Knowledge about climate changes is crucial for understanding past and current anthropogenic ecosystem changes, but individual palaeoclimate proxies involve different habitat-dependent confounding factors. Continuously ombrotrophic bogs are an excellent system for palaeoclimate reconstructions because their functioning depends tightly on water table depth (WTD), which varies exclusively with the balance between precipitation and temperature. Here, we investigate a 7000-year-long record from the Puscizna Wielka bog (Poland). We focused on developing the first palaeoclimatological reconstruction for the Western Carpathians, which together includes testate amoebae (TA), the isotopic signal in Sphagnum stems (513C and 518O), and plant macrofossils (PM), the latter enabling to trace micro-topographical changes and assess if the consistent ombrotrophic conditions needed for unbiased reconstruction were met. Both the regional (TAREG, PM) and continental (TAEU) calibration training sets were used for quantitative WTD reconstructions. Our WTD reconstructions were compared with the downscaled CCSM3 simulations. Pollen data provided information on the surrounding vegetation. Reconstructed pH and species composition of PM confirmed continual ombrotrophy. At the Middle-Late Holocene boundary (ca 4300-4200 cal yr BP), the TA-rich lawn phase with Sphagnum magellanicum and Eriophorum vaginatum replaced the initial hollow-like phase with Scheuchzeria, Sphagnum sec. Cuspidata and Archerella flavum. The climate driver of this change (decreased humidity) is also suggested by a 100-200 years delayed increase in fir pollen at the expense of spruce. For the last ca 230 years, 513C and TA suggest that the bog had experienced unprecedented drought. The bog was dominated by Sphagnum rubellumdwarf shrub hummocks with Alabasta militaris, Assulina muscorum and Hyalosphenia elegans at this time. Apart from these major changes, we identified several other events that are otherwise documented only by individual studies across Europe for the Late Holocene, especially for the Little Ice Age. Six distinctly wet and five distinctly dry periods were consistent among at least two proxies, with a conspicuously warm and dry climate at the beginning of the Bronze Age, allowing human colonisation of previously harsh mountain areas. The consistency with CCSM3 was the highest for TAREG-inferred WTD and lowest for 518O. The temperature and precipitation of the warmest quarter were the most influential explanatory variables in multiple regression. Additively to CCSM3, isotopes in Sphagnum stems explained some WTD variation reconstructed by TAEU and PM, suggesting a more critical role of the microtopographic position for these proxies. Our results suggest that TA reconcile multiple equivocal reconstructions, reveal subtle fluctuations only occasionally reported by other proxies, and are less affected by climate-independent microtopography. However, the inclusion of PM in palaeoclimatic studies is essential to verify the continuous ombrotrophy of recent bogs.

An undesired succession of rich fens leads to the formation of dense Sphagnum carpets that outcompete brown mosses and some vascular plants, resulting in biodiversity loss in fen habitats of high conservation importance. Small-scale Sphagnum removal is a rarely implemented conservational measure, whose success may depend on soil alkalinity and fertility (i.e., nutrient availability). Therefore, characterizing the effects of pH and fertility levels would potentially allow for the development of better Sphagnum removal strategies. Two experiments were conducted across 24 rich fens of different alkalinity and fertility located in an area of ~32,000 km2 spanning from the Bohemian Massif to the Western Carpathians (Europe). We hypothesized that high alkalinity and low fertility support the restoration of rich fen vegetation after Sphagnum removal. Our study focused on four different Sphagnum groups. In Experiment 1, the treatment plots remained unfenced. In Experiment 2, the treatment plots were fenced off and target brown mosses were transplanted from the surroundings to overcome dispersal limitations. A repeated-measures design was used, with vegetation composition recorded over a 5-year period. High alkalinity rather than fertility facilitated species richness and the appearance of target brown mosses. High alkalinity generally hindered Sphagnum recovery, whereas high fertility supported the recurrence of S. teres and S. recurvum agg. Under high pH conditions, enhanced fertility further correlated with the spread of nonsphagnaceous generalist bryophytes of low conservation value. Despite sustaining a significant overall reduction, all Sphagnum taxa began to recover throughout the experiment, albeit less obviously in fens with S. warnstorfii. Sphagnum removal may reverse biodiversity loss and allow for the restoration of brown mosses in rich fens where Sphagnum cover had increased due to slight eutrophication, acidification, or a decrease in the water table. In alkaline and nutrient-poor conditions (e.g., S. warnstorfii fens), the effect is evident and long lasting and the intervention may not be extensive. In fens dominated by S. teres or S. recurvum agg., repeated or large-scale removal may be needed if high nutrient availability (potassium, phosphorus) or low alkalinity supports Sphagnum recolonization. Treatment plots with S. subgenus Sphagnum exhibited the least promising brown-moss restoration prospects.

