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Aim Pollen has been used before to reconstruct Holocene plant diversity changes in broadly delimited regions such as continents and countries. In this study we ask whether finer-scale differences in plant diversity, which are of interest to biogeographers and ecologists, are also detectable in the fossil pollen record coming from a single, biogeographically complex region of temperate Europe. Location Central Europe (Czech Republic, Slovakia). Taxon Vascular plants. Methods Fossil pollen extracted from 18 high-quality profiles was used as a proxy of past plant diversity. Pollen counts of tree taxa were corrected by pollen productivities and pollen assemblages were resampled to 100 grains per sample and 150 grains per 500-year time window. SiZer analysis was used to test and visualize multi-scale diversity patterns. SiZer maps were compared using principal coordinate analysis, and linear modelling was used to identify the best predictors. Pollen composition was analysed using non-metric multidimensional scaling. K-means clustering and indicator species analysis were used to interpret ordination results. Results Mean Holocene plant diversity is significantly predicted by latitude, whilst its temporal pattern varies by biogeographical region. Major differences were found between the Mesic and Montane Hercynia (relatively low diversity, increasing only in the Late Holocene) and Pannonia, the Carpathians and the Warm Hercynia (higher diversity, increasing from the Early or Middle Holocene onwards). The low diversity in the Middle and Late Holocene is associated with the prevalence of woody and acidophilic taxa. High diversity is associated with numerous grassland and minerotrophic wetland taxa, crops and weeds. Main conclusions Plant diversity and its changes during the Holocene are geographically structured across temperate Europe. The main causes appear to be differences between biogeographical regions in the dynamics of landscape openness and vegetation composition. The differences reflect spatial patterns in climate and human impact and their temporal changes.

The history and continuity of lowland woodlands in Central Europe is closely connected with human activities. We studied a small wetland situated directly in a low-elevation oak-dominated woodland to evaluate the history and impact of humans on an oak woodland in south-eastern Slovakia. We used different proxies to obtain evidence of woodland history spanning at least 8,500 years. Pollen, diatom and physical analysis, including micromorphology, were used to study infill sediments and to determine the processes causing the influx of material into the wetland basin from its surroundings. The oak-dominated woodland community occurred throughout the Holocene, but its detailed history is impossible to trace because of reverse chronology caused by mixing of deposits. The stability of the oak woodland was determined by anthropogenic disturbances such as grazing. These disturbances are indicated by pollen taxa, signals of soil erosion in the deposits, and local development of the wetland that acted as drinking and hemp retting basin. The recent decline of human pressure has led to gradual changes in the species composition of the wetland itself (shrub encroachment) and of understory of the surrounding oak woodlands.

This research has been supported by the Leverhulme Trust (grant no. RC-2018-023), the European Research Council (grant no. 694481), the German Research Foundation (grant no. FE-1096/6-1), the Swiss Government Excellence Postdoctoral Scholarships (grant no. FIRECO 2016.0310), the National Science Centre of Poland (grant no. 2015/17/B/ST10/01656), the SCIEX Scholarship Fund (grant no. PSPB-013/2010), and the Estonian Research Council (grant no. MOBJD313)., Sedimentary charcoal records are widely used to reconstruct regional changes in fire regimes through time in the geological past. Existing global compilations are not geographically comprehensive and do not provide consistent metadata for all sites. Furthermore, the age models provided for these records are not harmonised and many are based on older calibrations of the radiocarbon ages. These issues limit the use of existing compilations for research into past fire regimes. Here, we present an expanded database of charcoal records, accompanied by new age models based on recalibration of radiocarbon ages using IntCal20 and Bayesian age-modelling software. We document the structure and contents of the database, the construction of the age models, and the quality control measures applied. We also record the expansion of geographical coverage relative to previous charcoal compilations and the expansion of metadata that can be used to inform analyses. This first version of the Reading Palaeofire Database contains 1676 records (entities) from 1480 sites worldwide. The database (RPDv1b – Harrison et al., 2021) is available at https://doi.org/10.17864/1947.000345., Leverhulme Trust RC-2018-023, European Research Council (ERC) European Commission 694481, German Research Foundation (DFG) FE-1096/6-1, Swiss Government Excellence Postdoctoral Scholarships FIRECO 2016.0310, SCIEX Scholarship Fund PSPB-013/2010, Estonian Research Council MOBJD313

