Petra Hájková

• PhD
• Masaryk University

In recent decades, global change and local anthropogenic pressures have severely affected natural ecosystems and their biodiversity. Although disentangling the effects of these factors is difficult, they are reflected in changes in the functional composition of plant communities. We present a comprehensive, large-scale analysis of long-term changes...

Alien plant invasions have been systematically studied for more than half a century and we already have extensive scientific evidence of their negative role in the current biodiversity decline. Here we aim to draw attention to expansive plants, i.e. native plant species that exhibit similar ecological behaviour to invasive alien plants, being promo...

Quantitative paleoecological reconstructions using biological proxies, such as diatoms, Cladocera, and chironomids, have revolutionized paleolimnology and have greatly contributed to the understanding of the past local and regional environmental changes, as well as to nature conservation. While macrophytes are good ecological indicators, they have...

Northern glacial refugia are a hotly debated concept. The idea that many temperate organisms survived the Last Glacial Maximum (LGM; ~26.5 to 19 thousand years) in several sites across central and northern Europe stems from phylogeographic analyses, yet direct fossil evidence has thus far been missing. Here, we present the first unequivocal proof t...

We describe the vegetation of small-sized non-forest wetlands in the forests of Bystrá dolina, located in the western part of the Pilsko massif in the Orava region of northern Slovakia. The sites are situated between 1126 and 1293 meters a. s. l. In the vicinity of active springs or streams, a spring habitat of national interest has been inhabited...

Plant macro-remains provide valuable environmental information of the past, but reconstruction of past vegetation is challenging, because a macrofossil sample may include material from various habitats and also because its species composition is biased and incomplete. Therefore, we aimed to propose, test and evaluate an objective tool for data reco...

15 The historical development of the vegetation of semi-dry grasslands in Central Europe is 16 not satisfactorily understood. Long-term continuity of open vegetation or, conversely, 17 deep-past forest phases are considered possible sources of current extreme species 18 diversity of these ecosystems. We aimed to reveal trajectory of paleovegetation...

According to the International Code of Phytosociological Nomenclature, a younger name of a syntaxon may be conserved against its older name to improve the stability of the nomenclature and avoid misunderstandings in scientific communication. Here, we propose conserving the name Philonotidion seriatae Hinterlang 1992 for arctic-alpine, bryophyte-dom...

Quantitative paleoecological reconstructions using biological proxies, such as diatoms, Cladocera, and chironomids, have revolutionized paleolimnology and have greatly contributed to the understanding of the past local and regional environmental changes, as well as to nature conservation. While macrophytes are good ecological indicators, they have...

Peat is an important archive allowing the reconstruction of past mire environments and surrounding vegetation. The Pihoviny site, one of the oldest peat deposits in the Bohemian-Moravian Highlands, was analysed for macrofossils and pollen and compared with other profiles in the region. The local mire development started in the Late Glacial as sedge...

Understanding large‐scale drivers of biodiversity in palustrine wetlands is challenging due to the combined effects of macroclimate and local edaphic conditions. In boreal and temperate fen ecosystems, the influence of macroclimate on biodiversity is modulated by hydrological settings across habitats, making it difficult to assess their vulnerabili...

W latach 2022 i 2023 podjęto prace geologiczno-geobotaniczne i chronostratygraficzne zmierzające do rekonstrukcji rozwoju wybranych torfowisk wysokich i przejściowych w Masywie Śnieżnika. Celem pierwszego etapu tych badań jest określenie genezy badanych torfowisk oraz wyznaczenie początku ich rozwoju na podstawie oznaczeń wieku radiowęglowego spągu...

The class Montio-Cardaminetea includes vegetation of springs with constant water flow. These habitats, which function as islands for highly specialized and sensitive biota, are endangered by ongoing landscape and climatic changes. Although a harmonized classification into vegetation units is necessary for effective habitat conservation, there is cu...

Aims and background Groundwater-dependent minerotrophic fens are globally threatened biodiversity hotspots. The supply of groundwater keeps their soil thermally stable and mitigates climatic extremes by thermal buffering. This stability has been shown to influence species composition variation at the between-site scale but has not been studied at...