Testate amoebae play an important role in biomonitoring and the understanding of peatland (palaeo)ecology. However, their application has been mainly limited to Sphagnum-dominated peatlands, especially ombrotrophic bogs. To facilitate wider use of these microorganisms, we explored their ecology along a gradient from mineral -poor acidic bogs to mineral-rich calcareous fens with tufa formation using a new calibration dataset of over 250 samples from East-Central Europe. Specifically, we examined environmental controls on testate amoebae along the complete gradient and separately in the minerotrophic (pH > 5.5) and ombrotrophic (pH < 5) parts. Based on these findings, we developed and statistically evaluated transfer function models for the dominant factors con-trolling the community composition of these protists. Multivariate statistical analysis showed that groundwater pH was the main driver of species composition in the full and minerotrophic datasets. In contrast, testate amoeba communities in the ombrotrophic dataset were primarily structured by depth to water table (DWT). Under leave -one-out cross-validation (LOO), the best-performing model for DWT gave a prediction error (RMSEP) of 5.43 cm. The most robust models for groundwater mineral richness yielded RMSEPLOO of 0.45 and 0.27 pH units, for the full and the minerotrophic dataset respectively. This is the first study to present a complete set of testate amoeba -based transfer functions that allow reconstructions of Holocene hydrochemical and hydrological (hydroclimatic) variability in different mire types within one region. The new models open up the possibility for testate amoebae to become a valuable tool in palaeoecological research, although further work is needed to fully assess their performance and usefulness in practice.

Aims Classification of European bog vegetation (Oxycocco-Sphagnetea class); identification of diagnostic species for the class and vegetation subgroups (orders and alliances); development of an expert system for automatic classification of vegetation plots; and production of distribution maps of the Oxycocco-Sphagnetea class and its alliances. Location Europe. Methods A data set of vegetation-plot records was compiled to include various bog types over most of the European continent. An unsupervised classification (beta-flexible linkage method, Sorensen distance measure) and detrended correspondence analysis (DCA) ordination were applied. Formal definitions of syntaxa based on species presence and covers, and respecting the results of the unsupervised classification, were developed and included in a classification expert system. Results The Oxycocco-Sphagnetea class, its two orders (Sphagno-Ericetalia tetralicis and Sphagnetalia medii) and seven compositionally distinct alliances were formally defined. In addition to the syntaxa included in EuroVegChecklist, three new alliances were distinguished: Rubo chamaemori-Dicranion elongati (subarctic polygon and palsa mires); Erico mackaianae-Sphagnion papillosi (blanket bogs of the northwestern Iberian Peninsula); and Sphagno baltici-Trichophorion cespitosi (boreal bog lawns). The latter alliance is newly described in this article. Conclusions This first pan-European formalized classification of European bog vegetation partially followed the system presented in EuroVegChecklist, but suggested three additional alliances. One covers palsa and polygon mires, one covers Iberian bogs with endemics and one fills the syntaxonomical gap for lawn microhabitats in boreal bogs. A classification expert system has been developed, which allows assignment of vegetation plots to the types described.

