdigestatesderivedfrommaizeandsugar beet to examine thewetting behavior of soils after amendment. Therefore, thewettingproperties were determined by calculating the sorptivity‐based Repellency Index (Tilllman,1989)withmoistsoilsamples.Additionally,thecontactangleofair‐driedsamples(<2mm)wasmeasuredusingtheWilhelmy‐Plate‐Method(Bachmannetal.,2003)andaditionallythesessiledropmethod. To account for the impacts of the digestates for hydrophobicity, the functionalgroups of the organic fractions were investigated applying FT‐IR (Fourier‐Transform‐Spectroscopy)andDRIFT(DiffuseReflectanceInfraredFourierTransformSpectroscopy)(Eller‐brocketal.,2005).Asaresult,thedigestatesclearlyinfluencethewaterrepellencyofthesoil.Theapplicationof30m³ha‐1ofdigestatescausesasignificantresistancetowettabilityinbothsoils. In comparison to the loamy soil, the sandy soilmaterial shows an enhancedwettabilityafteranapplicationrateof90kgh‐1ofdigestates.Thecompositionof thesoilorganicmatterexhibits different portions of functional groups (C‐O/C=O) after the application of digestateswhichinfluencethewettingbehaviorofthesoils.Weconcludefromtheresultsthatthesoiltex‐tureisthedecisivefactorcontrollingtheimpactofdigestates.ReferencesAryeGT,TarchitzkyJandChenY.2011.Treatedwastewatereffectsonwaterrepellencyandsoilhydraulicpropertiesofsoilaquifertreatmentinfiltrationbasins.JHydrol397:136‐145.

BachmannJ,WocheSK,GoebelM‐O,KirkhamMBandHortonR.2003.Extendedmethodologyfordeter‐miningwettingpropertiesofporousmedia.WaterResourRes39:1353‐1359.

EllerbrockRH,GerkeHH,BachmannJ,GoebelM‐O.2005.Compositionoforganicmatterfractionsforex‐plainingwettabilityofthreeforestsoils.SoilSciSocAmJ69:57‐66.

TillmanRS,ScotterD,WallisMandClothierB.1989.Waterrepellencyanditsmeasurementusingintrin‐sicsorptivity.SoilRes27:637‐644.

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Session3:MicrobialEcologyofBGIs:Soil(Micro‐)Organismsas“Architects”&“Actors”ofBGIs

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Session3:MicrobialEcologyofBGIs:Soil(Micro‐)Organismsas“Architects”and“Actors”ofBGIsPosterNo.14

BiosorptionMechanismsofCu(II)byExtracellularPolymericSubstances(EPS)fromBacillusSubtilisWentingMa,XingLiuandPengCai

StateKeyLaboratoryofAgriculturalMicrobiology,CollegeofResourcesandEnvironment,HuazhongAgri‐culturalUniversity,Wuhan430070,ChinaBiosorption mechanisms of Cu(II) by extracellular polymeric substances (EPS) from Bacillussubtiliswereinvestigatedusingacombinationofbatchexperiments,Fouriertransforminfraredspectroscopy(FTIR),isothermaltitrationcalorimetry(ITC),andX–rayabsorptionfinestructure(XAFS)spectroscopy.A threediscretesitenon‐electrostaticmodel fit thepotentiometric titra‐tiondatabest,withthepKavaluesof4.25,6.53,and9.09,andsiteconcentrationsof4.70×10−3,2.04×10−3, and 2.99×10−3mol per gram drymass of EPS, respectively. The FTIR results con‐firmedthepresenceofthefunctionalgroupswithabovepKavaluesontheEPSmolecules,andfurtherdemonstratedthatcarboxylicandphosphoricgroupsonEPSareinvolvedinCu(II)bind‐ing. The calculated enthalpies and entropies of Cu(II) adsorption on EPS suggest that Cu(II)bindswithanionicoxygen‐bearingligandsandformsinner‐spherecomplexeswiththeEPSfunc‐tionalgroups.TheXAFSresultsareconsistentwith inner‐spherebindingofCu(II)bycarboxylsites at an average Cu‐C distance of 2.96 Å. Similar extended X‐ray absorption fine structure(EXAFS)spectraandCu‐Cdistance(2.79Å)werealsoobservedinCu(II)bindingonB.subtilis,suggestingthatEPShavesimilarfunctionswithbacteriainthebindingofCu(II).Themolecularbindingmechanismsobtainedinthisstudywillimproveourunderstandingonthefateofheavymetalsinnaturalenvironments.KeywordsEPS,adsorption,heavymetal,XAFS,ITC

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Diversityof2,4‐DichlorophenolDegradersinAgriculturalSoilandDrilosphereAnjaDallingerandMarcusA.HornDepartmentofEcologicalMicrobiology,UniversityofBayreuth,Bayreuth,GermanyEarthwormsplayanimportantrole inprocessingsoilorganicmatterandcontributetothere‐movaloforganicpollutantsfromsoil.2,4‐dichlorophenol(2,4‐DCP)representstheinitialdegra‐dation product of 2,4‐dichlorophenoxyacetic acid (2,4‐D), one of themostwidely used herbi‐cides.Degradationoccursinsoilduetoaerobicandanaerobicmicrobialprocesses.Hotspotsofmicrobialactivityinsoilsincludethedrilosphere,i.e.,earthwormgutcontent,cast,andburrows.Theeffectof theendogeicearthwormAporrectodeacaliginosaand/or2,4‐DCPon the2,4‐DCPdegradingmicrobialcommunityinsoilcolumnswasresolvedbyacomparativeanalysisoftfdB(encodinga2,4‐DCPhydroxylase)sequencesderivedfrombarcodedampliconpyrosequencingandclone libraries. In siturelevant concentrationsof2,4‐DCP (25μggdw‐1)were consumed insoil columnswithin19and41days in thepresenceandabsenceof earthworms, respectively.Pyrosequencing of tfdB yielded 23800 sequences that were assigned to 58 operational taxo‐nomicunits(OTUs)belongingtoActinobacteria,Alpha‐andBetaproteobacteriaandVerrucomi‐crobia.MostOTUs(26)wererelatedtoMycobacteriaceaeandMicrococcaceae.Sequencesaffili‐atedtoComamonadaceaewereonlydetectedinburrowwalls,castandbulksoilpre‐exposedtoearthwormsand2,4‐DCP.TheanalysisoftfdBclonelibraries,including290sequences,revealed16OTUsbelongingtoActinobacteria,Alpha‐andBetaproteobacteria.Similartothepyrosequenc‐ingdatamostOTUs(9)wererelatedtoMycobacteriaceae.Statisticalanalyses(i.e.non‐paramet‐ricMANOVA)indicatedasignificantimpactof2,4‐DCPonthetfdB‐harboringmicrobialcommu‐nityindrilosphereandbulksoilmaterial.Thecollectivedataindicatedthat(a)agriculturalsoilharbors diverse putative 2,4‐DCPdegrading bacteria, (b) 2,4‐DCP rather than earthworms af‐fectsbacterialcommunitystructureofdetected2,4‐DCP‐degraders,and(c)“highthroughput‐“aswellas“classical”‐techniquescanleadtoalmostidenticalresults.

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BentazonDegradationCapabilitiesofSoil‐DerivedIsolatesandPureCulturesAnjaDallingerandMarcusA.HornDepartmentofEcologicalMicrobiology,UniversityofBayreuth,Bayreuth,GermanyBentazon (3‐isopropyl‐1H‐2,1,3‐benzothiadiazin‐4(3H)‐one 2,2‐dioxide) is a highly selectiveherbicide thathasbeenusedworldwide since the70's.Bentazon ismobileandsusceptible toleachingintogroundwater,andconsequentlyofenvironmentalconcern.Informationonthefateofbentazon in soils are scarceandprokaryotesassociatedwithbentazondegradation in soilsareessentiallyunknown.Therefore,microorganismsthatarepotentiallylinkedtobentazondeg‐radationinsoilwereenrichedandisolatedfromagriculturalsoilofScheyern.25bacterialandfourfungalisolateswereobtainedafteratotalbentazonconsumptionof0.65mg.Bentazondeg‐radationcapabilitiesoffourfungalisolatesandthreepureculturesprovidedfromaculturecol‐lection were tested under oxic conditions in presence and absence of additional carbon. Nogrowthinhibitionwasobservedwhen0.01%(w/v)bentazonwasadded.ApurecultureofPae‐cilomyces lilacinus (Trichocomaceae, Ascomycota) and isolate AD13 [(closely related toMor‐tierella elongata (Mortierellaceae, Zygomycota)] transformed bentazon to 6‐ hydroxybentazon(6‐OH‐bentazon).Thedetectedconcentrationsof6‐OH‐bentazonaftersevendaysofincuba‐tionwereintherangeof6%to20%oftheinitialappliedbentazon.Transformationofbenta‐zonmainly occurred in the presence of additional carbon, indicating a co‐metabolic process.CellsofTrametesversicolor, a laccase‐producing fungusaffiliated toPolyporaceae(Basidiomy‐cota) transformed50%of the initial bentazon.However, no transformation productwas de‐tected by HPLC. Cell suspensions of the remaining three fungal isolates and the pure cultureshowednodecreaseinbentazonconcentration.Investigationofthebacterialbentazondegrada‐tionpotentialisstillinprogress,howeverpreliminarytestssuggestatleastatolerancetowardsan elevated bentazon concentration. The collective data indicate that (a) agricultural soil ofScheyernharborsdiversebentazon‐ tolerant andbentazon‐ transformingmicroorganisms, (b)transformationofbentazonisaco‐metabolicprocess,and(c)laccase‐producingfungiareasso‐ciatedwithbentazontransformationinsoil.

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EarthwormsRatherThan2,4‐DichlorophenolImpactonDenitri‐fierandNitrifierCommunitiesinAgriculturalSoilAnjaDallinger,MariannaM.S.Weller,ChristianA.HofmannandMarcusA.HornDepartmentofEcologicalMicrobiology,UniversityofBayreuth,Bayreuth,GermanyNitrousoxide(N2O)isthethirdmostimportantanthropogenicgreenhousegaswith300timestheglobalwarmingpotential of carbondioxide.TheproductionofN2O resultsprimarily frommicrobial transformations of nitrogenous compounds (i.e. denitrification and nitrification).Earthwormsarethepredominantsoilmacrofauna inmostterrestrialhabitatsandemitN2O insitu, due to soil‐derived denitrifying bacteria. Pesticides and their degradation products arewidespread in nature and affectN2O‐forming processes in soils. 2,4‐dichlorophenol (2,4‐DCP)representstheinitialdegradationproductof2,4‐dichlorophenoxyaceticacid(2,4‐D),oneofthemost widely used herbicides. Soil columns were set up to assess the impact of soil feedingearthworms (Aporrectodeacaliginosa) and/or2,4‐DCPonN2Oproduction.N2O‐formation ratewas2.5xhigherinsoilpre‐exposedtoearthwormsthaninsoilwithoutearthworms.However,theapplicationofinsiturelevantconcentrationsof2,4‐DCP(21μggdw‐1)showednosignificanteffect.DenitrifierswerequantifiedbyqPCRandmostprobablenumber(MPN)approaches,nitri‐fierswerequantifiedbyqPCRonly.MPNsofdenitrifiersinbulksoilofcolumnswithandwithoutearthwormsapproximated4.9x106and8.3x105gdw‐1,respectively.MPNsofdenitrifiersap‐proximated5.9x108gdw‐1ingutcontents,indicatingthatearthwormsstimulatedreplicationofdenitrifyingmicroorganisms.2,4‐DCPpre‐treatmentresultedindecreasingandincreasingMPNsfor drilosphere and bulk soil material, respectively. Structural genes associated with(de)nitrification(i.e.narG,nirK,nirS,nosZandamoA)tendedtobemoreabundantinearthwormtreatedsoilthaninsoilwithoutearthwormsandwerenotsignificantlyaffectedby2,4‐DCP.Bac‐terialamoAgenes (encodinganammoniamonooxygenase)were ingeneralmore abundant indrilosphereandbulksoilmaterialthanamoAgenesofArchaea,indicatingthatammoniaoxidiz‐ingbacteriahaveanimportantroleintheammoniaoxidizingcommunityinagriculturalsoilofScheyern.Terminalrestrictionfragmentlengthpolymorphism(TRFLP)analysisofnosZ(encod‐ing a N2O‐reductase) revealed dominance of Bradyrhizobium japonicum affiliated TRFs indrilosphereandbulksoilmaterialirrespectiveof2,4‐DCPtreatment.Thecollectivedatasuggestthatendogeicearthwormsratherthan2,4‐DCPimpacton(a)theN2O‐formationinagriculturalsoil,and(b)theabundanceofdenitrifyingandnitrifyingmicroorganisms

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SuccessionofSoilMicrobialCommunitiesandEnzymeActivitiesinArtificialSoilsFranziskaDitterich1,AureliaGebala1,ChristianPoll1,GeertjeJ.Pronk2,3,KatjaHeister2,IngridKögel‐Knabner2,3andEllenKandeler11InstituteofSoilScienceandLandEvaluation,SoilBiologySection,UniversityofHohenheim,Stuttgart,Germany2LehrstuhlfürBodenkunde,TechnischeUniversitätMünchen,Freising‐Weihenstephan,Germany3InstituteforAdvancedStudy,TechnischeUniversitätMünchen,Garching,GermanySoilsareheterogeneousmixturesofdifferentminerals,organicandbiologicalcompoundswhichare associated in complex hierarchical structures. More than 80‐90% of microorganisms areattachedtomineralsurfacesormineral‐organiccomplexes.Theabundance,diversityandfunc‐tionofmicroorganismare regulatedby several environmental factors suchas substrateavail‐ability,habitatpropertiesandmineralcomposition.Untilnow,lessisknownaboutthecoloniza‐tionandsuccessionofdifferentsoilmineralsbymicroorganisms.Furthermore,theeffectofsoilmineralcompositiononthemicrobialcommunitystructurehasbeenrarelyexplored.Theuseofartificial soils which differ only in their mineral, but not in their organic composition, offersauniquepossibility tostudymicrobial‐mineral‐interactions insoils.Wehypothesized that themineral composition as well as substrate availability regulate the colonization of microbialcommunitiesofartificialsoils.Eightdifferentartificialsoilswiththesamesoiltexture(42%finesand,52%siltand6%clay),butwithdifferentmineral compositionwereused.Theartificialsoilsconsistedofquartz+(a)onemineralcomponent(montmorillonite;illite;ferrihydrite),(b)twomineralcomponents(montmorillonite+ illite;montmorillonite+charcoal; illite+ ferrihy‐drite;illite+boehmite),(c)threemineralcomponents(illite+ferrihydrite+charcoal),sterilizedorganic manure (carbon source) and a microbial inoculum from an Eutric Cambisol (Ultuna,Sweden).Thesoilswereincubated3,6,12and18monthsunderconstanttemperature(20°C)andwaterconditions(60%ofmaximumwaterholdingcapacity)inthedark.Wequantifiedtheenzyme diversity, the phospholipid fatty acids (PLFAs) and the abundance of eight bacterialgroupsatthephylumorclasslevelsbyusingqPCRtocharacterizethefunctionandstructureofmicrobialcommunities.DiscriminantanalysesofPLFAsshowedthat themicrobialcommunitystructurechangedoveraperiodof18monthstowardssimilarcommunitiesattheendofincuba‐tion,whichcouldbeprobablyexplainedbynutrientlimitation.Molecularanalysesforthediffer‐entmineralcomponentsystemsshowedsimilarresults.Wedetectedamicrobialsuccessionofthe soilmicrobial community from a dominance of r‐ strategists (e.g. ß‐proteobacteria) usingmainlyeasilyavailableorganicsubstratesduringthefirstsixmonthsoftheincubationtowardssystemswithahigherdominanceofK‐strategists(e.g.acidobacteria)usingmainlyrecalcitrantcompounds.Thesuccessionoftheenzymeactivitiesgaveclearevidencethatnutrientlimitationoccurredduring the incubation.Thisstudyshowedthatmicrobialcolonizationandsuccessiononmineralsurfacesisaffectedbymineralpropertiesandnutrientavailability.

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ImpactofLaccasesontheDecompositionofMCPAattheSoil‐LitterInterface–ASoilMicrocosmExperimentAureliaGebala1,FranziskaDitterich1,HolgerPagel2,ThiloStreck2,ChristianPoll1andEllenKandeler11InstituteofSoilScienceandLandEvaluation,SoilBiologySection,UniversityofHohenheim,Stuttgart,Germany2InstituteofSoilScienceandLandEvaluation,Biogeophysics,UniversityofHohenheim,Stuttgart,GermanyThesoil‐litterinterfaceisabiogeochemicalhotspotinsoil,whereabundanceandactivityofsoilmicroorganismsare increasedandprimingphenomenaoccur.Accordingly, it hasbeen shownthat soilorganicmatter turnoverand thedegradationoforganicchemicals isenhancedat thesoil‐litterinterface.Ithasbeenhypothesizedthatstimulationoffungalgrowthbylitter‐derivedcarbonandincreasedproductionofunspecificfungalexo‐enzymesmaypartlyexplaintheaccel‐erateddegradationofMCPA(4‐chloro‐2‐methylphenoxyaceticacid)atthesoil‐litterinterface.Inparticular,laccaseshavebeenreportedtooxidizeawiderangeofxenobioticsubstances.There‐fore,wehypothesizedthat1)MCPAdegradationisimmediatelyenhancedduetothepresenceofactivefungallaccasesandthat2)thiseffectisevenmorepronouncedatthesoil‐litterinterfacedue to higher availability of co‐substrates. In order to test these hypotheses, we performeda microcosm experiment using a Luvisol soil from the experimental farm Scheyern (Bavaria,Germany).Wesetupsevendifferenttreatments:(a)Control(withoutMCPAandenzymes),(b)MCPA,(c)MCPA+litter,(d)MCPA+inactivelaccase,(e)MCPA+activelaccase,(f)MCPA+litter+ inactive laccase and (g) MCPA + litter + active laccase. Treatments (b)‐(g) were uniformlyspikedwithMCPA(50mgkg‐1DM).Treatments(c),(f)and(g)wereuniformlymixedwith2‐10mmshreddedmaizeleaf litterandstems(0.01gkg‐1).Intreatments(d)‐(g)soilwasamendedwithamixtureofthreedifferentlaccases,eitheractiveorinactivatedbyautoclaving.Soilsam‐pleswere taken2,22and40daysafterstarting theexperiment.Thesamplingdateswerese‐lectedaccordingto14Cmineralizationdatameasuredataparallelsetofmicrocosmsspikedwith14C‐labeledMCPA. Soil sampleswere analyzed for residualMCPA concentrations and enzymeactivityoflaccases.Afteraperiodof22days,theresultsoftreatments(f)and(g)indicatedthatadditionofbothactiveandinactivelaccasesincombinationwithlittermoststronglystimulatedMCPA degradation. Despite higher enzyme activities in the treatmentswith added active lac‐cases,theadditionoflaccaseswithoutlitterhadnosignificanteffectonMCPAdegradationcom‐paredtothelittertreatment(d).Inconclusion,wemustrejectourhypotheses.Rather,ourre‐sultssuggestthattheappliedlaccasesonlyactasadditionalnutrientsources(particularlynitro‐gen)anddonotdirectlystimulateMCPAdecomposition.Nonetheless,thesoil‐litterinterfaceisa fungalhotspothereandotherunspecific fungalexo‐enzymesmayberesponsible forstimu‐latedMCPAdegradationinthismicrohabitat.

