From Chernozem to Luvisol or from Luvisol to Chernozem? A ... · cords or ice core records (e.g....
Transcript of From Chernozem to Luvisol or from Luvisol to Chernozem? A ... · cords or ice core records (e.g....
From Chernozem to Luvisol or from Luvisol to Chernozem? A discussion about the relationships and limits of the two types of soils. A case study of the soil catena of Hrušov, Czechia
BARBORA STROUHALOVÁ1, ANNE GEBHARDT2,3, DAMIEN ERTLEN2, LUDĚK ŠEFRNA4, KRISTÝNA FLAŠAROVÁ4, PETR KOLAŘÍK4, DOMINIQUE SCHWARTZ2
GEOGRAFIE 125/4 (2020)
1 InstituteofArchaeologyoftheCzechAcademyofSciences,Prague,v.v.i.,Prague,Czechia;e-mail:[email protected]
2 UniversityofStrasbourg,FacultédeGéographie etd’Aménagement,Laboratoire Image,Strasbourg,France;e-mail:[email protected],[email protected],[email protected]
3 InstitutNationaldeRecherchesArchéologiquesPréventivesGrandEstNord,Ludres,France4 CharlesUniversityinPrague,FacultyofScience,DepartmentofPhysicalGeographyand
Geoecology,Prague,Czechia;e-mail:[email protected],[email protected],[email protected]
ABSTRACT ThepatchycharacterofthedistributionofChernozemsandLuvisolsformedonloessisoftenobservableonthepedologicalmaps,onalargescale,inCzechia.ThefocusofthepaperistoexaminethefeaturesofthesoilcatenaofHrušov(Czechia),whichischaracterizedbythesimultaneouspresenceofChernozem,LuvisolandLuvicChernozem–withoutobviousenvironmentalreasons.Acatenaofonly330metersisconsideredasystemoftransformationbetweenthesesoils.Alongwithfieldworkandthepedologicalanalysis,weusedthesoilmicro-morphologymethodtounderstandtheprocessesofpedogenesis.Weconcludedthatthepresenceofconsiderablydifferentsoiltypesonasmallscaleisduetointensiveagriculture.WefoundthatthepresentChernozemisformedontheLuvisolbyretrogradesoilevolution,whichincludedashiftinthevegetation,erosion,andrecarbonation.TheevolutionofLuvisolinthelowerpartofthecatenahasbeenconsiderablymodified.
KEY WORDS soilcatena–chernozem–luvisol–soilmicromorphology–Czechia
STROUHALOVÁ,B.,GEBHARDT,A.,ERTLEN,D.,ŠEFRNA,L.,FLAŠAROVÁ,K.,KOLAŘÍK,P.,SCHWARTZ,D.(2020):FromChernozemtoLuvisolorfromLuvisoltoChernozem?Adiscussionabouttherelationshipsandlimitsofthetwotypesofsoils.AcasestudyofthesoilcatenaofHrušov,Czechia.Geografie,125,4,473–500.https://doi.org/10.37040/geografie2020125040473ReceivedFebruary2020,acceptedJuly2020.
©Českágeografickáspolečnost,z.s.,2020
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1. Introduction
Loess is awidespread type of sediment,which covers about one-fifth of thesurfaceofEurope(Haaseetal.2007).Itistheparentmaterialofseveraltypesofsoils.ChernozemsandLuvisolsareespeciallywidelyrepresentedinEurope(Figure1).Inthispaper,wereviewtheexistingconceptsabouttherelationshipbetweenthesesoilswhichisdescribedintheliteratureas(i)spatialor(ii)tem-poral.WecontinuebypresentingnewdataonaLuvisol-ChernozemcatenainHrušov(Czechia)wheretheChernozemandLuvisolcoexistinverytightcontactdespiteidenticalenvironmentalconditions.Wehypothesisethatthesiteisazoneoftransformationwhereonetypetransformstoanotheranddiscusstheprocessesparticipatingonthesoil’sevolution.Thestudyisbasedonthefielddescriptions,soilmicromorphologicalobservationsandthebulksoilanalysis.
1.1. Spatial distribution of Luvisols and Chernozems
Chernozems–withtheirthickblackorgano-mineralhorizon–areconsideredaszonalsoilsthataretypicalforadrycontinentalclimate(Dokuchaev1883,FAO2015).Onthecontrary,theformationofLuvisolsisconditionedbyatemperateoceanicclimateandforestvegetation(Duchaufour1998,Němečeketal.2001,FAO,ISRIC,ISSS2006;Baize,Girard2008).TheseenvironmentalconditionsmaketheilluviationofclaysandthetexturaldifferentiationbetweentheeluviationEho-rizonandilluviationBthorizonpossible.OnthecontinentalscaleofEurope,thedistributionofthetwosoilsseemstofollowtheclimaticvariationsbetweentheoceanicconditionsintheWestandthecontinentalconditionsintheEast(Fig.1).
WhenwefocusonCzechiainCentralEurope,weseethatbothtypesofloesssoilsarepresent.Theenvironmentalconditionsoftheirdistributionoverlap(Table1),thegeographicaldistributionofLuvisolsandChernozemsdifferintheregionalclimaticconditions.TwofactorsareomittedforChernozemsinthedefinedcon-ditions:thetopographyandpastvegetation(Němečeketal.2011).AccordingtoHauptmannetal.(2009),bothtypesofsoilsaremostlyformedinplainareas,buttheycanbealsoformedinhillyareasandonplateaus.However,therearenot currently existingChernozemsabove300ma.s.l. of altitude inCzechia.Theclimaxvegetationoftheregionswiththepresenceofbothtypesofsoilsislandpredominatedbyoaks(Quercetea)oroak-hornbeams(Carpinus – Quercetea; Chytrý,Kučera,Kočí2001;Neuhäuselová1998).Onlarge-scalesoilmaps,amosaicofChernozemsandLuvisolscanoftenbeobserved.Onthelocalscaleandinthefield,theoriginofthespatialdistributionofChernozemsandLuvisolsisdifficulttoexplain,becausetheclimatic,topographicalandgeologicalconditionsseemtobeidentical(Bailly1972;Ložek,Smolíková1978;Vysloužilováetal.2014).These
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Tab. 1 – The environmental characteristics of the Chernozems and Luvisols in Czechia (Němeček et al. 2011)
Environmental characteristic
Chernozem Luvisol
Climate Climate region B 1–3Mean annual precipitation (7) 8–9°CMax. 650 (700) mm
Climate region B 3–5(6)Mean annual precipitation 7–9°C450–900 mm
Vegetation altitude zonation
1–2Oak zone (Quercus spp. mainly Quercus petraea agg.) and – Beech–Oak zone (Fagus sylvatica–Quercus petraea agg.)
