The extreme disjunction between Beringia and Europe in Ranunculus glacialis s. l. (Ranunculaceae) does not coincide with the deepest genetic split – a story of the importance of temperate mountain ranges in arctic–alpine phylogeography

Abstract

The arctic-alpine Ranunculus glacialis s. l. is distributed in high-mountain ranges of temperate Europe and in the North, where it displays an extreme disjunction between the North Atlantic Arctic and Beringia. Based on comprehensive sampling and employing plastid and nuclear marker systems, we (i) test whether the European/Beringian disjunction correlates with the main evolutionary diversification, (ii) reconstruct the phylogeographic history in the Arctic and in temperate mountains and (iii) assess the susceptibility of arctic and mountain populations to climate change. Both data sets revealed several well-defined lineages, mostly with a coherent geographic distribution. The deepest evolutionary split did not coincide with the European/Beringian disjunction but occurred within the Alps. The Beringian lineage and North Atlantic Arctic populations, which reached their current distribution via rapid postglacial colonization, show connections to two divergent pools of Central European populations. Thus, immigration into the Arctic probably occurred at least twice. The presence of a rare cpDNA lineage related to Beringia in the Carpathians supports the role of these mountains as a stepping stone between temperate Europe and the non-European Arctic, and as an important area of high-mountain biodiversity. The temperate and arctic ranges presented contrasting phylogeographic histories: a largely static distribution in the former and rapid latitudinal spread in the latter. The persistence of ancient lineages with a strictly regional distribution suggests that the ability of R. glacialis to survive repeated climatic changes within southern mountain ranges is greater than what recently was predicted for alpine plants from climatic envelope modelling.

The evolutionary history of Antirrhinum in the Pyrenees inferred from phylogeographic analyses

“…Similar west–east vicariant lineages abutting along the Etsch Valley and the Brenner Pass in the Alps have been reported [18,59-61]. Indeed, this discontinuity accounts for the most important phytogeographic and biogeographic boundary in the Alps e.g.…”

Taxonomic and geographic differentiation ofPinus mugocomplex on the needle characteristics

“…Most differences detected between East and South Carpathian and the other populations of P. mugo (Fig. 5) can be explained by the Holocene history of the species in particular mountain ranges and by Pleistocene isolation (Lata»owa, Tobolski, & Nalepka, 2004;Magyari et al, 2012), causing independent genetic processes and possibly different demographic events, which are recognized in other high mountain species (Ronikier, Schneeweiss, & Sch€ onswetter, 2012;Stachurska-Swako n, Cie slak, & Ronikier, 2013). The different characters of East and West Carpathian populations of P. mugo s. s. were described based on cone characteristics (Staszkiewicz & Tyszkiewicz, 1976), and differences between the East Carpathian and the West Carpathian, Sudetan and Alpine populations were described based on needle and cone characteristics (Boraty nska et al, 2005).…”

Persistent history of the bird-dispersed arctic–alpine plant Vaccinium vitis-idaea L. (Ericaceae) in Japan

“…As such range shifts are expected to have distinct genetic consequences (Hewitt 2000), phylogeographic analyses can shed light on population dynamics in response to the Pleistocene climate changes, and provide notable insights into the biogeographic history of arcticalpine plants (Abbott 2000;Abbott and Brochmann 2003). Numerous phylogeographic studies of arctic-alpine plants have focused on genetic consequences at large geographic scales, and found strong genetic structure throughout their extant ranges (e.g., Alsos et al 2005;Eidesen et al 2007;García et al 2012;Ronikier et al 2012;Winkler et al 2012). A comparative phylogeographic approach revealed several shared genetic borders throughout the ranges of arctic-alpine plants, reflecting dispersal barriers that seem to act in concert upon several species (Eidesen et al 2013).…”

“…Long-term isolation will usually lead to strong genetic differentiation and accumulation of unique genotypes in marginal populations. Some studies have detected unique genetic diversity in southern marginal populations, suggesting isolation and long-term persistence; e.g., in western North America (Albach et al 2006;Allen et al 2012;Alsos et al 2005), the Carpathians (García et al 2012;Ronikier et al 2012), central Asia (Allen et al 2012;García et al 2012;Skrede et al 2006) and the central part of the Japanese Archipelago (central Japan) (Ikeda et al 2008a(Ikeda et al , 2009. However, given the high long-distance dispersal ability demonstrated for many arctic-alpine plants Eidesen et al 2007;Popp et al 2011;Westergaard et al 2011), it is also possible that their marginal populations on high mountains at lower latitudes may have resulted from southward colonization during the last glacial period when suitable habitat was more widespread or via postglacial long-distance dispersal.…”