AIM: Current species‐richness patterns are sometimes interpreted as a legacy of landscape history, but historical processes shaping the distribution of species during the Holocene are frequently omitted in biodiversity models. Here, we test their importance in modelling current species richness of vascular plants in forest and grassland vegetation. LOCATION: Western Carpathians and adjacent regions. TAXON: Vascular plants. METHODS: Numbers of all species and of habitat specialists were extracted from plot records of forest and grassland vegetation. For each plot, environmental and historical data were derived from thematic maps. Historical data related to the persistence of (a) temperate taxa during the Late Glacial and Early Holocene, (b) open‐landscape taxa during the Middle Holocene and (c) taiga taxa during the Late Holocene were based on 112 fossil pollen profiles. Boosted regression trees were used to model spatial patterns in species richness. RESULTS: Historical variables always appeared among the best predictors of current species richness. In light forests, species richness highly mirrored both the Late Glacial (12.5% contribution) and Middle‐Holocene (8.6%) landscape history. The latter factor became an important predictor also for species richness of steppe grasslands (8.3%) along with temperature seasonality (11.9%). Species richness of dark coniferous forests was best predicted by the Late‐Holocene occurrence of taiga forests (14.8%), which had an even stronger effect on the richness of habitat specialists (20.5%). MAIN CONCLUSIONS: Landscape changes since the Last Glacial Maximum are important predictors of current plant species richness. The historical effects were found to be habitat specific and, because they may interact with recent environmental conditions and anthropogenic pressures, they often show a nonlinear relationship with species richness. We provide one possible direction of incorporating past landscape changes to the models of species richness.

The Western Carpathians have recently been examined in several palaeoecological studies. However, some of their parts remain underexplored in terms of the Holocene history of mountain woodlands. We...

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 ∼2500 cal BP that was after ∼1500 years reversed to a poor fen by intense deforestation and pastoralism. Pollen analysis and its intra-regional 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.

Lowland Scots pine (Pinus sylvestris L.) forests cover extensive areas in Central Europe. Most of them are considered to be the results of relatively recent plantation-oriented forest management. We investigated the long-term history of lowland pine forests in the Zahorska Lowland region of aeolian sands in the northern margin of the Pannonian Basin. Pine monocultures were planted there already in the mid-seventeenth century and currently prevail in the land cover of the region. Our aim was to challenge the commonly accepted idea that the present pine-dominated forests lack connections to pre-plantation pine forests of the Early Holocene. Using multi-proxy data, we compared palaeoeocological data with archaeobotanical data, anthracological finds and evidence on past human settlement. Palaeoecological results suggested a distinct compositional linkage of recent pine-dominated forests with their Early Holocene predecessors. Moreover, no significant change was detected in tree dominants in at least the past two millennia. Contrary to palaeoecology, archeaeobotany suggested that broadleaved trees (mostly oak) dominated during the past 4000 years. However, this result is probably strongly biased by human preferences for wood for specific purposes. On the other hand, pine in palaeoecological data is doubtless overrepresented because of its abundant pollen production. We conclude that pine forests with a significant admixture of oak continuously covered the sandy substrates of the Zahorska Lowland throughout the Holocene. The present pine forests can therefore be considered fairly close to the original vegetation of the study region.

Understanding pollen-vegetation relationships is crucial for accurate land-cover and climate reconstructions, yet important parameters for quantifying past vegetation abundance are mostly unknown for large parts of Europe harbouring temperate thermophilous ecosystems. We collected pollen and vegetation data in central-eastern Europe, a region covered by patchy cultural landscapes of high biodiversity to estimate relative pollen productivity (RPP) for important pollen-equivalent taxa. Our study area was situated in the south-western part of the White Carpathians (Czechia–Slovakia borderland), where we collected 40 modern moss pollen samples scattered over 250 km2 and mapped vegetation within 100 m around each pollen site. Additional vegetation data were compiled from Forest management plans, Natura 2000 habitat mapping and floristic inventories over the entire area. We calculated RPP (referenced to Poaceae) by testing two approaches: the extended R-value (ERV) model by estimating relevant source area of pollen and the REVEALS-based productivity using regional scale vegetation estimates. Two models were applied to depict pollen dispersal: Lagrangian stochastic and the Gaussian plume (Prentice) models. We estimated RPP for 16 taxa using the ERV model and an additional nine taxa using REVEALS. Both approaches found Plantago lanceolata-type to be a high pollen producer, Quercus medium-to-high, Asteraceae subf. Cichorioideae, Anthemis-type, Ranunculus acris-type and Rubiaceae low-to-medium and Brassicaceae and Senecio-type as low pollen producers. Results for other, mainly tree taxa, significantly differed in both approaches mainly due to largely uneven representation in both local and regional vegetation. In comparison with other studies, our data demonstrate a high variability in the estimated RPPs which could be influenced by climatic conditions or potentially vegetation structure. We suggest that the accuracy of RPP estimates could be enhanced by comparing modern pollen data with large-scale vegetation data in the future.