Classification of European bog vegetation ( class); identification of diagnostic species for the class and vegetation subgroups (orders and alliances); development of an expert system for automatic classification of vegetation plots; and production of distribution maps of the class and its alliances. Europe. A data set of vegetation-plot records was compiled to include various bog types over most of the European continent. An unsupervised classification (beta-flexible linkage method, Sørensen distance measure) and detrended correspondence analysis (DCA) ordination were applied. Formal definitions of syntaxa based on species presence and covers, and respecting the results of the unsupervised classification, were developed and included in a classification expert system. The class, its two orders ( - and ) and seven compositionally distinct alliances were formally defined. In addition to the syntaxa included in EuroVegChecklist, three new alliances were distinguished: - (subarctic polygon and palsa mires); - (blanket bogs of the northwestern Iberian Peninsula); and - (boreal bog lawns). The latter alliance is newly described in this article. This first pan-European formalized classification of European bog vegetation partially followed the system presented in EuroVegChecklist, but suggested three additional alliances. One covers palsa and polygon mires, one covers Iberian bogs with endemics and one fills the syntaxonomical gap for lawn microhabitats in boreal bogs. A classification expert system has been developed, which allows assignment of vegetation plots to the types described.

Water resources and associated ecosystems are becoming highly endangered due to ongoing global environmental changes. Spatial ecological modelling is a promising toolbox for understanding the past, present and future distribution and diversity patterns in groundwater-dependent ecosystems, such as fens, springs, streams, reed beds or wet grasslands. Still, the lack of detailed water chemistry maps prevents the use of reasonable models to be applied on continental and global scales. Being major determinants of biological composition and diversity of groundwater-dependent ecosystems, groundwater pH and calcium are of utmost importance. Here we developed an up-to-date European map of groundwater pH and Ca, based on 7577 measurements of near-surface groundwater pH and calcium distributed across Europe. In comparison to the existing European groundwater maps, we included several times more sites, especially in the regions rich in spring and fen habitats, and filled the apparent gaps in eastern and southeastern Europe. We used random forest models and regression kriging to create continuous maps of water pH and calcium at the continental scale, which is freely available also as a raster map (Hájek et al., 2020b; https://doi.org/10.5281/zenodo.4139912). Lithology had a higher importance than climate for both pH and calcium. The previously recognised latitudinal and altitudinal gradients were rediscovered with much refined regional patterns, as associated with bedrock variation. For ecological models of distribution and diversity of many terrestrial ecosystems, our new map based on field groundwater measurements is more suitable than maps of soil pH, which mirror not only bedrock chemistry but also vegetation-dependent soil processes.

Question Filtering vegetation plot records according to sampling size is an essential methodological step in vegetation studies. In fens, the variation of traditionally used plot sizes seems to limit continental-scale syntheses following the Braun-Blanquet approach. Which plot sizes harbour the analogous number of habitat specialists (i.e., diagnostic/indicator species) and capture the main compositional gradients identically? Location Scandinavia, central Europe. Methods The data set of fen vegetation plot records was compiled using large databases and categorised into four distinct habitats. For each habitat, semi-log species-area curves of specialists and other species were fitted using generalised additive models (GAM). In addition, we surveyed 72 sites in a series of plot sizes (0.07, 0.25, 1, 4, 16 m(2)) where we applied, separately for each plot size, Non-Metric Multi-Dimensional Scaling (NMDS) and compared the resulting patterns with Procrustes analysis. Results Consistently across different fen habitats, the species-area curves of specialists increased steeply up to the plot size of 1 m(2), while increasing negligibly in the plot size range of 1-25 m(2). In contrast, the species-area curves of other species displayed mostly linear to linear-exponential trends. NMDS ordinations of medium (1 and 4 m(2)) and large plots (16 m(2)) were the most congruent, while the patterns captured in the ordination of the smallest plots (0.07 m(2)) differed most from the others. Conclusions In fens, plot sizes of at least 1 m(2) describe sufficiently the broad-scale pattern in specialists' diversity as well as the main environmental gradients. The range of plot sizes of 1-25 m(2) may be safely merged in broad-scale analyses of fen vegetation without introducing substantial bias, at least when compared with other possible uncertainty sources.