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PhagesasBiologicalandColloidalVectorsofMassandGeneticIn‐formationintheEarth’sCriticalZone(PHAGE)NawrasGhanem,AnjaNarr,HaukeHarms,AntonisChatzinotasandLukasY.WickDepartmentofEnvironmentalMicrobiology,HelmholtzCentreforEnvironmentalResearch–UFZ,Leipzig,GermanyAlthoughvirusesrepresentthemostabundantentitiesonearth,researchhasfocusedmainlyonmarine ecosystems neglecting terrestrial habitats. Viruses that infect specific host bacteria,knownasbacteriophages,haveavast influenceontheirhostsmortality,evolution,physiologyandcommunitystructure,andthusonbiogeochemicalcycles.Despitetheirrelevancestilllittleisknownabout their transportbehavior in terrestrialhabitats, their interactionswithbiogeo‐chemicalinterfaces(BGI)andtheimplicationsof(transported)phagesforthegeneticlandscapeoftheterrestrialdeepsubsurfacebiosphere.Herewewouldliketopresentanddiscussourre‐centlystarted“PHAGE”projectintheframeworkoftheDFGCollaborativeResearchCenter1076–AquaDiva.Theoverallaimof“PHAGE”istostudy(transducing)phagesasbiologicalandcol‐loidalvectorsofmassandgeneticinformationinthesubsurfacezonebetweenthehighestden‐sityofplantroots(~0.3m)andthefirstaquifers(upto100m),knownastheEarth’sCriticalZone.Asbothmobilityandtheabilityofinfectiondeterminethecontributionofphagesineco‐systems,wewillassesstheirroleasdriversandindicatorsformicrobialdiversityandsubsur‐facetransport.Morespecifically“PHAGE’aimsat:(i)Identifyingbacteriaparticipatingintrans‐duction‐mediatedgenetransferindifferentlayersoftheCriticalZoneusingIlluminasequencingof16SrRNAgenesisolatedfromphageheads.Moreover,using454shotgunsequencingwewillinvestigate theviral functionalmetagenome inselected fieldcoresamples.Finally,wewant tooverallscreenthemorphologicalandgeneticvirusdiversitywithtransmissionelectronmicros‐copyandPCR‐basedfingerprintingtechniques.(ii) Investigatingthe factorsdrivingsubsurfacephagetransportandassessingtheeligibilityofmarinephagesasspecificmarkersofhydrologi‐calflowandreactivetransportofcolloidalparticlesalongBGIandintheCriticalZone.Labora‐torycolumnexperimentswillbeappliedtotestthepossibleeffectsofdifferentfactorssuchasphagemorphology,different flowregimesaswellastheroleofeukaryotic(fungal,plantroot)networksonphagetransport.

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MicrobialDomainsRespondDifferentlytoSoilMineralsinTheirMicrohabitatsasRevealedbyStudieswithArtificialSoilsMichaelHemkemeyer1,FrederikeImbusch1,GeertjeJ.Pronk2,3,KatjaHeister2,IngridKögel‐Knabner2,3,RainerMartens1andChristophC.Tebbe11ThünenInstituteofBiodiversity,Braunschweig,Germany2ChairofSoilScience,DepartmentEcologyandEcosystemManagement,TechnicalUniversityofMunich,Freising‐Weihenstephan,Germany3InstituteofAdvancedStudy,TechnicalUniversityofMunich,Garching,GermanyArtificialsoils(AS)ofdifferentmineralcompositionscanbeusedtoelucidatetheimportanceofselectedsoilpropertiesfortheestablishmentofmicrobialcommunities.ThisstudydescribestheimpactofmineralcompositionsonBacteria,ArchaeaandFungiinsoils,fractionatedafterincu‐bationof6and18monthsintothefollowingsizes:63–2000μm,20–63μm,and<20μm,respec‐tively. Three AS were supplied with different clay minerals and iron oxide: montmorillonite(MT), illite (IL), and illiteplus ferrihydrite (IL+FH).Thecarbonsourcederived fromsterilisedmanure and the whole mixtures were inoculated with a standardised microbial soil extract.Fractionation was achieved by mild sonication, wet sieving and centrifugation, as previouslydescribed(Neumannetal.,2013).DNAwasextractedfrombulk(notfractionated)soilandsizeseparates.PopulationsizesofthethreedomainsweredeterminedbyquantitativePCR(qPCR)ofsmallsubunit(SSU)rRNAgenesandthesamegeneswereusedforgeneticprofilingofthecom‐munitiesusing terminal restriction fragment lengthpolymorphism (T‐RFLP).Gene copynum‐bers inbulk soil rangedbetween1.1–2.7·1010g‐1 soil forbacteria, 0.9–6.7·108 for archaea,and0.6–11·109 for fungi, respectively. Illite containingmixtures supportedmore bacteria and ar‐chaea,whiletheadditionofferrihydritefosteredbacteriaandfungi.Theclaymineralsdrovethecommunity compositionofbacteriaand,evenmorepronounced,of fungi.The latteronesalsowere affected by ferrihydrite after 18months of incubation. No effect was seen for archaealcommunitystructure.Generally,patternsofthepopulationsizesfrombulksoilwerereflectedinthe finest fraction,butnot in the coarsest fraction.Themicrohabitatwas a commondriverofcommunity structuring.However, archaeaneeded18months to establish a community in thefinest fractiondistinct from thebothcoarser fractions.While fungi responded to thedifferentclaymineralsacrossmostparticlesizeseparates,theprokaryoteswereaffectedonlyinthefin‐est fraction.The threedomains responded in theirmicrohabitats to themineral compositionseitherinformofabundanceorcommunitystructureorboth.Thedifferentmineralsandthepar‐ticlesizeseparatesshoweddifferentselectiveeffectsand, thus,suggestthatthese factorscon‐tribute toniche separation.Considering thediversityofminerals innatural soils, our findingssuggestthatthemineralcompositionandheterogeneityofsoilshasatremendouseffectonthediversityoftheirresidingmicroorganisms.ReferenceNeumannD,HeuerA,HemkemeyerM,MartensR,TebbeCC.2013.Responseofmicrobialcommunitiestolong‐termfertilizationdependsontheirmicrohabitat.FEMSMicrobiolEcol86:71‐84.

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WoodantNestsasHotSpotsofMicrobialActivityinForestEco‐systemsVeronikaJílková1,2andJanFrouz1,21InstituteofSoilBiology,ASCR,ČeskéBudějovice,CzechRepublic2InstituteforEnvironmentalStudies,CharlesUniversityinPrague,CzechRepublicWoodantsbuildlargeandlong‐lastingnestsfromorganicmaterialsandmineralsoilwhichhavea very special structure. Nests arewell‐aerated due to numerous chambers and galleries andstabletemperatureandmoisturearemaintainedtherethankstoantactivities.Theseconditionstogetherwiththeconstantinputofeasilyavailablenutrientsfromfoodofantssupportmicrobialactivity.Duetorespirationofantsandmicrobes,woodantnestsareknownashotspotsofCO2productioninforestecosystems.AlthoughthemainsourceofCO2isrepresentedbyantrespira‐tion,asignificantamountofCO2originatesalsofrommicrobialdecompositionoforganicmate‐rials.Severalconditionsaffectmicrobialrespiration,suchasmoistureofnestmaterial,changesintemperaturesorfoodinput.Asmineralnutrientsarereleasedfromorganicmaterials,woodantnestsrepresenthotspotsofmineralnutrientsinforestecosystemswhichcanbeexploitedbyother organisms, such as roots of trees, and can also causeheterogeneity in species abun‐danceandcomposition.

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SoilMacrofaunaWebmastersofEcosystemsJanFrouz1,2andVeronikaJílková1,21InstituteofSoilBiology,ASCR,ČeskéBudějovice,CzechRepublic2InstituteforEnvironmentalStudies,CharlesUniversityinPrague,CzechRepublicTheroleofplantrootsandmicroflorainshapingmanyecosystemprocessesisgenerallyappre‐ciated.Inthecontrary,theroleofsoilmacrofaunainthiscontextisassumedtobenegligibleandratheranecdotic.Butmorethanhalfofthelitterfallisconsumedbysoilfaunaandsoilfaunacanalsoconsumeand/ortranslocatesubstantialamountofsoil.Herewedemonstrateonexampleofpostminingchronosequenceshowsitecolonizationbysoil faunaaffectscompositionofwholesoil biota community, plant succession and soil formation. Field and laboratory experimentsshowedthatdecompositionoffaunafecesmaybespedupcomparedtolitterattheverybegin‐ningbutinalongtermfaunafecesdecomposedslowerthanlitter.Thisisalsosupportedbymi‐cromorphologicalobservationwhichshowedthatfaunafecesformsubstantialpartofsoil.Fau‐nafecesalsoinducelowerorevennegativeprimingeffectwhenintroducedinsoilincompari‐sonwithlitterthattriggerspositiveprimingeffect.Alaboratoryexperimentshowedthatfaunaeffectiscontextsensitiveandismorepronouncedinsystemsalreadyaffectedbysoilfauna.Soilmixingbysoilfaunaconsequentlyaffectsenvironmentalconditionsinsoilssuchaswaterhold‐ingcapacityornutrientavailability,italsoaffectscompositionofadecomposerfoodwebinclud‐ingmicrobialcommunity(fungal/bacterialratio)whichfeedsbackinalternationofplantcom‐munitycompositionduringsuccession.Thisfaunalactivityisnotconstanteverywhere,thehigh‐ereffectoffaunaactivityonlitterlayerwasobservedintemperatesoilsofdeciduousforestsandwithlitterhavingC/Nratiobetween20‐30.Inconclusion,soil faunausesdirectlyonlyasmallproportionofenergyinthelitterbutcansubstantiallyaffectsoilcarbonturnover,soilformation,decomposerfoodwebandplantcommunity.

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GypsumandHaliteDepositiononCyanobacteriaandAlgaeinSalt‐AffectedSoilsLoredanaCanfora1,PietroIavazzo3,ElisaVendramin4,GiuseppeLoPapa2,CarmeloDaz‐zi2,AnnaBenedetti1,PaolaAdamo3andFlaviaPinzari11ConsiglioperlaSperimentazioneelaRicercainAgricoltura,CentrodiRicercaperlostudiodellerelazionitraPiantaeSuolo,Rome,Italy(CRA‐RPS)2DipartimentodiScienzeAgrarieeForestali,UniversitàdegliStudidiPalermo,Italy3DipartimentodiAgraria,UniversitàdiNapoliFedericoII,Portici,Italy4ConsiglioperlaRicercaeSperimentazioneinAgricoltura,CentrodiricercaperlafrutticolturadiRoma(CRA‐FRU)Soilsurfacecommunitiesaredifferentfromthoseofbulksoilduetothedevelopmentofphoto‐syntheticcommunitiescomprisingcyanobacteria,algae,andotherbacteriawhichcontributetothe formation of biological soil crusts. The structure of ecological niches forming biologicalcrustsinsalinesoilenvironmentsischaracterizedbycommunitiesdominatedbyextremophilesorganisms likearchea,halophilicbacteriaandcyanobacteria that canhaveadirector indirectroleinshapingsoilproperties.Forexamplegypsumandhalitewerefoundbysomeauthorsas‐sociatedwiththecyanobacteriumEntophysalis(BraithwaiteandWhitton,1987);moreoverthecrystallization of gypsum and halite around filamentswas observed inmarine cyanobacterialmatsofaridregionsinthePersianGulf(Golubic,1973).Inallthesecasesnocausalrelationshiphasbeenestablishedbetweenthecrystallizationofgypsumorhaliteandcyanobacterialoralgalmetabolism, and nomention ismade of specific sedimentary structures. The present accountdescribestheoccurrenceofgypsumandhaliteinasalinesoilcommunityandsuggestshypothe‐sis onhow theorganismsmayhave exerted aphysical control over thedistinctive structuresproduced. The study site is a naturally salt‐affected soil located in an area,PianadelSignore,where some ecological variables acted as strong shaping factors in above and belowgroundcommunities distribution, driven by a spatial salinity gradient. Scanning electronmicroscopeobservationsandmicroanalysis(SEM‐EDS)coupledwithX‐Raydiffractionanalysis(XRD)werecarriedout to investigate thebiogeochemical interfaces insoil,withadeeperoverviewonthemorphologyof themineralsoccurring in the soil surface. Soil bulk samples and selected frag‐mentsof the salted crustof the soil surfacewereanalyzed.Threewelldefinedmineralswereidentified: halite, sulfates and gypsum. Energy Dispersive Spectroscopy confirmed the cubicmineralformtobehalite.Theresultsshowedaconspicuousdepositionofhaliteandgypsumontheverysuperficiallayersofthesoilareascharacterizedbya100%ofsaltcrustcover,andtheSEM‐EDSanalysisprovidedevidenceof thepresenceof cyanobacteriaandalgaeassociated tohaliteandgypsumdeposits.Thelossofwaterfromthesoilsurfaceduetothenaturalevapora‐tioncaneasilyexplainthedepositionofhaliteandtheformationofcharacteristicsulfatecrys‐tals. The inner association and stratification of theseminerals along cyanobcateria and algaebodiesmightbeexplainedbyamorecomplexphenomenonthatinvolvetheC02depletionatthebiogeochemicalinterface,duetothealgalandbacterialphotosyntheticandmetabolicactivity.ReferencesBraithwaiteCJR,WhittonBA.1987.GypsumandhaliteassociatedwiththecyanobacteriumEntophysalis,GeomicrobiolJ.5:43‐55,DOI:10.1080/01490458709385956.

GolubicS.1973.Therelationshipbetweenblue‐greenalgaeandcarbonatedeposits,p.434‐472.InNGCarrandBAWhitton(eds.),Thebiologyofblue‐greenalgae.Blackwell,Oxford.

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ClayMineralsandMetalOxidesStronglyInfluencetheStructureofAlkaneDegradingMicrobialCommunitiesDuringSoilMatura‐tionAnnelieSteinbach1,StefanieSchulz2,JuliaGiebler1,StephanSchulz2,GeertjeJ.Pronk3,4,IngridKögel‐Knabner3,4,HaukeHarms1,5,LukasY.Wick1andMichaelSchloter2,31DepartmentEnvironmentalMicrobiology,HelmholtzCentreforEnvironmentalResearch–UFZ,Leipzig,Germany2ResearchUnitEnvironmentalGenomics,HelmholtzZentrumMünchen,Munich,Germany3DepartmentEcologyandEcosystemManagement,ChairofSoilScience,TechnischeUniversitätMünchen,Munich,Germany4InstituteforAdvancedStudy,TechnischeUniversitätMünchen,Munich,Germany5GermanCentreforIntegrativeBiodiversityResearch(iDiv)Halle‐Jena‐Leipzig,GermanyThehugestructuralheterogeneityofsoilsisbelievedtofosteranenormousmicrobialdiversity,andsoilbiogeochemicalinterfaces(BGIs)areassumedtobehotspotsofmicrobialdiversityandactivity(Totscheetal.,2010).Duetotheeonsofpedogenesisitis,however,difficulttoinferim‐portant soil properties shaping microbial diversity and ecosystem functioning. We thereforestudied temporal changesof theabundanceanddiversityof alkanedegradingbacteriaduringthematurationofeightdifferentartificialsoils,andanalysedtheirresponsetodisturbance in‐ducedbysupplementinganadditionalsoil‐litterinterfaceasanutrientrichBGIwithhighalkanecontent.Theartificial soilscontainedsinglecomponentsormixturesofmontmorillonite, illite,charcoal, ferrihydrite or boehmite in addition to quartz sand and silt as structural elements(Pronketal.,2012).Themodelsoilswereinoculatedwithamicrobialinoculumfromanagricul‐turalsoilandmaturedforthree(T3)ortwelvemonths(T12).Subsequently,soilsamplesfrombothtreatmentswereincubatedwithwinterwheatlitterfortwoweeksinamicrocosmexperi‐mentformingasoil‐litterinterfaceontopofthecosms.Samplingofspatialsubsamplesallowedtodifferentiateeffectsinthesoil layerwithdirectcontacttolitterandbulksoilwithoutdirectlittercontact.QuantitativePCR(qPCR)andterminalrestrictionfragmentlengthpolymorphismanalysis(T‐RFLP)targetingaalkBgene(i.e.amarkercodingforthealkanemonooxygenaseaskeyenzymetobacterialalkanedegradation)wereappliedtorevealquantitativeandqualitativedifferentiation of alkane degrading bacterial communities during maturation of the differentsoils.GenerallyhigheralkBgenecopynumbersweredetectedatT3comparedtoT12inallsoils.However, the communities at T12 responded much stronger to litter amendment. Concomi‐tantly,strongercommunityshiftsweredetectedafterlitteramendmentatT12comparedtoT3with convergingcommunity compositions in response to substrateavailability. Ingeneral, thealkanedegradingcommunitiesofdifferentsoiltypesincreasinglydivergedwithongoingmatu‐ration and influences of different soil components (e.g. illite, charcoal and ferrihydrite) weredetectedat thedifferentstagesofsoildevelopment.Hence,ourdatasuggest that thedevelop‐mentof functionalcommunities isstronglycoupledtothecomplexstructuredBGIs.Moreover,withincreasingmaturation,theseimpactsbecomemoreprominentsuggestingadynamicinter‐playoftheBGIsandmicrobialcommunities.Structure‐diversityandstructure‐functionrelation‐shipsareemergingpropertiesofthesemicrohabitats.ReferencesPronkGJ,HeisterK,DingG‐C,SmallaK,Kögel‐KnabnerI.2012.Developmentofbiogeochemicalinterfacesin artificial soil incubationexperiment:Aggregation and formationof organo‐mineral associationsGe‐oderma,189–190(0):585‐594.

Totsche KU, Rennert T, GerzabekMH, Kögel‐Knabner I, Smalla K, SpitellerM, Vogel H‐J. 2010. Biogeo‐chemicalinterfacesinsoil:Theinterdisciplinarychallengeforsoilscience.JPlantNutrSoilSci,173:88‐99.