The drivers of the long-term development of high-mountain woodlands are still unexplored in the central European mountains north of the Alps, where archaeologists and palaeoecologists traditionally report no significant human influences on vegetation before the late Middle Ages. Recent but fragmentary palaeoecological reports are gradually changing...

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 fert...

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 mine...

Continentality is a globally significant gradient influencing broad-scale biogeographical patterns. An excellent example is the transition from the European temperate forest biome to the continental steppe and forest-steppe of Eurasia. One of the biogeographic crossroads where the two biomes meet is the Western Podillia in the western part of Ukrai...

While the importance of conservation mowing for mesic grasslands is generally accepted, its use for fens and fen grasslands interspersed within agricultural land is still controversial. Although fens may persist naturally, ongoing environmental changes increase productivity and accelerate succession. These processes can be mitigated through conserv...

This poster presents the results of our study „Ecology of testate amoebae along an environmental gradient from bogs to calcareous fens in East-Central Europe: development of transfer functions for palaeoenvironmental reconstructions“ published in Palaeogeography, Palaeoclimatology, Palaeoecology – issue September 2022. DOI of the paper is 10.1016/j...

Increasing evidence for the effects of Holocene history on modern biotic communities suggests that current explanations of community patterns and conservation strategies require revisiting. Here we focused on Central European rich fens that are at high risk among mire habitats because of their relatively low environmental stability, and hence sensi...

Rising temperatures may endanger fragile ecosystems because their character and key species show different habitat affinities under different climates. This assumption has only been tested in limited geographical scales. In fens, one of the most endangered ecosystems in Europe, broader pH niches have been reported from cold areas and are expected f...

We report new maxima of vascular plant species richness ever recorded in 10-m2 plots (115 and 110 species in two adjacent plots). Both come from a steppe meadow at a well-known site Valea Lui Craiu, located in the Fânaţele Clujului grassland complex close to the city of Cluj in Transylvania, Romania, where maximum values have been observed before....

Question : Rich fens of the Sphagno warnstorfii-Tomentypnion nitentis alliance require a specific combination of base richness and climate to occur. Their rarity at the southeastern margins of their European range has previously prevented rigorous vegetation classification. We asked how many associations may be delimited here and whether some of th...

Groundwater-dependent ecosystems represent globally rare edaphic islands of scattered distribution, often forming areas of regionally unique environmental conditions. A stable groundwater supply is a key parameter defining their ecological specificity, promoting also soil thermal buffering. Still, a limited number of studies dealt with the importan...

Czech forestry is in an ecological, economic, political and social crisis. A bark beetle disaster has ravaged Czech forests, while the landscape is affected by a huge change. The price of timber and firewood has dramatically dropped. A conflict between economic and environmental ideologies is considered a basic problem of Czech forestry. To cultiva...

Human activities have enormous impact on current biodiversity distribution across all spatial scales. Despite the numerous studies showing the difference between preserved and impaired sites, only little is known about the regional scale. Therefore, we selected four European regions differing in habitat conservation status (HCS) to explore if the v...

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....

The moss Drepanocladus lycopodioides, considered extinct in the Czech Republic, has been rediscovered. The population occurs in an abandoned sandstone quarry with a shallow water pool; the site known as Lom Rasová is located in the Bílé Karpaty Mts (the White Carpathians) in the south-eastern part of the Czech Republic. The species has not been rec...

Calcareous and rich fens harbour the unique biodiversity of plants and invertebrates. They areextremely sensitive to landscape changes because oftheir island nature. In the Carpathians, theyare still well-preserved, but their number has substantially decreased. Knowledge about theirvariability and classification into vegetation units, a baseline fo...

Palaeoecological analyses of old peat deposits can bring information on the past distribution of bryophyte species. In this paper, we report historical occurrence of fen mosses that are currently rare and declining in Central Europe. This paper brings new data about the presence of fen mosses in old peat deposits in (i) the forest-steppe zone of Uk...

Water resources and associated ecosystems are becoming highly endangered due to ongoing global environmental changes. Spatial ecological modelling is a widely used tool 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....

The Western Carpathians have recently been examined by several palaeoecological studies. However, they are still a region that remains underexplored in terms of the Holocene history of mountain woodlands. We analysed an 8,000 years old peat sequence from the southern part of the Western Carpathians (the Bykovo site) for pollen, needles and stomata,...

