How a Sphagnum fuscum-dominated bog changedinto a calcareous fen: the unique Holocene historyof a Slovak spring-fed mire

PETRA HAJKOVA,1,2* AB GROOTJANS,3,4 MARIUSZ LAMENTOWICZ,5 ELIS

ˆ

KA RYBNIC

ˆ

KOVA,2 MIKULAS

ˆ

MADARAS,6y

VE

ˆ

RA OPRAVILOVA,1 DIERK MICHAELIS,7 MICHAL HAJEK,1,2 HANS JOOSTEN7 and LESL/AW WOL/EJKO8

1Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlar

ˆ

ska 2, CZ-61137 Brno, Czech Republic2Department of Vegetation Ecology, Institute of Botany, Academy of Sciences of the Czech Republic, Brno, Czech Republic3Center of Energy and Environmental Studies, University of Groningen, The Netherlands4Institute of Water and Wetland Research, Radboud University Nijmegen, The Netherlands5Department of Biogeography and Palaeoecology, Adam Mickiewicz University, Poznan, Poland6Daphne, Institute of Applied Ecology, Bratislava, Slovak Republic7Institute of Botany and Landscape Ecology, Ernst-Moritz-Arndt-University, Greifswald, Germany8West Pomeranian University of Technology in Szczecin, Szczecin, Poland

Received 5 March 2011; Revised 23 June 2011; Accepted 25 June 2011

ABSTRACT: In general,mires develop by autogenic succession frommore groundwater-fed tomore rainwater-fed. Thisstudy from a calcareous mire in theWest Carpathians (Slovakia) describes a similar development in the Early Holocene,followed by a reverse development in the Middle and Late Holocene. Pollen, macrofossil and testate amoeba analysesshow that the site started as a minerotrophic open fen woodland. After 10 700 cal a BP autogenic succession led to theaccumulation of at least 1m of Sphagnum fuscum peat. Around 9000 cal a BP, as climate could no longer sustain a stablewater regime, the bog desiccated and a fire broke out. The fire removed part of the peat layer and as a consequencerelative water levels rose, leading to the establishment of a wet minerotrophic swamp carr with Thelypteris palustris,Equisetum sp. and Alnus sp. with extremely slow peat accumulation. After 600 cal a BP, rapid peat accumulation withcalcareous tufa formation resumed as a result of anthropogenic deforestation and hydrological changes in the catchmentand resulting increased groundwater discharge. At present themire still hosts a wealth of relict and endangered plant andanimal species typical of calcareous fens and fen meadows. Copyright # 2011 John Wiley & Sons, Ltd.

KEYWORDS: calcite precipitation; fen development; hydrology; multi-proxy; stratigraphy.

Introduction

Mires are important hot spots of biodiversity as well as globallyrelevant stocks of carbon (Rydin and Jeglum, 2006). As archivesof past environmental change (Chambers and Charman, 2004),they allow us to reconstruct their own long-term history (Talbotet al., 2010) and that of their wider surroundings. Detailedreconstruction of past climate and human impact requires amulti-proxy approach (De Vleeschouwer et al., 2009) and hightemporal resolution (Barthelmes et al., 2010, Lamentowiczet al., 2010), but even lower resolution studies may identifydistinct shifts in peatland development (Hughes and Dumayne-Peaty, 2002, Dudova et al., 2010). Multi-proxy palaeoecolo-gical studies, especially those including macrofossils andtestate amoeba data, thus allow tracking millennial-scalesuccessional pathways, which are impossible to study byconventional ecological research (Hughes and Dumayne-Peaty, 2002). The palaeoecology of groundwater-fed springfens, although being extremely endangered and displayingvarious, barely predictable successional pathways, has beenlittle studied because of the poor condition of their archives as aresult of strong decomposition.In general, peatlands develop autogenically from ground-

water-fed fens to rainwater-fed bogs, as the accumulated peatcreates a larger resistance to inflowing CaCO�

3 and HCO�3 -rich

groundwater with a high pH (Clymo, 1963; Walker, 1970;Kuhry et al., 1993; Soudzilovskaia et al., 2010). RapidSphagnum growth above the water table then results inacidification and ombrotrophication (fen–bog transition).Although this hydroseral succession was often assessed as

autogenic (Walker, 1970; Kuhry et al., 1993; Lamentowiczet al., 2008), some studies have demonstrated that it can bebrought about by allogenic forcing, which leads to contrastingpathways to ombrotrophy (Hughes and Dumayne-Peaty, 2002)or even to reversed succession (Glaser et al., 1990; Hughes andDumayne-Peaty, 2002; Barthelmes, 2009). Such divergencesfrom common succession patterns may help us to understandthe dynamics of mire ecosystems in general. The Belanske Lukymire in the West Carpathians, where ombrogenous Sphagnumfuscum peat is found beneath calcareous fen deposits(Grootjans et al., 2005), provides a unique opportunity tostudy the extremely rare successional pathway from ombro-trophic bog to calcareous spring fen.In general, spring fens differ fundamentally from ombro-

trophic bogs. They are characterized by a constant discharge ofgroundwater (Grootjans et al., 2006) whose chemical compo-sition differs considerably depending on the size of thecatchment feeding the aquifer and the properties of thebedrock (Hajek et al., 2002). In calcareous mires, precipitationof calcite (CaCO3; marl, travertine or tufa) may occur afterdegassing (CO2 release; Gilvear et al., 1993; Pentecost, 2005).The co-precipitation of phosphorus with iron hydroxides orcalcite makes such mires often very nutrient-poor (Rozbrojovaand Hajek, 2008) and creates habitats for large numbers of low-competitive plant and animal species (Wassen et al., 2005).Many calcareous fens in the West Carpathians are rather

young and have emerged after human settlement somecenturies ago (Rybnıc

ˆ

kova et al., 2005), but older calcareousfens that trace back to theWeichselien Late Glacial exist as well(Hajek et al., 2011). Little detailed information exists on thesuccession of calcareous fens during the Holocene. Severalauthors have described repeated shifts between peat formationand calcite precipitation (Almendinger and Leete, 1998;Futyma & Miller, 2001) and suggested that these shifts reflect

JOURNAL OF QUATERNARY SCIENCE (2012) 27(3) 233–243 ISSN 0267-8179. DOI: 10.1002/jqs.1534

Copyright � 2011 John Wiley & Sons, Ltd.

*Correspondence: P. Hajkova, 1Department of Botany and Zoology, as above.E-mail: buriana@sci.muni.czy Present address: Crop Research Institute Prague, Drnovska 507, 161 06 Prague 6– Ruzyne

ˆ

, Czech Republic

changes in climate (Goudie et al., 1993). However, no studyhas yet described such great reversal in mire succession asindicated by the stratigraphy of the Belanske Luky mire(Grootjans et al., 2005). Here we address the possiblemechanisms for Sphagnum bog formation in a locality suppliedbymineral-rich groundwater, the subsequent unusual shift frombog to fen, and the eventual formation of a calcareous springmire with calcite precipitation.