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EffectofBiogeochemicalInterfaceFormationontheMicrobialAbundanceandDiversityinMaturedSoil‐LikeSystemsandNatu‐ralSoilDuringthePlantLitterDegradationIrinaTanuwidjaja1,2,NicolasWeithmann1,StefanieSchulz1,FranzBuegger3,AnnelieSteinbach4,JuliaGiebler4,GeertjeJ.Pronk5,6,CordulaVogel5,LukasY.Wick4,HaukeHarms4andMichaelSchloter11ResearchUnitEnvironmentalGenomics,HelmholtzCentreMunich,Neuherberg,Germany2WissenschaftszentrumWeihenstephan,TechnicalUniversityofMunich,Munich,Germany3InstituteofSoilEcology,HelmholtzCentreMunich,Neuherberg,Germany4DepartmentEnvironmentalMicrobiology,HelmholtzCentreforEnvironmentalResearch–UFZ,Leipzig,Germany5ChairofSoilScience,DepartmentEcologyandEcosystemManagement,TechnicalUniversityofMunich,Freising–Weihenstephan,Germany6InstituteforAdvancedStudy,TechnicalUniversityofMunich,Garching,GermanyMultitudeofmicrohabitatsandbiogeochemicalinterfaces(BGIs)makesoilonethemosthetero‐geneousandcomplexecosystems thatmicroorganismscan inhabit.The formationofBGIsde‐pendsonthemineralcompositionofsoilandthepresenceofeasilyavailablenutrients,whichinturnstrongly influences theestablishmentanddevelopmentofmicrobial communities. In thisexperiment,westudiedtheeffectofplantlitteradditiononthemicrobialabundanceanddiver‐sityinwell‐definedsoil‐likesystemsandonenaturalLuvisol,whichhadbeenunderagriculturaluse.Soil‐likesystemswerematuredforovertwoyearstoallowBGI formation.Four“artificialsoils” that consisted of quartz sand and silt and varied in presence ofmontmorillonite, illite,charcoalandferrihydrite,wereinoculatedwithmicroorganismsextractedfromanagriculturalsoil togetherwithsterilemanure.Manurewasreappliedafter562days tomaintainmicrobialactivities.ThematuredartificialsoilsaswellasthenaturalLuvisolwereincubatedwith15Nand13Clabelledpotatoandmaizelitterandincubatedinthedarkat14°Cand60%oftherespectivewaterholdingcapacity.Totalnucleicacidswereextractedfromsoilsamplestakenat0,7,21and63daysaftertheplantlitteraddition.Abundanceofbacteriaandfungiaswellastherespectivecommunitystructurewasassessedbasedonamplifiedribosomalgenes.Thegenecopynumbersforbacteriaandfungiwerecomparableinallsoils.Despitetheplantlitteradditionnosignificantincrease in bacterial and fungal abundancewas observed over the time. rRNA (“transcripts”)valueswerehigherinartificialsoilstreatedwithplantlitterwhencomparedtothecontrolsoils.The increase inactive community abundance in artificial soilswasobserveddirectlyafter thelitteraddition,whereasinnaturalLuvisolpossiblyduetothenutrientreactionwithpre‐existingcomplexBGIs, the increasewas delayed.MolecularDNA‐fingerprinting suggests that both thebacterialandfungalcommunitystructuredependsonsoilcompositionaswellasonlitteraddi‐tionandtime.16SrRNAprofilesshowednosignificantdifferencesin“active”bacterialcommu‐nitiesamongartificialsoils.Theseresultssuggestthatthesoilcompositioninfluencestheoverallmicrobial structure whereas the plant litter addition conceals said effect on active bacterialcommunity.

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BiologicalActivityImpactontheDynamicsofAggregatesWithinaTechnosol:DirectVisualizationandQuantificationina14MonthsExperimentationFrancoiseWatteau1,2,NouhouSalifouJangorzo1,DorianHajos1andChristopheSchwarz11LaboratoireSolsetEnvironnement,UMRINRA1120,UniversitédeLorraine,Vandoeuvre‐les‐Nancy,France2UMSCNRS3562,15rueNotre‐‐‐DamedesPauvresBP20,F‐‐‐54501Vandoeuvre‐les‐Nancy,FranceEvaluatethedynamicsofsoilstructure,particularlyundertheinfluenceofbiological factors isamajorchallengeinanobjectiveoftheirpedogenesismodeling.Byusinganinnovativedeviceofautomaticacquisitionofhigh‐resolutionimages,SOILINSIGHTR,wespecifiedinrhizotronsdur‐ing 14months the porosity and aggregation dynamics of a constructed Technosolwithin therhizosphereofaleguminousplant(Lupinusalbus)inpresenceofearthworms(Lumbricuscasta‐neus).The constructedTechnosol is, bydefinition, consideredas a good candidate for thepe‐dogenesismodeling,insofarasitsinitialcharacteristicsandimplementationconditionsarecon‐trolled(Sereetal.,2010).Avideocanshowthedynamicsofbiologicalagents:rootsystemarchi‐tecturefromgerminationtosenescenceofplants,formationofsymbioticnodules,movementsofearthwormswithin rhizotron. Specific imageprocessingswereused toquantify total porosity(50μm‐2mm), total area of aggregates (100μm‐2mm) and various descriptive parameters ofpores or aggregates: number, size, diameter, form index (Jangorzo et al., 2013). “Actions" ofworms‐diggingorfillingburrows,crossing‐wererecordedovertime.After14months,theporesurfaceis10timeshigherinrhizotronswithplantandmacrofaunaincomparisonwiththecon‐trols.Ifthebiologicalactivitypromotedthegenesisofaggregates,theirdynamicswasirregularinthattheproportionofaggregatesincreasedordecreaseddependingontheactionsofworms.Characterizationofbioturbationsonsoilthinsectionsoratmicroaggregationscalebytransmis‐sionelectronmicroscopyspecifiedtheirconstitutionandthecontributionofmicroorganisms.

(1)Viewoftherhizosphereattherhizotronssurface.(2)Intensityofwormactionsat208days.(3)Detailsoftheearthworm/soilinterfaceatphotonicand(4)electronicscale(caption‐b:bacteria;om:organicmatter;m:mineral;w:earthworm).ReferencesJangorzoNS,WatteauF,SchwartzC.2013.Evolutionof theporestructureofTechnosolsduringearlypedogenesisquantifiedbyimageanalysis.Geoderma.207‐208:180‐192.

SereG,SchwartzC,OuvrardC,RenatJC,WatteauF,VilleminG,Morel,JL.2010.Earlypedogeneticevolu‐tionofconstructedTechnosols.JSoilSediment10:1246‐1254.

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Fungal‐BacterialInterplaysatBiogeochemicalInterfaces:Co‐occurrenceofFungiandBacteriainArtificialSoilsAnnelieSteinbach1,IrinaTanuwidjaja2,JuliaGiebler1,FlorianCentler1,StefanieSchulz2,GeertjeJ.Pronk3,4,CordulaVogel4,TesfayeWubet5,IngridKögel‐Knabner3,4,HaukeHarms1,6,MichaelSchloter2,4andLukasY.Wick11DepartmentEnvironmentalMicrobiology,HelmholtzCentreforEnvironmentalResearch–UFZ,Leipzig,Germany2ResearchUnitEnvironmentalGenomics,HelmholtzZentrumMünchen,Munich,Germany3InstituteforAdvancedStudy,TechnischeUniversitätMünchen,Munich,Germany4DepartmentEcologyandEcosystemManagement,ChairofSoilScience,TechnischeUniversitätMünchen,Munich,Germany5DepartmentSoilEcology,HelmholtzCentreforEnvironmentalResearch–UFZ,Leipzig,Germany6GermanCentreforIntegrativeBiodiversityResearch(iDiv)Halle‐Jena‐Leipzig,GermanyContrarytobacteria,mycelial fungidonotrelyoncontinuouswaterpathsduringcolonizationandforagingofspatiallyheterogeneousbiogeochemical interfaces(BGIs) inwaterunsaturatedzones.Thankstotheirhighsurfacetovolumeratiomyceliatakeupnutrientsandenergysourcesefficiently,andwithhyphallengthsofuptoonekilometerpergramsoilbuilduphighlycomplexnetworkstructures.Recentstudiesunraveledthatmyceliaresemblefunctionallogisticdispersalnetworks along which bacteria (“fungal highway”) and nutrients and contaminants (“fungalpipeline”)canbetransported(Harmsetal.,2011).MyceliamayhencealsocontributetoaBGI‐dependentcolonizationandtheformationofmicrobialnichesinsoil.Suchknowledge,however,stillissparse.Inthisstudyweinvestigatedtheimpactoffourmodelsoilhabitatsonthedevel‐opmentof fungalandbacterialcommunitiesandtheir interplaysatBGIs.Foursterileartificialsoilswereinoculatedwithawater‐extractedmicrobialinoculantfromanagriculturalsoil,fertil‐izedwithsterilemanureandmaturedfortwoyears.Thesoilscontainedquartzsandandsiltincombinationwith(i)montmorillonite, (ii) illite, (iii)montmorilloniteandcharcoalor (iv) illiteand ferrihydrite.Aftermaturation the soilswereamendedwithmaize‐potato litter, incubatedforanother7,21and63daysandthefungalandbacterialcommunitiesanalysedwithmolecularfingerprintingandhigh‐throughputsequencing.Communitystructureanalysesrevealeddistinct,BGI‐dependentcolonizationpatternsforthetwomicrobialgroups.Soilmaturationandtheaddi‐tionofplant litterstronglyaffectedthecommunitycompositionof the fungiandbacteriawithmostexpliciteffectdetectedincharcoalcontainingsoil.Clearlydistinctpatternswerealsofoundin response to the type of clay (illite vs.montmorillonite),whereas the ferrihydrite asmodelmetaloxideimpactedbacterialcommunitiesonly.MicrobialcommunitynetworkanalysesbasedonFisher´s exact test further revealeddistinct co‐occurrence relationshipsbetween fungi andbacteriainresponsetothecompositionoftheartificialsoils(i.e.theabioticmicrobialhabitat)ortheadditionoftheplantlitter.OurdatasuggestthatBGIsaredriversforbacteriaandfungibothduringcolonizationofnewhabitats,aswellastheirresponsestoenvironmentalchanges,asin‐ducedbytheadditionofplant littersubstrates.Combinationsofsharednichepreferencesandhelper‐effects(“fungalhighways”effect),hence,mayexplainthesoiltypedependentcommunitypatternsandiscurrentlyenlightenedvianextgenerationsequencinganalysis.ReferencesHarmsH,SchlosserD,WickLY.2011.Untappedpotential:Exploitingfungiinbioremediationofhazardouschemicals.NatRevMicro9:177‐192.

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EffectofMCPAonN‐AcetylglucosamineDegradationbyChiti‐nolyticandSaccharolyticBacteriaunderDynamicRedoxCondi‐tionsAdamS.Wieczorek1,StefanieA.Hetz1,HaroldL.Drake1andSteffenKolb1,21DepartmentofEcologicalMicrobiology,UniversityofBayreuth,Bayreuth,Germany2DepartmentofAquaticGeomicrobiology,InstituteofEcology,FriedrichSchillerUniversityofJena,Jena,GermanyPesticides, like the in agriculture widely applied herbicide MCPA (2‐methyl‐4‐chlorophenoxyaceticacid),havethepotentialtoimpairthemetabolismofsoilmicroorganisms(Schellenbergeretal.,2012).Increasingapplicationofpesticidesoverthepastdecadesinagri‐culturehasresultedinaccumulationofpesticideresiduesinsoilsthatmayaffectmicrobialme‐tabolism.Chitin,consistingofalternatingβ‐1,4‐linkedNacetylglucosamine(GlcNAc)residues,isanabundantbiopolymerinsoils,andisdegradedbychitinolyticandsaccharolyticsoilmicrobesbysequentialenzymatichydrolysis toGlcNAc. Inanaeratedsoil,oxygendistribution ishighlyheterogeneous,anddynamiconthemicro‐tomillimeterscaleduetodifferentporosityin‐andoutsideof soil aggregates and complex interactions in ´Biogeochemical Interfaces´ (Totscheetal.,2010).However,chitinolyticandsaccharolyticBacteriaenablecontinuedchitindegradationdespitefluctuationsofoxygenconcentrationastheyarecatabolicallydiverseandoccupydiffer‐entecologicalnicheswithregardtooxygenavailability(Wieczoreketal.,2014).TheaimofthisstudywastoassesstheeffectofMCPAonGlcNAcdegradationbychitinolyticandsaccharolyticBacteriaunder dynamic redox conditions. Agricultural soil slurrieswere sequentially flushedwithsyntheticair (oxicconditions)ordinitrogengas (anoxicconditions) toestablishdynamicredoxconditions.SupplementationsofGlcNAc(3mM)werefollowedbyadropoftheredoxpo‐tential from positive (+ 400‐200mV) to negative (‐ 300mV) values under anoxic conditionswhereastheredoxpotentialofunsupplementedcontrolswasstable.Underoxicconditionstheredoxpotentialofsupplemetedslurriesincreasedtoalmostinitialvalues.GlcNAcwasdegradedby aerobic respiration, ammonification, and nitrification to carbon dioxide and nitrate underoxicconditions.Whenoxygenwasabsent,likelybutyrateandpropionicacidfermentationwerealongwithammonificationandnitraterespirationresponsibleforGlcNAcdegradation.Supple‐mentationofinsiturelevantconcentrations(60μM)ofMCPAhadnoeffectonthedegradationofGlcNAcunderdynamicredoxconditions. InslurriessupplementedwithhighconcentrationsofMCPA(860μM)GlcNAcconsumptionwasapparentlynotimpaired.However,reducedaccumu‐lationof acetateduringanaerobicdegradationofGlcNAccompared to controlswithoutMCPAsuggestedapotentialtoxiceffectofMCPAontheanaerobicmetabolismofchitinolyticandsac‐charolyticBacteria.TheeffectofdynamicredoxconditionsandthesupplementationMCPAonchitinolyticandsaccharolyticBacteriawillbedeterminedbycomparativetranscriptanalysisof16SrRNAgenes.ReferencesSchellenbergerS,Drake,HLandKolbS.2012.Impairmentofcellulose‐andcellobiose‐degradingsoilBac‐teriabytwoacidicherbicides.FEMSMicrobiolLett327:60–65.

TotscheKU,RennertT,GerzabekMH,Kogel‐KnabnerI,SmallaK,SpitellerMandVogelHJ.2010.Biogeo‐chemicalinterfacesinsoil:Theinterdisciplinarychallengeforsoilscience.JPlantNutrSoilSci173:88‐99.

WieczorekAS,HetzSAandKolbS.2014.Microbial responses to chitinandchitosan inoxicandanoxicagriculturalsoilslurries.Biogeosciences11:3339‐3352.

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MetabolicResponsesofChitinolyticandSaccharolyticBacteriatoOxygenAdamS.Wieczorek1,StefanieA.Hetz1,HaroldL.Drake1andSteffenKolb1,21DepartmentofEcologicalMicrobiology,UniversityofBayreuth,Bayreuth,Germany2DepartmentofAquaticGeomicrobiology,InstituteofEcology,FriedrichSchillerUniversityofJena,Jena,GermanyChitin,consistingofalternatingβ‐1,4‐linkedN‐acetylglucosamine(GlcNAc)residues,isanabun‐dantbiopolymerinsoils,whichare‘hotspots’ofproductionanddegradationofchitin.Aerobicandanaerobicsoilmicrobescandegradechitinbyinitialhydrolyzationviaexo‐andendochiti‐nases to N,N´‐diacetylchitobiose ([GlcNAc]2) and longer oligomers of GlcNAc. An alternativedegradationpathwayinvolvespriordeacetylationtochitosanandthesubsequenthydrolyzationtochitobiose([GlcN]2)and longeroligomersofglucosamine(GlcN).Thepreferredpathwayofchitinhydrolysisinsoilmicrobialcommunitieshasyetnotbeenresolved.Inanaeratedsoil,ox‐ygendistributionishighlyheterogeneous,anddynamiconthemicro‐tomillimeterscaleduetodifferentporosityin‐andoutsideofsoilaggregatesandcomplexinteractionsin´BiogeochemicalInterfaces´(Totscheetal.,2010).Therefore,differentredoxprocesses,suchasfermentationoroxygenrespiration,cansimultaneouslybeactivewhenchitinisdegraded.Theaimofthisstudywas to resolve thepreferredpathwayof chitinhydrolysisand toassess the responseof chiti‐nolytic taxa and theprocesses associatedwith chitin hydrolysis under oxic and anoxic condi‐tions.Chitinwasdegradedunderoxicandanoxicconditionsinagriculturalsoilslurries,whereaschitosanwasnotsubstantiallydegraded.Thus,hydrolysisofchitinwaspreferredtothepathwaythatstartswithdeacetylationtochitosan. 13C labelledchitinwasdegradedbyaerobicrespira‐tion,ammonification,andnitrificationtocarbondioxideandnitrateunderoxicconditions.Whenoxygenwasabsent,likelybutyrateandpropionicacidfermentationwerealongwithammonifi‐cation,nitrateandironrespirationresponsibleforchitindegradation.Chitinolytictaxaactivelyassimilating carbon derived from 13C labelled chitin under oxic and anoxic conditionswill beidentified by comparative transcript analysis of 16S rRNAgenes.TRFLP analysis showed thatdifferent chitinase genotypes responded to chitin supplementation and affiliatedwith a noveldeep‐branchingbacterial chitinasegenotype (anoxic conditions), genotypesofBeta‐ andGam‐maproteobacteria(oxicandanoxicconditions),andPlanctomycetes(oxicconditions).Thefind‐ingsprovideevidencethatdetectedchitinolyticBacteriawerecatabolicallydiverseandoccupieddifferentecologicalnicheswithregardtooxygenavailabilityenablingcontinuedchitindegrada‐tiondespitefluctuationsofoxygenconcentrationinsoil.ReferencesTotscheKU,RennertT,GerzabekMH,Kogel‐KnabnerI,SmallaK,SpitellerMandVogelHJ.2010.Biogeo‐chemicalinterfacesinsoil:Theinterdisciplinarychallengeforsoilscience.JPlantNutrSoilSci.173:88‐99.

WieczorekAS,HetzSAandKolbS.2014.Microbial responses to chitinandchitosan inoxicandanoxicagriculturalsoilslurries.Biogeosciences11:3339‐3352.

