title: Testing the efficiency of nested barriers to dispersal in the Mediterranean high mountain plant Edraianthus graminifolius (Campanulaceae).
abstract: 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.
authors.affiliation: Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria; Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, SI-6000, Koper, Slovenia.
authors.forename: Boštjan
authors.initials: B
authors.lastname: Surina
authors.forename: Gerald M
authors.initials: GM
authors.lastname: Schneeweiss
authors.forename: Peter
authors.initials: P
authors.lastname: Glasnović
authors.forename: Peter
authors.initials: P
authors.lastname: Schönswetter
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D063368:Balkan Peninsula; D001499:Bayes Theorem; D044822:Biodiversity; D029422:Campanulaceae / Q000235:genetics*; D018742:DNA, Chloroplast / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D014644:Genetic Variation; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D058974:Phylogeography; D063148:Plant Dispersal; D017422:Sequence Analysis, DNA
chemical_list: D018742:DNA, Chloroplast; D018744:DNA, Plant
keywords: Adriatic Sea; Balkan Peninsula; Pleistocene refugia; alpine plant; barriers; dispersal; ecological niche modelling; range connectivity