Extensive range persistence in peripheral and interior refugia characterizes Pleistocene range dynamics in a widespread Alpine plant species (Senecio carniolicus, Asteraceae)

Abstract

Recent evidence suggests that survival of arctic-alpine organisms in peripheral or interior glacial refugia are not mutually exclusive and may both be involved in shaping an organism’s Pleistocene history, yet potentially at different time levels. Here, we test this hypothesis in a high-mountain plant (diploid lineage of Senecio carniolicus, Asteraceae) from the Eastern European Alps, in which patterns of morphological variation and current habitat requirements suggest survival in both types of refugia. To this end, we used AFLPs, nuclear and plastid DNA sequences and analysed them, among others, within a graph theoretic framework and using novel Bayesian methods of phylogeographic inference. On the basis of patterns of genetic diversity, occurrence of rare markers, distribution of distinct genetic lineages and patterns of range connectivity both interior refugia in the formerly strongly glaciated central Alps and peripheral refugia along the southern margin of the Alps were identified. The presence of refugia congruently inferred by markers resolving at different time levels suggests that these refugia acted as such throughout several glacial cycles. The high degree of range persistence together with gradual range expansion, which contrasts with the extent of range shifts implied for other Alpine species, is likely responsible for incipient lineage differentiation evident from the genetic data. Replacing a simplistic peripheral vs. interior refugia dualism by more complex models involving both types of refugia and considering different time levels will help identifying common phylogeographic patterns with respect to, for instance, location of refugia and colonization routes and elucidating their underlying genetic and/or ecological causes.

Quaternary range and demographic expansion of Liolaemus darwinii (Squamata: Liolaemidae) in the Monte Desert of Central Argentina using Bayesian phylogeography and ecological niche modelling

“…; Escobar‐Garcia et al . ) to infer the diffusion dynamics of L . darwinii over continuous space and time.…”

Ecological differentiation, lack of hybrids involving diploids, and asymmetric gene flow between polyploids in narrow contact zones of Senecio carniolicus (syn. Jacobaea carniolica, Asteraceae)

“…; Escobar García et al. ). In contrast to the majority of heteroploid taxa, S. carniolicus does not form a single contact zone containing otherwise geographically well‐separated cytotypes (Husband and Schemske ; Hardy et al.…”

“…The AFLP procedure followed Escobar García et al. (). Six plants were extracted twice to test the reproducibility of AFLP fingerprinting (Bonin et al.…”

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

“…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.…”

“…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).…”