Study site

The study site, Belanske Luky, (4981203700–4981300800N,2082203800–2082304700E; 670–700m a.s.l.), is the largest springfen in Slovakia. The wetland complex of about 100 ha issituated in the northern part of Slovakia near the High TatraMountains on the southern slope of the River Bela valley closeto the former village of S

ˆ

arpanec. The river has formed severalstrath terraces, one of which is an aquifer that supplies the fenwith calcareous groundwater. The underlying bedrock largelyconsists of Palaeogene sandstones and calcareous claystones,but limestone and conglomerates also occur in the catchmentarea. The climate of the region is moderately warm with wetsummers and cold and dry winters. Mean annual temperature is5 8C and mean annual precipitation is 750mm. The vegetationconsists of groundwater-fed fen, fen meadow and – especiallywhere drainage is evident – small alder and willow forest. Thearea is very rich in orchids such as Dactylorhiza incarnata,Epipactis palustris and the critically endangered Dactylorhizalapponica. The large stands of Pedicularis sceptrum-carolinumprobably constitute the most viable population of this speciesin Europe. The extremely endangered glacial relic snailVertigo geyeri (Vavrova et al., 2009) is also found in BelanskeLuky.

Materials and methods

Peat profiles were studied along seven transects across the mireusing a chamber corer (50 cm length, 5 cm diameter). In June2003, a 2.3-m-long peat profile (SAR-1: 4981205200N,2082303200E) was collected in metal boxes (10� 10� 50 cm)from the wall of a pit dug in the deepest part of the mire (Fig. 1).

In April 2004, a distance of 43m from the first profile, a secondcore (SAR-2: 4981205100N, 2082302900E) was collected with thechamber corer in order to explore mire development in fenhollows with relict species (Carex limosa, Meesia triquetra,Calliergon trifarium) where no Sphagnum macrofossils hadbeen found during preliminary stratigraphical research (Fig. 1).Both profiles were wrapped in plastic film and stored at 4 8C.

To establish an absolute chronology, above-ground plantmaterial (which derives its CO2 solely from the atmosphere, seeTable 2 below) was selected from peat slices (1 cm thick, 5 cmdiameter) from depths with conspicuous palynologicalchanges. The plant material was treated with 5% KOH(5min below boiling point), dried overnight at 40 8C and sentto Poznan Radiocarbon Laboratory (Poland) for 14C acceleratormass spectrometry (AMS) dating. Two earlier bulk datings (50–52 cm depth, Gd-12766; 120–122 cm, Gd-12763) wereadditionally used. All datings were calibrated with the programOxCal v3.10 (Bronk Ramsey, 2005). Bayesian modelling wasperformed in R (RDevelopment Team, 2011) using the softwareBacon (Blaauw and Christen, 2011) to create an age–depthmodel for the SAR-1 profile.

Samples for macrofossil analysis (100 cm3) were takencontiguously (i.e. without interspace) at 5- to 10-cm intervalstaking visible stratigraphic changes into account and sievedinto three fractions (> 1mm, 630mm – 1mm, 200mm –630mm). The larger fractions were analysed using a stereo-microscope with magnifications of 10–40� , whereas one slideof the finest fraction was examined at 100–400�magnificationto identify small seeds (e.g. of Juncus). Seeds were determinedaccording to Berggren (1969), Mauquoy and van Geel (2007)and other available guides and generally checked against thereference seed collection of the Botanical Institute AV CR.Schweingruber (1978) was used for determining tree wood,Gregus (1959) for Vacciniaceae and Ericaceae wood, Hedenas(2003) for brown mosses, and Lange (1982) for Sphagnumspecies. Values are presented as absolute numbers per sample(countable fossils such as seeds or bryophyte stems) or asvolume percentages relative to the original sample volume.

Samples for pollen analysis (ca. 1–2 cm3) were taken at 5-cmintervals and treated by standard acetolysis (Faegri and Iversen,1989). Samples with clastic material were pre-treated with cold

Figure 1. Location of Belanske Lukymirewith position of the study transect and the peat profiles used for palaeoecological analysis (SAR-1 and SAR-2).

Copyright � 2011 John Wiley & Sons, Ltd. J. Quaternary Sci., Vol. 27(3) 233–243 (2012)

234 JOURNAL OF QUATERNARY SCIENCE

concentrated hydrofluoric acid for 24 h. Pollen percentageswere calculated against a pollen sum consisting of pollenattributable to ‘upland’ plant species (i.e. without pollen thatmight have been produced by wetland plants). For calculationand presentation of the palynological data we used thecomputer programs TILIA 1.12, TILIA GRAPH 1.18 andTGView 2.0.2 (Grimm, 2004).Samples for testate amoeba analysis (1 cm3) were taken from

eight selected depths of SAR-1, washed over a 206-mm meshfilter and left standing for 24 h. One millilitre of extract wasanalysed, yielding 600–3500 individuals for determination.The identification of testate amoebae was carried out at thehighest possible taxonomic resolution, and identification wasbased on available literature (Grospietsh, 1958; Ogden andHedley, 1980; Charman et al., 2000; Mazei and Tsyganov,2006; plus specialized monographs Decloitre, 1962; Defla-ndre, 1928, 1929, 1936). To reconstruct pH values, we applieda mixed Pomeranian (148 samples) and West Carpathian(CZþ SK; 37 samples) training set of surface samples fromnatural mires (Opravilova and Hajek, 2006; Lamentowiczet al., 2008). The root mean square error of prediction (RMSEP)was calculated by bootstrap cross-validation (Crowley,

1992) using the model with the lowest RMSEP (weightedaveraging) (r2¼ 0.8, RMSEP(boot)¼ 0.5 pH). To reconstructwater level we applied an Alpine Swiss training set(r2¼ 0.81, RMSEP(boot)¼ 4.88 ; Lamentowicz et al., 2010).The trophic status of the peatland was reconstructed qualitat-ively, based on testate amoebae and plant macrofossils.To study groundwater flow patterns we placed piezometers

at various depths across the spring mire (transect G; see Fig. 1).Temperature profiles were measured in this transect inJune 2003, using a 2-m-long steel probe with a temperaturesensor at the base.Groundwater was sampled using PVC bottles, which were

filled to the brim. The samples were stored at 4 8C in the darkbefore analysis in Groningen. The concentration of SO2�

4 andCl� in the water was determined with an auto analyser (Skalar5100), that of Mg2þ, Kþ, Ca2þ and Naþ with atomic absorbtionspectroscopy (Perkin-Elmer 3030 and Varian 220FS). HCO�

3was determined titrimetrically. Electric conductivity (WTWRetsch) and pH (Sentron 1001) were measured in thelaboratory.Soil samples were taken from the upper 10 cm, dried at room

temperature and sieved through a 2-mm mesh. CaCO3 content

Table 1. Stratigraphy and lithology of the SAR-1 and SAR-2 profiles.