1–2 (3)Oak zone (Quercus spp. mainly Quercus petraea agg.), Beech–Oak zone (Fagus sylvatica–Quercus petraea agg.) and Oak–Beech zone (Quercus petraea agg. – Fagus sylvatica)
Soil moisture regime Ustic Limit between ustic and udic
Parent material Loess, sandy loess, marls Loess, polygenic silts
Topography Not defined Flat, gently undulating terrain
Native vegetation Not defined Oak, oak-hornbeam forest
Fig. 1 – The spatial relationship of Chernozems and Luvisols. The distribution of loess (in red), Cher-nozems and Luvisols in Europe (Haase et al. 2007, ESDC 2013).
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observationsshowthatthereisaneedformorein-depthstudiestounderstandtheroleofenvironmentalfactors,inparticularvegetationandpaleo-environmentalconditions,ontheformationofthesetypesofsoils(Eckmeieretal.2007).
1.2. Temporal relationship of Chernozems and Luvisols in the Holocene
Nexttothespatialrelationshipofthetwosoils,thereisatemporalrelationship.Bothsoilsareplacedinthesameseriesofdevelopment(Leser,Maqsud1975).TheHoloceneevolutionmodelfromtheinitialloesstoaLuvisoltakesplaceun-dernaturalvegetation(Fig.2,accordingtoLorz,Saile2011).Accordingtotheseauthors,after thesedimentationof theupperWeichselian (Würm) loess, theinitialcalcareoussoildevelopsunder thesteppevegetation.ThewarmerandwetterclimateintheEarlyHolocene(PreborealandBoreal)allowstheforma-tionofaCalcicRegosol.ThehumichorizonthickensandattheendoftheBorealandtheChernozemwasformed(Leser,Maqsud1975;Lorz,Saile2011;Scheffer,Meyer1963).Forestconditionsinduceddecarbonationandleachingofclays.Theclayilluviationdownwardsthesoilprofilecausedtheloweringofthedecalcifica-tionlimit.Thisresultedfirstintheformationofacambichorizon,thenargillichorizonwhilepreservingthesuperficialAhorizon.Finally,ChernozemtakesitsLuvisolmorphologywithdevelopedEandBthorizons(Lorz,Saile2011;Němeček,Smolíková,Kutílek1990).
ThetransformationofaChernozemintoaLuvisolhasbeenwellstudiedintheNorthCaucasus:thesuccessiveconstructionsoftumulihasmadeitpossibletopre-servethestagesofthegenesisofaLuvisolfollowingthereplacementofasteppebyaforest(Alexandrovskiy2000).ThetransformationofaChernozemtoaLuvisolhasalsobeenhypothesiseduponbyHejcmanetal.(2013)whodiscoveredaburiedAhorizonofaChernozemunderabell-beakerbarrow(2500–2200BC)inCentralMoravia,eveniftheLuvisolsaredominantintheregionnowadays.Intheirview,theincreasingannualprecipitationanddecreasingtemperaturesinducedthedegradationofChernozemstoLuvisols.ThesameevolutioninducedbytheclimatewasdescribedrecentlybyKabaƚaetal.(2019)insouthwesternPoland.
SchefferandMeyer(1963)describethedevelopmentofaninitialsoilloessto-wardsaChernozemandaPhaeozeminsouthernLowerSaxony,Germany.Therateofdevelopmentofthisseriesanditscontrolmechanismarecarbonatedynamicsandtheloweringofthedecarbonationlimit(Scheffer,Meyer1963;Rohdenburg,Meyer1968).DecarbonationwascontrolledbyclimatechangeintheHolocene.ItwasminimalatthebeginningoftheHolocene,itstrengthenedatthebeginningoftheAtlanticwithanincreaseinthepluviometryandthedevelopmentofthefor-ests.However,conversely,thedecarbonationmechanismlinkedtoclimatechangecanbesloweddownbyvariousfactorssuchasahighcarbonatecontentofthe
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parentrockorthestorageofcalcareousgroundwaterfromtheAtlanticperiod.Inthiscase,GleyicandpseudogleyicChernozemsareformed(Scheffer,Meyer1963;Fischer-Zujkov,Schmidt,Brande1999).CarbonatedynamicsarealsoconsideredasacrucialfactorinpersistenceofChernozemsbyvonSuchodoletzetal.(2019).
ThetightcontactbetweentheChernozemsandLuvisols(distinctChernozempatches in the Luvisol area) is not explained by this evolutionary approach.Accordingtotheevolutionarymodel,theChernozemispreventedfromdegrada-tionbydeforestationorbyaclimatechange.DistinctpatchesofChernozemsintheLuvisolareashavebeendescribedaszonesofancientsettlementsandintensiveagriculture(Ložek1973,Kabaƚaetal.2019),theheterogeneityoftheparentmate-rialinhighercarbonatecontents(Altermannetal.2005,vonSuchodoletzetal.2019)orastheconsequenceofprehistoricburningpractices(Eckmeieretal.2007,Kasielke,Poch,Wiedner2019).
1.3. Spatiotemporal relationship of Chernozems and Luvisols in the Pleistocene
InCentralEurope,loess-paleosolsequences(Flašarováetal.2020,Antoineetal.2013)containseveraldifferentsoiltypes.ThemostobviousareLuvisols,represent-inginterglacialclimaticconditions,similarastotoday,andChernozems,reflectingdrierandcoolerclimateatthebeginningoftheglacialperiods.However,thepale-oclimatewasoscillatingalsoduringtheglacialperiods,andlesswell-developedsoilssuchasRegosols,weakCambisolsortundraGleyswereformedaswell(Ložek1973,Hošeketal.2015).
Fig. 2 – The temporal relationship of the Chernozems and Luvisols in the Holocene. Source: after Lorz, Saile 2011.
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Loess-paleosolsequencesareimportantpaleoenvironmentalarchivesbecauseoftheirlong-termcontinuouspaleoclimaterecord,analogoustomarineproxyre-cordsoricecorerecords(e.g.Muhs2007;Sheldon,Tabor2009).PaleosolsformedattheEarth’ssurfacewereindirectcontactwiththeenvironmentalconditionsprevailingatthetimeoftheirformationandtheyreflecttheprevailingtempera-tureandprecipitation.Paleosolscanbeconsideredasanequivalenttorecentsoilswiththecorrespondingmorphologicalsigns(Němeček,Smolíková,Kutílek1990).