Sedimentary charcoal records are widely used to reconstruct regional changes in fire regimes through time in the geological past. Existing global compilations are not geographically comprehensive and do not provide consistent metadata for all sites. Furthermore, the age models provided for these records are not harmonised and many are based on older calibrations of the radiocarbon ages. These issues limit the use of existing compilations for research into past fire regimes. Here, we present an expanded database of charcoal records, accompanied by new age models based on recalibration of radiocarbon ages using INTCAL2020 and Bayesian age-modelling software. We document the structure and contents of the database, the construction of the age models, and the quality control measures applied. We also record the expansion of geographical coverage relative to previous charcoal compilations and the expansion of metadata that can be used to inform analyses. This first version of the Reading Palaeofire Database contains 1681 records (entities) from 1477 sites worldwide. The database (DOI: 10.17864/1947.319) is available from https://researchdata.reading.ac.uk/id/eprint/319.

AimsReconstruction of the Holocene diversity changes in a biogeographically complex region. Description of major diversity patterns, testing their predictors, and their interpretation in the palaeoecological and biogeographical context. Testing the assumption that pollen record is informative with respect to plant diversity in our study area.MethodsFossil pollen extracted from 18 high-quality profiles was used as a proxy of past plant diversity. Pollen counts of tree taxa were corrected by pollen productivity, and pollen assemblages were resampled to 100 grains per sample and 150 grains per 500-years time window. SiZer analysis was used to test and visualize multi-scale diversity patterns. Linear modelling was used to identify the best predictors. SiZer maps and pollen composition were analysed using non-metric multidimensional scaling. K-means clustering and indicator species analysis were used to interpret ordination results.ResultsMean Holocene plant diversity is significantly predicted by latitude, while its temporal pattern followed the biogeographical region and elevation. Major differences were found between the Mesic and Montane Hercynia (lower diversity, increasing only in the Late Holocene) and Pannonia, the Carpathians and Warm Hercynia (higher diversity, increasing from the Early or Middle Holocene on). Low diversity in the Middle and Late Holocene is associated with the prevalence of woody and acidophilic taxa. High diversity is associated with numerous grassland and minerotrophic wetland taxa, crops and weeds. Fossil-modern pollen diversity and modern pollen-plant diversity show significant positive relationships.ConclusionsPlant diversity and its changes during the Holocene are geographically structured across temperate Europe. Main causes appear to be differences in past dynamics of the landscape openness and vegetation composition, driven mainly by changes in climate and human impact and their different timing. Fossil pollen, if appropriately treated, is a useful proxy of past plant diversity.

Pollen is an abundant fossil and the most common proxy for plant diversity during the Holocene. Based on datasets in open, forest, and mixed habitats, we used the spatial distribution of floristic diversity to estimate the source area of pollen diversity and identify factors influencing the significance of this relationship.Our study areas are Bohemian-Moravian Highlands and White Carpathians (the Czech Republic and the Slovak Republic).Sampling 60 sites in forest and open habitats in two study regions with contrasting floristic diversity, we calculated taxonomic richness (alpha diversity) and total spatial variance (beta diversity) for pollen and floristic data along two transects, each 1 km long. Following this, we calculated the correlation between floristic and pollen diversity. We also assessed the consistency of the relationship in different habitats. Finally, we regressed local contributions of individual sites to the beta diversity of pollen and floristic data in each of the regions.There was a positive correlation between pollen and floristic richness in both habitats in both regions; open and mixed datasets were significant. The highest correlation (adjusted R2) mostly occurred within the first tens of metres (1.5–70) and then within the first hundreds of metres (250–550). Variances of pollen data significantly correlated with variances of floristic data between 100 and 250 m. Local contributions to beta diversity of pollen and plants significantly correlated in the forest and one of the mixed datasets.Floristic richness at the pollen site and position of the site within the landscape structure determine the sequence of the appearing species in the increasing distance. The number of species sets the source area of pollen richness and dissimilarity of appearing species controls the source area of pollen variance. These findings, linking pollen and floristic diversity, provide an essential stepping-stone for the reconstruction of historic plant diversity.

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 (Klaťa and Palenica) in the Slovenske rudohorieMts (Slovakia), aiming to reconstruct the regional vegetation composition before humans started to have a strong influence to determine the major developmental stages of the woodland vegetation and to date significant deforestation events. According to the results of radiocarbon dating, the Klaťa fen initiated around 1230 AD whereas the Palenica fen initiated around 570 CE. Both profiles exhibited small differences in their tree composition and its development. Pollen data indicate a prevalence of Fagus, Abies and Picea, with an admixture of Quercus, Ulmus, Fraxinus, Acer and Tilia in the oldest layers of both profiles. The abundance of spruce pollen was higher in the Palenica fen, where fossilised stomata of spruce provide evidence of its local occurrence. The Klaťa fen, however, exhibited a lower abundance of spruce pollen and was locally more encroached by fir, as evidenced by its macrocopic remains. Young layers of both profiles showed signs of strong deforestation between ca 1530 and 1750 CE,which was indicated by a decrease in pollen of climax trees, an increase in pollen of grassland species and an increase in anthropogenic indicators. Such changes in the composition of pollen spectra clearly coincided with increased human pressure during the colonisationwaves since the 16th century and with the development of industry. Human pressure has had a decisive influence on compositional changes in woodlands and their transformation into grasslands and arable fields.