Depth (cm) Troels–Smith system Description

SAR-1 (pit)0–3 – Recent vegetation with snail shells3–35 Th43, Tb (Hyp)þ 3, Dgþ , Dhþ , Asþ Brown-moss sedge peat35–55 Th33, Tb (Hyp)13, Dgþ , Dhþ , Gaþ Moderately decomposed brown-moss sedge peat55–120 Tl22, Thþþ2, Dg2, [A] Very decomposed wood and herbaceous peat120–132 Tb (Sph)22, Th1, Dg1 Well-preserved Sphagnum peat132–180 Tb (Sph)32, Thþþ, Dg1 Well-preserved Sphagnum–Polytrichum peat180–205 Tb (Sph)32, Thþþ, Dg1 Well-preserved Sphagnum–Polytrichum peat205–210 Th1, As2, Dg1, Tlþþ, [A] Clay with herbaceous wood peat and small pieces of charcoal210–225 Th12, As3, Tlþþ, Gaþ , [A] Clay with herbaceous wood peat and small pieces of charcoal225–235 As2, Ga2 Clay with sandBelow 235 Asþþ, Gg(min)2, Gg(maj)2 Fluvioglacial gravel

SAR–2 (core)0–10 – Recent vegetation10–28 Tb (Hyp)33, Th13, Dgþ , Dhþ Brown-moss sedge peat with calcite and snail shells28–41 Th33, Tb (Hyp)13, Dgþ , Dhþ , [A] Brown-moss sedge peat with calcite precipitation41–52 Tb (Hyp)23, Th13, Dg1, Dhþ , [A] Brown-moss sedge peat with calcite precipitation52–105 Tl32, Thþþ, Dgþ , [A] Slightly decomposed wood peat105–110 Gg(maj)2, Gg(min)1, As1, Dhþþ, Dlþ , [A] Fluvioglacial gravel with clay and small pieces of charcoal

Tb (Hyp), moss peat; Tb (Sph), Sphagnum peat; Th, herbaceous peat; Tl, wood peat; Dh, herbaceous detritus; Dg, granular detritus; Dl, wood detritus;As, fine clay; Ga, fine sand particles; Gmin, small stones; Gmaj, large stones; [A], charcoal.

Table 2. 14C samples and dating results of the Belanske Luky peat profiles.

SampleDepth(cm)

Datingmethod

Age(a BP)

Calibrated age(cal a BP, 95.4% interval) Material

SAR-1 (excavated pit)Poz-23804 38–39 AMS 350�35 494–314 PotentillaþCarex fruitsPoz-35892 40–42 AMS 590�30 652–537 PotentillaþCarex fruitsGd-15820 50–52 conventional 3490� 60 3940–3630 bulkPoz35891 59–63 AMS 5160� 40 5995–5755 Eupatorium fruitsþ charcoalPoz-23805 97–98 AMS 8000� 50 9011–8655 charcoalPoz-23806 117–118 AMS 8550� 70 11 080–10 589 Sphagnum stemsGd-12763 120–122 conventional 9010�105 10 560–9760 Bulk (Sphagnum)Poz-2380 197–198 AMS 9500� 50 10 648–10 285 Sphagnum stemsPoz-23776 216–217 AMS 9290� 50 11 080–10 589 charcoal

SAR-2 (core)GrN-30199 51–54 conventional 3090� 40 3391–3212 bulkGrN-30200 96–99 conventional 8000� 70 9030–8631 wood

Copyright � 2011 John Wiley & Sons, Ltd. J. Quaternary Sci., Vol. 27(3) 233–243 (2012)

BOG–FEN TRANSITION 235

was determined from the CO2 volume released after addition ofconcentrated HCl in a calibrated apparatus.Nomenclature of vascular plants follows Marhold and

Hindak (1998) and that of bryophytes follows Hill et al.(2006). The names of pollen types are given in italics (inkeeping with the Journal of Quaternary Science style) not insmall capitals (cf. Joosten and de Klerk, 2002).

Results

The age–depth curve of core SAR-1 (Fig. 2), based on nineradiocarbon dates, shows rapid peat accumulation between 11200 and 9000 cal a BP but much slower accumulation between9000 and 6000 cal a BP. Peat accumulation was extremelyslow between 6000 and 600 cal a BP. The latter peat layer wasvery decomposed and contained little recognizable remnants.In the uppermost 42 cm of the profile, i.e. after 600 cal a BP,accumulation rates increased again.

Pollen

The following zones can be distinguished in the pollen diagramof profile SAR-1 (Fig. 3).Subzone SAR-1-A1 (Betula-Polypodiophyta, 230–195 cm;

before 10 800 cal a BP) is characterized by high values of Betulaand Pinus pollen and Polypodiophyta spores. Trees of initialsuccession stages were probably supported by repeated fireson the mire, as indicated by a large amount of microscopiccharcoal and the presence of macroscopic charcoal. Theunderstorey apparently consisted of Sphagnum, other bryo-phytes (Bryales spores) and Cyperaceae, as indicated by thepresence of Gaeumannomyces cf. carici. Pollen of Valerianadioica t. and Potentilla t. indicate the presence of calcareous fen

vegetation in the surroundings of the study site. At the end of thesubzone, Poaceae and Equisetum increase and Vaccinium t.pollen appears.

Subzone SAR-1-A2 (Sphagnum–Vaccinium, 195–118 cm;10 800–9650 cal a BP) is characterized by high frequencies ofSphagnum spores and Poaceae pollen. Polypodiophyta sporesand Betula pollen are present at lower levels than in subzoneSAR-A1. The high values of Sphagnum (up to 40%) andVaccinium (up to 10%) indicate that the mire had becomeacidic and vegetation was no longer influenced by mineral-richgroundwater. The decline of Equisetum spores in the secondpart of the subzone indicates further expansion of a Sphagnum-dominated mire. The presence of pollen of insect-pollinatingherbs (e.g. Cirsium t., Petasites t., Polygonum bistorta t.,Filipendula, Utricularia and Pinguicula cf. vulgaris) indicatesthat nearby parts of the mire complex were still occupied by fenvegetation fed by mineral-rich groundwater.

Zone SAR-1-B (Calluna vulgaris–Sphagnum, 118–98cm;9650–9070 cal a BP) marks the end of Sphagnum dominance(Fig. 4), although abundant Sphagnum spores are still found(Fig. 3). The Calluna vulgaris pollen indicates that the mire wasdrier. Also, Polypodiophyta spores, Picea and Alnus pollenincrease in frequency, whereas Pinus decreases. This probablyreflects regional development around the mire (e.g. Picea, Pinus),but also changes in local vegetation growing in the mire complex(Alnus and pollen of some tall herb species). This stage came to anend by fire, as indicated by burned wood in the peat (Fig. 4).

Zone SAR-1-C (Polypodiophyta–Alnus, 98–38 cm; 9070–400 cal a BP) covers the period after the change of mirevegetation from a Sphagnum-dominated system to a fern-richsystem. In the beginning of this zone, Sphagnum spores andVaccinium pollen suddenly disappear, most likely due to a firethat destroyed the previous bog vegetation and triggeredthe expansion of alder and ferns. Cyperaceae, Equisetum andCichoriaceae undiff. increase in frequency. In this zone themiddle Holocene pollen assemblages are represented verypoorly because of a high degree of peat decomposition.

In Zone SAR-1-D (Cyperaceae–Equisetum, 38–0 cm;ca. 400–0 cal a BP) fern spores and tree pollen (Betula, Alnusand Picea) decrease, while Equisetum and Bryales spores andCyperaceae pollen increase abruptly. The pollen assemblagesreflect distinct calcareous conditions where sedges, small herbs(Potentilla erecta, Pedicularis), grasses and mosses, especiallythose of Amblystegiaceae sensu lato (see macrofossils in Fig. 4)prevail and indicate a vegetation type that is very similar to thatof today. Salix shrubs increased in area, probably replacingalder–spruce forests destroyed as a result of human activity.The increase of Juniperus pollen indicates pasture activitiesin the landscape, which might have taken place even onthe mire itself. The higher densities of Centaurea cyanus,Chenopodiaceae, Plantago lanceolata t., Secale and Triticum t.pollen indicate increasing human activities in the surroundinglandscape.