2. Materials and methods
2.1. Study site of Hrušov
ThestudiedcatenaissituatedinthewestfromthevillageofHrušov(50°21'N,14°50'E)inCzechia.Thecatenaislocatedinaflatzone,attheupperpartofapla-teaucoveredbyaloess.Thelengthofthestudiedtransectis331.2meters, itsmaximalslopeinclinationreaches0.6%.ThespatialdistributionoftheexaminedsoilsisdescribedinFigure3.
Theparentmaterialisformedbyaloess(Českágeologickáslužba2013).Theannualprecipitationreachesbetween500and600mm,themeanannualtem-peraturevariesbetween8°Cand9°C.Theevapotranspirationreaches550 to600mm(Tolaszetal.2007).
TheMacro-physical Climatemodel (Bryson,McEnaney DeWall 2007) forPrague-Karlov(ca.50kmsouthwestfromHrušov)showsthatfromtheWeichselLate-glacialtoBorealperiod,theprecipitationishigherthantheevaporation,butthedifferenceislow(Fig.4).Between7500and5500BP,thevaluesofthepotentialevapotranspirationmightevenexceedtherainfallinthegrowingseason.During
Fig. 3 – The location of the studied soils. Source: ČÚZK 2019.
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theAtlanticperiod,theevaporationdecreasedwhiletheprecipitationstayedrela-tivelyconstantwithmorefluctuations.Theclimatehasbecomerelativelymorehumidandcolderwithsomefluctuations(Dreslerová2012).
Nowadays,thezoneisanarablelandwiththealternationofvariouscrops:wheat,corn,colza,sugarbeet.TheregionhasbeensettledsincetheNeolithicperiod(Pavlů,Zápotocká2007).ThearchaeologicalevidenceofHrušovisquitescarce, thereareobjectsof stroke-ornamentedware ceramics (Neolithic, ca.5000BC),objectsfromtheÚněticeculture(ca.2200–1600BC).MostoftheobjectsfoundcomefromtheLusatiancultureandtheHallstattone(ca.1000–400BC)(unpublishedarchivesoftheArchaeologicalInstitute,Prague).Thevillagewasdocumentedinhistoricaldocumentsforthefirsttimein1346.
2.2. Soils in the catena
Throughthepaper,weusetheWRB2014soilclassification(FAO2015).SevenpitslabelledHRU20,HRU21,HRU22,HRU23,HRU24,HRU25andHRU26(Fig.5)wereduginordertoproceedwithadetailedphysicalandchemicalanalysisandamicromorphologicalstudyofsoilsinthecatena.Theexactlocationofthepits(determinedbyGPSandTST)isindicatedinTable2andFigure5.
Accordingtothesoilmorphology,therearethreetypesofsoilsinthecatenaofHrušov:HaplicChernozem,LuvicChernozemandLuvisol(Fig.5).TheChernozemmarkedasHRU21hasachernichorizon.Itispartlyplougheddowntothedepthof43cm–theAandChorizonsaremixedinthere.TheAhorizoniscompactedbyploughing;itispartiallydecarbonated.Thereareloessdollsandnumerouslom-bricgalleriesintheChorizon(Fig.5).TheprofilesofHRU20,HRU22andHRU23
Fig. 4 – The potential mean annual precipitation and evaporation for Prague-Karlov (alt. 261 m a.s.l.). Source: according to Bryson, McEnaney DeWall (2007). Modelled by Bryson and Cummings.
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areLuvicChernozemswithasimilarmorphology.Thetransitionbetweenthemisclearandirregular.OnlytheHRU20profilehasapreservedpartofanaturalAhorizonbetweentheApandtheBt.TheprofilesofHRU24,HRU25andHRU26areLuvisolswhicharedeeplyreworkedbyploughing.Therefore,theEhorizonandtheupperpartoftheBthorizonaremixedtogetherandthelimitbetweentheploughinghorizonandtheBthorizonissharp(Fig.5).
2.3. Soil micromorphology
Thesoilmicromorphologystudiestheundisturbedsamplesunderapetrographicmicroscopetoidentifyvarioussoilcomponentsandtoanalysetheirorganisation.Ataveryfinescale,itallowsonetoobservetheprocessesanddynamicsthataremacroscopicallyhardlyperceptibleornotperceptibleatall(Fedoroff,Bresson,Courty1987,Stoops2003,Stoops,Marcelino,Mees2010).
Followingthefieldobservation,themicroscaleobservationhighlightsthenatu-ralevolutionofthesoils,likevariouschangesinthevegetationcover(Smolíková1969)oranthropogenicactivities,e.g.,ancientagriculturalpractices(Gebhardt1995;Deáketal.2017;Macphail,Goldberg2017).Thishelpstobetterunderstandthelocalevolutionofthelandscape(Gebhardt,Fechner,Occhietti2014).Themi-cromorphologicalapproachisbasedonthestudyof15thinsectionsofthepro-filesHRU21(HaplicChernozem),HRU20,HRU23(LuvicChernozem)andHRU24(Luvisol).Thethinsectionsaredescribedfollowingtheinternationalsoilthinsectiondescriptionmethods(Bullocketal.1985,Stoops,Marcelino,Mees2010).
Tab. 2 – The list of the studied pits at the site of Hrušov
Profile Code Coordinates Soiltype
Latitude NLongitude E
Altitude m a.s.l.