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 geographical position and contain suitable sediments. One represents a foothill site (initiated ca 13,000 cal. BP) whereas the other a low-mountain site (initiated ca 7,400 cal. BP). We investigated fossil pollen, spores, and macroscopic remains of plants and molluscs from their sediments. We further reviewed archaeological data, constructed a macrophysical climate model (MCM) and confronted it with other palaeoclimatic proxies. Temperate deciduous trees (Quercus, Corylus and Ulmus) occurred since the Allerod, but their expansion was blocked by a harsh climate in Younger Dryas, when Larix, Pinus and Betula nana still occurred. The climate firstly moistened at ca 9,500 cal. BP and more distinctly at ca 8,500 cal. BP, which was reflected by a strong calcium carbonate precipitation and expansion of Tilia cordata t., Hedera helix, and Ustulina. Although the MCM predicted a rather stable climate since 8,000 cal. BP, certain changes in aquatic mollusc abundances may indicate hydrological fluctuations, as they are paralleled by changes in climate humidity indicated by other evidence from the Western Carpathians. Younger hydrological fluctuations may be alternatively explained by human activities as they correspond with macro-charcoal abundance and indicators of wetland openness. During their existence, both fens harboured only few fen plant and mollusc species specialized to low-productive sedge-moss fens. In the Middle Holocene both sites were encroached by woody plants (Alnus, Picea and Salix), as most other spring fens in the Western Carpathians. Contrary to some other spring fens with similar site conditions in the Western Carpathians, few fen specialists established in the study sites since deforestation, presumably because of severe disturbances caused by grazing and/or hemp retting instead of the usual mowing.

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 Bile Karpaty mountains (White Carpathians), a region well-known for its biologically valuable ancient grasslands, an extensive spread of woodland could have occurred in the Migration period (4th–6th century) and especially in the Confinium period (11th–12th century), when settling of this border region was legally prohibited. However, Holocene continuity of non-woodland vegetation was suggested as an explanation for the unique species richness of the local grasslands. If this explanation is true, then the turbulent times in medieval history could not have led to complete re-establishment of woodland. To test this idea palaeoecologically, we analysed four new profiles from wetland deposits for pollen, macrofossils and abiotic proxies, and re-dated some old profiles from the area. The results show the continual presence of human impact indicators since the Migration period in the southwest of the Bile Karpaty, where these unique grasslands occur. Agricultural activities were indicated by pollen of crops, ruderals, weeds and grassland taxa and by macrofossils of fen-grassland plants. Grazing and burning seem to have been the main disturbances during the older period, while mowing of meadows by scythe became more important since the 17th century. Fossil records differed among the sites as a consequence of differences in altitude and disturbance regimes, but converged gradually with time. Despite intensification of human activities, the landscape remained mosaic-like. Indicators of undisturbed woodlands have been detected only in the northeast. Continuous yet perhaps never too intensive disturbances might therefore have maintained the ancient grassland species pool in the long term.

Temperate oak-dominated woodlands are plant communities characterized by relatively open canopy structure and often rich assemblages of light-demanding understory species. This vegetation prevailed in Central European lowlands during the early and middle Holocene. Where open woodlands persisted in later periods, several main factors might have prevented the expansion of shade-tolerant tree species: climate, soil, and disturbances. The last factor includes both natural and human induced agents (fire, grazing of wild or domestic herbivores, management). In our study we focused on the relative impact of the humans and climate on long-term forest vegetation changes in the northerwestern part of the Panonnian Basin. Two peat cores covering the vegetation history of the past 12,000 years have been investigated by means of pollen and charcoal analyses. Palaeoecological data were interpreted in the context of a climatic model and archaeological evidence. Our results showed that the early Holocene vegetation in the study region was composed of open wooded steppe with the dominance of pine. Succession to temperate oak and hazel woodland started in about 7500 cal BP and coincides with the first traces of permanent human settlement in the vicinity of both study sites. Since the Neolithic, different types of woodland management have created a more open forest structure, which has benefited light demanding trees, such as oak and hazel. However, during the middle Holocene several humid oscillations were recorded, which might have triggered the expansion of temperate woodlands. Although the natural or anthropogenic drivers behind the dynamics of temperate woodland could not be separated from each other, it seems probable that long-term human impact influenced the dynamics of temperate woodlands from the middle and late Holocene until the present.