Plant macrofossils and testate amoebae

Profile SAR-1

The macrofossil (Fig. 4) and testate amoeba analyses (Fig. 5) ofprofile SAR-1 show that before 10 900 cal a BP the site was aminerotrophic, probably semi-open fen woodland (zone 1,Figs 4 and 5). Remains of Pinus sylvestris and Picea/Larixwoodtogether with mycorrhizal Cenococcum geophilum sclerotiaindicate the presence of trees or woody shrubs in the closevicinity of the study site. In the herb layer we recorded remainsof Equisetum stems and leaves of Sphagnum palustre. Testateamoeba assemblages were dominated by Difflugia glans andPlagiopyxis declivis and show close resemblance to recent

0 02

051

0 01

050

0 2000 4000 6000 8000 10000

Depth

cal BP

Figure 2. Age–depth model of Belanske Luky mire (SAR-1 profile).This figure is available in colour online at wileyonlinelibrary.com.

Copyright � 2011 John Wiley & Sons, Ltd. J. Quaternary Sci., Vol. 27(3) 233–243 (2012)

236 JOURNAL OF QUATERNARY SCIENCE

testacean assemblages. pH values reconstructed from testateamoeba data of the top (3 cm) and bottom (220 cm) layers werealso quite similar (7.3 and 7.2, respectively; for all predictedvalues see Table 3). In contrast, the reconstructed water tabledepth values differed slightly between the top (2 cm below thesurface) and bottom layers (9 cm below the surface).After 10 900 cal a BP autogenic succession continued (zone

2, Figs 4 and 5). This is indicated by the presence of Polytrichumstrictum leaf bases, the disappearance of calciphilous testateamoeba species and a sharp decline of reconstructed pH (5). Inthis stage, testate amoeba assemblages are characterized byArcella catinus and abundant Trigonopyxis arcula. The diverseminerotrophic testate community shifted to a poor onedominated by species characteristic of acid, dry Sphagnum.Reconstructed water table depth dropped to 40 cm below thesurface (Table 3) which could explain the establishment ofSphagnum fuscum. Trees, such as Pinus cf. sylvestris and Betulasp., were still present, but not abundant.Between 10 600 and 9650 cal a BP (zone 3, Figs 4 and 5)

Sphagnum peat accumulated rapidly, forming a layer of 100 cmthickness (probably more if part of the peat was later destroyedby fire). Polytrichum strictum, Vaccinium spp. (V. vitis-idaeaandV. uliginosum) andOxycoccus palustris agg. also occurred.The testate amoeba assemblages consisted of acidophilousspecies (e.g. Assulina seminulum, A. muscorum, Trigonopyxisarcula and Arcella catinus) and the reconstructed pH wasextremely low (4.2). The species composition clearly suggestsombrotrophic conditions. At the end of this stage tree coverincreased and testate amoebae of drier habitats such asAssulinamuscorum, Bullinularia indica and Pyxidicula ornata increasedin numbers, indicating drying out of the mire surface, whichcould have led to fires in the desiccated mire. We identified adistinct charcoal layer between 110 and 80 cm (zone 4, Fig. 4)containing large fragments of charcoal of Pinus cf. sylvestrisand Betula sp. wood.The next peat layer (zone 5, Fig. 4; zone 4, Fig. 5) contained

only few determinable macrofossils due to strong decompo-

sition. We found seeds of Eupatorium cannabinum, rhizomesand tracheids of Thelypteris palustris, tissues and spores ofEquisetum sp. and tracheids of Alnus sp. Reconstructed waterlevel was near the peat surface at the beginning of this zoneand then decreased to ca. 8 cm below the surface (Table 3).Reconstructed pH was between 5.1 and 5.5.Between 50 and 42 cm depth (zone 6, Fig. 4; zone 5, Fig. 5),

corresponding to 3400–600 cal a BP, remnants of calciphiloussedges and mosses appear (e.g. Carex davalliana, C. flacca,C. panicea, Philonotis calcarea, Scorpidium cossonii), indi-cating development to a calcium-rich fen. Around 400 cal a BPmany calciphilous vascular plant species, bryophytes andtestate amoeba species were already present. Calcite precipi-tation started quite recently and is clearly indicated by thehigher species richness of all studied taxonomic groups, and byhigher absolute numbers of testate amoebae, of whichCentropyxis cassis, C. sylvatica and Trinema enchelys weredominant. Paraquadrula irregularis clearly indicates a wetcalcareous fen.

Profile SAR-2

Plant macrofossils were also analysed in the second peat profileSAR-2 (Fig. 6) situated further towards the top of the sloping fen,43m south of SAR-1 (Fig. 1). In this profile the Sphagnumfuscum peat layer is entirely lacking and peat accumulation didnot start before 9000 cal a BP. The bottom of the profile isformed by stones and small pieces of charcoal. Apparently,peat formation here started after the fire event recorded in thefirst profile. Vegetation development started with fen woodlandwith Pinus cf. sylvestris and Salix species and an understoreywith Sphagnum palustre, Carex flava sensu lato and Erio-phorum sp. (zone 1, Fig. 6). Later, Alnus cf. glutinosa started todominate the tree layer and the understorey consisted ofnutrient-demanding species of forested springs, such asGlyceria notata, Rubus sp. and Sambucus nigra (zone 2,Fig. 6). At about 3500 cal a BP, large amounts of macroscopic

Figure 3. Relative pollen diagram of Belanske Luky mire (SAR-1 profile; selected curves only). Relative frequencies are presented as actual values(closed curves) and with 5� exaggeration (open curves). Pollen were analysed by Elis

ˆ

ka Rybnıckova.

Copyright � 2011 John Wiley & Sons, Ltd. J. Quaternary Sci., Vol. 27(3) 233–243 (2012)

BOG–FEN TRANSITION 237

charcoal indicate another fire, and similarly to SAR-1,calciphilous fen sedges and bryophytes appeared (Carex nigra,Scorpidium cossonii). Calcite precipitation was recorded in theupper 50 cm of the profile, corresponding to a well-developedspecies-rich bryophyte layer dominated by Scorpidium cossonii.

Peat transects

The peat profiles along the seven transects displayed a similarstratigraphy, with small differences in layering. Therefore weonly show the results of the transect nearest to thepalaeoecological profiles (Fig. 7).We found that the top layers were well preserved. Further

down the profiles several layers of decomposed peat testify toperiods of desiccation. Wood peat was found at the base of the

mire, but also at higher positions in the profile (110–80 cmbelow the surface). The Sphagnum fuscum layer (60–100 cmthick) present in several transects documents the earlyHolocene existence of a Sphagnum fuscum bog at least800m long in a 40- to 80-m broad strip along the slope betweentwo terrace steps.

