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Plant endemism in the European Alps is clustered into particular geographic areas. Two contrasted and non exclusive hypotheses have been suggested to explain these hotspots of endemism: (i) those areas were glacial refugia, where endemism reflects survival-recolonisation dynamics since the onset of Pleistocene glaciations, (ii) those are high elevation mountain areas, where endemism was fostered by local speciation events due to geographic isolation and harsh environmental niches, or by low dispersal ability of inhabiting species. Here, we quantitatively compared these two hypotheses using data of species distribution in the European Alps (IntraBioDiv database), species phylogenetic relationships, and species ecological and biological characteristics. We developed a spatially and phylogenetically explicit modeling framework to analyze spatial patterns of endemism and the phylogenetic structure of species assemblages. Moreover, we analyzed interrelations between species trait syndromes and endemism. We found that high endemism occurrs in potential glacial refugia, but only those on calcareous bedrock, and also in areas with high elevation. Plant assemblages in calcareous refugia showed phylogenetic overdispersion − a signature of non-selective conservation forces, whereas those located in high mountain areas showed phylogenetic clustering − a signature of recent diversification and environmental filtering. Endemic species were either stress-tolerant, poorly dispersing species, or high elevation specialists with a wide distribution within the European Alps. While both calcareous refugia and high-elevation hotspots harbour a large portion of plant endemism in the European Alps, the species they host have substantially different characteristics. Our results suggest that hotspots of endemism in calcareous refugia are more important for nature conservation planning, as they host many range restricted endemic species and rather isolated evolutionary lineages. [ABSTRACT FROM AUTHOR]

Plant endemism in the European Alps is clustered into particular geographic areas. Two contrasted and non exclusive hypotheses have been suggested to explain these hotspots of endemism: (i) those areas were glacial refugia, where endemism reflects survival-recolonisation dynamics since the onset of Pleistocene glaciations, (ii) those are high elevation mountain areas, where endemism was fostered by local speciation events due to geographic isolation and harsh environmental niches, or by low dispersal ability of inhabiting species. Here, we quantitatively compared these two hypotheses using data of species distribution in the European Alps (IntraBioDiv database), species phylogenetic relationships, and species ecological and biological characteristics. We developed a spatially and phylogenetically explicit modelling framework to analyze spatial patterns of endemism and the phylogenetic structure of species assemblages. Moreover, we analyzed interrelations between species trait syndromes and endemism. We found that high endemism occurrs in potential glacial refugia, but only those on calcareous bedrock, and also in areas with high elevation. Plant assemblages in calcareous refugia showed phylogenetic overdispersion – a signature of non-selective conservation forces, whereas those located in high mountain areas showed phylogenetic clustering – a signature of recent diversification and environmental filtering. Endemic species were either stress-tolerant, poorly dispersing species, or high elevation specialists with a wide distribution within the European Alps. While both calcareous refugia and high-elevation hotspots harbour a large portion of plant endemism in the European Alps, the species they host have substantially different characteristics. Our results suggest that hotspots of endemism in calcareous refugia are more important for nature conservation planning, as they host many range restricted endemic species and rather isolated evolutionary lineages. [ABSTRACT FROM AUTHOR]

Aim North-west Africa, because of its position at the crossroads between Macaronesia and the Iberian Peninsula, has played an important role on the emergence and maintenance of Mediterranean plant diversity. In this study, we reconstruct the phylogeographical history of a lineage of bellflowers comprising the north African-south Iberian species Campanula kremeri and the Canarian Campanula occidentalis ( Azorina-group), to investigate the genetic imprints left by past climatic and palaeogeographical events on the northern African flora. Location North-west Africa, Iberian Peninsula, and the Canary Islands. Methods We reconstructed the biogeographical history of the Azorina-group to provide a phylogenetic background. We then investigated the phylogeographical patterns within C. kremeri and C. occidentalis using the AFLP and sequence data. We integrated these results with the past species-distribution modelling to understand the current biodiversity patterns within this lineage. Results The ancestor of C. kremeri- C. occidentalis diverged in the Late Miocene/Early Pliocene. Nuclear data supported species monophyly, whereas plastid data suggested that C. kremeri is paraphyletic. Maghrebian populations of C. kremeri showed high genetic diversity, whilst Iberian ones and those of C. occidentalis exhibited lower values. Main conclusions Repeated expansion-retraction events associated with Pleistocene climatic changes in North Africa facilitated gene flow across Maghrebian ranges in C. kremeri. Mountain massifs in north-west Africa likely acted as refugia for Mediterranean plants during interglacial periods, whereas range expansion in cooler periods triggered dispersal to neighbouring regions. The range of C. kremeri expanded to the Iberian Peninsula by long-distance dispersal across the Strait of Gibraltar during the Pleistocene. The relatively old age inferred for C. occidentalis together with its low genetic diversity point to a recent colonization of the Canary Islands from north-west Africa followed by extinction in the mainland or an old lineage that underwent a recent genetic bottleneck. [ABSTRACT FROM AUTHOR]