HRU20 50°20.822'14°50.393'
263.053 Luvic Chernozem
HRU21 50°20.816'14°50.367'
263.074 Haplic Chernozem
HRU22 50°20.813'14°50.345'
262.997 Luvic Chernozem
HRU23 50°20.811'14°50.331'
263.121 Luvic Chernozem
HRU24 50°20.805'14°50.293'
263.017 Luvisol
HRU25 50°20.769'14°50.228'
262.323 Luvisol
HRU26 50°20.724'14°50.171'
261.815 Luvisol
FROM CHERNOZEM TO LUVISOL OR FROM LUVISOL TO CHERNOZEM? … 481
HRU22
HRU26
HRU25
HRU24
HRU21
HRU20
HRU23
Luvic Chernozem
Luvic
Chernozem
Luvic
Chernozem
Luvisol
Luvisol
Studied thin section
Haplic
Chernozem
Luvisol
Ap1 0 to 3–5 cm
,YR 3/2, silty, granular structure, not
effervescent, net transition
Ap2 3–5 to 45–48 cm
, YR3/2, silty, not
effervescent, polyhedral angular
structure, subhorizontal abrupt
transition
Ah 45–48 to 55 cm,
10 YR 2/2, silty, granular structure,
not effervescent, irregular
transition to
A/B 55 to 70 cm,
transition horizon, not
effervescent, gradual transition
Bt 70 to 80 cm,
10 YR 4/6, loamy clay, not
effervescent, slightly marbled,
with rusty spots, mottles of organic
material, net subhorizontal
transition
Ck > 80 cm,
10 YR 5/5; loess, effervescent,
galleries of earthworms to the
bottom of the profile
Ap1 0 to 3–5 cm
,YR 3/2, silty, granular
structure, few roots
Ap2 3–5 to 25 cm,
YR 3/2, silty, angular
polyhedral structure, not
effervescent, few roots,
presence of decomposed
straws almost continuous
between 10 and 23 cm
Ap3 25 to 38–43 cm
,YR 3/2, silty, effervescent
(at first weakly, then more
clearly), few roots, abrupt
transition
Ck > 38–43 to 68 cm,
YR 5/4, loess, silty, many
loess dolls, micro-aggregated
structure, many biogalleries
Ap 0 to 40 cm,
YR 3/2 silty,
granular structure,
not effervescent,
few roots, presence
of decomposed
straws almost,
abrupt transition
Bt 40 to 52 cm,
10 YR 4/5, net
decarbonation limit
around 52 cm,
gradual transition,
subhorizontal
Ck > 52 cm,
10 YR 5/4, loess
with loess dolls
Ap1 0 to 5 cm
,YR 4/3, dry: granular
structure, numerous
anthropogenic
elements (pieces of
bricks, charcoals)
Ap2 5 to 45 cm,
YR 3/2, angular
polyhedral structure,
clear but
interdigitated
transition
Bt 45 to 58–63 cm
,YR 3.5/6, net
decarbonation limit
around 60 cm,
gradual
subhorizontal
transition
Ck > 58–63 cm
,YR 5/4; loess dolls
around 70 cm
Ap 0 to 30 cm,
YR 4/3, dry, silty, granular
structure, numerous
antropogenic elements
(bricks and pieces of limes),
abrupt, subhorizontal
transition
Bt 30 to 70 cm,
YR 4.5/5, decarbonated,
net transition,
subhorizontal, with
Ck > 88 cm,
YR 5/4, silty (carbonate
loess), presence of loess
dolls and crotovinas
Ap 0 to 38–42 cm
,YR 3.5/3, silty, not effervescent,
angular polyhedral structure,
presence of straws and anthropic
elements, relatively compact,
abrupt subhorizontal transition
Bt 38–42 to 68 cm,
10 YR 3/6 at the top, 10 YR 4/6 at
the base, silty clay, weak
effervescence, and the presence of
decarbonated zones, subangular
polyhedral structure, good
interaggregate porosity, numerous
galleries of earthworms, net
subhorizontal transition
Ck > 68 cm,
YR 5/4, silty (carbonate loess),
numerous galleries of earthworms,
presence of loess dolls from 80 cm
Ap 0 to 35–40 cm
,10 YR 3/2, silty, not effervescent,
granular structure at the surface
(0 to 8 cm
), angular polyhedron,
presence of straw and anthropic
elements (brick and lime fragments),
relatively compact, abrupt irregular
transition with:
Bt 35–40 to 60–62 cm
,YR 4/6, silty-clay, weak effervescence,
and the presence of decarbonated zones,
subangular polyhedral structure,
interaggregate porosity, numerous
biogalleries, wavy transition
C > 62 cm
,YR 5/4, silty (carbonate loess), numerous
biogalleries, presence of loess dolls
and crotovinas
Fig. 5 – The characteristics of the studied soils
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2.4. Soil analyses
Samples,ofapproximately50g,weretakenatevery5 cmindepthfromeachstudiedsoil(exceptfromHRU22).Theyweredriedat40°Candsievedtopassthrougha2mmmesh.Theparticle-sizedistributionwasmeasuredwithalasergranulometer(typeBeckmann-CoulterLS230).Beforethemeasurementoftheparticle-sizedistributionwasmade,thesampleshadbeentreatedbyH2O2todestroytheSOM(soilorganicmatter).ThesampleshadbeenwashedbyKClalso,distilledwaterandsodiumhexametaphosphatetodeflocculatetheaggregateswithoutdestroyingthecarbonates.Thetotalorganiccarbon(TOC)wasestimatedbynear-infraredspectroscopy(Cécillonetal.2009).ThecontentofCaCO3wasquantifiedbymeasuringthevolumeoftheCO2lostinthereactionwiththeHClinaclosedatmosphere.
3. Results
3.1. Analytical properties
Theinterpretationmusttakeintoconsiderationthatsoilsarefarmedintensively.Agriculturaltechniquesincludetheapplicationofcommonagriculturalamend-mentsanddeepploughingdownto45cm.Weobservedthatthepredominantfractioninalltheanalysedsoilswasthesiltfraction(Fig.6).Itgenerallyrepre-sentsbetween63and68%ofthemineralfraction.Theclayfractionrepresentsbetween15and26%ofthemineralfractiondependingonthesoil.Theclaycontentisrelativelyconstant,exceptLuvisolHRU24whereaclaypeakappearsclearlyintheBthorizon.ThistrendismuchlesspronouncedintheLuvisolHRU25andtheHRU26.ThesetwoprofilesareclearlyLuvisolsaccordingtothemorphologyinthefield.Itmustbepointedoutthattheclaycontentintheloessparentmaterialisimportant(from20to23%).Theparticlesizemeasurementswereperformedwithoutdecarbonation,whichmayhavecausedtheaggregationoftheclays.Thefinesandcontentisabout10to14%,thecoarsesandiszerooralmostzero.Somecoarsesandsareelementsofanthropogenicwaste(bricksorlimepieces).
ThepHvaluesreachbetween6.7and8.4.ThedifferencesbetweentheLuvisolsandtheChernozemsarenotsignificantlymarkedduetotheagriculturalcalcimag-nesicamendments(weobservedlimefragmentsduringthefieldobservationsandinthethinsectionsaswell)appliedtothesoils.
AllthestudiedsoilprofilescontainCaCO3.Inthesurfacehorizons,theCaCO3contentvariesbetween0and3%.ItsmaximumisreachedintheCkhorizon.
