Deciduous forests form the dominant natural vegetation of Europe today, but were restricted to small refugia during Pleistocene cold stages, implying an evolutionary past shaped by recurrent range contractions and expansions. Cold-stage forest refugia were probably widespread in southern and central Europe, with the northwestern Balkan Peninsula being of particular importance. However, the actual number and location of deciduous forest refugia, as well as the connections between them, remain disputed. Here, we address the evolutionary dynamics of the deciduous forest understorey species Euphorbia carniolica as a proxy for past forest dynamics. To do so, we obtained genomic and morphometric data from populations representing the species' entire range, investigated phylogenetic position and intraspecific genetic variation, tested explicit demographic scenarios and applied species distribution models. Our data support two disjoint groups linked to separate refugia on the northwestern and central Balkan Peninsula. We find that genetic differentiation between groups started in the early Pleistocene via vicariance, suggesting a larger distribution in the past. Both refugia acted as sources for founder events to the southeastern Alps and the Carpathians; the latter were likely colonised before the last cold stage. In line with traditional views on the pre-Pleistocene origin of many southeastern European deciduous forest species, the origin of E. carniolica was dated to the late Pliocene. The fact that E. carniolica evolved at a time when a period of continuous forestation was ending in much of Eurasia provides an interesting biogeographical perspective on the past links between Eurasian deciduous forests and their biota.

• Klíčová slova
• Alps, angiosperms, demographic modelling, forest understorey, glacial refugia, phylogeography,
• MeSH
• Euphorbia * genetika   MeSH
• fylogeneze MeSH
• fylogeografie MeSH
• genetická variace genetika   MeSH
• haplotypy MeSH
• lesy MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Balkánský poloostrov MeSH
• Evropa MeSH

AIM: Our knowledge of Pleistocene refugia and post-glacial recolonization routes of forest understorey plants is still very limited. The geographical ranges of these species are often rather narrow and show highly idiosyncratic, often fragmented patterns indicating either narrow and species-specific ecological tolerances or strong dispersal limitations. However, the relative roles of these factors are inherently difficult to disentangle. LOCATION: Central and south-eastern Europe. TIME PERIOD: 17,100 BP - present. MAJOR TAXA STUDIED: Five understorey herbs of European beech forests: Aposeris foetida, Cardamine trifolia, Euphorbia carniolica, Hacquetia epipactis and Helleborus niger. METHODS: We used spatio-temporally explicit modelling to reconstruct the post-glacial range dynamics of the five forest understorey herbs. We varied niche requirements, demographic rates and dispersal abilities across plausible ranges and simulated the spread of species from potential Pleistocene refugia identified by phylogeographical analyses. Then we identified the parameter settings allowing for the most accurate reconstruction of their current geographical ranges. RESULTS: We found a largely homogenous pattern of optimal parameter settings among species. Broad ecological niches had to be combined with very low but non-zero rates of long-distance dispersal via chance events and low rates of seed dispersal over moderate distances by standard dispersal vectors. However, long-distance dispersal events, although rare, led to high variation among replicated simulation runs. MAIN CONCLUSIONS: Small and fragmented ranges of many forest understorey species are best explained by a combination of broad ecological niches and rare medium- and long-distance dispersal events. Stochasticity is thus an important determinant of current species ranges, explaining the idiosyncratic distribution patterns of the study species despite strong similarities in refugia, ecological tolerances and dispersal abilities.

• Klíčová slova
• Europe, Pleistocene refugia, dispersal limitation, forest herbs, long‐distance dispersal, post‐glacial recolonization, range filling, spatio‐temporally explicit modelling,
• Publikační typ
• časopisecké články MeSH

The Balkan Peninsula played an important role in the evolution of many Mediterranean plants and served as a major source for post-Pleistocene colonisation of central and northern Europe. Its complex geo-climatic history and environmental heterogeneity significantly influenced spatiotemporal diversification and resulted in intricate phylogeographic patterns. To explore the evolutionary dynamics and phylogeographic patterns within the widespread eastern Mediterranean and central European species Aurinia saxatilis, we used a combination of phylogenomic (restriction-site associated DNA sequencing, RADseq) and phylogenetic (sequences of the plastid marker ndhF) data as well as species distribution models generated for the present and the Last Glacial Maximum (LGM). The inferred phylogenies retrieved three main geographically distinct lineages. The southern lineage is restricted to the eastern Mediterranean, where it is distributed throughout the Aegean area, the southern Balkan Peninsula, and the southern Apennine Peninsula, and corresponds to the species main distribution area during the LGM. The eastern lineage extends from the eastern Balkan Peninsula over the Carpathians to central Europe, while the central lineage occupies the central Balkan Peninsula. Molecular dating places the divergence among all the three lineages to the early to middle Pleistocene, indicating their long-term independent evolutionary trajectories. Our data revealed an early divergence and stable in situ persistence of the southernmost, eastern Mediterranean lineage, whereas the mainland, south-east European lineages experienced more complex and turbulent evolutionary dynamics triggered by Pleistocene climatic oscillations. Our data also support the existence of multiple glacial refugia in southeast Europe and highlight the central Balkan Peninsula not only as a cradle of lineage diversifications but also as a source of lineage dispersal. Finally, the extant genetic variation within A. saxatilis is congruent with the taxonomic separation of peripatric A. saxatilis subsp. saxatilis and A. saxatilis subsp. orientalis, whereas the taxonomic status of A. saxatilis subsp. megalocarpa remains doubtful.

• Klíčová slova
• Aurinia saxatilis, RAD sequencing, demographic modelling, glacial refugia, ndhF, species distribution modelling,
• Publikační typ
• časopisecké články MeSH