Present hydrological conditions

Temperature profiles

Isolines of soil temperature closely follow the surface, withlowest temperatures of 6–8 8C on the right-hand side of thefigure at about 1m below the surface (Fig. 8). The highesttemperatures were recorded at the surface and reached about14 8C. Detailed temperature mapping around the area close to

Figure 4. Macrofossil diagram of Belanske Luky mire (SAR-1 profile). Macrofossils are presented in volume percentages (black bars) or as absolutenumbers (grey bars). Vacciniaceae species are shown with 10� exaggeration. Abbreviations: s, seed, fruit; scl, sclerotium; w, wood; nod, nodus(Poaceae); st, lvs, stem and leaves of bryophytes. Not shown in diagram: 0–3 cm: Betula sp. (42 s), Eleocharis quinqueflora (1 s), Fissidens adianthoides(5 st, lvs),Molinia caerulea (2 s), Plagiomnium elatum (3 st, lvs), Valeriana simplicifolia (2 s); 3–11 cm: Betula sp. (1 s); 19–27 cm:Glyceria notata (2 s);27–35 cm: Ranunculus sp. (1 s), Rubus sp. (1 s), Thuidium sp. (7 st), 35–42 cm: Glyceria notata (1 s); 42–50 cm: Ranunculus sp. (1 s), Sambucus nigra(1 s); 55–71 cm: Alnus sp. (wood elements, not quantified); 172–180cm: Andromeda polifolia (w,< 1%); 180–188cm: Betula sp. (3 s).

Figure 5. Composition of testacean assemblages in absolute numbers. For species with low frequency and abundance see Supporting information,Table S1.

Copyright � 2011 John Wiley & Sons, Ltd. J. Quaternary Sci., Vol. 27(3) 233–243 (2012)

238 JOURNAL OF QUATERNARY SCIENCE

the top where cold groundwater discharges and where acomplex of small pools is present shows that highesttemperatures prevail in the pools. At the right-hand side, wesee at 40 cm below the surface higher temperatures (13.5 8C)than at 20 cm (13.2 8C), indicating that warm water from thepools is infiltrating into deeper layers downslope.

Groundwater chemistry

Groundwater analyses from transect G (Table 4) show thatcalcium-poor, iron-rich groundwater is present at the southernflank of the mire. Groundwater from deeper layers (90–200 cm)has lower calcium and also lower chloride concentrations thanthe shallow groundwater that is in the pools and that leaves thepools. Deep groundwater in the mineral soil in the centre (G11)has relatively high sulphate values. Shallow groundwater in thepeat layers has low concentrations of sulphate, but it is very richin calcium and hydrogen carbonate.The CaCO3 content of the top soil along the investigated

transect G is very high between sites G9 and G13 and is the

highest in the pool system, where calcite is visibly precipitating(Fig. 7). Calcite deposition is not restricted to the pools, but alsohas occurred upslope and downslope of the pools.

Discussion

Age determination

Our radiocarbon dates appear reliable as they fit existingknowledge on vegetation development in the region (Jan-kovska, 1972, 1988), such as high representation of Pinus andBetula and the absence of Carpinus, Fagus, Tilia and Abies inthe Lateglacial/Early Holocene. An apparent inversion betweenPoz-2380 (197–198 cm) and Poz-23776 (216–217 cm) couldbe caused by different dating methods (bulk conventionalversus AMS), but the overlap between the 2s ranges of the twodates of about 70 years suggests that both dates may be correct.Two conventional datings from SAR-2 yielded very similar(GrN-30199) or the same (GrN-30200) dates as the AMS

Table 3. Absolute numbers of individuals and number of species of testate amoeba assemblages and pH and water table depth (WTD) predicted bytestate amoebae.

Developmental zone

1 2 3 4 5

Rich-fenwoodland

Poorfen

Sphagnum fuscumhummocks

Waterloggedminerotrophicfen with Alnus

Richfen

Calcareousfen

Depth below surface (cm) 220 190 135 118 70 60 30 3Predicted pH 7.3 5.0 4.2 5.4 5.1 5.5 7.0 7.2Bootstrap error 0.5 0.6 0.5 0.8 0.5 0.5 0.6 0.5Predicted WTD (cm) �9.0 �38 �44.5 �45 �0.2 �8.8 �2.8 þ2.2Bootstrap error 5.5 10.7 10.4 12.2 4.9 5.0 5.0 5.0Absolute no. of individuals per ml 615 3484 788 936 107 46 189 1566Number of species 23 17 13 16 9 11 22 36

Water level below the surface is indicated by ‘�‘ and above the surface by ‘þ ’. Developmental zones correspond to those in Fig. 5.

Figure 6. Macrosossil diagram of Belanske Luky mire (SAR-2 profile). Abbreviations: s, seed, fruit; scl, sclerotium;w, wood; nod, nodus (Poaceae); st,lvs, stem and leaves of bryophytes. Not shown in diagram: 10–19 cm: Betula sp. (10 s), Carex dioica (2 s), Linum catharticum (1 s), Fissidensadianthoides (1 lvs), Sambucus nigra (1 s); 19–28 cm: Betula sp. (1 s), Equisetum sp. (tiss.,< 1%), Eriophorum (1 s), Carex dioica (1 s), Rubus sp. (1 s);28–35 cm: Equisetum sp. (tiss.,< 1%); 35–41 cm: Betula sp. (1 s); 41–51 cm: Equisetum sp. (tiss.,< 1%); 60–69 cm: Sambucus nigra (1 s); 78–87 cm:Betula sp. (2 s), Rubus sp. (1 s); 87–96 cm: Betula sp. (1 s).

Copyright � 2011 John Wiley & Sons, Ltd. J. Quaternary Sci., Vol. 27(3) 233–243 (2012)

BOG–FEN TRANSITION 239

datings from the same depths in SAR-1, allowing directcomparison of the two chronosequences.

Mire system development

We recorded successional development from fen to bog in theEarly Holocene, which corresponds to the classic model of miredevelopment (Walker, 1970; Kuhry et al., 1993; Magyari et al.,2001; Payne, 2011). However, this succession was reversedback to a minerotrophic wetland during the Middle Holocene,and later even to calcareous fen with calcite formation duringthe Late Holocene. According to ecological theory, thesereversals are caused by allogenic impacts (Tansley, 1939),which are represented by fire and human interference with

landscape hydrology in our study. Anyway, the transition froman ombrotrophic bog to a calcareous fen found in our study siteis possible only under a unique combination of climatic,topographic and hydrological conditions and is recorded onlyexceptionally in the literature (cf. Glaser et al., 1990; Hughesand Dumayne-Peaty, 2002; Barthelmes, 2009). Several eventsduring mire development produced this unique succession.

1. Between 10 800 and 9650 cal a BP Sphagnum fuscumbecame established in a groundwater-fed fen. This establish-ment was probably facilitated by topography. Macrofossilanalysis shows that Sphagnum fuscum is entirely lacking inthe higher SAR-2 peat profile, suggesting that the S. fuscumhabitat was restricted to the lower part of the slope. It is notclear what triggered the establishment S. fuscum, but mostlikely a shallow rainwater lens developed in a flatter part ofthe mire during a relatively dry period in which discharge ofcalcium-rich groundwater decreased (Hughes, 2000). Afterestablishment, the Sphagnum layer increased hydraulicresistance and allowed the persistence and expansion ofthe precipitation lens, preventing calcareous groundwater(pH> 6, [Ca2þ] usually> 2mmol/l, [HCO�

3 ]> 4mmol/l)reaching the growing Sphagnum. Testate amoeba assem-blages reflect almost the same pH for the initial fen ca11 000 cal a BP (pH¼ 7.3) and for the recent surface(pH¼ 7.2). Macrofossil analyses, however, reveal the pre-sence of Sphagnum palustre in the Early Holocene fen,suggesting the absence of calcite precipitation. A high pHas reconstructed from testate amoeba assemblages and theoccurrence of Sphagnum species in the peat are not necess-arily conflicting. As long as hydrogen carbonate concen-trations do not exceed 1mmol/l, Sphagnum species cangrow in groundwater-influenced mires (Lamers et al., 1999).