Thetotalorganiccontent(TOC)ofthestudiedsoils,assessedbetween0and2%isrelativelystableintheploughinghorizons.TheBtintheLuvicChernozem
FROM CHERNOZEM TO LUVISOL OR FROM LUVISOL TO CHERNOZEM? … 483
0
10
20
30
40
50
60
70
80
90
100
0,0 1,0 2,0 3,0
TOC (%)
HRU20HRU21HRU23HRU24HRU25HRU26
0
10
20
30
40
50
60
70
80
90
100
6,0 7,0 8,0 9,0
pH
HRU20HRU21HRU23HRU24HRU25HRU26
0
10
20
30
40
50
60
70
80
90
100
0,0 5,0 10,0 15,0 20,0
CaCO₃ (%)
HRU20HRU21HRU23HRU24HRU25HRU26
0
10
20
30
40
50
60
70
80
90
100
12,0 17,0 22,0 27,0 32,0
Clay (%)
HRU20HRU21HRU23HRU24HRU25HRU26
Fig. 6 – The TOC, CaCO3, clay contents and pH of the studied soils in the Hrušov catena
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Tab. 3 – The micromorphological features of the soil of the catena of Hrušov
Profile
Horizon
Depth
Microstructure
Porosity
Illuvial clay
coatings –
limpid/dusty
Fe, Mn
nodules
Secondary
carbonates
Bioturbation
Phytoliths
Charcoals
HRU20
limit Ap/Ah
41–50 cm
SCh, F
L, D
——
Xx
X
HRU20
limit Ah/Bt
47–56 cm
HfF Ch
L, D
X—
Xx
—
HRU20
Bt 53–62 cm
SF, Ch
L, D
X—
X—
—
HRU20
limit Bt/C
65–74 cm
SCh
L, D
XX
X—
—
HRU20
top of the C
77–86 cm
SCh
—X
X—
——
HRU21
Ap 30–39 cm
SCh, F
L, D
—X
XX
XHRU21
Ap/Ck 36–45
SCh
LX
XX
X—
HRU21
Ck 42–51 cm
S
Ch—
—X
——
—HRU22
Bt 41–51 cm
S
Ch, V
L, D
X—
X—
—HRU23
Bt 43–52 cm
S
ChL, D
X—
X—
—HRU23
Bt 49–58 cm
S
Ch, V
L, D
XX
X—
XHRU23
limit Bt/Ck
55–64 cm
HCh
L, D
XX
X—
—
HRU24
Limit Ap/Bt
36–45 cm
SCh, V
L, D
XX
XX
—
HRU24
Bt 48–57 cm
SCh, V
L,D
XX
X—
*HRU24
Limit Bt/C
60–69 cm
HCh, V
L,D
XX
X—
—
S – subangular blocks, with a porphyric distribution, H – heterogeneous, x – presence, – – absence, Ch – channel, F – fissure, V – void, L – limpid coatings, D – dusty coatings,
I – infillings, E – excrement
FROM CHERNOZEM TO LUVISOL OR FROM LUVISOL TO CHERNOZEM? … 485
showsatrendofslowadecreaseintheTOCwiththedepth.ThecontentsoftheTOCinLuvisolsfallsharplyundertheAphorizon.
3.2. Micromorphological observations
ThemicromorphologicalobservationshavebeenpreferentiallyundertakeninthehorizonsbeneaththeAp(Table3).
3.3. Micromorphological evidence of the pedogenic processes
3.3.1. Luvisol HRU24
AttheAp/Btlimit,wecanobservetracesofbioturbationandmanybio-galleriesfilledwithsilt.Dustysilty-claycoatingsareclearlyvisible.Theycorrespondtothesplasheffectofrainonnakedsoilsurfacesandarecommonintheactualorinanancientarableland(Jongerius1970;Macphail,Courty,Gebhardt1990;Deáketal.2017).InthelowerpartoftheBthorizon,therearealsoyellow-orangeandlimpidclaycoatings,whichareconsideredtobetypicalfortheleachingenvironmentalconditions(Macphail,Courty,Gebhardt1990,Gebhardt1993).
Thewell-developedluvicBthorizon,whichappearsjustundertheAphorizon,suggeststhatdeepploughinghomogenisedtheupperAandEhorizons.
IntheBthorizon,therearespariticcarbonatecoatingsonclayilluviations(Fig.7).Thecarbonatehypo-coatingsareformedinsidethelargerporesbywaterevaporationorbyasuddendecreaseintheCO2inthesoil(Zamanian,Pustovoytov,Kuzyakov2016).Thisfactindicatesthatthephasesofcarbonatationsucceededthephasesofleachingasaconsequenceofashiftintheenvironmentalconditions.ThisobservationiscoherentwiththeanalyticaldatathatindicatethepresenceofsmallamountsofcarbonatesintheBthorizon.
3.3.2. Haplic Chernozem HRU21
IntheAphorizon,thesilts(loess)arewellsortedandhomogeneousandformaporphyricgroundmass.Thefinematrixisveryorganicandbioturbated.Therearefragmentsofmolluscshells,phytoliths,charcoals,ferruginousconcretionsandlimefertilisergrainfragments.Theobservationoftheresiduesofnon-decomposedorganicmattercorrespondstotheobservationsmadeinthefield.
IntheAphorizonandatthelimitoftheApandCkhorizons,thereareclearclaycoatingsofalimpidyellowororangecolourthatarecompletelyreworkedbyploughing(notin situ).ThesecoatingsarerelicsofaformerexistenceofaluvicBt
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Fig. 7 – Soil HRU24 – Left: the Bt horizon of the relict Luvisol. The calcareous coatings (Ca) over the clay coatings (Cl) are evidence of post-luvic re-carbonation. Right: The micritised mass of the Bt horizon.
Fig. 8 – Soil HRU21 – Limpid, dislocated yellow-orange clay coatings, which attests to the existence of a reworked ancient Bt horizon (RBt) in the Ap horizon (on the left) and in the Ap horizon at the limit between the ploughing and the C horizons (on the right).
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horizonwhichdisappeared(Fig.8).IntheCkhorizon,themicromassismicriticwithasecondarycalcareousprecipitationinanacicularform.Theymaybecausedbytheclimaticconditionbetweenthelasttillageandthesampling.Secondarycarbonatesarealsopresentintheformofsmallnodules.
