Holocene plant diversity dynamics show a distinct biogeographical pattern in temperate Europe

Abstract

AbstractAimPollen 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.LocationCentral Europe (Czech Republic, Slovakia).TaxonVascular plants.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 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.ResultsMean 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 conclusionsPlant 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.