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 Europe (Western Carpathians and adjacent regions). Methods We compiled pollen spectra from 112 sites distributed across various landscapes for six time-periods from the Late Glacial to the present. Compositional patterns were assessed by principal coordinates analyses (PCoA) with a sensitivity analysis based on a bootstrap technique. Site PCoA scores were interpolated geographically and correlated with palaeoclimatic models. Results Consistently over the last 15,000 years, the first ordination axis sorted samples according to the proportion of deciduous temperate trees, while the second axis consistently followed an altitudinal gradient that coincided with temperature. The principal gradient was more important than the altitudinal gradient except for the Late Glacial and Bronze & Iron Ages, when both gradients were of similar importance. The fine-grained pattern in the present mountain landscape was formed as late as during early modern colonization. Main conclusions Since the Late Glacial, the landscape has been differentiated into temperate, continental and cold regions. This finding supports the hypothesis that refugia are a key factor for understanding current biogeography in Central Europe. The Late Glacial occurrence of temperate trees is unlikely to be explained only by gradual migrations from southern Europe. Humid but relatively warm mountains hence might have acted as glacial refugia of temperate forest species, while lowlands and leeward basins might have acted as post-glacial refugia of steppe grasslands. The strong contrast between forested (temperate) and more open continental landscapes during the Early Holocene seems to correspond with recent diversity patterns. Our results highlight the relevance of integrating past landscape trajectories into modern biogeographical models.

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 regional environment at the Western Carpathian/Pannonian Basin border, including a first chironomid-based paleoclimate reconstruction and delta18O and delta13C records from travertine, to investigate abrupt biota and climate shifts since the Marine Isotope Stage (MIS) 2. A range of biotic and abiotic proxy data in organic-calcareous sediment sequence were analysed using a multi-proxy approach to produce a detailed reconstruction of past ecosystem conditions. The results illustrate that the most prominent abrupt change in the local environment occurred directly at the MIS 2/MIS 1 transition at 14,560 cal BP as a consequence of increased precipitation and an increase in reconstructed mean July temperature by -2.2 °C. Abrupt changes in local environment during the early Holocene were closely linked to travertine precipitation rate around thermal springs and thus indirectly to the climate until the arrival of the Late Neolithics around 6400 cal BP. Regional vegetation response (derived from pollen data) to the climatic fluctuations lagged, with the most prominent changes around 14,410 cal BP and 10,140 cal BP. Our data suggest the presence of a steppe-tundra ecosystem with evidence for low amounts of temperate broadleaf trees during the MIS 2, indicating close proximity to their northern glacial refugium. We demonstrate the ability of delta18O and delta13C stable isotope record from travertine to reflect abrupt climatic and environmental changes. The study provides evidence about benefits using travertine deposits coupled with high-resolution paleoecological data to investigate past biotic and abiotic responses to abrupt climate change.

Environmental change can be viewed as the combined result of long-term processes and singular events. While long-term trends appear to be readily available for observation (in the form of temporal comparisons or space-for-time substitution), it is more difficult to gain information on singular events in the past, although these can be equally significant in shaping ecosystems. We examined the past 700 years in the history of a lowland wetland landscape in the Czech Republic with the help of palaeoecological, ecological, landscape archaeological, and archival data. Macrofossil and pollen data were compared to known drainage works in the area and historical climatological data. Trends and events in habitat conditions were assessed using species indicator values. Results showed that ecological succession was the general process in the study area, detected as a trend towards eutrophication, desiccation, and vegetation closure. Short-term events influenced development at the sites mainly from the second half of the nineteenth century. This is consistent with drainage history, although bias related to sample frequency cannot be excluded. On the whole, long-term trends and discrete events were complementary on different scales. We conclude that humans facilitated and accelerated background processes, which can be most likely associated with the succession of open wetlands towards terrestrial ecosystems.

