Biogeography of the Carpathians: evolutionary and spatial facets of biodiversity

MtDNA genetic diversity and phylogeographic insights into giant domestic pigeon (Columba livia domestica) breeds: connections between Central Europe and the Middle East

Humans have selectively bred domestic pigeons (Columba livia domestica) to create breeds with a diversity of shapes, colors and other attributes. Since Darwin, the domestic pigeon has always been a popular model species for scientific research because of its richness of form, colouration and behaviour. It is believed that the world's squab pigeon industry uses breeds and hybrids from the Mediterranean region. An exception is the indigenous giant pigeon breeds of the Carpathian Basin, whose origin is not known. Therefore, our aims were 1) to understand the phylogenetic relationships of giant pigeons, which sheds light on the origin of Hungarian breeds and their relationship to the Mediterranean giant pigeon breed group; 2) to contribute molecular genetic data to the genealogy of 2 Iraqi pigeon breeds close to the pigeon domestication center, including the culturally important Iraqi Red Pigeon, and 3) to compare the genetic diversity of European and Middle Eastern domestic pigeon populations and to draw conclusions on the phylogenetic relationships between pigeon breeds and molecular clues to their different breeding practices of both regions. A 655-bp-long sequence of the cytochrome oxidase 1 (COI) region of the mitochondrial DNA was studied in a total of 276 pigeons (19 breeds). A total of 27 haplotypes were found, of which 22 were unique. The highest genetic diversity was found in the Carpathian Basin, and the lowest in the Iraqi region. STRUCTURE analysis revealed low structurality, K=3 was the most likely. The majority of the samples belong to the most ancient haplotype H_2=219, however the Jacobin pigeon is on a very separate evolutionary branch with a large number of mutations. None of the 19 breeds investigated in this study have been previously studied in phylogenetics, and most of these breeds have potential as squab pigeons, and have good meat forms for utilization, therefore the results of this study may also be of help to the squab pigeon industry.

Glacial history of Saxifragawahlenbergii (Saxifragaceae) in the context of refugial areas in the Western Carpathians

Despite the wealth of data available for mountain phylogeography, local-scale studies focused on narrow endemic species remain rare. Yet, knowledge of the genetic structure of such species biogeographically linked to a restricted area is of particular importance to understand the history of the local flora and its diversity patterns. Here, we aim to contribute to the phylogeographical overview of the Western Carpathians with a genetic study of Saxifragawahlenbergii, one of the most characteristic endemic species of this region. We sampled populations from all discrete parts of the species' distribution range to apply sequencing of selected non-coding cpDNA and nuclear ribosomal DNA (ITS) regions, as well as Amplified Fragment Length Polymorphism (AFLP) fingerprinting. First, while ITS sequences showed weak diversification, the genetic structure based on cpDNA sequences revealed two well-differentiated groups of haplotypes. One of them is restricted to the main center of the distribution range in the Tatra Mountains (Mts), while the second group included a series of closely related haplotypes, which in most cases were unique for particular isolated groups of populations in peripheral mountain ranges and in the south-eastern part of the Tatra Mts. AFLP fingerprinting also revealed a pattern of divergence among populations, while only partly corroborating the division observed in cpDNA. Taking into account all the data, the pattern of genetic structure, supported by the high levels of unique genetic markers in populations, may reflect the historical isolation of populations in several local refugia during the last glacial period. Not only the center of the range in the Tatra Mts, but also other, neighboring massifs (Malá Fatra, Nízke Tatry, Chočské vrchy, Muránska planina), where populations are characterized by separate plastid DNA haplotypes, could have acted as separate refugia.

Geographical and environmental patterns of Carpathian land snail faunas in a region of high endemicity

The land snail faunas of limestone gorges of Romanian Carpathians were sampled to test the effect of geographic and environmental factors on the malacofauna richness and composition. A total of 134 sites within 28 limestone gorges were surveyed during 2011-2019 using a combined strategy of visual search and litter/topsoil analysis. Environmental variables such as geographic location, altitude, climate, microhabitat type, dominant vegetation, tree cover and width of the gorge were recorded to detect the relationship with species richness and composition. While the numbers of species, their identities and their abundance varied greatly among samples, both presence and absence data and quantitative multivariate analyses showed that region and climate or altitude (both strongly associated with region) accounted for far more variation than differences in tree cover and dominant microhabitat. Nevertheless, the effects of different habitat preferences were evident. The mixture of species with very restricted ranges within this Pleistocene refugium and those that have spread widely during the Holocene raise questions about the meaning of region when related to local richness and composition.

