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8|TeroleofbeaversintheHolocenelandscapeevolutionofthesmallrivervalleys
huntsontheterritoriesunderhisrule.Atthattime,theofceofbeaverhunt
master(so-calledcastorarius),whosupervisedtheterritoriesinhabitedby
theseanimals,wasestablished.InPolandthepopulationofbeavershassur-
vivedtothesedaysinspiteofthefactthatinthe1950stherewereonly130of
them.Now,theirnumberisestimatedatmorethan130thousand.
DuetotherelativelyearlydecreaseinthepopulationofCastorfberin
manyregionsinEuropeitwasforgottenthatinthepasttheEuropeanbeaver
wasaninseparableelementoftheHolocenebiomeoftheEuropeanforests
andhadasignificantimpactonthewaterregimeinthecatchmentsofthis
zone.InPoland,despitetherecentpublicationofworksontheefectsofthe
present-dayexpansionoftheserodents,thereisstillnointerestinhowthey
shapedthehistoricalimageofthevalleysintheHolocene.Tofillthisgap,it
isnecessarytoprovokediscussionaboutefectivemethodsofrecognising
thesignsofbeaveractivityinHolocenesedimentsaccumulatedontheflood
plain.Westartedourstudiesinsmallvalleys(order1and2accordingto
Strahler’ssystem)intheareawherebeaversappearedimmediatelyaferthe
lastdeglaciationandwheretheyweresignificantlandscapeformingagents
untilthe19thcentury.Weidentifiednumerouscircumstancespointingto
alargeshareofbeaverpondsedimentsinthestructureofthestudiedsec-
tionsofvalleys.Butwearenotpioneersinthisrespect.Americanresearchers
formulatedsuchfindingsasearlyasthefirsthalfofthe20thcentury.How-
ever,theywerenotsupportedbyextensivestudiesoffloodplainsedimentsin
manycatchmentareasofthetemperateforestzone.Tiswasduetoserious
difcultiesrecognisingsedimentsthatwithoutanydoubtcouldbeassociated
withtheactivityofbeavers.Teestablishedcriteriaforrecognisingbeaver
pondsedimentswithinourstudyareamostlikelydonotexhaustallthepos-
siblemethodsofdiagnosis.Bypublishingtheresultsofourstudies,wewish
totakeapositiononresearchpostulatesaboutcollectingcomparativedata
fromvariousareasthathavealreadybeenformulatedinreferenceliterature.
Worksdescribingrelictbeaverpondsarestillrare.Publishingtheresults
ofourmodeststudies,atthesametime,wewishtosuggestthat,giventhe
presentstateofknowledge,theoldmodelexplainingtheevolutionofvalley
bottomsinthezoneofevergreenforestswithouttakingtheresultsofthe
activityofCastorfberintoaccountcannotbemaintainedanylonger.