The occurrence of a transitional poor fen between fen andbog is indicated by the abundant presence of the testateamoeba Trigonopyxis arcula and the absence of indicatorsof dry conditions. T. arcula may indicate wetter phases inbog development (Wilmhurst et al., 2002) and has a pre-ference for poor fens in recent spring mires in the WesternCarpathians (Opravilova and Hajek, 2006). After the poorfen stage, ombrotrophic conditions rapidly expanded.Mineral-rich spring water discharging from the upperterraces was probably insufficient to stop the spread ofS. fuscum hummocks, but it is likely that a transitional laggzone existed at the bog margin, as indicated by pollen ofsome wetland herbs (see above). Similar minerotrophic laggzones with Triglochin palustris are still present in the NatureReserve ‘‘Klin’’ (Slovakia), where recent S. fuscum bogsoccur.

2. Around 8500 cal a BP a fire broke out when the climate wasprobably no longer able to maintain a high and stable waterregime and the bog started to desiccate. The top peat layersstarted to decompose and shrub and tree cover increased.Part of the dried out bog apparently caught fire. Macrofossilanalysis (Fig. 4) showed a rather thick layer of charcoalparticles (at a depth of 110–80 cm) in the middle part of theprofile and the absence of other plant remains. After this fire,the peat surface was probably lower and the relative watertable higher. A wet minerotrophic swamp carr with The-lypteris palustris, Eupatorium cannabinum and Equisetumsp. developed at SAR-1, possibly dominated by Alnus(similar to SAR-2) as indicated by the presence of Alnus-wood tracheids. Peat under alder carrs is usually aerated inthe root layer and undergoes strong decomposition (Bennettand Birks, 1990; Barthelmes et al., 2006). This might explainwhy peat accumulation was so slow in this developmentalstage.

Figure 7. Peat stratigraphy along transect G in Belanske Luky mireand CaCO3 contents in the top soil along this transect.

Figure 8. Temperature profiles along transect G, with details in thepool areas.

Copyright � 2011 John Wiley & Sons, Ltd. J. Quaternary Sci., Vol. 27(3) 233–243 (2012)

240 JOURNAL OF QUATERNARY SCIENCE

3. Between 3400 and 600 cal a BP a calcareous mire emerged.The first signs of renewed growth of bryophytes and smallsedges during this period can be observed in the lower partof the spring mire (SAR-1). An exact date for this event isdifficult to give because of the low accumulation rate in thispart of the profile. Higher upslope (in SAR-2) the bryophytesappeared at an earlier stage. Also, calcite precipitationstarted earlier and thus the calcite layer is thicker. Furtherdownslope, calcite precipitation began relatively recently.A similar date (ca. 350 cal a BP) was found for the startof calcite precipitation in a calcareous spring mire veryclose to Belianske Luky (Vysoka Bazic

ˆ

ka spring fen),where peat formation started ca. 5900 cal a BP (Hajeket al., 2011).

Hydrological mechanism behind calciumcarbonate deposition

In peatlands, calcium carbonate deposition usually occurs ifsupersaturated groundwater with high levels of CO2, calciumand bicarbonate is exposed to the air. When groundwater‘escapes’ to the surface and enters the pool system, outgassingof CO2 occurs and CaCO3 (calcite) can precipitate (Pentecost,2005). Calcite precipitation is enhanced by higher tempera-tures and by water plants, such as Chara species andbryophytes, that actively take up CO2 from the water layer.Supersaturated groundwater entering the surface of the mirefrom below can deposit considerable calcite, especially duringwarm summers. When the water again infiltrates into the soil, itcan take up additional CO2 and dissolve even larger amounts ofcalcite that has been deposited in the past. We observed thisprocess in the shallow groundwater of the mire. Grootjans et al.(2006) showed that in a small calcareous mire close to thenearby village of S

ˆ

trba, groundwater flows through a cascade ofpools and deposits calcite on its way. Temperature in the poolsand topmost layers of the mire can gradually reach high valuesduring summer because of repeated infiltration and exfiltration.In this way, calcite is reprocessed and spread over the upperlayers of the mire.

Factors that triggered calcite precipitation

Water chemistry (Ca2þ and Mg2þ concentrations) in BelianskeLuky varies around the threshold for calcium carbonateprecipitation found in the West Carpathians (Hajek et al.,2002) and the species composition of land snail communitiescorresponds rather to fens lacking calcium carbonate precipi-tation (M. Horsak, unpubl. data). Under such conditions, smallchanges in groundwater composition or summer temperaturesmay trigger calcite precipitation (Pentecost, 2005). It appearsthat most calcite precipitation has occurred in small pools. Incore SAR-2, situated directly beneath recent pools, calcite

deposition is much more pronounced and reaches deeper (to50 cm) than in profile SAR-1 (only to 3 cm).Human interference with hydrology could have triggered

calcite deposition on the mire surface. The first impact ofhumans on forests in the recharge area is dated to about 2000BP, when cutting of local forests for metallurgy started(Jankovska, 1972). Further deforestation occurred after 770BP, when German colonists settled in Spis

ˆ

ska Bela, whichquickly became a regionally important town with substantialeffect on the neighbouring land. Whereas forest clearance cancause both increased and decreased runoff (e.g. Warner et al.,1989; Lamentowicz et al., 2007), the simultaneous appearanceof spring-fen elements and human indicators in the pollenspectrum suggests rather increased infiltration in the catchmentand stronger groundwater discharge in the mire. The Germansettlers also modified watercourses in the infiltration areas ofBelianske Luky. Water from natural springs east of the studyarea has since ca. 750 BP been redirected into artificial watercourses cutting through the permeable Pleistocene sediments,which may have added considerable amounts of surface waterto the aquifer feeding the mire (A. Novak, pers. comm.).

Conclusions

The Belanske Luky mire was initiated ca. 11 000 years ago as aminerotrophic fen woodland influenced by alkaline ground-water. After 10 700 cal a BP the mire changed into anombrotrophic Sphagnum fuscum bog. Such bog developmentcan only occur under a special combination of environmentalconditions, i.e. sufficiently wet to allow continuous Sphagnumgrowth and absence of regular inundation with calcareousgroundwater (Granath et al., 2010). Testate amoeba assem-blages indeed suggest the prevalence of lowwater levels. Theselow water levels were probably caused by a relatively dryclimate during the early Holocene, which reduced ground-water discharge from the aquifer, thus preventing regularsurface inundation. Conditions for bog growth deterioratedsubstantially between 9000 and 8600 cal a BP. Parts of the miredried out and were destroyed by fire. The fire event wasfollowed by re-wetting of the mire by spring water. However,hydrological conditions were not favourable for mire devel-opment at this site and peat accumulation rates remainedextremely low. Calcite precipitation started rather recentlyduring a short phase of renewed fen development. We suggestthat human activities including forest clearance and modifi-cation of watercourses in the infiltration areas triggered orstimulated calcite formation in the mire. Our multi-proxyanalyses thus show that large spring mires can have diversedevelopmental histories, which can deviate considerably fromthe standard autogenic mire succession described in theliterature.