Subfosilni krytenky, jejichž schranky se dobře zachovavaji v jezernich a raselinistnich sedimentech, jsou cenným zdrojem informaci pro paleoekologicke studie. Na zakladě druhoveho složeni subfosilnich skupin krytenek, doplněných o sedimentologicka a paleobotanicka data, byl popsan komplexni vývoj raselinistě Kotelnice, jenž zahrnuje sest fazi. Studovana lokalita vznikla zazemněnim interkoluvialni deprese na přelomu pleistocenu a holocenu. Inicialni vývojovou fazi byl mineralně chudý mokřad s ostřici Carex rostrata uprostřed smisených borů (~11400-10500 BP), který se po přisunu minerogenniho materialu změnil na živinově bohatý mokřad se skřipinou Scirpus sylvaticus (~10500-8000 BP). Dalsi sesuv půdy podpořil vznik mokřadu s nizkými ostřicemi (~8000-6200 BP). Z teto vývojove faze se dochovaly nejstarsi subfosilni skupiny krytenek, ve kterých dominoval půdni taxon Plagiopyxis penardi a zastupci z celedi Centropyxidae a Difflugiidae. Po zpevněni svahu doslo ke stabilizaci vodniho režimu a poklesu pH vody na lokalitě. Vznikl mokřad s výskytem vrchovistnich druhů rostlin a krytenek (~6200-2500 BP). Nasledujici vývojovou fazi představovalo ombrotrofni vrchovistě, obklopene smrkojedlovým lesem (~2500-1000 BP). Působenim clověka (odlesňovani, pastva) dochazelo k postupnemu zamokřeni, mineralnimu a živinovemu obohaceni lokality a k ustupu vrchovistnich druhů. K definitivni změně vrchovistě na soucasne přechodove raselinistě doslo v průběhu 17. stoleti. Soucasne druhove složeni, podminky prostředi a moderni historie raselinistě Kotelnice jsou podobne ostatnim přechodovým raselinistim v Moravskoslezských Beskydech. Zaznamenaný výskyt ombrotrofniho raselinistě je ale unikatni, neboť vrchovistě (i historicka) jsou v zajmovem uzemi vzacna. Studie byla financovana granty GA CR (P209/17-17712S, P504/17-05696S) a institucionalni podporou MU.

Landslides are an important natural phenomenon of the flysch Outer Western Carpathians that diversify the local topography and provide valuable microrefugia in the geomorphologically uniform region. For the first time, we reconstructed the continuous history of Carpathian landslide wetland - the Kotelnice mire, which initiated at the Pleistocene-Holocene transition, using joint analysis of abiotic proxies, pollen, plant macrofossils and testate amoebae (TA). We utilised modern training datasets of plants and TA to define ecological requirements of species and to determine indicators of either bog or fen habitats. We further compared pollen representation of selected woody species between two landslide-related wetlands and two spring fens, not related to landslides within the study region. The unique feature of the Kotelnice mire is the development of a nearly ombrotrophic bog at similar to 2500 cal BP that was after similar to 1500 years reversed to a poor fen by intense deforestation and pastoralism. Pollen analysis and its intraregional comparison demonstrate a dual refugial role of landslides in the Carpathians. In the Early Holocene and perhaps even in the Late Glacial, landslides provided refugia for warmth-and moisture demanding species (e.g. lime, elm, hazel, beech, maple). On the contrary, they provided shelter for cold-demanding boreal species (e.g. spruce, Eriophorum vaginatum, Sphagnum medium/divinum) in the Middle and Late Holocene. Because the analogous refugial role of landslides at both the recent and the Quaternary time scales has been reported from the flysch-like and volcanite bedrocks across the Northern Hemisphere, landslides deserve more attention in searching for regionally or even globally crucial refugia. (C) 2019 Elsevier Ltd. All rights reserved.