Perhaps there were northern refugia in LGM? The phylogeographic structure of the thermophilic tree Carpinus betulus in the Carpathian region

Carpinus betulus L., the hornbeam, is a component of lowland and highland forests in Europe. By examining the postglacial migratory history of thermophilic tree species, the study aimed to unravel their putative glacial microrefugia in the Carpathian region. The present study points to the two distinct genetic AFLP groups of C. betulus in the Carpathian region that represent different genetic lineages based on Bayesian analysis. They differed in Nei's gene diversity index h, and the analysis of molecular variance AMOVA showed a percentage variation of the populations between the groups of 13.74 %. Principal coordinate analysis (PCoA) of 368 AFLP tree samples confirmed the presence of two genetic groups. Ninety-five populations underwent principal component analysis (PCA) to show the main correlations between genetic diversity indices and bioclimatic/climate variables (WorldClim and Carpatclim). The generalized logistic model (GLM) showed the significance of Nei's genetic index h in delimiting genetic groups. The results of population-genetic and multivariate analyses determined that the two genetic groups nowadays are spatially diffused and do not show a clear geographic pattern, pointing to a genetic melting pot. We found ecological links between genetic diversity and bioclimatic characteristics, especially the precipitation in the coldest quarter - Bio19. The refugial Maxent model indicates a significant contribution of the Bio7 variable (both linked with a continental type of climate) to the occurrence of the species during the LGM in Europe. We suggest the relict character of hornbeam populations in a specific climatic-terrain niche in the northern part of the Carpathian Basin.

Phylogenetics and Population Genetics of the Petrolisthes lamarckii-P. haswelli Complex in China: Old Lineage and New Species

Petrolisthes lamarckii (Leach, 1821) and P. haswelli Miers, 1884 are a pair of sister species of porcelain crabs, both of which are common in the intertidal zone of southern China, typically found under rocks and in the crevices of coral reefs. However, the distribution, genetic relationship and diversity of the two species in China have not been rigorously studied. Meanwhile, P. lamarckii is considered as a complex of cryptic species due to their diverse morphological features. In this study, we identified 127 specimens of the P. lamarckii-P. haswelli complex (LH complex) and recognised a new species through morphological and molecular analysis. Furthermore, we constructed a time-calibrated phylogeny of the LH complex using three mitochondrial and two nuclear genes from all three species, finding that the divergence of the LH complex can be traced back to the Miocene epoch, and that the genetic diversity increased during the Mid-Pleistocene transition period. Glacial refugia formed during the Pleistocene climatic oscillations has been regarded as one of the contributing factors to the diversification of marine organisms in the north-western Pacific. Petrolisthes haswelli demonstrates a wide distribution along the southern coast of China, while other lineages display more restricted distributions. The research on the demographic history and gene flow of P. haswelli revealed that the Chinese coastal populations experienced an expansion event approximately 12.5 thousand years ago (Kya) and the asymmetrical gene flows were observed between the two sides of the Taiwan Strait and Qiongzhou Strait, respectively, which is likely influenced by the restriction of ocean currents.

Checklist, distribution, diversity, and rarity of mayflies (Ephemeroptera) in Slovakia

Despite the essential role of mayflies (Ephemeroptera) in freshwater ecosystems and their long-term use in research and routine biomonitoring in the Carpathian and Pannonian ecoregions, their distribution data are fragmentary and outdated. All published and unpublished data on mayflies from Slovakia was gathered and a database of > 15,000 species records from 2206 localities built with the aims (i) to critically revise available data and assess the completeness of the species inventory, (ii) to identify hotspots of species diversity, and (iii) to provide a benchmark for assessment of species rarity and conservation status in the region. After the critical revision of the data covering more than 100 years, the occurrence of 109 mayfly species in Slovakia was confirmed. The species inventory appears to be nearly complete, as evidenced by the rarefaction curve and a nonparametric species richness estimator. The highest mayfly gamma diversity was recorded below 500 m a.s.l. and in streams of the fifth order, which can be considered hotspots of mayfly diversity in the region. Six species were last recorded before 1990 and thus can be considered extinct in Slovakia. Twenty-nine species could be classified as very rare, with their occurrence frequency decreasing with increasing altitude and most of them being restricted to large lowland rivers and stagnant water habitats in their floodplains. In conclusion, our study provides comprehensive data on key freshwater bioindicators and suggests increasing conservation priorities, especially in lowland river floodplains occupied by several very rare mayfly species.