3.3.3. Luvic Chernozem HRU20
WefocusedontheexaminationofthethickestprofileHRU20thatcontains–undertheploughinghorizon–residuesoftheAhhorizonwhichareundisturbedbytillage.ThemicromassofApandAhishumic,duetothestrongbioturbation,itisheterogenous,withfissuredporosity.Themainobservedfeatureisthesimultane-ouspresenceofthedustycoatingandlimpidyellowcoatinghorizons(Fig.9).
Themainobservedpedofeaturesare:dustyclay/siltcoatings(limitAp/Ah),phytoliths(limitAp/AhandlimitAh/Bt)andastrongbioturbation(Ap,AhandBt).Themostimportantobservationsarethesimultaneouspresenceofthelimpidyellow-orangeclaycoatingsin situ–sometimesreworkedbybioturbation–andthedustyclay/siltycoatingscomingfromthebareploughedsurface.
Fig. 9 – The soil HRU20, the Bt horizon of the Luvic Chernozem. The yellow-orange limpid clay coat-ings (LCl), partly dislocated and thin brown dusty silty coatings (DS) in the Bt horizon.
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3.3.4. Luvic Chernozems HRU22 and HRU23
ThetwosoilprofilesoftheLuvicChernozems,HRU22andHRU23,areverysimilar.Hereagain,themostimportantobservation,intheBthorizons,isthesimultaneouspresenceofthelimpidyellow-orangeclaycoatingsin situ–sometimesreworkedbybioturbation–andthedustysiltycoatingscomingfromthebareploughedsurface.
Inbothsoils,thereareferruginousconcretions,whichprovethehumidityofthesite.IntheCkhorizonofHRU23,therearegreymicritichypo-coatings(Fig.10).
3.4. Interpretation of the soil evolution
Thesimultaneouspresenceoftheyellow-orangelimpidclaycoatings,thebrowndustysiltcoatingsandthesignsofre-carbonationclearlyindicatethattheob-servedcatenaisofapolygenicorigin.Accordingtoourobservation,wehypoth-esisethatthesoilsatthesiteofHrušovpassedathree-stageevolution.
Fig. 10 – Soil HRU23: Yellow-orange limpid clay coatings (LCl), and thin brown dusty silty coatings (DS) in the Bt horizon of the Luvic Chernozem (on the left). Grey micritic stains of root origin and impregnations of Fe (Fe) on the calcareous concretions in the Ck horizon (on the right).
FROM CHERNOZEM TO LUVISOL OR FROM LUVISOL TO CHERNOZEM? … 489
3.4.1. First phase
Wesupposethatbeforethearrivalofthefirstfarmers,theformationofthesoilhappenedinanaturalway.Thenaturallateglacialsurface,bareloess,usedtobenotsoflatastoday(Pavlů,Zápotocká2007).ThefirststageofpedogenesisintheHoloceneischaracterisedbytheformationofahumichorizonontheloesssediment.
Then,weobserveaphaseofforestationwhichisperceptibleduetothelimpidyellow-orangeclaycoatings.Itcorrespondstotheclayleachingofthedecarbon-atedupperhorizonsundertheforestvegetationbeforetheagriculturalpracticesweresetup.WesupposeLuvisolusedtobepresentatthesiteatthattime.
3.4.2. Second phase
Thesecondphaseislinkedtothebeginningsoftheagriculture.Theagriculturewassetupbythedeforestationandthereintroductionofsteppeconditions.ThecultureofcerealssimulatesthesteppevegetationofPoaceaebyhighinputsofsoilorganicmatterbytherootsystem.Thesetupoftheagricultureleadstoerosionprocessesandthelevellingofthesurface.Partoftheobservedfeaturesisduetothecolluviation.TheChernozematthetopofthecatenamaybeconsideredasaproductofthepolygenicevolution,erosionandre-carbonationbybioturbation(Fig.11).
Fig. 11 – The retrograde evolution of the Chernozem at the site of Hrušov
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ThesecondphaseobservedintheBthorizonismarkedbydusty,brownsiltycoatings.Thissecondstagecouldhavestartedasearlyasthebeginningofthesoilcultivation.TheLuvisolatthelowerpartofthecatenabecamethicker,thecultiva-tionandorganicamendmentsleadtothedestructionoftheApandEhorizons.Accordingtoacquireddata,wecannotstateifthezonewasdeforestedatthesametimeorinmultiplephases.
3.4.3. Third phase
Lateron,weidentifiedthethirdstageofthesoilformation.ItischaracterisedbythecarbonateprecipitationontheclaycoatingsintheBthorizon.Thisstageofcarbonatationhastobelinkedtothenewinputofcarbonates.Thisinputcanbecausedbynaturalandhumanfactors,itisconfirmedbytheunusualhighpHofallthestudiedsoils.
Ourobservationsmayleadtotheconclusionthatthedifferentiationofthesoiltypes,whichmustbeaconsequenceofanenvironmentalchangethatoriginatedinalong-termshiftinthevegetation.Thefactorofthevegetationchange,whichwasinducedbyhumanactivitiesinthearea,dominatesthepedogenesisofthesesoils.Thedeforestationledtothechangeintheleachingparametersofthesoilsandthechangeintheacidificationprocesses.Aninorganicamendmentandanorganicwaste,dungfromhouseholdshavebeenappliedbecausethelandhasbeenusedasanarablefield.Thisissupportedbyfindingsofsherdsandpiecesofbricksfoundinthefieldsaroundthevillage.Thethirdphaseendswiththemodernagricultureperiod,whichcompletedthere-carbonationofthesoilbydeepploughingandinorganicinputsandterrainlevelling.
4. Discussion
Theobservationsdonotofferuniqueandclearinterpretations.Inaddition,wemustremindonethattheknowledgeofthepastsoilcoverisveryfragmentary.Ifsoilshavedevelopedsincetheendofthelasticeage(Duchaufour1998),theywere,atthetimeofthearrivalofthefirstfarmers,aboutathalf-timeoftheircurrentdevelopment.Theirphysico-chemicalcharacteristicswereundoubtedlydifferentfromthoseknowntoday.However,thereasoningheldontheevolutionaryseriesareallmadeonthebasisoftheobservationofthepresentsoils.
FROM CHERNOZEM TO LUVISOL OR FROM LUVISOL TO CHERNOZEM? … 491
4.1. Transformation of the soils
ThesoiltransformationfromChernozemtoLuvisolrequiresthedecarbonationoftheChernozemasaconsequenceofanincreaseintheprecipitation,intensifyingachangeintheleachingconditionsandoftheinducedshiftinthevegetation.ThenthetransformationfromLuvisoltoChernozemwouldneedthere-carbonationanddeclineoftheBthorizon.