Wildfire occurrence is influenced by climate, vegetation and human activities. A key challenge for understanding fire-climate-vegetation interactions is to quantify the effect vegetation has in mediating fire regime. Here, we explore the relative importance of Holocene land cover and dominant functional forest type, and climate dynamics on biomass burned in temperate and boreo-nemoral regions of Central and Eastern Europe over the past 12 ka BP years. We used an extensive data set of Holocene pollen and sedimentary charcoal records, in combination with climate simulations and novel statistical modelling. Biomass burned was highest during the early Holocene and lowest during the mid Holocene in all three ecoregions, but diverged more markedly over the past 3–4 ka BP. Although the climate was an important driver of fire hazard during the warm and dry early Holocene, tree cover was consistently the strongest predictor of past biomass burning. In temperate forests, biomass burned was high at ~ 45 % tree cover and decreased strongly towards 60 % tree cover. In needleleaf dominated forests, biomass burned was highest at ~ 60–65 % tree cover and abruptly declined at > 65 % tree cover. Biomass burned also increased when arable lands and grasslands reached ~ 15–20 %, although this relationship was highly dynamic depending on land use intensity throughout ignition and fuel type and availability. Our observations cover the full range of Holocene climate variability and land cover changes and illustrates that percentages of land cover is a key predictor of the probability of fire occurrence over timescales of centuries to millennia. We suggest that long-term fire risk may be effectively reduced through land cover management, given that land cover has controlled fire regimes under the dynamic climates of the Holocene.

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 Holocene continuity of the current plant and mollusc communities occupying one of the best-preserved travertine fens in Europe. Our novel results, based on two complete cores throughout the fen deposits, document an anthropogenic origin of the current communities, despite their richness in rare and relict species. The habitat originated in the very beginning of the Holocene, later it was encroached by a semi-open woodland with spruce and alder and then by a dense reed bed that suppressed fen species even more than woodland encroachment. When compared with a fen site on shallow-circulation groundwater, the Holocene succession to woodlands has been blocked by travertine formation, allowing survival of light-demanding relicts in small patches. The current communities were established once the woody plants, and especially reed, were reduced by medieval land use. The community itself is therefore not relict, but it harbours probable descendants of relict populations that survived in neighbouring small refugia throughout the Holocene. Our results strongly support the need for active conservation actions as mowing and extensive grazing, mimicking the traditional type of land use, which has conditioned the recent travertine assemblages in the past.

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 successional patterns, regional vegetation development and occurrence of rare species. The small distance between the two profiles situated within homogeneous vegetation enabled us to explore small-scale differences in local vegetation history. The sediment started to accumulate at the end of the Allerød (ca. 12950 cal. yr BP), when a shallow oligotrophic/mesotrophic lake with macrophytes developed. Open pine-birch forests dominated in the landscape. During the early Holocene, the lake was infilled, mire vegetation appeared and broad-leaved forests spread in the surroundings. Two fire events indicated by increases in number of macroscopic charcoal particles were recorded. The first one, which occurred at the end of the Late Glacial, was found only in one of the profiles, while the second one affected entire mire and probably caused a hiatus spanning the middle and late Holocene. Fagus started to spread no later than 5800 cal. yr BP. Open mire vegetation reappeared after the fire (ca. 400 cal. yr BP). During the 19th century, the mire was overgrown by a birch bog woodland. The two profiles showed basically the same successional patterns, but some local events and occurrences of rare species ( Potamogeton alpinus, Potamogeton praelongus, Scorpidium scorpioides and Pleurospermum austriacum) were traced only in one of them.

The south-western part of the White Carpathians (Czech Republic, Slovakia) is known for its exceptional grassland diversity and occurrence of many species with disjunct distribution patterns, including isolated populations of continental forest-steppe species. The north-eastern part of the mountain range lacks many of these species and has clearly lower maxima of grassland species richness. While climatic and edaphic conditions of both regions largely overlap, their specific environmental history has been hypothesized to explain the exceptional richness in the south-western part. We explored an entire-Holocene record (9650 BC onwards), the first one from the north-eastern part, to find out whether differences in history may explain regional patterns of species rarity and richness. We analysed pollen, macrofossils and molluscs and dated the sequence with 13 radiocarbon dates. We further reconstructed past human activities using available archaeological evidence. Based on this analysis, the Early-Holocene landscape was reconstructed as semi-open with broad-leaved trees (elm and lime) appearing already around 9500 BC. Lime reached a relative abundance of as much as 60% around 8700 BC. All analysed proxies support the existence of dense lime-dominated woodland during the forest optimum starting after climate moistening around 6800 BC, some 2200 years before the first signs of slight forest opening in the Late Neolithic. During the Bronze and Iron Ages, human pressure increased, which led to a decrease in lime and an increase in oak, hornbeam, grasses and grassland snails; nevertheless, forests still dominated the landscape and beech spread when human impact temporarily decreased. Colonisation after AD 1350 created the modern grassland-rich landscape. All available evidence confirmed an early post-Glacial expansion of broad-leaved trees, supporting the hypothesis on their glacial refugia in the Carpathians, as well as presence of closed-canopy forest well before the Neolithic. This environmental history was unfavourable for the survival of Early-Holocene forest-steppe species in the north-eastern White Carpathians and may explain the impoverished grassland flora compared to the south-western part. We conclude that contrasting Holocene histories may explain those patterns in species richness and distributions, which cannot be explained by recent environmental conditions alone.