Limited congruence in phylogeographic patterns observed for riverine predacious beetles sharing distribution along the mountain rivers

Riverine predacious beetles (RPB) (Carabidae, Staphylinidae) are highly diverse and numerous elements of riverine ecosystems. Their historical and contemporary distribution and diversity are highly dependent on natural flow regimes and topography of watercourses. Despite broad knowledge of their ecology, data on population genetic diversity and connectivity are lacking. This study aimed to fill this gap in order to solve two principal hypotheses assuming (i) congruence of phylogeographic patterns observed for RPB indicating that they share a common history and the ecological adaptations to the dynamic environment, (ii) genetic structuration of populations according to river basins. The Carpathian populations of four ground beetles and three rove beetles were examined using cytochrome oxidase and arginine kinase sequencing. There are substantial differences in RPB demographic history and current genetic diversity. Star-like phylogeny of Bembidion and complex haplotype networks of Paederus/Paederidus, with some haplotypes being drainage-specific and others found in distant populations, indicate a general lack of isolation by distance. Signs of recent demographic expansion were detected for most RPB with the latest population collapse for some rove beetles. To some extent, migration of examined species has to be limited by watersheds. Observed phylogeographic patterns are essential for correctly understanding RPB meta-population functioning.

Evolutionary dynamics of Euphorbia carniolica suggest a complex Plio-Pleistocene history of understorey species of deciduous forest in southeastern Europe

Deciduous forests form the dominant natural vegetation of Europe today, but were restricted to small refugia during Pleistocene cold stages, implying an evolutionary past shaped by recurrent range contractions and expansions. Cold-stage forest refugia were probably widespread in southern and central Europe, with the northwestern Balkan Peninsula being of particular importance. However, the actual number and location of deciduous forest refugia, as well as the connections between them, remain disputed. Here, we address the evolutionary dynamics of the deciduous forest understorey species Euphorbia carniolica as a proxy for past forest dynamics. To do so, we obtained genomic and morphometric data from populations representing the species' entire range, investigated phylogenetic position and intraspecific genetic variation, tested explicit demographic scenarios and applied species distribution models. Our data support two disjoint groups linked to separate refugia on the northwestern and central Balkan Peninsula. We find that genetic differentiation between groups started in the early Pleistocene via vicariance, suggesting a larger distribution in the past. Both refugia acted as sources for founder events to the southeastern Alps and the Carpathians; the latter were likely colonised before the last cold stage. In line with traditional views on the pre-Pleistocene origin of many southeastern European deciduous forest species, the origin of E. carniolica was dated to the late Pliocene. The fact that E. carniolica evolved at a time when a period of continuous forestation was ending in much of Eurasia provides an interesting biogeographical perspective on the past links between Eurasian deciduous forests and their biota.

The Perspective of Arctic-Alpine Species in Southernmost Localities: The Example of Kalmia procumbens in the Pyrenees and Carpathians

High-mountain and arctic plants are considered especially sensitive to climate change because of their close adaptation to the cold environment. Kalmia procumbens, a typical arctic-alpine species, reaches southernmost European localities in the Pyrenees and Carpathians. The aim of this study was the assessment and comparison of the current potential niche areas of K. procumbens in the Pyrenees and Carpathians and their possible reduction due to climate change, depending on the scenario. The realized niches of K. procumbens in the Pyrenees are compact, while those in the Carpathians are dispersed. In both mountain chains, the species occurs in the alpine and subalpine vegetation belts, going down to elevations of about 1500-1600 m, while the most elevated localities in the Pyrenees are at ca. 3000 m, about 500 m higher than those in the Carpathians. The localities of K. procumbens in the Carpathians have a more continental climate than those in the Pyrenees, with lower precipitation and temperatures but higher seasonality of temperature and precipitation. The species covered a larger area of geographic range during the Last Glacial Maximum, but its geographic range was reduced during the mid-Holocene. Due to climate warming, a reduction in the potential area of occurrence could be expected in 2100; this reduction is expected to be strong in the Carpathians and moderate in the Pyrenees.