The extreme species richness of some temperate grasslands is a globally relevant yet understudied phenomenon. Until now, few records from thoroughly sampled, though not permanently fixed, vegetation plots were available. We therefore established a network of 40 permanent 4 × 4-m2 plots in species-rich grasslands of the White Carpathians (Czechia),...

Bioindication systems based on the occurrence of plant species are widely used in vegetation science, palaeoecology, community ecology, geographical modelling and global change biology. Although the existing systems are mostly regional, the development of large-scale vegetation databases calls for the establishment of a pan-European indication syst...

Abstract: Mosses Meesia triquetra, Paludella squarrosa, Pseudocalliergon trifarium, and Scorpidium scorpioides represent umbrella species of pristine rich fens. They are considered to be endangered taxa and glacial relicts in temperate Europe. We analysed species composition of vegetation with the target species in the Alps, Central Europe, the Bal...

The development of biotic communities since the last glaciation has been shaped by both dramatic climate changes and pathways of species colonisation from glacial refugia. Although the growing body of literature has emerged recently on possible scenarios of postglacial colonisation, less is known about the effect of climate. We analysed the dynamic...

We analysed a continuous andwell-dated record of pollen, non-pollen palynomorphs, geochemistry and plant macroremains from the best preserved peat bog in the Bohemian-Moravian Highlands (Czech Republic). Dářko peat bog is an isolated site of a pine bog woodland dominated by the central-European endemic Pinus uncinata subsp. uliginosa. It is protect...

Origin and dynamics of spruce woodlands in central Europe is an important topic due to the current disturbances triggered by bark beetle outbreaks and extreme climatic events. We focused on the Late Holocene development of spruce-dominated woodlands at their southern margin in the Western Carpathians. We analysed eight peat profiles along an altitu...

Western-Carpathian travertine fens developed on deep-circulation groundwater are highly localised and harbour unique communities that combine rare species of calcareous fens and salt marshes, with many species considered glacial or Early-Holocene relicts. Using a multi-proxy palaeoecological approach, we tested the assumption of naturalness and Hol...

Question Filtering of 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. diagn...

This paper reports the results of new malacological analyses from a thick tufa sequence at Direndall (Luxembourg). The study is temporally contextualised with radiocarbon dates and an age–depth model. The malacological study focuses on species associations to reconstruct palaeoenvironmental developments. The gradual appearance of several shade-dema...

This paper reports the results of new malacological analyses from a thick tufa sequence at Direndall (Luxembourg). The study is temporally contextualised with radiocarbon dates and an age–depth model. The malacological study focuses on species associations to reconstruct palaeoenvironmental developments. The gradual appearance of several shade-dema...

Research on past abrupt climate change and linked biotic response is essential for understanding of the future development of biota under changing climatic conditions, which, in turn, is necessary for adequate progress in ecosystem management and nature conservation. The present study presents the first comprehensive reconstruction of local and reg...

Aims: Western Podolia is one of several regions in the Eurasian forest-steppe zone where diverse steppe vegetation has been relatively well preserved. Our aims were to describe compositional turnover of steppe vegetation along different environmental gradients, to identify the patterns of species richness and evenness across complete compositional...

Calcareous fens represent an endangered type of peatlands, acting as refugia for stress-tolerant species in the currently changing landscapes. The resurveys across many regions have reported their recent disappearance or deterioration despite both the extreme habitat conditions (carbonate richness, presence of calcareous tufa, nutrient limitation,...

We report new maximum values of vascular plant species richness ever recorded at 10 m2 and 16 m2-plots. Both come from sites where world record species numbers were reported before but from different plot size or with indication of different management regime. Our results support the view that extreme species richness is a temporally stable feature...

Question Fens have a well‐developed bryophyte layer covering most of the ground. Non‐sphagnaceous bryophytes, especially the group of so‐called brown mosses, prevail over sphagna under alkaline conditions. In sub‐alkaline conditions, rich fens allow the co‐occurrence of both these functional groups, but sphagna are competitively superior over non‐s...

The proportion of taxa in a pollen spectrum may not correspond to their proportion in vegetation. Quantitative reconstruction models therefore consider pollen productivities or fall speeds. We argue that azonal presence of spruce, an otherwise zonal tree species, in wetlands may confound the pollen-inferred reconstructions of vegetation cover as we...