The Rand Flora describes the disjunct phytogeographical pattern of a wide range of taxa distributed at the periphery of Africa and adjacent islands, as well as the Arabian Peninsula. We focused on Volutaria (Compositae: Cardueae: Centaurineae), a genus of ca. 18 species that conforms to the Rand Flora pattern; yet its phylogeny, interspecific relationships, and biogeographical history remain poorly known. We aim to construct a robust phylogeny that will allow us to interpret the biogeography and the diversification of this genus, together with its present distribution pattern, and to ascertain whether the latter arose by single or multiple gradual expansion processes, vicariance, or long‐distance dispersal events. We sampled all extant Volutaria species, covering its entire geographical range, and generated sequences of nuclear‐ribosomal DNA and three plastid regions, which were analyzed by Bayesian inference and maximum parsimony. Samples yielding more than one sequence in direct sequencing were cloned. Historical biogeographical analysis was performed using BioGeoBEARS based on a phylogeny dated using a relaxed molecular clock calibrated with a previous dating undertaken for the tribe Cardueae. Volutaria is a monophyletic taxon, having an Asian ancestor, and its present diversity is represented by four main clades that emerged in the Miocene. The earliest taxa of Volutaria to diverge are preserved in North Africa, whereas clades that diverged more recently have done so on both sides of the Sahara. This process involved both ancient and recent interspecific introgression and hybridization events, as indicated by incongruities between plastid and nuclear results, and by cloning of the ITS region. The distribution of Volutaria around two diversity poles conforms to the Rand Flora pattern, but this did not arise by a single event or process. Instead, the historical biogeography of Volutaria involves at least one migration wave from east to west, followed by the extinction of ancestral taxa and subsequent expansion and retraction events, together with speciation processes on both sides of the Sahara. The intense tectonic and climatic changes that occurred in North Africa and western Asia throughout the Neogene and Pleistocene periods might explain the present diversity and distribution pattern of the genus. [ABSTRACT FROM AUTHOR]

Whether the success of alien species can be explained by their functional or phylogenetic characteristics remains unresolved because of data limitations, scale issues and weak quantifications of success. Using permanent grasslands across France (50 000 vegetation plots, 2000 species, 130 aliens) and building on the Rabinowitz's classification to quantify spread, we showed that phylogenetic and functional similarities to natives were the most important correlates of invasion success compared to intrinsic functional characteristics and introduction history. Results contrasted between spatial scales and components of invasion success. Widespread and common aliens were similar to co-occurring natives at coarse scales (indicating environmental filtering), but dissimilar at finer scales (indicating local competition). In contrast, regionally widespread but locally rare aliens showed patterns of competitive exclusion already at coarse scale. Quantifying trait differences between aliens and natives and distinguishing the components of invasion success improved our ability to understand and potentially predict alien spread at multiple scales. [ABSTRACT FROM AUTHOR]

Climate and land cover changes are important drivers of the plant species distributions and diversity patterns in mountainous regions. Although the need for a multifaceted view of diversity based on taxonomic, functional and phylogenetic dimensions is now commonly recognized, there are no complete risk assessments concerning their expected changes. In this paper, we used a range of species distribution models in an ensemble-forecasting framework together with regional climate and land cover projections by 2080 to analyze the potential threat for more than 2500 plant species at high resolution (2.5 × 2.5 km) in the French Alps. We also decomposed taxonomic, functional and phylogenetic diversity facets into α and β components and analyzed their expected changes by 2080. Overall, plant species threats from climate and land cover changes in the French Alps were expected to vary depending on the species' preferred altitudinal vegetation zone, rarity, and conservation status. Indeed, rare species and species of conservation concern were the ones projected to experience less severe change, and also the ones being the most efficiently preserved by the current network of protected areas. Conversely, the three facets of plant diversity were also projected to experience drastic spatial re-shuffling by 2080. In general, the mean α-diversity of the three facets was projected to increase to the detriment of regional β-diversity, although the latter was projected to remain high at the montane-alpine transition zones. Our results show that, due to a high-altitude distribution, the current protection network is efficient for rare species, and species predicted to migrate upward. Although our modeling framework may not capture all possible mechanisms of species range shifts, our work illustrates that a comprehensive risk assessment on an entire floristic region combined with functional and phylogenetic information can help delimitate future scenarios of biodiversity and better design its protection. [ABSTRACT FROM AUTHOR]