The distribution pattern of relict and specialised species in calcareous fens was revealed to be non-stochastic, with ancient fens harbouring more of these species than younger ones. This phenomenon could be caused by long-lasting in situ survivals over millennia, but direct palaeoecological evidence is lacking. We addressed the question whether at least some ancient calcareous fens indeed retained open-fen patches throughout the Holocene, using a palaeoecological approach involving proxies with different taphonomies (pollen, vascular plants, bryophytes, molluscs). We identified three old fens in the Western Carpathians, where several postglacial relict species have recently been found, and we reconstructed their histories with respect to sedimentary processes, vegetation structure and dynamics of relict species. The development at all the sites started with a (semi)-open fen community dominated by sedges and brown mosses. The site with the highest recent number of relict species was reconstructed to harbour open patches continually since the late Glacial to the present, including the middle Holocene when open-fen patches were restricted. By contrast, at the site with the lowest recent number of relict species, a large sedimentary hiatus suggested peat mineralisation or erosion that prevented the survival of light-demanding species. At all the sites, characteristic snails of European Glacial periods occurred during fen initiation, but disappeared around the early/middle Holocene transition. The probability of a relict species being present in a modern fen community increases with fen age, but it also depends on the continual existence of open-fen patches and peat accumulation throughout the middle Holocene.

Using a multi-proxy analysis of a postglacial sedimentary sequence from a lowland wetland, we address the possible drivers of change in the wetland habitats and surrounding landscapes of southwestern Slovakia. A 5 m-deep core in the Parížske močiare marshes was investigated for pollen, plant macro-remains, molluscs, organic content and magnetic susceptibility. The palaeoecological record extends from the Pleistocene–Holocene transition (≥11,200 cal. BP) to the 5th millennium cal. BP and was correlated with a macrophysical climate model (MCM) and archaeological data. Our results show the transformation of an open parkland landscape with patches of coniferous forest to a temperate deciduous forest at the onset of the Holocene. The record is remarkable for an early occurrence of Quercus pollen and macro-remains around 11,200 cal. BP and its early expansion (10,390 cal. BP) in the vegetation. Such an early spread of Quercus has not previously been recorded in the region, where Corylus is usually the first to expand among temperate trees. This unusual development of forest communities was most probably triggered by a short-lived increase in precipitation and decrease in temperature, as reconstructed by the MCM model. Higher moisture availability and low temperature inhibited Corylus and favoured the spread of Quercus. Later, the climate became drier and warmer, which, together with fires, supported the expansion of Corylus. Since 7300 cal. BP, human activities became most likely the dominant influence on the landscape. Deforestation contributed to soil erosion, which halted the accumulation of organic material after 5520 cal. BP, followed by the accumulation of clay sediments.

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 well. Based on a large database of vegetation plots from the Western Carpathians, we demonstrate that spruce is the tree species which most frequently colonizes peatlands, more so than alder, whose effect on local pollen spectra has been frequently admitted. Using 73 sequences we further demonstrated significantly greater pollen percentages of spruce of about 20–25% when the sediments contain spruce macrofossils. Finally, we compared the proportions of spruce and beech in modern surface pollen spectra with their real proportions in the surrounding landscape where beech acts as zonal tree. We found that even a small patch of spruce alters the proportion of spruce to beech. By contrast in an open fen we observed pollen spectrum corresponding well with the real proportions of spruce and beech. All these results suggest, contrary to the premises of current models of pollen-based quantitative reconstructions in Central Europe, that fossil pollen counts from wetlands did not underestimate the representation of spruce. Instead, its representation may even be overestimated where it occurred within or in close vicinity of a wetland. We appeal to palynologists to consider macrofossils or stomata in interpretations, and to adjust quantitative reconstruction models for sites that have experienced a woodland history.

Fire occurrence is driven by a complex interplay between vegetation, climatic, landform and human factors making it challenging to separate the individual effect of each variable. Here we present a reconstruction of the Holocene biomass burning history of two regions located in the Central European temperate zone that differ in the timing of the Middle Holocene expansion of broadleaf-dominated forest communities. This allowed us to investigate the effect of biotic changes on past fire activity. Multiple-site charcoal accumulation records were used to estimate regional-scale trends in biomass burning and to compare them with major trajectories of vegetation development. Extensive 14C-dated soil charcoal records collected within both regions were amalgamated using a cumulative probability function to identify a stand-scale proxy of past fire occurrence. Our results suggest that rising vegetation productivity driven by rapid Early Holocene climate amelioration enhanced biomass burning. The increased fire activity during this period was driven by both a drier- and warmer-than-present climate and easily flammable fuels produced by conifer-dominated vegetation. We identified an inhibiting effect of the concomitant Fagus sylvatica expansion on levels of biomass burning that occurred asynchronously between our mountain and mid-elevation sandstone regions 6500 cal yr BP and 4900 cal yr BP, respectively. The amount of compositional change in plant communities was more related to the transformation of major vegetation types than to fluctuations in fire activity levels. The divergent timing of the fire decline in response to the Fagus sylvatica expansion implies biotic control over biomass burning that is independent of a direct climatic influence.