We surveyed 17 locations of salt marshes along the Barents Sea coast in northern Norway (Finnmark, Nordkinnhalvøya and Varangerhalvøya), where 86 phytosociological relevés were recorded and analyzed. Two main vegetation groups were identified: Caricion glareosae and Puccinellion phryganodis, both alliances belonging to the class Juncetea maritimi,...

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-Ho...

The southern part of the Western Carpathians is relatively poorly investigated from the perspective of vegetation changes in the Late Holocene. We analysed two fen profiles (Kláťa and Pálenica) in the Slovenské rudohorie Mts (Slovakia), aiming to reconstruct the regional vegetation composition before humans started to have a strong in-fluence to de...

Calcareous tufas are great archives of geochemical information for the reconstruction of past climate. Their importance increases in the regions where other proxies are rare, such as Western Carpathians. Here, we present the first whole-Holocene palaeoclimatic reconstruction for this region based on geochemical proxies. We analysed δ 18 O, δ 13 C...

Modern databases containing large amounts of botanical data are a promising source of new results based on large data analyses. We used a new database of plant macrofossils of the Czech and Slovak Republics to compare the recent distributions of putative relict species of fen bryophytes with their past distributions since the late glacial. All the...

The species richness–productivity relationship is one of the most debated patterns in ecology. Species coexistence theory suggests that it could be tightly linked to the type of nutrient limitation (no limitation, single‐nutrient limitation, colimitation by several nutrients). Yet, the effects of nutrient limitation on the species richness–producti...

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 int...

There is still not enough palaeoecological data from the southwestern part of the Western Carpathians, where mountain ridges steeply rise from the dry and warm Pannonian basin. The reason is a low availability of sites with sediments harbouring fossil remains. In the Považský Inovec Mts, two small protected calcareous wetlands occur in different ge...

Bryophyte species occurring in calcium-rich fens are endangered and retreating in all European countries, including those in Northern Europe, because of fen degradation in intensively exploited landscapes. During our field investigation of mires in northwestern Belarus in July 2017, we discovered new localities of some rare fen bryophyte species. T...

GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (relevés) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots...

Steppe‐tundra is considered to have been a dominant ecosystem across northern Eurasia during the Last Glacial Maximum. As the fossil record is insufficient for understanding the ecology of this vanished ecosystem, modern analogues have been sought, especially in Beringia. However, Beringian ecosystems are probably not the best analogues for more so...

Fluctuations in intensity of human impact and corresponding vegetation changes have been reported from different parts of Europe for the period from the beginning of the 1st millennium ad to the high Middle Ages. In the Bílé Karpaty mountains (White Carpathians), a region well-known for its biologically valuable ancient grasslands, an extensive spr...

A unique remnant of forest dating back to the period 9733–7897 yr BC and consisting of hundreds of tree bases was discovered in the Czech Republic. We aimed to reveal the complex disturbance history of this (sub)fossil forest using dendrochronology, and to describe its detailed plant species composition changes using palaeobotanical techniques. Ana...

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 Sphag...

Aim We investigate whether (1) environmental predictors allow to delineate the distribution of discrete community types at the continental scale and (2) how data completeness influences model generalization in relation to the compositional variation of the modelled entities. Location Europe. Methods We used comprehensive datasets of two community...

Travertine deposits are unique archives for multidisciplinary studies of past climate changes, associated vegetation development and the evolution of human societies. Despite their high potential in palaeoecological and palaeoclimate reconstructions, investigations of travertines are rather scarce in central Europe and particularly in Slovakia. The...

Calcareous tufas are continental open-air carbonates that routinely host evidence of past environmental conditions via well-preserved faunal and floral assemblages. As they mostly comprise of calcite precipitated at ambient temperature, tufas are also suitable targets for geochemical research, especially concerning oxygen and carbon isotopes, and t...

Aim We present the first continental‐scale study of factors controlling the species richness of groundwater‐fed fens, comparing land snails, vascular plants and bryophytes. We separately analyse two ecologically distinct groups differing in conservation value and colonization/extinction dynamics, that is habitat specialists, and matrix‐derived spec...

This study investigates the effects of sample volume, resolution and accumulation time on the interpretation of a mollusc record from terrestrial deposits. We tested (i) if, and to what extent, small sample sizes impoverish the reconstructed mollusc species richness, and (ii) whether fine-resolution sampling is worth the effort. We analysed three m...