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Session4:BGIsinChangingEnvironments:BGIsDynamics&HeterogeneitywithConsequencesforProperties&ProcessesPosterNo.31

EffectofSoilStructureonIronOxideColloidMobilityJannisFlorianCarstens1,JörgBachmann1andInsaNeuweiler21InstituteofSoilScience,UniversityofHannover,Hannover,Germany2InstituteofHydromechanics,UniversityofHannover,Hannover,GermanyThemobilityof ironoxidecolloidsinsoils isstronglyaffectedbyporestructureaswellashy‐draulic,physical,andchemicalpropertiesofbiogeochemicalinterfaces,fluidphase,andcolloids.Colloidal ironoxidesareof importance fornaturalsoil‐formingprocessesandhuman‐inducedprocessesincludingtechnicalapplications.Theaimofthisstudywastoinvestigatetheeffectofporestructureonironoxidecolloidmobilityingoethite‐coatedquartzsandpackingsaswellasindisturbedandundisturbednatural soil samples rich innaturallyoccurring ironoxide coat‐ings.Moreover, the influenceofdissolvedorganicmatter(DOM)ontransportandretentionofironoxidecolloidswasexamined.Byadsorptionontosolidparticles,DOMcanmodifybiogeo‐chemicalinterfacesandsimultaneouslyaltersoilwettability.Aspecialemphasiswasputonde‐terminingifeffectivephysico‐chemicalsurfaceparametersderivedfromcontactangleandzetapotentialmeasurementscanbeusedasatooltopredictgeneraltendenciesforironoxidecolloidtransportand retention inporousmedia. Ironoxide colloidmobilitywasexamined in columnbreakthroughexperimentsbypercolatinggoethitecolloids(particlesize:200‐900nm)throughpackingsofgoethite‐coatedquartzsand(grainsize:100‐300μm)atdifferentDOMconcentra‐tions. Furthermore, goethite colloids were percolated through flow cells filled with both dis‐turbedandundisturbedsoilsamplesfromaforestsubsoilrichinironoxidecoatings,inordertoexamine (i) if results of flow columns packedwith goethite‐coated quartz sand can be trans‐ferredtonaturalsoil,and(ii)whetherdifferencesbetweentheundisturbedandthedisturbedsoil samplesoccur.Additionally, sessiledropcontactanglesandzetapotentialsof theappliedmaterials were measured. By means of these surface parameters, both classic and extendedDLVO energies including Lewis acid‐base parameterswere estimated. Experimentswith goe‐thite‐coated quartz sand elucidate that the both the goethite colloids and the goethite‐coatedsandneedtobecoatedwithDOMinordertoenablecolloidtransport.Thesebasicinteractionswere transferable to theundisturbedsoil:Pre‐conditioning thenatural soilwithDOMwasre‐quiredtofacilitatethetransportofDOM‐coatedgoethitecolloidsthroughtheflowcell.Ascom‐paredtotheundisturbedsoil,goethitecolloidmobilityinthedisturbedsoilwasreduced,likelydue to the destruction of the original pore structure and the concomitant loss of preferentialflowpaths, aswell as themodificationofbiogeochemical interfaces, i.e. due to abrasionof theoriginalcoatings.DLVOinteractionenergycalculationsdemonstratedthatprimaryenergywellsandenergybarriersyieldedbytheclassicDLVOapproacharesufficienttopredictgeneraltrendsofgoethitecolloidmobility.ExtendedDLVOcalculationsrevealedstrongsurface‐near(~5nm)interactionenergiesdue toLewisacid‐base interactions that apparentlydonot influencegoe‐thitecolloidtransport.Theseshort‐rangeenergiesmayhavebeenweakenedbysurfacerough‐nessofsandgrainsandcolloids.ItcanbeconcludedthattheimpactofDOMconcentrationandgoethite coatings of the solidmatrix are transferable from flow columns filledwith goethite‐coatedquartzsandtoflowcellsfilledwithundisturbedsoil,andfurthermorethatthemobilityofgoethitecolloidsisreducedindisturbedsoilsamples.Moreover,withrestrictionsfortheinter‐pretation of close‐distance interactions, DLVO interaction energies are capable of predictinggeneraltrendsofgoethitecolloidmobility.

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SensitivityofDeepSoilCtoClimateChange:MineralizationofSoilOrganicMatteratDifferentMoisturesinanAmazonanPOD‐ZOSOLKevinPotard1,NaoiseNunan1,2,YvesLucas3andClaireChenu11AgroParisTech,IEES‐EGC,ThivervalGrignon,France2CNRSIEES,ThivervalGrignon,France3LaboratoirePROTEE‐UniversitéduSudToulon‐Var,LaGardeChanges in soilswater regimewill be akey componentof future climate change.Whilemanyrecent studies focused on the effect of temperature on soil C dynamicsmuch less studies aredevoted to the impact ofwater regimes, although soilmoisture strongly influencesmicrobialactivity (Moyano etal., 2013). Bph horizons of Amazonian podzols represent a huge stock oforganiccarbon,i.e.,13.6PgC(Montesetal.,2011).Thesehorizonsareoftenwater‐‐saturated,which is hypothesised to limit decomposition. Predicted changes in climate for this Areawillresultindrierandmorevariableswaterregimesascomparedtothepresentsituation.Weinves‐tigatedhowheterotrophicrespirationof thedifferentsoilhorizonsof thesesoilsreactstosoilmoisture.For thiswe incubatedundisturbedsoilcores fromtheOH,E,Bph,andIIMsoilhori‐zonsatdifferentmatricpotentials(pF0,1.7,2.5,3.5,4.2)andmonitoredtheCmineralisationbymeasuringtheevolvedCO2usingaμGC.TheresultsshowedverylittlevariationofCmineraliza‐tionrateswithintheconsideredrangeofmatricpotentials.Thisisexplained,fortheBphhori‐zons,bythedominanceofsoilporesbyverysmall(dia<0.95μm)pores,whichremainwatersaturatedevenatpF4.2.Absenceofimpactofmatricpotentialvariationsmayalsobeexplainedbyother factors limitingdecomposition in thesesoils.Wediscuss thepossible impactsofpre‐dictedvariationsofthewaterregimeofthese.SoilswithclimatechangechangingclimateonthestabilityoftheirCstocks.ReferencesMontesCR,LucasY,PereiraOJR,AchardR,GrimaldiM,MelfiAJ.2011.DeepCarbonStorageinAmazonianpodzols.Biogeoscience8:113‐120.

MoyanoFE,ManzoniS,ChenuC.2013.ResponsesofSoilHeterotrophicRespirationtoMoistureAvailabil‐ity:AnExplorationofProcessesandModels.SoilBiolBiochem59:72‐85.

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RestructuringofBiogeochemicalInterfaces:RoleofCationsandHeatTreatmentforSOMThermalPropertiesDörteDiehl1,Marc‐O.Goebel2,TatjanaSchneckenburger4,5,JaaneKrüger5,SusanneK.Woche2,AnastasiaShchegolikhina3,6,JetteSchwarz1,BerndMarschner3,FriederikeLang5,SörenThiele‐Bruhn4,JörgBachmann2andGabrieleE.Schaumann11InstituteforEnvironmentalSciences,DepartmentofEnvironmentalandSoil,UniversitätKoblenz‐Landau,Landau,Germany2InstituteofSoilScience,LeibnizUniversitätHannover,Hannover,Germany.3InstituteofGeography,DepartmentofSoilScienceandSoilEcology,Ruhr‐UniversitätBochum,Bochum,Germany4FBVIGeography/Geosciences,SoilScience,UniversitätTrier,Trier,Germany5ChairofSoilEcology,Albert‐Ludwigs‐UniversitätFreiburg,Freiburgi.Br.,Germany6NationalResearchTomskPolytechnicUniversity,Tomsk,RussiaMolecular arrangement of soil organicmatter (SOM) is subjected to continuous restructuringprocessesunderchangingenvironmentalconditions(Piccolo,2002)withconsequencesforSOMstability andmatrix rigidity (Schaumann and LeBoeuf, 2005). SOM thermal stability is linkedwith biogeochemical stability and can be characterized via thermal combustion (Plante etal.,2011). Cations are suggested to increase SOM stability against degradation (e.g., Scheel etal.,2008)althoughthiseffectwasstudiedonlyrarelyinnon‐fractionatedsoilsamples.SOMmatrixrigiditydescribestheflexibilityofpolymerchainsandinfluencestheabilityandrateofchangesinsupramolecularstructure(Piccolo,2002)withconsequencesforsorptionandwettingbehav‐ior. SOMmatrix rigidity is suggested to increase by cross‐links betweenmolecule chains, likecation bridges (CaB) (Kunhi Mouvenchery et al., 2012) or water molecule bridges (WaMB)(SchaumannandLeBoeuf,2005).Thepresentstudyaimedatunderstandingtheprocessesoc‐curringinSOMuponchangesincationcomposition,temperaturetreatmentandaging.Forthispurpose,weenrichedsoilsampleswith(Na+,Ca2+,Al3+)andsubjectedthemtodifferenttem‐peratures(25,40,60,and105°C).SOMmatrixrigiditywasdeterminedviasteptransitiontem‐peratureT*withDSCasafunctionofagingtime.Thermalstabilitywasdeterminedattheendofaging.Whilecationeffectsonmatrixrigidityevolvedonlyslowlyafter8weeksofageing,signifi‐canteffectsoftreatmentabove40°Ccausedanonreversiblelossofwatermoleculebridgesandabove60°Capartlyreversiblemeltingprocessprobablyofsemi‐crystallinepoly(methylene).Incontrast,thermalstabilityincreasedwithincreasingcationsvalenceanddegreeofprotonation(desalination)whereastemperaturetreatmentrevealednosignificanteffect.Weconcludethatdryingatelevatedtemperatures(>40°C)mayirreversiblychangeSOMstructureviadisruptionoflabilecross‐linksandmeltingofsemi‐crystallinedomains.ReferencesKunhiMouvencheryY,KučeríkJ,DiehlD,SchaumannGE.2012.Cation‐mediatedcross‐linkinginnaturalorganicmatter‐areview.RevEnvironSciBiotechnol11:41‐54.

Piccolo A. 2002. The supramolecular structure of humic substances: A novel understanding of humuschemistryandimplicationsinsoilscience.AdvAgron75:57‐134.

PlanteAF,FernandezJM,HaddixML,SteinwegJM,ConantRT.2011.Biological,chemicalandthermalindi‐cesofsoilorganicmatterstabilityinfourgrasslandsoils.SoilBiolBiochem43:1051‐1058.

SchaumannGEandLeBoeufEJ.2005.Glasstransitionsinpeat‐theirrelevanceandtheimpactofwater.EnvironSciTechnol39:800‐806.

ScheelT,JansenB,vanWijkAJ,VerstratenJM,KalbitzK.2008.Stabilizationofdissolvedorganicmatterbyaluminium:atoxiceffectorstabilizationthroughprecipitation?EurJSoilSci59:1122‐1132.

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TowardsFurtherUnderstandingoftheSoilGenesisControlonCarbonStabilization:TheLossofPhysicalProtectionofCarbonAlonga3000kyrChronosequenceSebastianDoetterl1,AsmeretAsefawBerhe2,JenniferW.Harden3,PascalBoeckx1andElisabetNadeu41IsotopeBioscienceLaboratory‐ISOFYS,GhentUniversity,Ghent,Belgium2LifeandEnvironmentalSciences,UniversityofCaliforniaatMerced,Merced(CA),USA3SoilBiogeochemistryGroup,USGS,MenloPark(CA),USA4TECLIM,UniversitéCatholiquedeLouvain,Louvain‐la‐Neuve,BelgiumMoststudiesonstabilityofcarbon(C) insoilsareconductedontimeseriesranging from1to100years.Annualscale(orshorter)timeseriestypicallyfocusontheinteractionofmicroorgan‐ismswiththesoilmineralmatrixandthetransformationoforganiccompoundsinlitter.Incon‐trast,soilgenesis,i.e.soilweathering,istraditionallystudiedonlongertime‐scales(centuriestomillennia)byusingsoil chronosequences.This temporaldiscrepancybetweenCsequestration(short‐termprocess)andsoilgenesis(long‐termprocess)representsamajorgapinourunder‐standingoftheinteractionofmechanismsthatcanstabilizeCinsoilsoverlongertimescales.Inthisstudywecharacterizethepathwaysofcarbontransformationsandstabilityfromthelittersourceintodifferentcompartmentsofthesoilmatrixinrangelandsoilswithsimilarbioclimaticcharacteristicsalongachronosequencerangingfrom0.1–3000kyrderivedfromgraniticallu‐viumonterracesoftheriverMerced(MercedCounty,CA,USA)(Harden1987).Inordertoin‐vestigate the changing effectiveness of geochemical and/or physical protection of C along thechronosequence, we conducted (i) a series of aggregate‐based soil fractionation experimentscombinedwith (ii) a biochemical characterization of the C in the isolated fractions using theabundanceoflabileaminosugarsastracersformicrobialresiduesinsoils,(ii)ananalysisoftheradiocarbonageofthedifferentfractions,(iii)ananalysisofthegeochemicalcompositionoftop‐andsubsoilsalongthesequenceand(iv)temperaturesensitivityincubationexperimentsonthebulksoilandisolatedmajorCfractions.OuranalysisshowsthatthedistributionofaggregatesandCassociatedwithaggregatefractionsaswellasthepotentialturnoverofthesefractionsarehighlyvariablealongthechronosequence.Whilesoilsdevelopedinyounger(<10kyr)depositsshowanincreaseinCstabilizedwiththemineralphase,soilsdevelopedinolderdeposits(>10kyr) lose the ability to form aggregates and to providephysical protection for C by occlusionwithincreasingage,leadingtolowersoilCcontent.Thisfindingisconfirmedbytheabundanceofaminosugarsandrelativechanges in the14Cageofdifferent fractions.Thepatternsweob‐servewithaggregation,aminosugars,andradiocarbonco‐evolvewithalterations in theabun‐danceofprimaryandsecondarymineralsofsoilsduetoongoingweathering.Theobservedef‐fectsdifferedbetweentop‐andsubsoilsmostlikelyrelatedtothefactthatbiomassCinput,animportantcomponentoflargeraggregates,decreasesnearlytenfoldfromtopsoilsdevelopedintheyoungestcomparedtotheoldestdeposits,whilethisdecreaseisinsignificantinsubsoils.Forfurtherresearchwehypothesizethatdecreases inCarealsorelatedtoareduction inreactivemineral surfaces due to ongoing weathering and that this effect will be stronger in top‐soils(high C input, limitation of reactive surfaces) than in sub‐soils (low C input, no limitation ofavailablesurfaces).ReferencesHardenJ.1987.SoilsdevelopedinGraniticAlluviumnearMerced,California,USGSBulletin1590–A,76p.

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ClassificationandModellingofNon‐ExtractableResidue(NER)FormationfromXenobioticsinSoil–ASynthesisMathiasKästner1,KarolinaM.Nowak2,AnjaMiltner1,StefanTrapp3andAndreasSchäf‐fer21DeptartmentofEnvironmentalBiotechnology,Helmholtz‐CentreforEnvironmentalResearch‐UFZ,Leipzig,Germany,2InstituteforEnvironmentalResearch,RWTHAachenUniversity,Aachen,Germany3DepartmentofEnvironmentalEngineering,TechnicalUniversityofDenmark,Lyngby,DenmarkThispresentationprovides a comprehensiveoverviewabout the formationofnon‐extractableresidues(NER)fromorganicpesticidesandcontaminantsinsoilandtriesclassifyingthediffer‐enttypes.Anthropogenicorganicchemicalsaredeliberately(e.g.pesticides)orunintentionally(e.g.polyaromatichydrocarbons[PAH],chlorinatedsolvents,pharmaceuticals)releasedinma‐jor amounts to nearly all compartments of the environment. Soils and sediments as complexmatricesprovideawidevarietyofbindingsitesandarethemajorsinks forthesecompounds.Manyofthexenobioticsenteringsoilundergoturnoverprocessesandcanbevolatilised,leachedtothegroundwater,degradedbymicroorganismsortakenupandenrichedbylivingorganisms.XenobioticNERmaybederived fromparentcompoundsandprimarymetabolites thatarese‐questered(sorbedorentrapped)withinthesoilorganicmatter(typeINER)orcanbecovalentlybound(typeIINER).EspeciallytypeINERmayposeaconsiderablyenvironmentalriskofpo‐tentialrelease.However,NERresultingfromproductivebiodegradation,whichmeansthecon‐versionofcarbon(ornitrogen) fromthecompounds intomicrobialbiomassmoleculesduringmicrobialdegradation(typeIII,bioNER),donotposeanyrisk.Experimentalandanalyticalap‐proaches to clearly distinguish between the types are provided and amodel to prospectivelyestimatetheirfateinsoilisproposed.

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PhysicochemicalCharacterofWaterMoleculeBridgesStabilizingSoilOrganicMatterJiriKucerik1,AlexanderJäger2,MarkoBertmer2andGabrieleE.Schaumann11InstituteforEnvironmentalSciences,GroupofEnvironmentalandSoilChemistry,UniversityKoblenz‐Landau,Landau,Germany2InstituteforExperimentalPhysicsII,GroupMQF,UniversityofLeipzig,Leipzig,GermanyEveninairdriedsoils,waterisstillinvolvedinmanyprocesses.Tounderstandthem,itisbene‐ficialtogetdeeperknowledgeaboutthephysicochemicalcharacterofwaterbinding.Combina‐tionofdifferentialscanningcalorimetry(DSC),NMRandmolecularmodelingshowedthatwaternanodropletsthatfunctionaswatermoleculebridges(WaMB),connectingandphysicallystabi‐lizingsoilorganicmatterareprogressivelyformedinawiderangeofsoils(HurrassandSchau‐mann, 2005; Schaumann and LeBoeuf, 2005; KunhiMouvenchery et al., 2013). TheWaMB issupportedbyhydrophobicsurroundingsofspatiallyarrangedpolargroups(Aquinoetal,.2011).WaMBisdetectedbyitsdisruption,manifestedasastepinheatcapacityonDSCrecords(Hur‐rass and Schaumann, 2005). In thiswork,we report results about a progressive formation ofWaMB after its disruption, separation of WaMB from accompanying processes and new ap‐proachestoanalyzeitsphysicochemicalcharacter.Asamodelsoil,asaprichistosolwasused.Inthefirststep,usingdifferentheatingprotocols,theWaMBtransitionwasseparatedfromaparal‐lel processes, which involvedmelting of aliphatic structures (Chilom and Rice, 2005). Unlikemelting,WaMBresponded to theheating rateandextrapolation to stationary conditions indi‐cateditsoccurrenceatambienttemperatures.Thetransitionenergy,whichinvolvestheenergyoftheH‐bondsbreakandwaterdiffusion,wasdetermined~54kJ/mol.AfterWaMBbreaking,itreformsquicklyatambientconditions,whereasatelevatedtemperatures,waterdiffusesawayandWaMBreformsslowly.Theexperiments furtherreveled that formationofWaMBdependsalsooncoolingconditions,thecondensationofmoleculesintoWaMBwasmanifestedasanexo‐thermalprocessesprecedingtheWaMBtransition(Kuceriketal.,2014).Thenewlydevelopedapproach,basedon thedeterminationof soilwater evaporationenthalpy, supportsmolecularmodeling results about the occurrence ofWaMB in the vicinity of hydrophobic domains. ThemeasuredenthalpiesdemonstratedthatbindingenergyofWaMBnanodropletsdependonrela‐tivehumidityandthermalhistoryofsoil.ReferencesAquinoAJA,TunegaD,PasalicH,SchaumannGE,HaberhauerG,GerzabekMH,LischkaH.2011.Moleculardynamics simulationsofwatermolecule‐bridges inpolardomainsofhumicacids.EnvironSciTechnol45:8411–8419.

ChilomG,Rice, JA.2005.Glasstransitionandcrystallitemelting innaturalorganicmatter.OrgGeochem36:1339‐1346.

HurrassJ,SchaumannGE.2005.Isglassinessacommoncharacteristicofsoilorganicmatter?EnvironSciTechnol39:9534‐9540.

KucerikJ,SchwarzJ,JaegerA,BertmerM,SchaumannG.2014.Characteroftransitionscausingphysico‐chemicalagingofasaprichistosol.JThermAnalCalorim.doi:10.1007/s10973‐014‐3971‐4.

KunhiMouvencheryY,JaegerA,AquinoAJA,TunegaD,DiehlD,BertmerM,SchaumannGE.2013.Restruc‐turingofapeatininteractionwithmultivalentcations:Effectofcationtypeandagingtime.PLoSONE8:e65359.

SchaumannGE,LeBoeufEJ.2005.Glasstransitionsinpeat‐theirrelevanceandtheimpactofwater.Envi‐ronSciTechnol39:800‐806.