We explored interactions among human activities, landscape development and changes in biotic proxies in two small calcareous spring fens in the Slovak Eastern Carpathians. These date back to cal. a.d. 930. Results of pollen, plant macrofossil, and mollusc analyses were compared with the settlement history. The regional pollen record reflected historical events and changes in the settlement density very well at both study sites. The natural mixed fir-beech-spruce forests with fern undergrowth were suppressed and replaced by light-demanding trees in the periods of high human impact (e.g. Wallachian colonization). The study area was affected several times by wars and raids followed by a consequent decline in the settlement density. Some of these events are well reflected in the pollen records that document tree recovery and decline of cereals, weeds, and pasture indicators. In comparison, only some landscape changes were reflected in the local fen development. Both spring fens originated after deforestation, Roskovce around a.d. 1347 and Mirol'a around a.d. 929. The most pronounced change involving the water regime stabilization and undisturbed development of plant and mollusc communities took place after the decline in human impact. We conclude that humans were the main drivers of landscape transformation in the last millennium; they directly created spring-fen ecosystems through deforestation and influenced fen species composition through husbandry activities.

The issue of continuity in deciduous oakwood vegetation has been in the forefront of woodland ecological studies for many decades. The two basic questions that emerge from existing research are whether or not oakwoods can be characterized by long-term stability and what may be the driving forces of the observed stability or change. To answer these questions in a well-defined case study, we examined the history of a large subcontinental oakwood (Dúbrava) in the southeastern Czech Republic with interdisciplinary methods using palaeoecological and archival sources. Palaeoecology allowed us to reconstruct the vegetation composition and fire disturbances in Dúbrava in the past 2000 years, while written sources provided information about tree composition and management from the 14th century onwards. The pollen profiles show that the present oakwood was established in the mid-14th century with an abrupt change from shrubby, hazel-dominated vegetation to oak forest. This change was most probably caused by a ban on oak felling in ad 1350. From the 14th to the late 18th centuries Dúbrava had multiple uses, of which wood-pasture and hay-cutting kept the forest considerably open. The second remarkable change was dated to the late 18th century, when multiple-use management was abandoned and Dúbrava was divided into pasture-only and coppice-only parts. The last major shift occurred in the mid-19th century, when modern forestry and Scotch pine plantation became dominant. We conclude that Dúbrava Wood did not show stability in the long run and that its species composition has dramatically changed during the last two millennia. The most important driving force in the shaping and maintenance of the unique vegetation of Dúbrava was human management.

Aim The term relict refers to a formerly widespread species currently occurring in refugia that provide a persistent combination of specific ecological conditions. In peatlands, direct palaeoecological evidence of relict status exists for some plant species and, in the case of calcareous sediments, for some snail species. We tested whether some species are significantly linked to old calcareous fens at the millennial scale independent of the effect of recent fen area. We focused on three organism groups - vascular plants, bryophytes and land snails - that differ in the degree of preservation of their remains in calcareous fen sediments and in their dispersal ability. Location Western Carpathians (Slovakia and the Czech Republic). Methods The sample sites comprised 47 well-preserved calcareous fens, from which we compiled complete recent species lists, measured the area and analysed radiocarbon-dated samples from the deepest sediment and from the beginning of complete deforestation, as indicated by plant and snail fossils. Using the species co-occurrences in large data sets, we identified calcareous fen specialists and compared their recent distribution patterns against a null model that controlled for the effect of fen area. Results Two land snail species, eleven vascular plant species and no bryophyte species have statistically significant affinities with old fens, independent of the effect of recent fen area. For one bryophyte and one snail, the effects of age and area are not distinguishable. Main conclusions The results for land snails, being abundantly preserved and easily determinable in calcareous fen deposits, are in full accordance with the direct macrofossil evidence. This suggests that our approach indirectly revealed a relict distribution of the species. Identification of species that are significantly linked to ancient localities at the millennial scale has great potential in palaeoecology for the detection of stands with old sediments, and in nature conservation as a tool for the identification of long-term-persisting rare species that infrequently colonize young sites and thus deserve priority in the protection of their habitats. From a theoretical perspective, limited dispersal from old to new localities of the same habitat can contribute to spatial effects in biotic assemblages, even at relatively fine scales.