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Modelingtheeffectofbiotaonsedimentdynamicsisadifficulttask.Inthispaperwere-analyze experimentalresultsof Willows etal.(1998) on theeffectsof Macoma balthica on sedimenterosion. A process-basedframeworkisproposed,fullycompatiblewithaphysicaldescriptionoferosionprocesses in caseofnobiogenicinfluences.Thebedisrepresentedbyaflufflayerontopofasubstrate.Acharacteristic featureoftheframeworkisthatthesedimentisrepresentedbyaprobabilitydensitydistributionforthe criticalshearstress,allowingforTypeIandTypeIIerosion. M. balthica increasesthesedimentmassinthe fluff layer.Thisincreaseisdeterminedbyconsideringtheactionradius,theoverlapoffeedingareas,and the feedingrateperanimal.Thecalibratedactionradiusandfeedingratewereintherangeasfoundinthe literature.Thedistributionofsedimentovertheerodibilityclassesandtheerosionrateparameterare hardly influencedatall.Duetooverlappingfeedingareas,theeffectisnon-linearwithdensityofthe animals.Themodelresultsareincloseagreementwiththemeasuredresults,suggestingthatnofurther formulationsofbiologicaleffectsareneededtosimulatetheexperimentsof Willows etal.(1998). In nature,othereffectslikedisruptingthebiofilmbygrazingcanbeofimportanceandshouldbeincludedin a laterstage.Thisstudyemphasizesthecrucialroleofsedimentavailabilityandtheeffectofbiotaonit. This aspectneedsmoreattentioninfutureexperiments.Theproposedmodelturnedouttoworkwellfor the effectsof M. balthica and offersopportunitiestoincludeotherbiogeniceffectsinaprocess-basedway as well.
Original languageEnglish
Pages (from-to)527-538
JournalContinental Shelf Research
Volume31
Issue number6
DOI
StatePublished - 2011

ID: 136599