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SpatialEcologyofBacteriaattheMicroscaleinSoilXavierRaynaud1andNaoiseNunan21SorbonneUniversités,UPMC,InstituteofEcologyandEnvironmentalSciences–Paris,Paris,France2CNRS,InstituteofEcologyandEnvironmentalSciences–Paris,CampusAgroParisTech,Thiverval‐Grignon,FranceDespiteanexceptionalnumberofbacterialcellsandspeciesinsoils,bacterialdiversityseemstohave little effect on soil processes, such as respirationor nitrification, that canbe affectedbyinteractionsbetweenbacterialcells.Theaimof thisstudy is tounderstandhowbacterialcellsaredistributedinsoiltobetterunderstandthescalingbetweencell‐to‐cellinteractionsandwhatcanbemeasured ina fewmilligrams,ormore,of soil.Basedon theanalysisof744 imagesofobservedbacterialdistributionsinsoilthinsectionstakenatdifferentdepths,wefoundthattheinter‐cell distancewas, on average12.46mmand that these inter‐cell distanceswere shorternearthesoilsurface(10.38mm)thanatdepth(>18mm),duetochangesincelldensities.Theseimageswerealsousedtodevelopaspatialstatisticalmodel,basedonLogGaussianCoxProc‐esses, to analyse the2Ddistributionof cells and construct realistic3Dbacterialdistributions.Ouranalysessuggestthatdespitetheveryhighnumberofcellsandspeciesinsoil,bacteriaonlyinteractwithafewotherindividuals.Forexample,atbacterialdensitiescommonlyfoundinbulksoil(108cellsg‐1soil), thenumberofneighboursasinglebacteriumhaswithinan interactiondistanceofca.20mmisrelativelylimited(120cellsonaverage).Makingconservativeassump‐tionsaboutthedistributionofspecies,weshowthatsuchneighbourhoodscontainlessthan100species.Thisvaluedidnotchangeappreciablyasafunctionoftheoveralldiversityinsoil,sug‐gestingthatthediversityofsoilbacterialcommunitiesmaybespeciessaturated.Allinall,thiswork provides precise data on bacterial distributions, a novelway tomodel them at themi‐crometer scaleaswell as somenew insightson thedegreeof interactionsbetween individualbacterialcellsinsoils.

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ChangesintheStructureofSapricPeatInducedbythePresenceofPhenolPavelOndruch1,JiriKucerik1,AlexanderJäger2,MarkoBertmer2andGabrieleE.Schau‐mann11InstituteforEnvironmentalSciences,UniversityKoblenz‐Landau,Landau,Germany2InstituteforExperimentalPhysicsII,GroupMQF,UniversityofLeipzig,Leipzig,GermanyPollutantsorptioninsoilhasalreadybeenwidelystudied,focusingmostlyonsorptionkineticsandmechanisms aswell as pollutant interactionwith soil organicmatter (SOM). Despite thiseffort,theeffectofpollutantsonsoilstructureisnotfullyunderstood,althoughithasanimpor‐tantinfluenceonpollutants’fateandsoilqualityintermsofsoilstabilityandfunctions.Inthiswork,we applied thermoanalyticalmethods, differential scanning calorimetry (DSC), thermo‐gravimetricanalysiscoupledwithmassspectrometry(TGA‐MS),andsolid‐state13CCPMASNMRtostudysoil structure thatwas treatedbydifferentsolventswithandwithoutphenol.To thispurposewechoseanorganicmatterrichsaprichistosol.Wefocusedontwosoilcharacteristics,characterof soilwatermoleculebridges (WaMB)andsoilaliphatic composition.Formationofwatermoleculebridges is an important factor of stabilizationof thephysical structureof soilorganicmatter(SchaumannandBertmer,2008)andrepresentsan importantpart in itsphys‐icochemicalaging(Kuceriketal.,2014).Theroleofcrystallinealiphaticregionsisnotfullyclear,anditisusuallyconnectedwithsorptioninactivityandevensolventimpermeability.Neverthe‐less, there are proposals that crystalline domains can reduce amorphous domainmobility intheir vicinity and thus indirectly cause nonlinear sorption behavior (Deshmukh, 2003). Fur‐thermore,theinfluenceofphenol incorporationonsoil thermalstabilitywasinvestigated.OurresultssuggestthattheeffectofphenolonWaMBandtheirdestabilizationisgovernedbyphys‐icochemicalpropertiesofthesolventthatwasusedforincorporationofphenol.Itwasobservedthat nonpolar solvents supportWaMB stability andmay increase its formation. Regarding toaliphaticcomposition,wedetectsignificantmeltingpointdepressiononlyifphenolwaspresentinsoil.Itsuggestschangesinaliphaticcrystallinedomains.Thiswasalsosupportedby13CNMRresults,whichindicatedecreaseofcrystallinityinphenolspikedsamples.Furthermore,weob‐served a decrease of onset temperature of organicmatter degradation thatwas indicated byreleaseofCO2asseenbyTGA‐MSanalysis.Insummary,ourinvestigationproposesdestabiliza‐tionofsoilphysicochemicalstructurecausedbyphenolandsolventsused.Thesefindingsmaycontributetoknowledgeofpollutantsorption,sequestration,andtheirimpactonenvironment.ReferencesSchaumannGE,BertmerM.2008.Dowatermoleculesbridgesoilorganicmattermoleculesegments?EurJSoilSci59:423‐429.

KucerikJ,SchwarzJ,JaegerA,BertmerM,SchaumannGE.2014.Characteroftransitionscausingphysico‐chemicalagingofsaprichistosol.JThermAnalCal,accepted(inpress).

DeshmukhAP.2003.Sorptionandsequestrationofphenanthrene inpolymethylenicplantbiopolymers:proxiesforsoilandsedimentaryorganicmatter,TheOhioStateUniversity(Dissertation).

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EffectiveDispersalofDegradingBacteriaImpedesOutgassingofOrganicContaminantsSallyOtto1,ThomasBanitz2,KarinJohst2,HaukeHarms1andLukasY.Wick11DepartmentofEnvironmentalMicrobiology,HelmholtzCentreforEnvironmentalResearch‐UFZ.Leipzig,Germany2DepartmentofEcologicalModelling,HelmholtzCentreforEnvironmentalResearch‐UFZ.Leipzig,GermanyContaminantsareonlyhazardous if theybecomebioavailable.Themosteffective remediationtechniqueshould leadtoanoptimalcoveragewithdegradingmicroorganismstopreventare‐leaseof contaminantsbound tobiogeochemical interfaces (BGI) to theenvironment.Here,weinvestigatedtheimpactofbacterialdispersalonBGIontheoutgassingofphenanthrene(PHE).Ourstudywasperformedtochallengethehypothesisthatthepresenceofdispersalnetworksofbacteria leads to: (i) bacterial distribution along the transport network, (ii) efficient bacterialdistributiononthesurface,and(iii)anincreasedbiomassproductionallowingforthedegrada‐tionofPHEreleasingfromthesystem.Wethereforedesignedalaboratorymicrocosmmimick‐ingacontinuousPHEreleasefromaPHEhotspottoamodelBGI(agarsurface)inpresenceandabsence of model dispersal networks which facilitated the transport of unless poorly motilePHE‐degradingPseudomonasfluorescensLP6aonagarsurfaces.Thepresenceoftheglassfibres(asalaboratorymimicthewidespreadsoilfungalnetworks)resultedinan(i)increasedspatio‐temporalspreadingofbacteria, (ii)an increasedbacterialcoverageofandgrowthontheagarsurface,and(iii)asubsequenteffectivedegradationofoutgassingPHEandeffectivereductionofPHE contaminationbeyond thePHEhotspot.Ourdatahence suggest that fungalmyceliamaypromote the formation of an adaptedmicrobial biomass thatwill degrade contaminantmole‐culesdesorbingfromthatsourceandthatsuchanactivitypotentiallycanresultinzeroemissionofcontaminantstotheporeandgroundwaterand,hence,tohigherorganisms.

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TransportofBacterialPesticideDegraders‐AnImportantProc‐essEnhancingDegradationofMCPAClosetotheSoil‐LitterInter‐face?HolgerPagel1,AureliaGebala2,ChristianPoll2,JoachimIngwersen1,FranziskaDitterich2,EllenKandeler2andThiloStreck11InstituteofSoilScienceandLandEvaluation,SectionofBiogeophysics,UniversityofHohenheim,Stuttgart,Germany2InstituteofSoilScienceandLandEvaluation,SectionofSoilBiology,UniversityofHohenheim,Stuttgart,GermanyTherateofpesticidedegradation insoilsdependson thespatialdistributionofdegradingmi‐croorganisms.Inadditiontosolutetransport,themovementofmicroorganismscanimprovetheconnectivityofpesticidedegradersandsubstrate.Inputoffreshlitter‐carbonstimulatesmicro‐bial growth and degradation of the herbicideMCPA (2‐Methyl‐4‐chlorophenoxyacetic acid) insoiladjacenttothesoil‐litter interface(detritusphere).TransportofbacterialMCPAdegradersenriched at the soil‐litter interfacemight contribute there to enhancedMCPA degradation byincreasing the activelydegradingbiomass. Inparticular, bacterial transport via fungal hyphae(“fungal highways”) couldpromote the translocationof bacterial pesticidedegraders, becausefungal growth is strongly enhanced at the soil‐litter interface.Therefore, ourobjectivewas toelucidate i) ifmovementofbacterialpesticidedegradersbyconvectiveanddiffusivetransportoccurs and ii) if growthof fungal hyphaepromotesbacterial transport.BothprocesseswouldenhanceMCPAdegradation.Wesetupsoilcores(33mmheight,56mmdiameter)consistingofa30mmsubsoillayercoveredbyathintopsoillayer(3mm).Thesoilwasasiltyloamfromanagriculturallyusedfield.Maizelitterwasthenplacedontopofaportionofthesesoilcores.Allsoilwassieved(2mm)andhomogeneouslyamendedwith50μgg‐1MCPA.Thetopsoilwaspre‐incubatedeitherafteramendmentof20μgg‐1MCPAorwithoutMCPAamendmenttoobtainsoilmaterialwith an increased abundanceof bacterialMCPAdegraders (inoculum)orwithout. Intotal, we prepared 4 treatments: i) MCPA amendment & non‐inoculated topsoil (control); ii)litter addition&MCPA amendment&non‐inoculated topsoil (litter); iii)MCPA amendment&inoculatedtopsoil(inoculated);iv)litteraddition&MCPAamendment&inoculatedtopsoil(lit‐terinoculated).Thesoilcoreswereincubatedinmicrocosms,irrigatedwith0.01MCaCl2solu‐tionattworates(1mmd‐1and24mmd‐1)andsampled1dayand10daysafteratotalvolumeoftwoporevolumeshadbeenapplied.DuringincubationwemeasuredCO2‐production.Thesoilcoreswereseparatedinto9layers,from0‐3,3‐4,4‐5,5‐6,6‐7,7‐8,8‐10,10‐15and15–33mm,using a newly developed sampling device and analysed for abundances of three molecularmarkers(tfdAgenes,16SrRNAgenesandfungalITSfragments)andresidualMCPAconcentra‐tion.Sinceanalysesarecurrentlystillrunning,firstresultswillbepresentedinadditiontothenewlydevelopedsamplingdevice.

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EffectsofAcidTreatmentonSoilHydraulicandTransportProp‐ertiesofFloodplainSoilsSabineSchaeferandKaiUweTotscheInstituteofGeosciences,FriedrichSchillerUniversityJena,GermanyBiological and physicochemical processes in soils, like root growth,mineral precipitation anddissolution,orcolloidaldispersionandflocculationmayresultinnotonlytemporalchangesofthe soil structure. Sucheffectswill in turnaffect theporenetworkarchitecture, thehydraulicandthetransportproperties.Usingsoilcolumnexperiments,westudiedtheinfluenceofmineraldissolution on thehydraulic conductivity, thewater retention characteristic and the apparentdispersivity.Twoundisturbedsoilcorespackedwithacalcareous floodplainsoil fromtheDa‐nubewere flushedwith aperchloric acid solution (10‐2.5M).Before andafter the acid treat‐mentweinvestigatedtheporenetworkbycomputertomography(CT)(UFZHalle,DepartmentofSoilPhysics)andmeasurethehydraulicandthetransportproperties.Transportexperiments(sodiumchlorideas tracer)showa fast increaseof thesolutionconcentrationwhichpoints todominance of preferential flow,most likely alongmacropores,which are related to old roots.Whereasleachingofthesolutionisretarded.Onlyweakeffectsondispersivityoccurred,model‐ingdispersivityyieldschangesbetween3.2cm(±0.9cm)and5.3cm(±2.3cm)beforeandafteracidpercolation.Becauseof thehigh standarddeviations thesevalues are less reliable. In thewater retention characteristicweobserve only small changes aswell.A slight increaseof thesaturatedwatercontentwasmeasuredafteracidpercolation.Atlowtensionintherangeofthefieldcapacity(pF1.8to2.5)atendencytolowerwatercontentsafteracidtreatmentisobserv‐able.However,wecan’texcludethatthesechangesarewithinrangeofthehysteresiseffect.Per‐colationwith a high concentrated acid, for nearly amonth, only leads to weak effects in thetransportpropertiesaswellasinthewaterretention.Thismeansthesoilweusedshowsahighresistanceagainstdisturbanceandcanbereferredasagoodresilientwaterconductor.

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EffectsofFreshOrganicMatterAccessibilityonCarbonDecompo‐sitionbyFungiSonjaSchmidt1,ClaireChenu2,RuthFalconer1,CyrilGirardin3,NaoiseNunan4,WilfredOtten1andValérie Pouteau31SIMBIOSCentre,AbertayUniversity,Dundee,UK2AgroParisTech,UMR7618Bioemco,BâtimentEGER,ThivervalGrignon,France3INRA,UMR7618Bioemco,BâtimentEGER,ThivervalGrignon,France4CNRS,UMR7618Bioemco,BâtimentEGER,ThivervalGrignon,FranceFungiplayanimportantroleincarbondecompositionandsequestrationbuthowsoilstructurecontrolstheiractivityisstillunclear.Soilstructureseemstobethekeyfactoronfungalspreadin soil, in particular the size, continuity and air filled fraction of soil pores. Physical access offungitoSOMwillalsodependontheabundanceofdecomposableSOM.Fungiarepredominantinvolved in residues cellwalldecompositionand in theprimingeffect (PE)whereold soilor‐ganicmatter(SOM)isdecomposedbyusingfreshcarbonasasourceofenergy.Informationonhowsoilstructureaffectscolonisationanddecompositionof freshorganicmatterandSOMbyfungicouldhelptogetabetterunderstandingoftheprocessesinvolvedincarbonsequestrationandCO2respiration.Theobjectiveofthisstudywastotesthowfungalexplorationofthesoilandprobability of contact betweenOM and hyphae determines Cmineralization. For thiswema‐nipulatedthesoilporesystembycompactionandtheabundanceofOMbyaddingfreshorganicmatter indifferentamounts.Maizestrawandsoilweresterilisedandmixedtodifferentratiosandpackedtotwodifferentbulkdensities(1.3and1.5Mgm‐3).Theinitialwatercontentineachsamplewasadjustedtoanairfilledporosityof17%.EachsamplewasinoculatedwithRhizocto‐niasolaniandstoredat20⁰C.CO2concentrationandtheisotopicratioofcarbonweremeasuredondayoveraperiodof42daystodistinguishtheC‐CO2originatingfromthefreshorganicmate‐rial(δ13C=12‰)andtheC‐CO2originatingfromthesoilorganicmatter(SOMδ13C=27‰).Fasterdecompositionrateswerefoundinthelesscompactedsoilsthaninverydensesoilasthefungalspreadisprobablyhinderedduetofewerporesthemyceliumcangrowthrough.GreateramountsofCCO2releasedfromSOMweremeasuredwhenlargeramountsoffreshorganicmat‐terwereaddedwithgreaterdifferencesinsoilsamplespackedto1.3Mgg‐3thaninsoilsamplespackedto1.5Mgg‐3,showingthattheabilityoffungitocolonizesoillimiteddecomposition.TheamountofC‐CO2producedpermgofC‐freshorganicmatterdecreasedas their concentrationincreased.Theadditionof freshorganicmatter inducedapositiveprimingofSOM.Thesedatawill helpus to calibrate anexistingmodelsof fungal growth in soil in response tonative andaddedsoilorganicmatter tobetterunderstand theroleof fungi incarbondecompositionandsequestration.

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TheDrilosphereofAnecicEarthworms:AHotspotofBiochemicalandBiologicalActivityWalterS.Andriuzzi1,2,PhuongNgo3,StefanGeisen4,KennethDumack4,TomBolger5,Mi‐chaelBonkowski4,CorneliaRumpel3andOlafSchmidt21DepartmentofSoilQuality,WageningenUniversity,Wageningen,TheNetherlands2SchoolofAgricultureandFoodScience,UniversityCollegeDublin,Dublin,Ireland3BIOEMCO,CNRS‐INRA‐UniversitéParisVI,Thiverval‐‐Grignon,France4DepartmentofTerrestrialEcology,InstituteofZoology,UniversityofCologne,Köln,Germany5SchoolofBiologyandEnvironmentalScience,UniversityCollegeDublin,Dublin,IrelandAnecicearthwormsforageonorganicdetritusatthesoilsurfaceandmaintainpermanentbur‐rowswhichactashotspotsofdecomposition,microbialactivityandwaterflowinsoil.Theeco‐logical importanceof thisearthwormgroupiswidelyrecognized,buttheassumptionthatdis‐tinct species are functionally redundant in their effects has rarely been investigated.Weper‐formedafieldexperimentintemperategrasslandtotestwhethertwospeciesinthisfunctionalgroup, Lumbricus centralis andAporrectodea longa, had the same impact on soil biochemicalheterogeneity, protists and nematodes.We usedmaize litter labelledwith 13C and 15N stableisotopes to detect incorporation of residue‐derived C and N into soil around burrows, eitheroccupiedbyoneofthetwospecies,orfromwhichtheearthwormwasmanuallyremoved.After50days,wesampledtopsoil(0–10cmdepth)atthinconcentriclayersaroundtheburrowwalls(upto8mm),representingthepotentialdrilosphere,andatafurtherdistance(50–75mm),rep‐resentingbulksoil.Although thedrilosphereofbothspecieshadahigherCcontent thanbulksoil,L.centralisincorporatedmore13C,i.e.morelitter‐derivedC,thanA.longa.Thiswasassoci‐atedtoalargercontributionofplant‐derivedsugarstothesoilorganicmatter(lower[galactose+mannose]/[arabinose+xylose]ratio),aswellasahighertotalsugarcontentinsoil.Multivari‐ateanalysesonC,NandorganicmattercompositionshowedthedrilosphereofA. longa tobebiochemicallymoresimilartounoccupiedthantoL.centralisdrilosphere.AlthoughwewerenotabletosampleenoughA.longaburrowstoprobespecies‐specificeffectsonprotistsandnema‐todes,wefoundinteractiveeffectsofL.centralispresenceandsoilmicrohabitat(drilospherevsbulksoil)onsomeprotistanclades,whilethesoilnematodeassemblagewasmorehomogene‐ous.