Table 4. Groundwater chemistry at various depths along transect G.

Transectstation

Depth(cm)

EC(mS m�1) pH

HCO�3

(mmol l�1)SO2�

4

(mmol l�1)Cl

(mmol l�1)Na

(mmol l�1)K

(mmol l�1)Ca

(mmol l�1)Mg

(mmol l�1)

G5 30–40 43.6 6.6 5097 52 149 422 13 1726 465G11 0–20 53.4 7.2 6261 136 140 222 8 2501 840G11 40–50 50.0 7.0 5848 61 138 287 33 2524 774G11 90–100 47.1 6.7 5239 198 104 191 13 2204 658G11 220 49.8 7.0 5921 59 70 196 15 2117 765G12 40–50 57.8 7.0 7162 24 130 278 8 2850 823G12 200 50.3 6.6 6193 1 110 178 5 2254 638

EC, electrical conductivity.

Copyright � 2011 John Wiley & Sons, Ltd. J. Quaternary Sci., Vol. 27(3) 233–243 (2012)

BOG–FEN TRANSITION 241

Supporting information

Additional supporting information can be found in the onlineversion of this article:Table S1 Testacean species with a low abundance.Please note: This supporting information is supplied by the

authors, and may be re-organized for online delivery, but is notcopy-edited or typeset by Wiley-Blackwell. Technical supportissues arising from supporting information (other than missingfiles) should be addressed to the authors.

Acknowledgements. The Dutch PIN/Matra project PM2001/033funded the ecohydrological research during 2001–2003. P.H., M.H.and V.O. received grant support from project P504/11/0429 (CzechScientific Foundation). Their research was also supported by the long-term research plans MSM0021622416 (Czech Ministry of Education)and AV0Z60050516 (Czech Academy of Sciences). Dr Pim de Klerkand the Palaeo-group of Greifswald University are acknowledged fortheir technical and conceptual support during the research andMaartenBlaauw and Francois De Vleeschouwer for age–depth curve modelling.J. Ripka, M. Horsak and D. Dıte

ˆ

kindly helped with peat sampling andR. Lasak created the map.

Abbreviations.AMS, accelerator mass spectrometry; RMSEP, root meansquare error of prediction.

ReferencesAlmendinger JE, Leete JH. 1998. Peat characteristics and groundwater

geochemistry of calcareous fens in theMinnesota River Basin, U.S.A.Biogeochemistry 43: 17–41.

Bartelmes A. 2009. Vegetation dynamics and carbon sequestration ofHolocene alder (Alnus glutinosa) carrs in NE Germany. Inaugural-dissertation Ernst-Moritz-Arndt-Universitat Greifswald.

Barthelmes A, Prager A, Joosten H. 2006. Palaeoecological research ofAlnus wood peats with special attention to non-pollen palyno-morphs. Review of Palaeobotany and Palynology 141: 33–51.

Barthelmes A, Gerloff D, de Klerk P, et al. 2010. Short-term vegetationdynamics of Alnus dominated peatlands: a high resolution palaeoe-cological case study from Western Pomerania (NE Germany). FoliaGeobotanica 45: 279–302.

Bennett KD, Birks HJB. 1990. Postglacial history of alder (Alnusglutinosa (L. Gaertn.) in the British Isles. Journal of QuaternaryScience 5: 123–133.

Berggren G. 1969. Atlas of seeds. Part 2 Cyperaceae. BerlingskaBoktryckeriet: Lund.

Blaauw M, Christen JA. 2011. Flexible paleoclimate age–depth modelsusing an autoregressive gamma process. Bayesian Analysis 6: 457–474.

Bronk Ramsey C. 2005. OxCal program, Version 3.10. https://c14.arch.ox.ac.uk/oxcal/OxCal.html

Chambers FM, Charman DJ. 2004. Holocene environmental change:contributions from the peatland archive. Holocene 14: 1–6.

Charman DJ, Hendon D, Woodland WA. 2000. The identification oftestate amoebae (Protozoa: Rhizopoda) in peats. Technical GuideNo. 9. Quaternary Research Association: London.

Clymo RS. 1963. Ion exchange in Sphagnum and its relation to bogecology. Annals of Botany 27: 309–324.

Crowley PH. 1992. Resampling methods for data analysis in compu-tation-intensive ecology and evolution. Annual Review of Ecologyand Systematics 23: 405–447.

Decloitre L. 1962. Le genre Euglypha Dujardin. Archiv fur Protisten-kunde 106: 51–100.

DeflandreG. 1928. Le genre Arcella Ehrenberg.Morphologie -Biologie.Essai phylogenetique et systematique. Arch. Protistenk. 64: 152–287.

Deflandre G. 1929. Le genre Centropyxis Stein. Arch. Protistenk. 67:323–375.

Deflandre G. 1936. Etude monographique sur le genre Nebela (Rhi-zopoda-Testacea). Annals. Protist. 5: 201–322.

De Vleeschouwer F, Cheburkin A, Le Roux G, et al. 2009. Multiproxyevidence of Little Ice Age; palaeoenvironmental changes in a peatbog from northern Poland. Holocene 19: 625–637.

Dudova L, Hajek M, Hajkova P. 2010. The origin and vegetationdevelopement of the Rejvız pine bog and the history of the surround-ing landscape during the Holocene. Preslia 82: 223–246.

Faegri K, Iversen J. 1989. Textbook of Pollen Analysis. Revised by KFaegri, PE Kaland & K Krzywinski. Wiley: Chichester.

Futyma RP, Miller NG. 2001. Postglacial history of a marl fen: vegeta-tional stability at Byron-Bergen Swamp, New York. Canadian Journalof Botany 79: 1425–1438.

Gilvear DJ, Andrews R, Tellam JH, et al. 1993. Quantification of thewater balance and hydrogeological processes in the vicinity of asmall groundwater-fed wetland, East Anglia, UK. Journal of Hydrol-ogy 144: 311–334.

Glaser PH, Janssens JA, Siegel DI. 1990. The response of vegetation tochemical and hydrological gradients in the Lost River peatland,northern Minnesota. Journal of Ecology 78: 1021–1048.

Goudie AS, Viles HA, Pentecost A. 1993. The late Holocene tufadecline in Europe. Holocene 3: 181–186.

Granath G, Strengbom J, Rydin H. 2010. Rapid ecosystem shifts inpeatlands: linking plant physiology and succession. Ecology 91:3047–3056.

Gregus P. 1959. Holzanatomie der Europaischen Laubholzer undStraucher. Akademiai Kiado: Budapest, Hungary.

Grimm EC. 2004. TGView 2.0.2. Illinois State Museum, Research andCollections Center.

Grootjans AP, Alserda A, Bekker REM, et al. 2005. Calcareous springmires in Slovakia; jewels in the crown of the mire kingdom. InMires,from Siberia to Tierra del Fuego, Steiner GM, (ed). Stapfia 85: 97–115.