Aim Soil pH is considered an important driver of fine‐scale plant species richness in terrestrial ecosystems. However, it is unclear to what extent this relationship is influenced by precipitation, which often directly affects both soil pH and species richness. We asked: (1) what is the relationship between fine‐scale vascular plant species richnes...

Increasing evidence suggests that past human activities have irreversibly changed soil properties and biodiversity patterns. In the White Carpathian Mts (Central-Eastern Europe), a mosaic of hyper-species-rich and species-rich patches have developed in a regularly mown dry grassland in the area of a glassworks abandoned in the eighteenth century. W...

Vertigo lilljeborgi (Westerlund, 1871) is one of the rarest terrestrial snail species in temperate mainland Europe, where it is traditionally considered a glacial relict. This contrasts with its occurrence in northern Europe where it is a widespread species. This species prefers constantly wet habitats that are neutral to slightly acidic and avoids...

Aim The regional co‐occurrence of contrasting bioclimatic elements (warm‐temperate, continental, boreal, arctic‐alpine) may be shaped by the distribution of their glacial or post‐glacial refugia. We tested this hypothesis using pollen proxies in a region where such refugia are expected, but not unequivocally demonstrated. Location East‐Central Eur...

Site-scale species richness (alpha diversity) patterns are well described for many present-day ecosystems, but they are difficult to reconstruct from the fossil record. Very little is thus known about these patterns in Pleistocene full-glacial landscapes and their changes following Holocene climatic amelioration. However, present-day central Asian...

Juncus castaneus and Juncus triglumis are umbrella species of moist calcareous tundra and arctic-alpine initial fens (the Caricion atrofusco-saxatilis alliance), being considered as relicts from the glacial times in Central-European mountains. Here we report their new recent records from the Western Carpathians, where they are extremelly rare, and...

Aims: Phytosociological classification of fen vegetation (Scheuchzerio palustris-Caricetea fuscae class) differs among European countries. Here we propose a unified vegetation classification of European fens at the alliance level, provide unequivocal assignment rules for individual vegetation plots, identify diagnostic species of fen alliances, and...

3 Oddělení vegetační ekologie, Botanický ústav AV ČR, Lidická 25/27, CZ-602 00 Brno Na rašelinné louce nedaleko rybníka Zlámanec u obce Vortová ve Žďárských vrších byl recentně ověřen výskyt kriticky ohroženého suchopýru štíhlého (Eriophorum gracile). Druh zde roste ve společenstvech asociace Agrostio caninae-Caricetum diandrae. Fytocenologické sní...

Questions On‐going rapid loss of fen biodiversity in Central Europe is well known, but rigorous testing of this is complicated. We compared historical and present‐day vegetation plot records from a cultural landscape rich in fishponds, where recent eutrophication and water table manipulations threaten the unique fen diversity. We assess species com...

Aims Phytosociological classification of fen vegetation ( Scheuchzerio palustris‐Caricetea fuscae class) differs among European countries. Here we propose a unified vegetation classification of European fens at the alliance level, provide unequivocal assignment rules for individual vegetation plots, identify diagnostic species of fen alliances, and...

Hilly regions along the Western Carpathian–Pannonian border are phytogeographically important, but their vegetation history remains largely unknown. We analysed two peat cores of Late Glacial origin from a bog woodland in the Malé Karpaty Mts (SW Slovakia) using plant macrofossil, pollen, peat chemistry and charcoal analyses to trace local successi...

Trichophorum alpinum is one of the rarest relic species of the Slovak flora. Up to now, its occurrence was documented on seven localities. Five of them from the Borská nížina lowland (Záhorie region), one from foothills of the Malá Fatra Mts and one from the Vysoké Tatry Mts. Since the 1990s the species has persisted only at one locality in the Vys...

The boreal-arctic species Carex vaginata Tausch (Sheathed Sedge) has been found in Romania in 2014 during research on fen ecology. The species grows in the Rarau Mts., in an alkaline sloping fen of the Caricion davallianae alliance, transitional to Cratoneurion commutati springs (SE margin of Mt. Popii Rarăului, close to Plaiul Todirescu grasslands...