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WettabilityandHydrophobic‐HydrophilicComponentsofHumicSubstancesofChernozemDensitometricFractionsEvgenySheinandEvgenyMilanovskiyMoscowStateUniversity,SoilScienceFaculty,Moscow,RussiaWaterstabilityoftheaggregatestructureisdirectlyrelatedtothesurfacepropertiesofelemen‐tarysoilparticles(ESP)inthesolidphaseofthesoil. IncaseofhighhydrophilicityofESP,thewaterflowsthroughthecapillariesinthedryaggregateandleadstoanincreaseofwaterpres‐sureintheaggregateanditsdestruction.WhenESParehydrophobic,theadhesionisreducedasthere is no attraction between thewatermolecules and the non‐polar surface. Contact angle(CA)isusedasawettabilitycharacteristicvalue; itquantifiesthephysicochemicalinteractionsattheliquid‐solidinterface(Leteyetal.,1962).Thepurposeofthisstudywastolinkthedensi‐tometricfractionssurfacewettabilitywiththehydrophobicandhydrophiliccomponentsofhu‐mussubstances(HS)contained in these fractions.Thesamplesweretaken fromthetwohori‐zons(10‐15,40‐45cm)ofchernozemwithinanoakwind‐proofforeststripwithoutgrasscover(Voronezh region,Russia).Weused theprocedure (Golchinetal., 1994) toobtain thedensityfractionsofsoilorganicmatter:occludedparticulateorganicmatter(oPOM)withadensity<1.6gcm‐3(oPOM<1.6);1.6–1.8gcm‐3(oPOM1.6–1.8);1.8–2.2gcm‐3(oPOM1.8–2.2)andmineralassoci‐atedOMwithadensity>2.2gcm‐3.Totalorganiccarbon(TOC)wasobtainedwithCNanalyzer(VarioEL,Elementar,Germany).StaticCAweredeterminedbymeansofthesessiledropmethodwith thehelpofadigitalgoniometer (DropShapeAnalysisSystem,DSA100,Krüss,Germany).UsingOctyl SepharoseCL‐4BHS, isolated fromDensitometry fractions (extractionby solutionNaOH+Na4P2O7), fractionatedbyhydrophobic interactionchromatography(HIC)at lowpres‐sure liquid chromatographBioLogicLP (BioRad,USA).TOCcontentandC/Nratioof the frac‐tionsdecreasedalongwiththeincreaseoftheirdensity(from47‐30%to0,6%andfrom28‐25to8respectively).AtthesametimethesurfaceoftheoPOM<1.6washydrophobic(CA90°)whiletherestwerehydrophilic(CA59‐50‐33°).HICallowstophysicallydivideasetofHSinextractintocomponents(5fractions),whichdifferinabilitytoparticipateinhydrophobicinteractionswithgelmatrix.ItwasfoundthatadecreaseinCAofwettingofdensitometricfractionswasac‐companiedbyanincreaseoftherelativecontentofhydrophiliccomponentsofHS(fraction1)andthereductionofhydrophobiccompounds(fraction4).ThevalueoftheCAwashighlycorre‐latedwithhydrophobic components (R2=0.93) content, butnotwith thehydrophilicHS.Hy‐drophobiccomponentsofsoilHSare indigenous formations, spatially localizedwithhumifica‐tionproductsoforganicmaterial in situwithin theaggregates (SheinandMilanovskiy,2003).Our results indicate theheterogeneityof surfacewettabilityof the solidphase componentsofsoils, causedbyheterogeneousdistributionofhydrophilic andhydrophobicHSwithin theag‐gregates(Urbaneketal.,2007).ReferencesGolchinA,OadesM,SkjemstadO,ClarkeP.1994.Studyoffreeandoccludedparticulateorganicmatterinsoilsbysolidstate13CCP/MASNMRspectroscopyandscanningelectronmicroscopy.AustJSoilRes32:285‐309.

LeteyJ,OsbornJ,PelishekR.1962.MeasurementofLiquidSolidContactAnglesinSoilandSand.SoilSci93:149‐153.

SheinE,MilanovskiyE.2003.TheRoleofOrganicMatterintheFormationandStabilityofSoilAggregates.EurasianSoilSci36:51‐58.

UrbanekE,HallettP,FeeneyD,HornR.2007.Waterrepellencyanddistributionofhydrophilicandhydro‐phobiccompoundsinsoilaggregatesfromdifferenttillagesystems.Geoderma.140:147‐155.

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ConsequencesofOrganicMatterCompositiononPAHAccumula‐tioninSoilsfromIndustrialAreasBozenaSmreczak,AleksandraUkalska‐Jaruga,AgnieszkaKlimkowicz‐PawlasandBar‐baraMaliszewska‐KordybachInstituteofSoilScienceandPlantCultivation–StateResearchInstitute,Pulawy,PolandSoils located in industrial areasmay be contaminatedwith polycyclic aromatic hydrocarbons(PAHs).PAHsentersoilsmainlywithatmosphericprecipitations.Majorityofthemareconcen‐tratedinthetoplayerofsoilswheretheysubjecttodifferentprocesses.Soilpropertiesplayanimportantroleintherateandtheextentofthosetransformations.PAHsexhibitstrongsorptionaffinitytosoilorganicmatter(SOM)whatinfluencethesequestrationandagingprocesses.Re‐centstudiesindicatethatSOMcompositionisthekeyfactorgoverningthefateofPAHsinsoils.Ofparticular importance is thepresenceof fractionsexhibitingstrongsorptionproperties likedissolved organic carbon (DOC), humic substances (HS) or black carbon (BC)which can limitPAH’sbioavailabilityandsolubilityand thuseffect itsdegradabilityandmovementwithinsoilprofile.TheaimofthestudywastoassesstherelationshipbetweenSOMcontentandcomposi‐tionandPAHconcentrationinhistoricallycontaminatedsoilswithregardstopropertiesofcon‐taminants.Soilsamples(n=9)werecollectedfromtheupperhorizon(0‐30cm)ofsoilssituatedinindustrialSilesiaRegion(Poland),exposedforafewdecadestoPAHsemissionsources.SOManalysis included determinations of: total organic carbon content ‐ TOC (CN apparatus), DOCcontent(coldwaterextraction,1h,20°C),blackcarboncontent(lostatignitionat375°CandCNapparatus)andHScontent(calculatedasadifferencebetweenTOCandBC).Thedeterminationsof PAHs included analysis of sixteen individual hydrocarbons from US EPA list (GC‐MS tech‐nique).Thegroupsofcompoundsofdifferentstructureandmolecularweight(2+3rings,4ringsand 5+6 rings)were distinguished. Soils exhibited high differences in the TOC content (19.6‐167.2 g·kg‐1) and individual SOM fractions: DOC: 0.19‐2.13 g·kg‐1; HS: 9.5‐198.6 g·kg‐1 andBC:1.1‐45.3g·kg‐1.Humicsubstancesaccountedfor73‐98%ofTOCwhileBCcoversonly2‐26%.ThetotalPAHsconcentrationsvariedfrom0,7to224,1mgkg‐1andweredominatedbylowermolecularweightfractions(≤4rings).AllPAHsgroups(2+3‐rings,4‐ringsand5+6‐rings)exhib‐ited significant (p≥0.05) positive correlation with BC (r>0.91) with the strongest link corre‐spondedto5+6ringhydrocarbons.NosignificantrelationshipwithHSandDOCwasobserved.Theresultssuggestblackcarbonfraction,derivingmainlyfromanthropogenicsources,asbeingthemostresponsiblefortheretentionofPAHsinsoilswithparticularregardtohighermolecu‐larweight compounds.Higher persistence of PAHs in soilswith increased content of BCmayreducetheriskofthemovementofthosecontaminantswithinsoilprofile(norelationwithDOCwas observed). The other dependencesmay be observed in soils from uncontaminated areaswithlimitedBCcontentandotherquantitativeandqualitativePAHscontamination.

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ReactivityofFerrihydrite‐OrganicMatterComplexesKarinEusterhues1,AnkeHädrich2,JuliaNeidhardt2,KirstenKüsel2andKaiUweTotsche11DepartmentofHydrogeology,FriedrichSchillerUniversityofJena,Jena,Germany2InstituteofEcology,FriedrichSchillerUniversityofJena,Jena,GermanyTheassociationoforganicmatterwithmineralsstronglyaffectsmineralsurfacepropertiessuchas solubility, charge andhydrophobicity. Thiswill influence their reactivity towardsnutrientsand pollutants, the adsorption of new organicmatter, and their interactionwithmicroorgan‐isms.Weproduced ferrihydrite‐organicmatterassociationsbyadsorptionandcoprecipitationinlaboratoryexperiments.Asasurrogatefordissolvedsoilorganicmatterweusedthewater‐extractable fraction of a Podzol forest‐floor layer under spruce. Biodegradation experimentswerecarriedoutwithaninoculumextractedfromthepodzolforest‐floorunderoxicconditionsat pH 4.8 to quantify the mineralization of the adsorbed and coprecipitated organic matter.These experiments showed that the associationwith ferrihydrite stabilized the associated or‐ganicmatter, but thatdifferences in thedegradability of adsorbed and coprecipitated organicmatter were small. We therefore conclude that coprecipitation does not lead to a significantformation ofmicrobial inaccessible organicmatter domains.Microbial reduction experimentswereperformedusingGeobacterbremensis.WeobservedthatincreasingamountsofassociatedOMledtodecreasinginitialreactionratesandadecreasingdegreeofdissolution.Reductionofcoprecipitated ferrihydriteswas faster than reductionof ferrihydriteswith adsorbedOM.Ourdatademonstrate that theassociationwith ferrihydritecaneffectivelystabilize labilepolysac‐charidesagainstbiodegradation.Viceversa,thesepolysaccharidesmayprotectferrihydritefromreductionbyGeobacter‐likebacteria.

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Session5:QuantitativeUnderstandingofBGIs:TheoreticalConcepts&ModelstoExplainStructure,Properties,&FunctionsofBGIs

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Topic5:QuantitativeUnderstandingofBGIs:TheoreticalConcepts&ModelstoExplainStructure,Properties&FunctionsofBGIsPosterNo.47

MicrobialDegradationofPropyleneGlycol:BatchExperiment,ModellingApproachandPotentialofGeophysicalMethodsforMonitoringAnnetteDathe1,Perrine M. Fernandez1, Lars R. Bakken1, Johannes C.L. Meeussen2, Esther Bloem3 and Helen K. French1,31Norwegian University of Life Sciences, Department of Environmental Sciences, 1432 Ås, Norway 2Nuclear Research and Consultancy Group, 1755 Petten, The Netherlands 3Bioforsk, Norwegian Institute for Agricultural and Environmental Research, Soil and Environment Division, 1432 Ås, Norway De‐icingchemicalsareappliedinlargeamountsatairportsduringwinterconditionstokeeptherunwaysandaircrafts ice‐free.AtGardermoenairport,Norway,mostof theappliedchemicalscanbecaptured,butabout10to20%infiltrateintothesoilalongtherunwaysandduringtake‐off. While the commonly used propylene glycol (PG) is easily degradable by local microbialcommunities, itsbiologicaloxygendemand ishigh, anoxic zones candevelopandsolubleFe+2andMn+2ionseventuallycanreachthegroundwater.Theobjectivesofthisstudyaretoquantifymechanismswhichcontroltheorderofreductionprocessesinanunsaturatedsandysoil,andtotestwhethermeasuredredoxpotentialscanhelptodetermineunderlyingbiogeochemicalreac‐tions.ThemicrobialinduceddegradationofPGfollowsaredox‐sequenceinthesubsurface,andin theory electrical signatures of these reactions can bemeasuredwith geophysicalmethods.However, thedegradation ishappeningat theporescale,andmeasurements takeplaceat thecentimeter to meter scale. To understand and quantify underlying biogeochemical reactionsbatch experiments were conducted under aerobic and anaerobic conditions. The results, inagreement with field observations, suggest that iron‐ and manganese reducing bacteria out‐numberdenitrifyingbacteria inthissoil,becauseanoxic incubationwithampleamountsofni‐trateresultediniron‐andmanganese‐reductionwhiledenitrificationwasinsignificant.InversemodellingofPGdecayunderaerobicconditionsrevealsthatnotonlythecommonlyusedredoxreactionbutbiomassgrowth,decayandrespirationhavetobetakenintoaccount.Withthecali‐bratedmodelweareworkingtowardsatooltoquantifymicrobialinducedredoxreactionsun‐der different soil water saturations to account for seasonal water fluxes especially duringsnowmelt.Additionally,geophysicalsignaturescanbesimulatedandthuscontributetobuildingaframeworkofmonitoringredoxreactionsbymeasuringtheelectricalconductivityortheself‐potentialinthefield.

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CadmiumSorptiononMontmorillonite‐Bacteria‐HumicAcidComposites:InvestigatedbyPotentiometricTitrationandIso‐thermalTitrationCalorimetryHuihuiDu1,2andQiaoyunHuang1,21StateKeyLaboratoryofAgriculturalMicrobiology,CollegeofResourcesandEnvironment,HuazhongAgriculturalUniversity,Wuhan,China2KeyLaboratoryofArableLandConservation(MiddleandLowerReachesofYangtzeRiver),MinistryofAgriculture,CollegeofResourcesandEnvironment,HuazhongAgriculturalUniversity,Wuhan,ChinaTracemetals speciation in soil systems are generally dominatedbyminerals, organicmattersand biological components. In natural environment, these ingredients are “glued” together toformaheterogeneouscomplexandthusthesurfacepropertiesofthecompositesdifferdramati‐cally from their individual ones. Understanding the speciation and distribution in min‐eral/organic matter/bacteria composites is of critical importance in predicting the fate andtransportoftracemetalsinbiogeochemicalinterface(BGI)(Huangetal.,2008;Songetal.,2009;Totscheetal., 2010). In thepresent study, potentiometric titration, batch adsorption and iso‐thermaltitrationcalorimetry(ITC)wereemployedtoinvestigateCdsorptionbehavioroncom‐plexsystemscontainedmontmorillonite,cellofPseudomonasputidaandhumicacid.Fivesam‐pleswerestudied,includingpureMontandP.putida,binaryMont‐bacteriaandMont‐HAcom‐posites, ternaryMont‐bacteria‐HAcomposites.Considerabledifference in theshapesandposi‐tionsof thepotentiometric titrationcurves for the5samples indicateddiversesurfaceacidityandprotonbindingbehaviorofthesecomposites.TheaveragebufferingcapacityforP.putida,overthepHrangeof2.5to10was6.1mmol/g,whilethisvaluewas2.5‐4.6mmol/gforthebi‐nary and ternary composites, andmontmorillonitewas the smallest (~1.9mmol/g). Cell ofP.putidadisplayedthestrongestaffinityforCdremovalfromthesolutionduetoagreatquantityof negative functional groups onbacteria surfaces. EnhancedCd adsorptionwas observed forMont‐HA composites as compared to pure montmorillonite at studied pH demonstrated theformationofsurfacecomplexes(metal‐ligand‐mineral).However,theternaryMont‐bacteria‐HAcomplexdidnotshowhighersorptioncapabilitythanMont‐bacteria,illustratinganinteractionbetweenhumicacid andbacteria cell thatmaymask the adsorption sites. ITC results showedthatsorptionofCdionsonMontandMont‐HAcomplexwereexothermicprocesseswhilethatonbacteria, Mont‐bacteria and Mont‐bacteria‐HA composites were endothermic reactions withenthalpy(ΔH)changesrangingfrom5.48to13.09kJmol‐1.Largerentropychanges(32.65‐71.49Jmol‐1k‐1) of Cd adsorptiononbacteria,Mont‐bacteria andMont‐bacteria‐HA composites sug‐gestedthe formationof inner‐sphereCdcomplexes.Resultsobtained fromthisstudyrevealedthe dominant role of bacteria in Cd distribution at the interface of mineral‐organic matter‐bacteriacomposites.ReferencesHuangQ,ChenW,ThengBK.2008.Roleofbacteriaandbacteria‐soilcompositesinmetalbiosorptionandremediating toxic metal‐contaminated soil systems. In: Soil Mineral Microbe‐Organic Interactions,HuangQ,HuangPM,ViolanteA(eds),Springer,pp.71‐98.

SongY,SwedlundPJ,SinghalN,SwiftS.2009.Cadmium(II)speciationincomplexaquaticsystems:astudywithferrihydrite,bacteria,andanorganicligand.EnvironSciTechnol43:7430‐7436.

Totsche KU, Rennert T, GerzabekMH, Kögel‐Knabner I, Smalla K, SpitellerM, Vogel H‐J. 2010. Biogeo‐chemicalinterfacesinsoil:Theinterdisciplinarychallengeforsoilscience.JPlantNutrSoilSci173:88‐99.

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Compound‐SpecificIsotopeAnalyses:ANewAngletoTracingtheFateofMicropollutantsatBiogeochemicalInterfacesShiranQiu,SandraReinnicke,KathrinSchreglmann,MichaelMaier,ArminH.MeyerandMartinElsnerInstituteofGroundwaterEcology,HelmholtzZentrumMünchen,Neuherberg,GermanyProcessesatbiogeochemicalinterfaceslikesorption,transportanddegradationarecontrollingfactorsforthefateofmicropollutantsintheenvironment.Tobetterpredicttherespectivecon‐tributionsofeachnovelanalyticalapproachesareneeded.WithintheSPP1315,itwasourob‐jectivetoestablishforthefirst timecompound‐specific isotopeanalysis formicropollutantsofenvironmental concern. Thismethod analyzes changes in isotope ratios (13C/12C ; 15N/14N) oforganiccompoundsatnaturalabundanceswhichenablestodifferentiatedegradationprocessesfromsorptionor transport (Schmidtetal., 2004). In the courseof theSPP1315weoptimizedenrichmentmethods and subsequent GC‐IRMS (gas chromatography isotope ratiomass spec‐trometry) analysis of important herbicides: atrazine (Meyer et al., 2008, Schreglmann et al.,2013), isoproturon(PenningandElsner,2007),dichlobenil,bentazone(Reinnickeetal.,2010)andphenoxyacids (Maieretal., 2013). Inbatch studieswe could successfully link changes in13C/12Cand15N/14Nratiostomicrobialdegradation(Reinnickeetal.,2011;Penningetal.,2010)For atrazine in particular,we could even demonstrate the power of two‐dimensional isotopeplotstodecipherdifferentnaturaldegradationpathways(MeyerandElsner,2013)(Figure1).Ina recent combined approach of enantiospecific gas chromatography–isotope ratiomass spec‐trometry(ESIA)andenantiomeranalysisofphenoxyacids(Qiuetal.,2014),contrastingcarbonisotope and enantiomer fractionation enabled distinction of bottlenecks in biodegradation onthemechanisticlevel(masstransferinsolutionvs.uptakeintothecellvs.enzymaticreaction).Tomatchsuchinsightonisotopefractionationduringdegradation,ongoingworktargetschang‐esinisotoperatiosduringsorption.