Nowadays,thepHofthestudiedsoilsistoohightobeconvenientforclayillu-viation(Quénardetal.2011).Calciumformsbetweentheclayandthesoilorganicmatter,averystrongcomplexwhichdoesnotenablethedispersionofclaysandtheirmigration(Masonetal.2016).
Ourobservationsofthesoilsintheexaminedcatenashowedthattherearerelictsoftheyellow-orangelimpidclaycoatingsinalmosteveryexaminedsoilprofile.WemayconcludethatthosefeaturesarerelictsfromtheperiodwhenthepHusedtobelower(beforere-carbonation).Theyellow-orangeclaycoat-ingsarenottypicalmicromorphologicalfeaturesintheChernozem(FAO2015),becauseclayilluviationfollowstheprofiledecarbonation(Duchaufour1998,VanVliet-Lanoë1992).Forexample,Smolíková(1972)demonstratesatypicalspongystructureofChernozemsontheAhorizonfromafossilPleistocenesoil.
ThemicromorphologicalobservationinHrušovrevealsthattheyellow-orangelimpid clay coatings are trapped under the secondary carbonates.This factdemonstratesthattheprocessofthetranslocationofclayisolderthanthere-carbonation.Theprocessofthetranslocationoftheclayisalsonotactiveanymore.Theyellow-orangelimpidclaycoatingsarenotin situ–theyweredislocatedbythebioturbationthatfollowedthestageofilluviation.
Atthesametime,thebioturbationisanaturalwayofthere-carbonationanddestructionofBthorizon.Thepresenceoffaunaisprovedbytheobservationofkrotovinasandofnumerous lombricgalleries in thestudiedsoils.There-carbonatationisaresultoftheliming.
Last,butnotleast,itmustbementionedthattheseprocessescanoccurunderclimatesconvenientfortheexistenceofChernozems(Němečeketal.2011,Table1),intheso-calledancientforest-steppezone(Ložek,Smolíková1978).
4.2. Role of erosion
Wehavetoconsiderthattheprocessofre-carbonationmaypartlybearesultoferosion.Evenifthesurfaceisquitelevellednow,theinclinationscouldhavebeensteeperinthebeginningoftheagriculturalera(Pavlů,Zápotocká2007).Thistheoryissupportedbythedifferentdepthsofthesoilprofiles.TheChernozemssituatedintheupperpartofthecatenaareasdeepastheLuvisolsdowntheslope.
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Soilerosionisaninevitableconsequenceofdeforestationandsoilplough-ingsincethebeginningsofagriculture(Dreslerováetal.2019).Accordingtothemapofthelong-termlossbyerosioninthestudiedarea,itreachesbetween1and4t.ha⁻1.year⁻1(https://mapy.vumop.cz/;15.4.2019).Studiesconcerningtheerosioninprehistoricandhistorictimesestimatethatthesoillossbyerosiononloesscanreachanaveragerateofseveralt.ha⁻1.yr⁻1(Froehlicheretal.2016,Kołodyńska-Gawrysiak,Poesen,Gawrysiak2018).
Whenweconsidertheerosionratesonacentennialormillennialscale,thesoillossmayhavereachedmoredecimetres.Intheupperpartofthecatena,theresiduesofthesurfacehorizonsarehomogenisedbymodernmechanisation.Therefore,theBthorizoncannotbeobservedanymore.Thetillage,theupliftofthecarbonatesandthecolluviationcouldhavecausedthere-carbonationdowntheslope.
Atthesametimethepartialdecreaseofthesoillevelintheupperpartsofthecatenacausesthatthecarbonates(loess)canbefoundatashallowerdepth,whichfacilitatestheupwellingbybioturbation.InatypicalLuvisolonloess,thecarbonatesappearatdepthsof100–110cm,whichlimitsthebioturbationtoreturnthecarbonatesintothesoilprofile.
Thementionedprocessesledtothetransformationofthenaturalpropertiesofthesoil,especiallythepHvaluesandgrain-sizedistributions.Thesoilshavebecomemoreunifiedespeciallyinthetextureandorganiccontents.
4.3. Role of vegetation
Accordingtothemicromorphologicalfindings,weassumethereusedtobeaforestatthesiteofHrušovinthepast.Theconclusionissupportedbytheclimatemodel(Bryson,McEnaneyDeWall,2007)whichshowsconditionsforthedevelopmentofaforest.Asdescribedabove,theChernozemsdegradetoLuvisolsunderstableforestconditionsNěmeček,Smolíková,Kutílek(1990).
Theroleofthevegetation,especiallyinthe“Chernozemquestion”hasbeenlargelydiscussed.AccordingtoLožek(1973),theChernozemsunderasteppewereconserved(notdegradedtoaLuvisol)untilthebeginningsoftheagricultureinsmallpatches(Fig.12)andtheLuvisolsformedintheareasthatwerenottrans-formedtotheagriculturalland.OthersclaimthatthefirstfarmerswereabletofindChernozemsunderthewoodlandoratleastundertheforest-steppevegetation(Vysloužilováetal.2014,Beneš,2004,Dreslerová2012,Strouhalováetal.2019).
Onthecontrary,theappearanceofclimaxforestsisnot,accordingtoFischer-Zujkov, Schmidt, Brande (1999), afactor likely to cause the degradation ofChernozems.Indeed,intheCentralEuropeanChernozemextentsarea,thenaturalforestmustlooklikeanoakgroveoranoakgrovewithanalwaysverydense
FROM CHERNOZEM TO LUVISOL OR FROM LUVISOL TO CHERNOZEM? … 493
Fig. 12 – The formation of the Chernozems in Central Europe according to Ložek (1973)
Fig. 13 – A Chernozem under woody vegetation in the Bulhary forest (Czechia). The game preserve has existed at the site since the 13th century.
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herbaceouslayer(Fig.13,Kreuz2007,Scheffer,Meyer1963).Underthesecondi-tions,theinputsoftheorganicmattertothesoilarenotverydifferentbetweenrelativelyclearforestsandsteppes,whichexplains,accordingtoFischer-Zujkov,Schmidt,Brande(1999),thataChernozemshowsacertainstabilityundertheforestvegetation.
Nonetheless,inthecaseofourstudy,itisveryhardtoimagineadistinctpatchofsteppenaturallyhavingadifferentevolutionduringthethousandsofyearswhichwouldresultinthesmall-scalesoilcoverdifferentiation.
