Aim We investigated Quaternary range dynamics of two closely related but ecologically divergent species (cold-tolerant Edraianthus serpyllifolius and thermophilic Edraianthus tenuifolius) with overlapping distribution ranges endemic to the western Balkan Peninsula, an important yet understudied Pleistocene refugium. Our aims were: to test predictions of the 'refugia-withinrefugia' model of strong genetic subdivisions due to population isolation in separate refugia; to explore whether two ecologically divergent species reacted differently to Pleistocene climatic fluctuations; and to test predictions of the displacement refugia model of stronger differentiation among populations in the thermophilic E. tenuifolius compared with the cold-tolerant E. serpyllifolius.Location The western Balkan Peninsula.Methods We gathered amplified fragment-length polymorphism (AFLP) data and plastid DNA sequences from two to five individuals from 10 populations of E. serpyllifolius and 22 populations of E. tenuifolius, spanning their entire respective distribution areas. AFLP data were analysed using a Bayesian clustering approach and a distance-based network approach. Plastid sequences were used to depict relationships among haplotypes in a statistical parsimony network, and to obtain age estimates in a Bayesian framework.Results In E. serpyllifolius, both AFLP and plastid sequence data showed clear geographic structure. Western populations showed high AFLP diversity and a high number of rare fragments. In E. tenuifolius, both markers congruently identified a major phylogeographic split along the lower Neretva valley in central Dalmatia. The most distinct and earliest diverging chloroplast DNA (cpDNA) haplotypes were found further south in the south-easternmost populations. North-western populations, identified as a separate cluster by Bayesian clustering, were characterized by low genetic diversity and a low number of rare AFLP markers.Main conclusions Clear evidence for multiple Pleistocene refugia is found not only in the high-elevation E. serpyllifolius, but also in the lowland E. tenuifolius, despite the lack of obvious dispersal barriers, in line with the refugia-withinrefugia model. Genealogical relationships and genetic diversity patterns support the hypothesis that cold-adapted E. serpyllifolius responded to climatic oscillations mostly by elevational range shifts, whereas thermophilic E. tenuifolius did so mainly by latitudinal range shifts, with different phases (and probably extents) of range expansion. In contrast to the displacement refugia hypothesis, the two elevationally differentiated species do not differ in their genetic diversity.

The Campanula pyramidalis complex is a group of closely related taxa with a distribution across the Balkans, from the Gulf of Trieste in the north to the Peloponnese Peninsula in the south, with small disjunct parts of the range in the south Apennines. Although 21 taxa were described within this complex, only three, C. pyramidalis, C. versicolor, and C. secundiflora, have been generally accepted in recent synoptical taxonomic treatments. Our molecular phylogenetic analyses based on sequences of three non‐coding chloroplast regions (psbA‐trnH, psbZ‐trnfM, trnG‐trnS) as well as of nuclear ribosomal internal transcribed spacers (nrITS), lend strong support to the recognition of several lineages which only partially correspond to generally accepted taxonomic concepts. Molecular data presented in this study showed that C. pyramidalis is a polyphyletic assemblage that segregates into three distinct lineages, one of which is described here as a new species, C. austroadriatica sp. nov. The lectotype of C. pyramidalis, redefined in a strict sense, is designated. Neither C. versicolor nor C. secundiflora were found to be strictly monophyletic, but their monophyly could not be rejected. Morphological and biogeographical implications are discussed.

Due to strong spatial heterogeneity and limited Pleistocene glaciation, the Balkan Peninsula is a major European biodiversity hot spot. Surprisingly little, however, is known about patterns and processes of intraspecific diversification of its biota in general and of high-altitude species in particular. A well-suited system to test hypotheses with respect to various isolating factors acting at different geographic scales and to explore full-range phylogeographic patterns on the Balkan Peninsula is Edraianthus graminifolius (Campanulaceae), distributed in the western Balkan mountain systems, the southwestern Carpathians and the Apennine Peninsula. To this end, we used a dense population sampling and employed amplified fragment length polymorphism (AFLP) markers and plastid DNA sequences supplemented by ecological niche modelling. The strongest splits were inferred to separate southern and northern Balkan populations from the central ones, from where range extension occurred to the Carpathians and, in more recent times, once or twice to the Apennine Peninsula. The three genetic groups in the western Balkan Peninsula were remarkably congruent among molecular markers, suggesting that the barriers to gene flow acted over long time periods facilitating allopatric differentiation. Each main group of Balkan populations contained genetically and geographically distinct subgroups, which likely are the result of local refugia during warmer periods. Evidently, the topographically highly complex and during the Last Glacial Maximum only locally glaciated Balkan Peninsula is a hot spot of species richness and endemism as well as a sanctuary of intraspecific genetic diversity, even if the underlying causes remain insufficiently understood.

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