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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.

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.

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.

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.