Figure1.TwodimensionalCandNisotopeplotsreflectdifferentnaturaldegradationprocessesofatrazine.Bluelinebiotichydrolysisandblacklinebioticoxidation.ReferencesSchmidtTC,ZwankL,ElsnerM,BergM,MeckenstockRU,HaderleinSB.2004.Compound‐specificstableisotopeanalysisoforganiccontaminantsinnaturalenvironments:acriticalreviewofthestateoftheart,prospects,andfuturechallenges.AnalBioanalChem378:283‐300.

MeyerAH,PenningH,LowagH,ElsnerM.2008.Preciseandaccuratecompoundspecificcarbonandni‐trogenisotopeanalysisofatrazine:criticalroleofcombustionovenconditions.EnvironSciTechnol42:7757‐7763.

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PenningH,ElsnerM.2007.Intramolecularcarbonandnitrogenisotopeanalysisbyquantitativedryfrag‐mentationofthephenylureaherbicideisoproturoninacombinedinjector/capillaryreactorpriortoGCseparation.AnalChem79:8399‐8405.

ReinnickeS,BernsteinA,ElsnerM.2010.Smallandreproducibleisotopeeffectsduringmethylationwithtrimethylsulfoniumhydroxide(TMSH):Aconvenientderivatizationmethodforisotopeanalysisofnega‐tivelychargedmolecules.AnalChem82:2013‐2019.

SchreglmannK,HoecheM,SteinbeissS,ReinnickeS,ElsnerM.2013.Carbonandnitrogenisotopeanalysisof atrazine and dethylatrazine at sub‐µg/L concentrations in groundwater.AnalBioanal Chem 405A:2857‐2867.

MaierMP,QiuS,ElsnerM.2013.EnantioselectiveStableIsotopeAnalysis(ESIA)ofpolarherbicides.AnalBioanalChem405:2825‐2831.

MeyerAH,ElsnerM.2013.C/CandN/Nisotopeanalysistocharacterizedegradationofatrazine:Evidencefromparentanddaughtercompoundvalues.EnvironSciTechnol47:6884‐6891.

Qiu S, Gözdereliler E,Weyrauch P, Lopez ECM, Kohler H‐PE, Sørensen SR, Meckenstock RU, Elsner M.2014.SmallC/Cfractionationcontrastswithlargeenantiomerfractionationinaerobicbiodegradationofphenoxyacids.EnvironSciTechnol48:5501‐5511.

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Hydrodynamic Parameter Estimation of 1D and 2D Axial Sym‐metricTransportSimulationsandConsequencesFortheReactiveTransportJohanna Lippmann‐Pipke1, Christin Stuhlfauth1,2, Holger Lippold1, Johannes Kulenk‐ampff1,FriederEnzmann2andLaurinWissmeier31InstituteofResourceEcology,HZDRResearchSiteLeipzig,Germany2InstituteforGeosciences,JohannesGutenbergUniversity,Mainz,Germany3AFConsult,Baden,SwitzerlandWith1Dandaxialsymmetric2Dfiniteelementsimulationsoftracertransportinporousmediacolumns,weconductedsystematic studiesof increasingheterogeneityon the resultingbreak‐throughcurves(BTC).WhilepreferentialflowcanstillhavecomparablylittleeffectontheBTCof non‐reactive tracer substances, for strongly adsorbing tracer preferential flow can signifi‐cantly shift the break‐through towards earlier arrival times by reducing the reactive surfacearea.MotivationforconductingthissystematicsimulationstudyisouruniqueGeoPETmethod(PositronEmissionTomography)thatallowsthevisualizationofthespatio‐temporaltracerdis‐tributioningeologicmedia(Richteretal.,2000;Gründigetal.,2007;Kulenkampffetal.,2008).The real complexity of thus directly observed flow fields is always surprising. Even for non‐reactivetracersquantitativetransportsimulationstypicallyremainachallengeduetotheneedfordetailedknowledgeofhydrodynamicparametervalues in3Dwithacertaincritical spatialresolution.HereweshowsimulationresultsobtainedbytheCOMSOLMultiphysicscodecoupledwith PHREEQC (Wissmeier and Barry, 2011) and compare them with measurement results(BTC)fromreactivetransport(herbicideMCPAongoethite/sand).CD‐MUSICadsorptionmodelparameterwereobtainedfromKerstenetal.,(2014).Theunderlyingstructuralheterogeneityofthe simulated column experiments reflects preferential flow along the column boundariescausedbylocallyelevatedpermeabilityinotherwisehomogeneoussandpackingasverifiedbytheGeoPETimagesfrombothconservativeandreactivetracerexperiments.ReferencesGründigM,RichterM,SeeseA,SabriO.,2007.Tomographicradiotracerstudiesofthespatialdistribution

ofheterogeneousgeochemicaltransportprocesses.Appl.Geochem.22:2334‐2343.Kersten M, Tunega D, Georgieva I, Vlasova N. 2014. Surface complexation modeling of herbicide

adsorption by goethite: 1. 4‐chloro‐2‐methylphenoxyacetic acid (MCPA). Environ. Sci. Technol.submitted.

KulenkampffJ,GründigM,RichterM,EnzmannF.2008.Evaluationofpositronemissiontomographyforvisualisationofmigrationprocessesingeomaterials.Phys.Chem.Earth33:937‐942.

Richter M, Gründig M, Butz T. 2000. Tomographische Radiotracerverfahren zur Untersuchung vonTransport‐ und Sorptionsprozessen in geologischen Schichten. Zeitschrift für Angewandte Geologie,46(2):101.

WissmeierL,BarryDA,2011.Simulationtoolforvariablysaturatedflowwithcomprehensivegeochemicalreactionsintwo‐andthree‐dimensionaldomains.Environ.Modell.Softw.26:210‐218.

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ToWhatExtentDoesWaterContentNexttoPreferentialFlowPathInfluenceColloidRetentioninStructuredSoils?RomainvandenBogaert1,2,3,EricMichel1,2,LoÿsMesnier1,2andSophieCornu31INRA,UMR1114EMMAH,Avignon,France2UAPV,UMR1114EMMAH,Avignon,France3INRA,UR1119GSE,AixenProvence,FranceColloidalparticlescanfacilitatethetransferthroughthevadosezoneofadsorbedcontaminantsorbethemselvescontaminants(e.g.bacteria,viruses).Mechanismsleadingtocolloidretentionhavebeenthoroughlystudied,essentiallyinhomogeneousmodelsoils(sand,glassbeads).How‐ever,resultsofthesestudiescannotbetransposeddirectlytoundisturbedsoils,whenpreferen‐tial flowoccurs through a small number ofmacropores, bypassingmost of the soilmatrix. Inthesesoils,colloidretentionhasreceivedascarceattention,andisstillpoorlyunderstoodandmodeled.Ina2009study,Ceyetal. (2009)showedthatparticleswereretained(i) inthefirstfewcentimetersbelowsoilsurface,(ii)atthemacroporewalls,and(iii)intheimmediatevicin‐ityofthemacropores.Thematrixpotentialgradientbetweenactivemacroporesandtheneigh‐boring soilmatrixdriveswater redistribution from thesemacropores towards thematrix.Wehypothesized that the retentionpatternobservedbyCeyetal. (2009) is causedby thiswaterredistribution.Wetestedthishypothesisandquantifiedtheimportanceofthisretentionprocessperformingsuccessiveandidenticalrainfallsontoundisturbedsoilcores.Tovarythewatercon‐tentof thematrixnext toactivemacropores, rainfallswereseparatedbyrain interruptionsofincreasingdurations(5to1200hours).Therainwatercontainedfluorescentmicrospheresdyedwithadifferentfluorophoreforeachrainfall.Microsphereconcentrationintheeffluentsandthenumberfractionofthesemicrospheresadsorbedtonaturalsoilcolloidswereanalyzedbyflowcytometry.Wefoundthatduringarainfalloccurringaftera5hourspause,45%ofthemicro‐sphereswere retained in the core. This fraction increasedwithpauseduration for the subse‐quenteventsuntilitbecameconstant(70%)forrainsoccurringafterinterruptionslongerthan350hours.Between0,2and1%ofmicrospheresretainedduringrainfallnwererecoveredintheeffluentsofrainfalln+1,and10to45%ofthemwereadsorbedtonaturalsoilparticles;recoveryand association to soil particles being inversely (respectively directly) correlated with pausedurationbeforerainn.Inthiscontribution,wewillproposeanddiscussaretentionmechanismcompatible with these experimental results, as well as the requirements to implement it inanumericalcolloidfatemodel.Wewillalsodiscussthebenefitsofflowcytometrytoinvestigatecolloidfateinsoils.AcknowledgementThisresearchwasfundedbytheANR10Blanc605‐AgripedprojectReferenceCey EE, Rudolph,DL, Passmore J. 2009. Influence of macroporosity on preferential solute and colloidtransportinunsaturatedfieldsoils.JContamHydrol107:45–57.

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EffectofBacterialbiofilms(ExtracellularPolymericSubstances)inGeosorbentsMobilityandReactivitySnehaPradipNarvekarandKaiUweTotscheChairofHydrogeology,InstituteofGeosciences,Friedrich‐Schiller‐UniversitätJena,Jena,GermanyBiofilmsandtheircomponentareoneoftheimportantcomponentsofthesoil,andalsothesoilorganicmatterpool.They impactvarious soilproperties like soil architecture,mineral forma‐tionsanddissociationsetc.TheaimofourworkistostudytheeffectofbiofilmsonthecolloidaltransportofnaturalgeosorbentslikeFe‐andMn‐oxyhydroxidesthatcanleadtoleadtomobilityandsolubilityofnutrientsandpollutant.Themobilityoftheseparticlesismainlydependentoncolloidal stability and aggregation of these particles, which in turn is affected by pH, ionicstrength,andthepresenceions.BiofilmsandEPScanalterthephysicalandcolloidalpropertiesofgeosorbentsbyredoxeffectsoralsobyproducingcompoundslikeacidsandalkalis.BiofilmandEPSmayalso interactwith theporousmaterialalteringthetransportofgeosorbents.EPSanditscomponentsareknowntoformcoatingofsubμmspacedprotein‐richandlipid‐richdo‐mainswithironoxidewhichwillaffectadsorptionandco‐precipitation(Liuetal.,2013).Inthisstudyweusedcolumnexperimentstostudythemobilityofhematitenanoparticlesthroughbio‐filmcoatedporousmediacolumns.EPScoatedporousmediawasalsostudied.Theporousme‐diawascoatedwithBacillussubtillisbiofilmandwithEPSextractedfrom,liquidculturesofBa‐cillus subtillis.Theattachment efficiencyof glassbeads coatedwithbiofilmsdecreasedsignifi‐cantlyfrom21.03x10‐3to5.36x10‐3oncoatingwithbiofilm.HematitewascolloidallystableandmobileinEPSandbiofilmcoatedporousmedia,whereasuncoatedporousmedia,hematitena‐noparticleslooseitscolloidalstabilityandaredepositedontheporousmedia.Alsothezetapo‐tentialofhematitechangesfrompositivevaluestonegativevaluesindicatingcoatingofhematitenanoparticleswithEPS. The reactivity of hematiteparticles to theporousmedium is reducedduetothemaskingofthereactivesurfacesitesontheporousmediawithEPS.AlsothereactivesiteonhematitemaybealteredbyEPSdepositions.EPSalsoleadstoremobilizationofsorbedhematite.8%ofsorbedhematitewasremobilizedbyEPS.ReferencesLiuX,EusterhuesK,ThiemeJ,CiobotaV,HöschenC,MuellerCW,KüselK,Kögel‐KnabnerI,RöschP,PoppJ,TotscheKU.2013.STXMandNanoSIMSInvestigationsonEPSFractionsbeforeandafterAdsorptiontoGoethite.EnvironSciTechnol47:3158‐3166.

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AdsorptionofPbbyNa‐BentoniteandAl‐PillaredBentoniteinthePresenceofOrganicAcidsLeonidPerelomov1,MahmudRahman2,BinoySarkar2,KristinaSyundyukova1andRavendraNaidu21TulaStateUniversity,Tula,Russia2CERAR,UniversityofSouthAustralia,MawsonLakescampus,Adelaide,AustraliaTherehavebeenvariousattemptstoimprovethequalityandsorptioncharacteristicsofclaysbymodifyingthemwithdifferenttechniques.Oneofcommontechniquesinthisregardisintercala‐tionandpillaring.However,theinteractionsofthemetalsandpillaredclaysintheenvironmentmaydifferfromthatpredictedbylaboratoryexperimentsbecauseofthepresenceofavarietyofinorganic and especially organic ions in natural solutions.Adsorption of Pb in the absence orpresenceoflowmolecularorganicacidswithdifferentfunctionalgroups:citricandlysineontoaNa‐bentonite andAl‐pillaredbentonite at the increasing concentrationsof the organic acidsandvarioussequencesofadditionofthetraceelementandtheorganicsubstanceswasstudied.OurdatashowsthatNaformofbentoniteismoreeffectivesorbentforPbthanAlpillaredben‐tonite.DuringsorptionexperimentsfinalpHincreasedsufficiently,butathighthemetalconcen‐trationinlowerextentthatshowsthepresenceofionexchangemechanism.AdsorptionofPbbyNaformofbentonitewasstronglyaffectedbycitricacid.TheamountofPbfixedbyNaformofbentonitedecreasedfrom174mmolkg‐1intheabsenceoftheorganicligandupto18mmolkg‐1atsimultaneousadditionofcitricacidandpracticallyzeroadsorptioninthecaseofpreliminaryadditionoftheacidatacid/metalratio8/1.CitricacidslightlychangedadsorptionofPbbyAl‐pillaredbentonite.AtadsorptionofPbonNabentonite in thepresenceofcitricacidaddedasmixtureorpreliminarypHdecreasedwithincreasingofcitricacidconcentrations.AtadsorptionbyAl‐pillaredbentonitepHinitiallyrise(uptomolarratio2/1)andthendecreased.However,pH changes practically don’t connectwith Pb adsorption. Our data shows strong competitionbetweenPbandcitricanionforadsorptionsitesofNabentoniteandcompletelydifferentmech‐anismofPbandcitricacidadsorptionontheAl‐pillaredbentonite.DuringexperimentwithAl‐pillaredbentonitehighamountofAlwasreleasedthatshowsnotstablestructureofthepillaredmaterial.Lysineisbasicpolaraminoacidwithisoelectricpoint(IEP)at9,7.AtpHbelowofIEPithaspositivecharge.However,whenweaddPbandlysinesimultaneouslytoNabentoniteandAlpillaredbentonite itpracticallydoesnotaffectPbadsorptionatany lysineconcentrations(ex‐ceptslightchangesathighestrations)thatshowstheiroccupationofdifferentsorptionsitesoftheminerals.Lysineadditionstwohoursbeforethemetaldecreaseleadadsorptionatratio1/1andthenslightlyincreaseatratio8/1forAl‐pillaredbentoniteonly.Thisdecreasingmayillus‐trateamountofsorptionsitesfornonspecificadsorptionofthemetalandorganicligand.FinalpHdoesnotdependfromPbdoses(exceptR=8/1forNabentonite)andwaslowerinthecaseoffirstacidadditionforbothmineralSoreactionsbetweentraceelementsandnaturalandmodi‐fiedclaymineralsinsoilsareaffectedbymanyfactors,suchaspHofsoilsolution,presenceandconcentrationoforganic ligands, includinghumicand fulvicacid,rootexudates,microbialme‐tabolitesandnutrients.

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IndicationsForanAlternativeSorptionMechanismFortheBind‐ingofAcetatetoGoethiteThomasWachandKaiUweTotscheInstituteofGeosciences,FriedrichSchillerUniversityofJena,Jena,GermanySorptionisoneofthemajorprocessesthatcontributetothe"filterfunction"ofsoil.Athoroughunderstandingofthemechanismsbehindsorptionistherebythebasisfordesignofappropriate,efficientandsite‐specificclean‐upandremediationstrategies. In thisstudyweexplore the in‐teractionof thecarboxylicmoiety frequentlywithgoethite,asecondary ironphaseofprimaryimportance innaturalporousmedia like soil, sediments andaquifers.The carboxylic group isnotonly frequently found ina largenumberofnaturalandanthropogenicorganicsubstances,but is known to compete with a large variety of inorganic pollutants including toxic metals,therebyaffectingmobilizationandtransport.Asmodelorganicsoluteweuseacetateasitper‐sistsboth inprotonatedanddeprotonatedstatesatenvironmentallyrelevantpH‐values.Sorp‐tionwasexploredwithbothbatchandcolumntechniques,therebytakingintoaccounttheim‐portantroleofthesolid/liquidratiofortheextentofsorption(Wangetal.,2009).WeinterpretourresultsandthepH‐dependentadsorptionofacetatetogoethiteaspresentedbyNorénandPersson (2007)withacooperative innersurfacecomplexationof theacetate/aceticacidcom‐plextodifferenthydroxo‐groupsofthegoethite.Basedonthesefindings,asorptionmodelhasbeendevelopedtakesintoaccounttheS/L‐ratio,also.WetestedtheperformanceofourmodelwiththedataofNorénandPersson(2007).Wewerealsoabletosuccessfullydescribethefind‐ingsontheattachmentofcarbonate(VillalobosandLeckie,2000;Rahnemaieetal.,2007)andMCPA(Iglesiasetal.,2010),respectively,tothegoethitesurface.BasedonthatwehypothesizethatbothcarbonatesandMCPAadsorbaccordingtothesameadsorptionmechanism.Thisim‐plies that this adsorptionmechanismmay be general important for the adsorption of soluteswith carboxylicmoieties to surfaces providing hydroxo‐groups, likemanganese or aluminiumoxides.References:Aquino A J A, TunegaD, Haberhauer G, GerzabekMH, LischkaH. 2007. Quantum Chemical AdsorptionStudiesonthe(110)SurfaceoftheMineralGoethite.J.Phys.Chem.C111:877‐885.

IglesiasA,LópezR,GondarD,AnteloJ,FiolS,ArceF.2010.AdsorptionofMCPAongoethiteandhumic‐acidcoatedgoethite.Chemosphere78:1403‐1408.

NorénK,PerssonP.2007.Adsorptionofmonocarboxylatesat thewater/goethite interface:The impor‐tanceofhydrogenbonding.Geochim.Cosmochim.Ac.71:5717‐5730.

RahnemaieR,HiemstraT,vanRiemsdijkWH.2007.Carbonateadsorptionongoethiteincompetitionwithphosphate.J.ColloidInterf.Sci.315/2:415‐425.

VillalobosM,Leckie JO.2000.CarbonateadsorptionongoethiteunderclosedandopenCO2conditions.Geochim.Cosmochim.Ac.64/22:3787‐3802.

WangT‐H,LiM‐H,TengS‐P.2009.Bridgingthegapbetweenbatchandcolumnexperiments:AcasestudyofCsadsorptionongranite.J.Hazard.Mater.161:409‐415.

