Abstract
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 language | English |
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Pages (from-to) | 527-538 |
Journal | Continental Shelf Research |
Volume | 31 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2011 |