4.4. Retrograde evolution of the soil
ThecatenaofHrušovanditscharacteristicsconfirmthatthesiteislocatedinatransitionzone.Itcorrespondstoachronosequencewhereonetypeofsoilisslowlytransformingintotheother,andweareabletosaythataLuvisolistrans-formedintoaChernozem.
Thisconclusioniscontradictorytothetraditionalviewofsoilformation(e.g.,Alexandrovskiy2000,Lorz,Saile2011).OurresultsgobeyondthehypothesisthatagriculturalmanagementpreventsthetransformationofaChernozemtoaLuvisol(e.g.Duchaufour1998,Pokornýetal.2015).ItislikelythatasetofhumaninfluenceandagriculturalpracticesinducetheformingoftheChernozem.Beneš(2004)proposestheideathattoday’spresenceofChernozemsintheLinearPotteryculturesettlementsisnotacause,butaconsequenceoftheancientagriculturalexploitation.HeclaimsthatasecondarygrasslandmayboostthedevelopmentoftheChernozem.Ourresultsconfirmthatthesoilevolutioninthestudiedcatenaoccurredinthisway.
Evenifitisnotwellknown,thesuggestedaffirmationofthissoilevolutionschemeisnotnew.Themicromorphologicalanalysescarriedoutinthe1970sbySmolíkovápresentedanidenticalconclusion(Smolíková1962,1969,1971,1972;Ložek,Smolíková1973;Němeček,Smolíková,Kutílek1990).Theseauthorscalledthesesoilspseudochernozemsandtheprocessesleadingtotheirformationretro-gressive soil evolution.Thefollowingagriculturalprocessesareinvolvedinthesoiltransformation:calcareous-magnesiumamendmentsblocktheleaching;cerealrootssimulatethesteppeconditions;thedeepploughinghomogenisesthesoilandthedistributionoftheorganicmaterialintoalargethickness.
The soil development recorded aprincipal turning point in placeswherewoodlandalternatedwiththesteppe.ThepolygenicChernozem(orpseudocher-nozem)startedtoexistwhenthevegetationontheLuvisolstransformedintoculturalsteppes(Smolíková1969).Bythemethodofsoilmicromorphology,wearenotabletobringanyexactconclusionconcerningthetimeofthevegetationchange.Weknowthatagriculturehasbeenpresentatthesiteforaverylong
FROM CHERNOZEM TO LUVISOL OR FROM LUVISOL TO CHERNOZEM? … 495
time–forthousandsofyears.AccordingtoAlexandrovskyi(2007),theformationofChernozemscanbeachievedwithin3000years.Thestudiedareamayhavebeenclearedatdifferentmomentsoftimeinhistory.
IntheEuropeanloessbelt,similarstudiesconcerningthepotentialofhu-manstoinfluencethesoilpropertiesinanimportantwayhavebeenobserved.Asabrightexampleoftheretrogradesoilevolution,wementiontheLuvisolsinBelgiumwheretheyareconsideredasman-madeAnthrosols(Langohr2001).Intheoceanicconditions,theclimaxvegetationontheloesssoilisadenseforest.InanundisturbedsiteoftheForêtdeSoignesforest,thesoilcanbecharacterisedasaRetisol(verydegradedloesssoils),whereastheagriculturallandintheregioncanbecharacterisedasaLuvisol,whichmeanstheprecursorofaRetisolinthesoilevolutionseries(Langohr2001).800kilometrestotheWestfromthesiteofHrušov,wefindthesamephaseshiftintheloesssoilevolutionseriesasinHrušovcausedbyhumanactivity.ThegenesisoftheLuvisolsisinfluencedbytheorganicandinorganicamendments,pastureintheforest,tillage,erosionandbioturbation(Langohr2001).
ThePhaeozemsinLowerRhinebasinandHallwegloessbeltareanotherexam-pleofhumaninducedchanges(Gerlachetal.2006;Kasielke,Poch,Wiedner2019).InbothcasesthedarksoilswereinitiallydescribedasdegradedChernozems.AfterdeeperanalysistheywerelabelledasLuvicPhaeozemsenrichedbyhighamountofblackcarboncomingfromtheslashandburntechniques.Here,aswellasinthepreviouscases,themaninfluencedthepedogenenisbysettingupofagriculturalpractices.InCzechia,therehasbeensofaronlyonestudyfocusedontheblackcarboncontentinChernozems(Danková,2012),whichdidnotconfirmthefirehistoryofChernozems.IntheHrušovcatena,werecordedpresenceofsomecharcoals,buttheanalysisofblackcarboncontentwasnotperformed.
5. Conclusion
ThedetailedstudyoftheHrušovcatenashowsthatthegivenenvironmentallocalconditionsofthepedogenesisareidentical.Wecanexcludethattheroleofclimate,exposition,reliefandparentmaterialplayasignificantroleinthedifferentiationofthesoilcover.
Maninfluencesthenaturalsoilsbythatmeasuresothatitishardlyabletodis-tinguishbetweenthenaturalandtheanthropogenicsoils.Theanalysedcatenais,therefore,anexampleofatransformingsoilsystem,inwhichtheinitialLuvisolsaretransformedintoChernozemsatthetoppartofthecatena.Ontheotherhand,atthelowerpartofthecatena,weobservetheconservationofaLuvisol,howeverconsiderablyreworkedbyman.Asaresultofcomplexprocesses,weobserveadif-ferentiationinthesoilcoveronasmallscale.
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Asconsequence,Chernozemscannotnecessarilybeconsideredasanindicatorforthepaleoenvironmentofanaturalsteppe.SomeChernozemsmayhavebeenformednaturallyunderconditionsofadrycontinentalclimate,buttherearesomeChernozemswhichareaconsequenceofthepastandpresentagriculturalpractices.ALuvicChernozemisnotanobligatoryproductofthedegradationofaChernozemunderhumidconditions.Apparently,itcanbeaproductofhumaninfluenceonthesoilformingprocesses.
OurresultsareimpossibletoextrapolatetothewholeChernozemregion.ItishighlypossiblethatthescenariosofsoilformationmaybevariouswithinlargeChernozemregionsinCentralEurope.
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ORCID
BARBORASTROUHALOVÁhttps://orcid.org/0000-0002-1430-4967
DAMIENERTLENhttps://orcid.org/0000-0002-0324-2342
LUDĚKŠEFRNAhttps://orcid.org/0000-0003-1032-9953
KRISTÝNAFLAŠAROVÁhttps://orcid.org/0000-0002-9176-8829
PETRKOLAŘÍKhttps://orcid.org/0000-0003-4440-902X