Quaking rich fens dominated by boreal semi-aquatic brown-mosses such as Scorpidium scorpioides and Calliergon trifarium are extremely rare in the Carpathians. These fens harbour endangered species persisting at few localities in the region. However, their phytosociological classification has not been sufficiently solved yet, because they lack Sphagnum species as well as calcicole species characteristic for the Caricion davallianae alliance. A recent pan-European synthesis on fen vegetation suggests that these fens belong to the Stygio-Caricion limosae alliance (boreal rich fen vegetation). The isolated occurrence of this alliance southward of the boreal zone and outside the Alps is rather exceptional and might represent a relict from an early post-glacial period. In this study, we compared phytosociological data for the Stygio-Caricion limosae alliance between Northern Europe and the Carpathians plus adjacent regions (the Bohemian Massif, the Dinaric Alps) using NMDS and cluster analysis. We found that the species composition of brown-moss quaking rich fens in Central and Southeastern Europe corresponds well with that in Northern Europe, confirming their assignment to Stygio-Caricion limosae. We further reconstructed the potential past distribution of the alliance in Czech Republic and Slovakia using available floristic and macrofossil data. Macrofossil data suggest that this vegetation type had been much more common in Central Europe and that today it persists only in ancient fens, showing the long-term stability of environmental conditions. The main causes of its present-day rarity are Middle-Holocene woodland phases in fens and recent water table decreases caused by anthropogenic deterioration of the water regime in the landscape.

The Puścizna Wielka bog is situated in the Orawa-Nowy Targ Basin, surrounded by the Western Carpathians. It is a large raised bog (area over 480 ha, peat thickness up to 10 m) and represents an excellent peat archive of Holocene hydrological changes and climate variability in central Europe. We have collected a 6.3 m long peat sequence from the intact part of the bog. Here, we present preliminary results of testate amoeba subfossil record from the upper 4 m long sequence. Depth to the water table and water pH were reconstructed using an unpublished training dataset from central European peatlands. Our results show that before the 14th century the hydrology was rather stable with moderately wet surface conditions and the dominance of wet indicator species Archerella flavum and Hyalosphenia papilio. We recorded a distinct and short-time wet shift around 1440 AD, corresponding with the onset of the Little Ice Age. Since the mid-16th century, the water table has been gradually decreasing as suggested by the dominance of drought indicator species (e.g. Difflugia pulex, Heleopera sylvatica, Nebela militaris and Trinema lineare). The cause of the water table decrease is unclear because it is difficult to distinguish between climatically and anthropogenically driven changes of the bog hydrology in this development phase. Our preliminary results are in good agreement with other reconstructions derived from bog sequences in the Orawa-Nowy Targ Basin and central Europe. We acknowledge the support of grant no. 17-05696S from the Czech Science Foundation.