Grootjans AP, Adema EB, Bleuten W, et al. 2006. Hydrological land-scape settings of base-rich fen mires and fen meadows an overview.Applied Vegetation Science 9: 175–184.

Grospietsh T. 1958. Wechseltierchen (Rhisopoden). Kosmos, Stuttgart.Hajek M, Hekera P, Hajkova P. 2002. Spring fen vegetation and water

chemistry in the Western Carpathian flysch zone. Folia Geobotanica37: 205–224.

Hajek M, Horsak M, Tichy L, et al. 2011. Testing a relict distributionalpattern of fen plant and terrestrial snail species at the Holocenescale: a null model approach. Journal of Biogeography 38: 742–755.

Hedenas L. 2003. The European species of the Calliergon-Scorpidium-Drepanocladus complex, including some related or similar species.Meylania 28: 1–117.

Hill MO, Bell N, Bruggeman-Nannenga MA, et al. 2006. An annotatedchecklist of the mosses of Europe and Macaronesia. Journal ofBryology 28: 198–267.

Hughes PDM. 2000. A reappraisal of the mechanisms leading toombrotrophy in British raised mires. Ecology Letters 3: 7–9.

Hughes PDM, Dumayne-Peaty L. 2002. Testing theories of mire devel-opment using multiple successions at Crymlyn Bog, West Glamor-gan, South Wales, UK. Journal of Ecology 90: 456–471.

Jankovska V. 1972. Pyloanalyticky pr

ˆ

ıspe

ˆ

vek ke sloz

ˆ

enı puvodnıch lesuv severozapadnı c

ˆ

asti Spis

ˆ

ske kotliny. Biologia 27: 279–292.Jankovska V. 1988. A reconstruction of the Late Glacial and Early

Holocene evolution of forest vegetation in the Poprad Basin. FoliaGeobotanica 23: 303–319.

Joosten H, de Klerk P. 2002. What’s in a name? Some thoughts onpollen classification, identification, and nomenclature in Quaternarypalynology. Review of Palaeobotany and Palynology 122: 29–45.

Kuhry P, Nicholson BJ, Gignac LD, et al. 1993. Development ofSphagnum-dominated peatlands in boreal continental Canada.Canadian Journal of Botany 71: 10–22.

Lamentowicz M, Tobolski K, Mitchell EAD. 2007. Palaeoecologicalevidence for anthropogenic acidification of a kettle-hole peatland innorthern Poland. Holocene 17: 1185–1196.

LamentowiczM, ObremskaM, Mitchell EAD. 2008. Autogenic succes-sion, land-use change, and climatic influences on the Holocenedevelopment of a kettle hole mire in Northern Poland. Review ofPalaeobotany and Palynology 151: 21–40.

Lamentowicz M, Van der Knaap P, Lamentowicz , et al. 2010. Anear-annual palaeohydrological study based on testate amoebaefrom an Alpine mire: surface wetness and the role of climateduring the instrumental period. Journal of Quaternary Science 24:190–202.

Copyright � 2011 John Wiley & Sons, Ltd. J. Quaternary Sci., Vol. 27(3) 233–243 (2012)

242 JOURNAL OF QUATERNARY SCIENCE

Lamers LPN, Farhoush C, Van Groenendael J, et al. 1999. Calcareousgroundwater raises bogs; the concept of ombrotrophy revisited.Journal of Ecology 87: 639–648.

Magyari E, Sumegi P, Braun M, et al. 2001. Retarded wetlandsuccession: anthropogenic and climatic signals in a Holocene peatbog profile from north-east Hungary. Journal of Ecology 89: 1019–1032.

Marhold K, Hindak F (eds) 1998. Checklist of non-vascular andvascular plants of Slovakia. Veda: Bratislava.

Mauquoy D, van Geel B. 2007. Mire and peat macros. In Encyclopediaof Quaternary Science, Volume 3. Elias SA (ed.). Elsevier: Amster-dam; pp. 2315–2336.

Mazei Y, Tsyganov AN. 2006. Freshwater testate amoebae. KMK:Moscow.

Ogden CG,Hedley RH. 1980.AnAtlas of Freshwater Testate Amoebae.Oxford University Press: London.

Opravilova V, Hajek M. 2006. The variation of testacean assemblages(Rhizopoda) along the complete baserichness gradient in fens: acase study from the Western Carpathians. Acta Protozoologica 45:191–204.

Payne RJ. 2011. Can testate amoeba-based palaeohydrology beetended to fens? Journal of Quaternary Science 26: 15–27.

Pentecost A. 2005. Travertine. Springer: Berlin.R Development Core Team. 2011. R: A language and environment for

statistical computing. R Foundation for Statistical Computing.Vienna, Austria; http://www.R-project.org/.

Rozbrojova Z, Hajek M. 2008. Changes in nutrient limitation ofspring fen vegetation across environmental gradients in the WestCarpathians. Journal of Vegetation Science 19: 613–620.

Rybnıc

ˆ

kova E, Hajkova P, Rybnıc

ˆ

ek K. 2005. The origin and develop-ment of spring fen vegetation and ecosystems - palaeogeobotanicalresults. In Ecology and palaeoecology of spring fens of the West

Carpathians, Poulıc

ˆ

kova A, Hajek M, Rybnıc

ˆ

ek K (eds). Universityof Olomouc: Olomouc; pp. 29–62.

Rydin H, Jeglum J. 2006. The biology of peatlands. Oxford UniversityPress: London.

Schweingruber FH. 1978. Microscopic wood anatomy. Swiss FederalInstitute for Forest, Snow and Landscape Research: Birmensdorf.

Soudzilovskaia NA, Cornelissen JHC, During HJ, et al. 2010. Similarcation exchange capacities among bryophyte species refute a pre-sumed mechanism of peatland acidification. Ecology 91: 2716–2726.

Talbot J, Richard PJH, Roulet NT, et al. 2010. Assessing long-termhydrological and ecological responses to drainage in a raised bogusing paleoecology and a hydrosequence. Journal of VegetationScience 21: 143–156.

Tansley AG. 1939. The British Islands and their Vegetation. CambridgeUniversity Press: Cambridge, UK.

Vavrova L, Horsak M, S

ˆ

teffek J, et al. 2009. Ecology, distribution andconservation of Vertigo species of the European Importance inSlovakia. Journal of Conchology 40: 61–71.

Walker D. 1970. Direction and rate in some British postglacial hydro-seres. In Vegetation History of the British Isles, Walker D, West RG(eds). Cambridge University Press: Cambridge; pp. 117–139.

Warner BG, Kubiw HJ, Hanf KI. 1989. An anthropogenic cause forquaking mire formation in southwestern Ontario. Nature 340: 380–384.

Wassen MJ, Olde Venterink H, Lapshina ED, et al. 2005. Endangeredplants persist under phosphorus limitation. Nature 437: 547–551.

Wilmhurst JM, McGlone MS, Charman DJ. 2002. Holocene vegetationand climate change in southern New Zealand: linkages betweenforest composition and quantitative surface moisture reconstructionsfrom an ombrogenous bog. Journal of Quaternary Science 17: 653–666.

Copyright � 2011 John Wiley & Sons, Ltd. J. Quaternary Sci., Vol. 27(3) 233–243 (2012)

BOG–FEN TRANSITION 243