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ListofParticipants

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ACHTENHAGEN,JanDepartmentofEnvironmentalBiotechnologyHelmholtzCentreforEnvironmentalResearch‐UFZPermoserstr.15,04318LeipzigGermanyBABIN,DoreenInstituteforEpidemiologyandPathogenDiagnosticsFederalResearchCenterforCultivatedPlants‐JuliusKühnInstituteMesseweg11/12,38104BraunschweigGermanyBACHMANN,JörgInstituteofSoilScienceGottfriedWilhelmLeibnizUniversityofHannoverHerrenhäuserStr.2,30419HannoverGermanyBAVEYE,PhilippeDepartmentofCivilandEnvironmentalEngineeringRensselaerPolytechnicInstitute1108thstreet,NewYorkTroyUnitedStatesBERTMER,MarkoInstituteforExperimentalPhysicsUniversityofLeipzigLinnestr.5,04103LeipzigGermanyBORISOVER,MikhailInstituteofSoil,WaterandEnvironmentalSciencesAgriculturalResearchOrganizationTheVolcaniCenterPOB6,50250BetDaganIsraelBRAX,MathildeInstituteforEnvironmentalSciencesUniversityofKoblenz‐LandauFortstr.7,76829LandauGermany

BUCHMANN,ChristianInstituteforEnvironmentalSciencesUniversityofKoblenz‐LandauFortstr.7,76829LandauGermanyCAI,PengHuazhongAgriculturalUniversityShizimountainstreetNo.1430070WuhanChinaCARSTENS,JannisFlorianInstituteofSoilScienceHerrenhaeuserStr.2,30419HannoverGermanyCEPÁKOVÁ,ŠárkaInstituteofSoilBiologyNaSádkách737005ČeskéBudějoviceCzechRepublicCHENU,ClaireAgroParisTechAv.deBrétignières78850Thiverval‐GrignonFranceDALLAVALLE,NicolasInstituteforBiogeochemistryMaxPlanckInstituteHandKnöllStr.10,07745JenaGermanyDALLINGER,AnjaDepartmentofEcologicalMicrobiologyUniversityofBayreuthDr.Hans‐Frisch‐Str.1‐3,95440BayreuthGermanyDATHE,AnnetteDepartmentofPlantandEnvironmentalSciencesNorwegianUniversityofLifeSciencesEkebergveien22,1440DrøbakNorway

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DECHESNE,ArnaudDepartmentofEnvironmentalEngineeringTechnicalUniversityofDenmarkMiljoevej,2100Kgs.LyngbyDenmarkDIEHL,DörteInstituteofEnvironmentalSciencesEnvironmentalandSoilChemistryUniversityofKoblenz‐LandauFortstr.7,76829LandauGermanyDITTERICH,FranziskaInstituteofSoilScienceandLandEvaluationUniversityofHohenheimEmil‐Wolff‐Str.27,70593StuttgartGermanyDOETTERL,SebastianDepartmentofAppliedAnalyticalandPhysicalChemistryISOFYS–IsotopeBioscienceLaboratoryCoupureLinks653,9000GentBelgiumDU,HuihuiHuazhongAgriculturalUniversityShizishanNo.1,HongshanDistrict,430070WuhanChinaEICKHORST,ThiloTheFacultyofBiology/ChemistryUniversityofBremenLeobenerStr./UFT0530,28359BremenGermanyVANELSAS,JanDirkDepartmentofMicrobialEcologyUniversityofGroningenNijenborgh7,9747AGGroningenTheNetherlandsELSNER,MartinInstituteofGroundwaterEcologyGermanResearchCenterfor

EnvironmentalHealthHelmholtzCentreMunichIngolstädterLandstraße185764NeuherbergGermanyFLAVEL,RichardDepartmentofAgronomySoilScienceUniversityNewEngland2351Armidale,NSWAustraliaGHANEM,NawrasDepartmentofEnvironmentalMicrobiologyHelmholtzCenterforEnvironmentalResearch‐UFZPermoserstr.15,04318LeipzigGermanyGÖBEL,Marc‐OliverInstituteofSoilScienceWilhelmLeibnizUniversityofHannoverHerrenhäuserStr.2,30419HannoverGermanyHABERHAUER,GeorgInstituteofSoilResearchUniversityofNaturalResourcesandLifeSciencesPeter‐Jordan‐Str.70,1190ViennaAustriaHANZEL,JoannaDepartmentofHydrogeologyFriedrichSchillerUniversityofJenaBurgweg11,07749JenaGermanyHARMS,HaukeDepartmentofEnvironmentalMicrobiologyHelmholtzCentreforEnvironmentalResearch‐UFZPermoserstr.15,04318LeipzigGermany

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HEISTER,KatjaChairofSoilScienceTechnischeUniversitätMünchenEmil‐Ramann‐Str.2,85354Freising‐WeihenstephanGermanyHEMKEMEYER,MichaelJohannHeinrichvonThünenInstituteBundesallee50,38116BraunschweigGermanyHORN,MarcusA.DepartmentofEcologicalMicrobiologyUniversityofBayreuthDr.Hans‐Frisch‐Str.1‐3,95440BayreuthGermanyHUANG,QiaoyunHuazhongAgriculturalUniversityShizishanNo.1,430070WuhanChinaJÄGER,AlexInstituteforExperimentalPhysicsUniversityofLeipzigLinnestr.5,04103LeipzigGermanyJILKOVÁ,VeronikaInstituteofSoilBiologyASCRNaSádkách737005ČeskéBudějoviceCzechRepublicKAISER,MichaelTheFacultyofOrganicAgriculturalSci‐encesUniversityofKasselNordbahnhofstr.1a37213Witzenhausen,GermanyKALTENBACH,RobinInstituteofEnvironmentalSciencesEnvironmentalandSoilChemistryUniversityofKoblenz‐LandauFortstr.7,76829LandauGermany

KANDELER,EllenInstituteofSoilScienceandLandEvaluationUniversityofHohenheimEmil‐Wolff‐Str.27,70593StuttgartGermanyKÄSTNER,MatthiasDepartmentEnvironmentalBiotechnologyHelmholtzCentreforEnvironmentalResearch‐UFZPermoserstr.15,04318LeipzigGermanyKELLEHER,BrianSchoolofChemicalScienceDublinCityUniversity9GLASNEVINIrelandKHAN,FaisalInstituteofGeosciencesJohannesGutenbergUniversityBecherweg21,55099MainzGermanyKIESEL,BärbelDepartmentofEnvironmentalMicrobiologyHelmholtzCentreforEnvironmentalResearch‐UFZPermoserstr.15,04318LeipzigGermanyKOLB,SteffenDepartmentofEcologicalMicrobiologyUniversityofBayreuthDr.‐Hans‐Frisch‐Str.1‐395448BayreuthGermanyKOWALCHUCK,GeorgeDepartmentofMicrobialEcologyNetherlandsInstituteofEcologyP.O.Box506700ABWageningenTheNetherlands

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KÖGEL‐KNABNER,IngridChairofSoilScienceTechnischeUniversitätMünchenAmHochanger2,D‐85350Freising‐WeihenstephanGermanyKÖNIG,ClaudiaInstituteforRadioecologyandRadiationProtectionLeibnizUniversitätHannover,IRSHerrenhäuserStr.2,30419HannoverGermanyKRÜGER,JaaneInstituteofSoilScienceandForestNutritionUniversityofFreiburgBertodlstr.17,79085FreiburgGermanyKUBICKI,JamesDepartmentofGeosciencesPennState335DeikeBuildingUniversityPark,PA16802UnitedStatesKUČERIK,JiříInstituteofEnvironmentalSciencesEnvironmentalandSoilChemistryUniversityofKoblenz‐LandauFortstr.7,76829LandauGermanyLANG,FriederikeInstituteofSoilScienceandForestNutritionUniversityofFreiburgBertodlstr.17,79085FreiburgGermanyLEHMANN,RobertDepartmentofHydrogeologyFriedrichSchillerUniversityofJenaWöllnitzerStr.7,07749JenaGermany

LEHOUX,AlizeeINRA228routedel'aerodrome,CS4050984914Avignoncedex9FranceLIPPMANN‐PIPKE,JohannaInstituteofRadiochemistryReactiveTransportDivisionResearchCentreDresden‐RossendorfPermoserstr.15,04318LeipzigGermanyLIU,XingHuazhongAgriculturalUniversityShizishan1st,430070WuhanChinaMA,WentingHuazhongAgricultureUniversityShizishan1st,430070WuhanChinaMATTHIES,MichaelInstituteforEnvironmentalSystemSciencesUniversityofOsnabrückBarbarastr.12,49076OsnabrückGermanyMICHEL,EricINRA228routedel'aerodrome,CS4050984914Avignoncedex9FranceMILANOVSKIY,EvgenyLomonosovMoscowStateUniversityLeninskieGory,119991MoscowRussianFederationMILTNER,AnjaDepartmentEnvironmentalBiotechnologyHelmholtzCentreforEnvironmentalResearch‐UFZPermoserstr.15,04318LeipzigGermany

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MOGUSU,EmmanuelInstituteofGroundwaterEcologyGermanResearchCenterforEnvironmentalHealthHelmholtzCentreMunichIngolstädterLandstraße185764NeuherbergGermanyMUNCH,JeanCharlesChairforSoilEcologyTechnischeUniversitätMünchenIngolstädterLandstr.185758OberschleißheimGermanyKUNHIMOUVENCHERY,YamunaDepartmentofChemistryNSSCollegeManjeri(UniversityofCalicut)Malappuram,KeralaIndiaNANNIPIERI,PaoloDepartmentofPlant,SoilandEnvironmentalSciencesUniversityofFlorence28PiazzaledelleCascine,50144FlorenceItalyNAPOLI,RosarioCRA‐ResearchCentreoftheSoil‐PlantSystemViadellaNavicella2‐4,00184RomaItalyNARR,AnjaDepartmentofEnvironmentalMicrobiologyHelmholtzCentreforEnvironmentalResearch‐UFZPermoserstr.15,04318LeipzigGermanyNARVEKAR,SnehaDepartmentofHydrogeologyFriedrichSchillerUniversityofJenaWöllnitzerStr.7,07749Jena,Germany

NIESSNER,ReinhardInstituteforHydrochemistryTechnischeUniversitätMünchenMarchioninistr.17,81377MunichGermanyNUNAN,NaoiseUMR7618CNRS‐ENSPARADISIPaola46rued'Ulm,75005PARISFranceONDRUCH,PavelInstituteofEnvironmentalSciencesEnvironmentalandSoilChemistryUniversityofKoblenz‐LandauFortstr.7,76829LandauGermanyOOSTENBRINK,ChrisInstituteofMolecularModelingandSimulation(MMS)Muthgasse18,1190WienAustriaOR,DaniSoilandTerrestrialEnvironmentalPhysicsETHZürichUniversitätstrasse16CHNF29.1,8092ZürichSwitzerlandO’ROURKE,SharonUSdyDepartmentofEnvironmentandAgricultureUniversityofSydneyRm116A,Level1,BiomedicalBuilding1CentralAvenue,ATP,EveleighNSW2006SydneyAustraliaOSWALD,SaschaInstituteofEarthandEnvironmentalScienceUniversityofPotsdamKarl‐Liebknecht‐Str.24‐2514476PotsdamGermany

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OTTO,SallyDepartmentofEnvironmentalMicrobiologyHelmholtzCentreforEnvironmentalResearch‐UFZPermoserstr.15,04318LeipzigGermanyPAGEL,HolgerInstituteofSoilScienceandLandEvaluationUniversityofHohenheimEmil‐Wolff‐Str.27,70593StuttgartGermanyPEDERSEN,LasseLuTechnicalUniversityofDenmarkMiljøvej113,building1152800Kgs.LyngbyDenmarkPERELOMOV,LeonidTulaStateUniversityLeninavenue,92,300012TulaRussianFederationPINZARI,FlaviaConsiglioperlaRicercaelasperimen‐tazioneinAgricolturaCentrodiRicercaperlostudiodellerelazionitrapiantaesuoloCRA‐RPSViadellaNavicella2‐4,00184RomeItalyPOHL,LydiaDepartmentofHydrogeologyFriedrichSchillerUniversitätJenaWöllnitzerStraße7,07749JenaGermanyPOLL,ChristianInstituteofSoilScienceandLandEvaluationUniversityofHohenheimEmil‐Wolff‐Str.27,70593StuttgartGermany

PRONK,J.GeertjeChairofSoilScienceTechnischeUniversitätMünchenEmil‐Ramann‐Straße2,85354Freising‐WeihenstephanGermanyPROSSER,JamesInstituteofBiologicalandEnvironmentalSciencesUniversityofAberdeenStMacharDrive,AberdeenAB24UUUnitedKingdomRAYNAUD,XavierSorbonneUniversités,UPMC‐Paris646rued'Ulm,75230ParisFranceRAZAVIDEZFULY,BaharsadatDepartmentofAgriculturalSoilScienceGeorgAugustUniversityGöttingenBüsgenweg2,37077GöttingenGermanyREICHEL,KatharinaDepartmentofHydrogeologyFriedrichSchillerUniversityofJenaWöllnitzerStr.7,07749JenaGermanyRIEBE,BeateInstituteforRadioecologyandRadiationProtectionLeibnizUniversitätHannover‐IRSHerrenhäuserStr.2,30419HannoverGermanyRITSCHEL,ThomasDepartmentofHydrogeologyFriedrichSchillerUniversityofJenaWöllnitzerStr.7,07749JenaGermanyRITZ,KarlEnvironmentalScienceandTechnologyDepartmentSchoolofAppliedSciences

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CranfieldUniversityNationalSoilResourcesInstituteCranfield,BedfordshireMK34OalUnitedKingdomRUDOLPH‐MOHR,NicoleInstituteofEarthandEnvironmentalScienceUniversityofPotsdamKarl‐Liebknecht‐Str.24‐2514476PotsdamGermanySANAULLAH,MuhammadInstituteofSoilScienceGeorg‐August‐UniversitätGöttingenBüsgenweg2,37077GöttingenGermanySCHAAF,WolfgangBTUCottbus‐SenftenbergKonrad‐Wachsmann‐Allee603046CottbusGermany

SCHAUMANN,GabrieleE.InstituteforEnvironmentalSciencesEnvironmentalandSoilChemistryUniversityofKoblenz‐LandauFortstr.7,76829LandauGermanySCHÄFER,SabineDepartmentofHydrogeologyFriedrichSchillerUniversityofJenaWöllnitzerStr.7,07749JenaGermanySCHÄFFER,AndreasInstituteforEnvironmentalResearch(BiologyV)EnvironmentalBiologyandChemodynamicsRWTHAachenUniversityWorringerweg1,52074AachenGermanySCHMIDT,SonjaAbertayUniversity40BellStreet

DD11HGDundee,UnitedKingdomSCHMIDT,OlafUniversityCollegeDublinSchoolofAgricultureandFoodScienceDublin4,DublinIrelandSCHLOTER,MichaelChairforSoilEcologyTechnischeUniversitätMünchenIngolstädterLandstr.185758OberschleißheimGermanySCHURING,ChristianTechnischeUniversitätMünchenWTT/EnvironmentalBiotechnologyEmil‐Ramann‐Str.2,85354Freising‐WeihenstephanGermanySCHWEIGERT,MichaelDepartmentEnvironmentalBiotechnologyHelmholtz‐CentreforEnvironmentalResearchPermosserstr.15,04318LeipzigGermanySHEIN,EvgenyLomonosovMoscowStateUniversityLeninskieGory119991MoscowRussianFederationSENESI,NicolaDepartmentofAgroforestalandEnvironmentalBiologyandChemistryUniversityofBari,70126BariItalySMALLA,K.InstituteforEpidemiologyandPathogenDiagnosticsFederalResearchCenterforCultivatedPlants‐JuliusKühnInstituteMesseweg11/12,38104BraunschweigGermany

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SMETS,BarthDepartmentofEnvironmentalEngineeringTechnicalUniversityofDenmarkAnkerEngelundsVej1/Building1152800KongensLyngbyDenmarkSCHMITZ‐MÖLLER,PatriciaGermanResearchFoundationLebenswissenschaften1,53170BonnGermanySMRECZAK,BożenaInstituteofSoilScienceandPlantCultivationStateResearchInstituteCzartoryskich8,24‐100PulawyPolandSMUCKER,AlvinDepartmentofCropandSoilScienceMichiganStateUniversityEastLansingMI48824‐1325UnitedStatesŠOLC,RolandInstituteofSoilResearchDepartmentofForestandSoilSciencesUniversityofNaturalResourcesandLifeSciencesViennaPeter‐Jordan‐Str.82,1190ViennaAustriaSTEINBACH,AnnelieDepartmentofEnvironmentalMicrobiologyHelmholtzCentreforEnvironmentalResearch‐UFZPermoserstr.15,04318LeipzigGermanySTRECK,ThiloInstituteofSoilScienceandLandEvaluationUniversityofHohenheimEmil‐Wolff‐Str.27,70593Stuttgart

GermanyTANUWIDJAJA,IrinaResearchUnitofEnvironmentalGenomicsTechnischeUniversitätMünchenIngolstädterLandstr.185764NeuherbergGermanyTIGHE,MatthewUniversityofNewEnglandRingRoad2351ArmidaleAustraliaTEBBE,ChristophC.JohannHeinrichvonThünenInstituteBundesallee50,38116BraunschweigGermanyTHIEL,EnricoSKWStickstoffwerkePiesteritzGmbHMöllensdorferStraße1306886LutherstadtWittenbergGermanyTOTSCHE,KaiUweDepartmentofHydrogeologyFriedrichSchillerUniversityofJenaBurgweg11,07749JenaGermanyTUNEGA,DanielInstituteofSoilResearchDepartmentofForestandSoilSciencesUniversityofNaturalResourcesandAppliedLifeSciencesPeter‐Jordan‐Str.82,1190ViennaAustria WACH,ThomasDepartmentofHydrogeologyFriedrichSchillerUniversityofJenaWöllnitzerStr.7,07749JenaGerman

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WATTEAU,FrancoiseLaboratoireSolsetEnvironnement2avenuedelaforetdeHayeTSA4060254518Vandoeuvre‐les‐Nancy,FranceWICK,Lukas,Y.DepartmentofEnvironmentalMicrobiologyHelmholtzCentreforEnvironmentalResearch‐UFZPermoserstr.15,04318LeipzigGermanyWIECZOREK,AdamDepartmentofEcologicalMicrobiologyUniversityofBayreuthDr.‐Hans‐Frisch‐Str.1‐3,95448BayreuthGermanyWOCHE,SusanneK.InstituteofSoilScienceWilhelmLeibnizUniversityofHannoverHerrenhäuserStr.2,30419HannoverGermanyWUTZLER,ThomasInstituteforBiogeochemistryMaxPlanckInstituteHandKnöllStr.10,07745JenaGermanyVOELKNER,AmreiInstituteofPlantNutritionandSoilScienceHermann‐Rodewald‐Str.2,24118KielGermanyVOGEL,Hans‐JörgDepartmentofSoilPhysicsHelmholtzCentreforEnvironmentalResearch‐UFZTheodor‐Lieser‐Straße406120Halle(Saale)GermanyYOUNG,IainM.SchoolofEnvironmentalandRuralSciencesNaturalResourcesUniversityofNewEngland

BilduingW55ArmidaleNSW2351AustraliaZÜHLKE,SebastianInstituteofEnvironmentalResearchFacultyofChemistry(INFU)DortmundUniversityofTechnologyOtto‐Hahn‐Str.6,44227DortmundGermany

spp1315 the book of abstracts 2014 · biological, physical and chemical properties of the bgi. a...

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