Krytenky (Amoebozoa & SAR) tvoři polyfyletickou skupinu ameboidnich prvoků, kteři si stavi druhově specificke schranky. V poslednich desetiletich se tyto organismy zařadily mezi cenne paleoindikatory, umožňujici rekonstrukci hydrologických podminek jezer a raselinisť v průběhu holocenu. Naroky jednotlivých taxonů se vsak mohou mezi regiony mirně lisit, proto je vhodne popsat vztahy mezi recentnimi spolecenstvy krytenek a faktory prostředi přimo v uzemi, kde bude daný paleoekologický výzkum probihat. Nami vytvořený trenovaci soubor zachycuje recentni ekologicke naroky krytenek na raselinistich v oblasti Zapadnich Karpat. Mechova spolecenstva krytenek, chemizmus vody a hloubka podzemni vody byly popsany celkem na 69 plochach (48 lokalitach) podel celeho gradientu vapnitosti. Druhove složeni spolecenstev krytenek v karpatskem trenovacim souboru primarně ovlivňoval gradient mineralni bohatosti vody, který nejsilněji odražely hodnoty pH vody. Podstatně slabsi vliv na strukturu spolecenstev měl vlhkostni gradient, reprezentovaný hloubkou podzemni vody. Pro zminěne dvě proměnne byly vytvořeny modely přenosových funkci s použitim jack-knife krosvalidace. Nejlepsi modely umožňuji rekonstrukci mineralni bohatosti vody s predikcni chybou ±0,37 jednotek pH a hloubky podzemni vody s chybou predikce ±3,6 cm na raselinistich ve studovanem uzemi. Predikcni schopnosti obou modelů byly negativně ovlivněny předevsim nerovnoměrným odběrem vzorků podel sledovaných ekologických gradientů. Nezbytným krokem proto bude doplněni vzorků z chybějicich nebo meně zastoupených casti gradientu mineralni bohatosti vody a vlhkostniho gradientu. Obsahlejsi trenovaci soubor s vyrovnaným rozloženim vzorků by pravděpodobně zachytil větsi pocet taxonů, zpřesnil znalosti o jejich recentni ekologii a umožnil by použiti přisnějsich filtracnich kriterii, jež by vedly k vytvořeni silnějsich a spolehlivějsich modelů přenosových funkci a kvantitativnich paleorekonstrukci.

Clanek pojednava o nových nalezech druhů Anastrophyllum michauxii, Cephalozia macrostachya, Riccia papillosa, Buxbaumia viridis, Orthotrichum pulchellum, Orthotrichum rogeri, Plagiothecium latebricola, Sphagnum centrale, Straminergon stramineum a Ulota coarctata.

Mosses are important ecosystem engineers in mires. Their pH optima and tolerances differ between regions, even though the high dispersal ability of mosses should prevent local adaptations. Nutrient availability is sometimes suggested as a reason for local niche differentiation. Are patterns in moss niche diversification, optima and tolerance with respect to pH consistent between regions differing in nutrient availability and abundance of calcareous bedrock? Location: Western Carpathians (a predominantly calcareous P- and K-poor region), Bohemian Massif (a predominantly crystalline, P- and K-rich region). Although the regions differ in abundance of calcareous fens, species pH optima were consistent between the regions and data sets. Calcium-tolerant peat mosses showed an optimum at pH 6 and rather narrow niches. Sphagnum fallax was the most acidophilous, and both S.palustre and S.flexuosum had rather wide intermediate niches. The pH amplitudes were largely consistent between the regions, but S.fallax and Aulacomnium palustre exhibited wider niches in the Bohemian Massif. Despite no significant difference in niche optimum and width, some more nutrient demanding and more generalist species occurred at higher frequency in specific parts of the pH gradient in the Bohemian Massif, while some fen specialists showed the opposite pattern. The small stratified data set and the database data set yielded rather consistent results regarding fen moss niches in the Bohemian Massif and the Western Carpathians. The consistency in pH niches corresponds to the lack of large-scale genetic differentiation in moss species. The observed inter-regional differences in species response curves may thus reflect an increased frequency of competitively strong species in certain parts of the pH/Ca gradient in the nutrient-richer Bohemian Massif rather than genetically conditioned niche shifts.