Highlights: [•] Macaronesia and Socotra were refugia for North-African species, leading to diversification through isolation. [•] C. hypocrateriformis may be related to species that colonised North Africa and dispersed to Cape Verde and Socotra. [•] Campanula jacobaea and C. balfourii are sisters that diverged around 1.0Mya. [ABSTRACT FROM AUTHOR]

Aim We still have limited understanding of the contingent and deterministic factors that have fostered the evolutionary success of some species lineages over others. We investigated how the interplay of intercontinental migration and key innovations promoted diversification of the genus Androsace. Location Mountain ranges and cold steppes of the Northern Hemisphere. Methods We reconstructed ancestral biogeographical ranges at regional and continental scales by means of a dispersal-extinction-cladogenesis analysis using dated Bayesian phylogenies and contrasting two migration scenarios. Based on diversification analyses under two frameworks, we tested the influence of life form on speciation rates and whether diversification has been diversity-dependent. Results We found that three radiations occurred in this genus, at different periods and on different continents, and that life form played a critical role in the history of Androsace. Short-lived ancestors first facilitated the expansion of the genus' range from Asia to Europe, while cushions, which appeared independently in Asia and Europe, enhanced species diversification in alpine regions. One long-distance dispersal event from Europe to North America led to the diversification of the nested genus Douglasia. We found support for a model in which speciation of the North American- European clade is diversity-dependent and close to its carrying capacity, and that the diversification dynamics of the North American subclade are uncoupled from this and follow a pure birth process. Main conclusions The contingency of past biogeographical connections combined with the evolutionary determinism of convergent key innovations may have led to replicated radiations of Androsace in three mountain regions of the world. The repeated emergence of the cushion life form was a convergent key innovation that fostered radiation into alpine habitats. Given the large ecological similarity of Androsace species, allopatry may have been the main mode of speciation. [ABSTRACT FROM AUTHOR]

Relatively, few species have been able to colonize extremely cold alpine environments. We investigate the role played by the cushion life form in the evolution of climatic niches in the plant genus Androsace s.l., which spreads across the mountain ranges of the Northern Hemisphere. Using robust methods that account for phylogenetic uncertainty, intraspecific variability of climatic requirements and different life-history evolution scenarios, we show that climatic niches of Androsace s.l. exhibit low phylogenetic signal and that they evolved relatively recently and punctually. Models of niche evolution fitted onto phylogenies show that the cushion life form has been a key innovation providing the opportunity to occupy extremely cold environments, thus contributing to rapid climatic niche diversification in the genus Androsace s.l. We then propose a plausible scenario for the adaptation of plants to alpine habitats. [ABSTRACT FROM AUTHOR]

Abstract: We reconstruct here the spatial and temporal evolution of the Campanula alliance in order to better understand its evolutionary history. To increase phylogenetic resolution among major groups (Wahlenbergieae–Campanuleae), new sequences from the rbcL region were added to the trnL-F dataset obtained in a previous study. These phylogenies were used to infer ancestral areas and divergence times in Campanula and related genera using a Bayesian approach to molecular dating and dispersal–vicariance analyses that takes into account phylogenetic uncertainty. The new phylogenetic analysis confirms Platycodoneae as the sister group of Wahlenbergieae–Campanuleae, the two last ones inter-graded into a well-supported clade. Biogeographic and dating analyses suggest that Western Asia and the Eastern Mediterranean have played a major role as centers of migration and diversification within the Campanula alliance, probably in relation to the intense orogenic activity that took place in this region during the Late Neogene, and that could have promoted isolation and allopatric speciation within lineages. Diversification rates within several Campanula lineages would have increased at the end of the Miocene, coinciding with the Messinian Stage. Strong selective pressures from climate changes and the expansion of mountainous regions during this period are suggested to explain the adaptation to drought, cold or disturbed environments observed in many Campanula species. Several independent long-distance dispersal events to North America are inferred within the Rapunculus clade, which seem to be related to high ploidy levels. [Copyright &y& Elsevier]