Předložena diplomova prace se zabýva paleoekologickou rekonstrukci vývoje raselinistě Kotelnice za použiti analýzy fosilnich skupin krytenek. Studovana lokalita patři mezi přechodova raselinistě s vegetaci svazu Sphagno-Caricion canescentis a nachazi se na ceske straně Slezských Beskyd pobliž města Jablunkov (okres Frýdek-Mistek). Prostřednictvim přenosových funkci, ktere byly založeny na trenovacim datovem souboru s recentnimi ekologickými naroky raselinistnich krytenek Zapadnich Karpat, byla predikovana hloubka podzemni vody a mineralni bohatost vody (vyjadřena proměnnou pH vody). Komplexni vývoj studovaneho raselinistě byl rekonstruovan pomoci fosilnich skupin krytenek a ostatnich proxy (tj. pylova zrna a spory, makrozbytky rostlin a sedimentologie), ktere byly analyzovany jinými autory. Raselinistě Kotelnice vzniklo zazemněnim interkoluvialni deprese na pocatku holocenu (cca 11370 kal. let BP). Inicialni vývojovou fazi představoval mineralně chudý mokřad s ostřicemi Carex rostrata, C. nigra a C. cespitosa uprostřed smisených borů, který se později změnil na živinově bohatý mokřad se Scirpus sylvaticus (cca 10400 kal. let BP). Sesuv nezpevněneho podloži okolo kalibrovaneho roku 8500 BP pozměnil hydrologicke podminky na lokalitě a umožnil vznik mezotrofniho mokřadu s dominanci Carex canescens. Z teto vývojove faze se dochovaly nejstarsi schranky krytenek, ktere indikuji vysokou hladinu podzemni vody a pH vody. Pozvolnou ombrotrofizaci se na lokalitě okolo kalibrovaneho roku 2560 BP vytvořilo vrchovistě s druhy Eriophorum vaginatum a Sphagnum magellanicum obklopene smrkojedlovým lesem. Působenim raně středověkeho clověka v krajině dochazelo k postupnemu zamokřeni, mineralnimu a živinovemu obohaceni lokality a k ustupu vrchovistnich druhů. Na přelomu 16. a 17. stoleti se vrchovistě změnilo na přechodove raselinistě s raselinikem Sphagnum fallax. Důvodem bylo nahle zvýseni hladiny podzemni vody a pH vody, jež bylo pravděpodobně spojeno s odlesněnim a pastvou během valasske kolonizace. Soucasne druhove složeni, podminky prostředi a moderni historie raselinistě Kotelnice jsou podobne ostatnim přechodovým raselinistim v Moravskoslezských Beskydech. Zaznamenaný reverzni vývoj z vrchovistě na přechodove raselinistě, způsobený lidskou cinnosti, je ale unikatni nejen pro zajmove uzemi, kde jsou ombrotrofni raselinistě vzacna, ale i v ramci celeho světa.

In the last decades testate amoebae became a valuable proxy for paleoreconstructions, especially as indicators of past lake and mire hydrology. To date, the greater part of paleoecological studies has been carried out on ombrotrophic mires worldwide. On the contrary, only a few studies have focused on groundwater-fed fens, where these organisms have also been used for pH inference. We investigated the relationship between testate amoebae communities, species composition of vegetation and environmental factors along the complete poor-rich gradient in mires of the Western Carpathians. The resulting data were then used as a base for transfer functions development. Testate amoebae communities from 22 mires (32 sites) were collected. The effect of water chemistry, depth to the water table (DWT), Ellenberg indicator values (EIVs) and vegetation composition was tested using redundancy analyses. The major variation in testate amoebae species data was related to the poor-rich gradient (represented either by EIV soil reaction or by water pH), while the second most important environmental factor controlling the species composition of communities was DWT. For these two significant environmental factors the transfer function models were constructed using jackknife cross-validation. Performance of the models was improved by selectively removing rare species and outlier samples from the data set. The best transfer function models allow for reconstructions of environmental conditions in mires of the Western Carpathians from fossil testate amoebae species data with prediction error of ±0.56 values for pH (PLS, 5 components) and of ±7.05 cm for DWT (WA-PLS, 2 components). Our results are generally consistent with previous studies on testate amoebae ecology from other regions, but contrary to most of them they describe species composition changes along the complete pH gradient. The strong correlation between pH and testate amoebae species composition highlights the importance of these unicellular organisms in paleoecology.