The Role of the Hercynian Mountains of Central Europe in Shaping Plant Migration Patterns in the Pleistocene-A Review

The climatic changes that took place in Europe during the Quaternary period influenced plant habitats as well as their species and vegetation composition. In this article, biogeographical studies on Hercynian mountain plants that include data for the Alps, Carpathians, and European lowlands are reviewed in order to discuss the phylogeographical structure and divergence of the Hercynian populations from those in other European mountain ranges, Scandinavia, and lowlands. The analyzed studies show specific phylogeographical relations between the Hercynian mountains, Alps, Scandinavia, Carpathians, and European lowlands. The results also indicate that the genetic patterns of plant populations in the Hercynian Mountains may differ significantly in terms of origin. The main migration routes of species to the Hercynian ranges began in the Alps or Carpathians. Some species, such as Rubus chamaemorus L., Salix lapponum L., and Salix herbacea L., are glacial relics that may have arrived and settled in the Hercynian Mountains during the Ice Age and that survived in isolated habitats. The Hercynian Mountains are composed of various smaller mountain ranges and are a crossroads of migration routes from different parts of Europe; thus, intensive hybridization has occurred between the plant populations therein, which is indicated by the presence of several divergent genetic lines.

From the Mountain to the Valley: Drivers of Groundwater Prokaryotic Communities along an Alpine River Corridor

Rivers are the “tip of the iceberg”, with the underlying groundwater being the unseen freshwater majority. Microbial community composition and the dynamics of shallow groundwater ecosystems are thus crucial, due to their potential impact on ecosystem processes and functioning. In early summer and late autumn, samples of river water from 14 stations and groundwater from 45 wells were analyzed along a 300 km transect of the Mur River valley, from the Austrian alps to the flats at the Slovenian border. The active and total prokaryotic communities were characterized using high-throughput gene amplicon sequencing. Key physico-chemical parameters and stress indicators were recorded. The dataset was used to challenge ecological concepts and assembly processes in shallow aquifers. The groundwater microbiome is analyzed regarding its composition, change with land use, and difference to the river. Community composition and species turnover differed significantly. At high altitudes, dispersal limitation was the main driver of groundwater community assembly, whereas in the lowland, homogeneous selection explained the larger share. Land use was a key determinant of the groundwater microbiome composition. The alpine region was more diverse and richer in prokaryotic taxa, with some early diverging archaeal lineages being highly abundant. This dataset shows a longitudinal change in prokaryotic communities that is dependent on regional differences affected by geomorphology and land use.

Morphological and environmental differentiation as prezygotic reproductive barriers between parapatric and allopatric Campanula rotundifolia agg. cytotypes

BACKGROUND AND AIMS

Reproductive isolation and local establishment are necessary for plant speciation. Polyploidy, the possession of more than two complete chromosome sets, creates a strong postzygotic reproductive barrier between diploid and tetraploid cytotypes. However, this barrier weakens between polyploids (e.g. tetraploids and hexaploids). Reproductive isolation may be enhanced by cytotype morphological and environmental differentiation. Moreover, morphological adaptations to local conditions contribute to plant establishment. However, the relative contributions of ploidy level and the environment to morphology have generally been neglected. Thus, the extent of morphological variation driven by ploidy level and the environment was modelled for diploid, tetraploid and hexaploid cytotypes of Campanula rotundifolia agg. Cytotype distribution was updated, and morphological and environmental differentiation was tested in the presence and absence of natural contact zones.

METHODS

Cytotype distribution was assessed from 231 localities in Central Europe, including 48 localities with known chromosome counts, using flow cytometry. Differentiation in environmental niche and morphology was tested for cytotype pairs using discriminant analyses. A structural equation model was used to explore the synergies between cytotype, environment and morphology.

KEY RESULTS

Tremendous discrepancies were revealed between the reported and detected cytotype distribution. Neither mixed-ploidy populations nor interploidy hybrids were detected in the contact zones. Diploids had the broadest environmental niche, while hexaploids had the smallest and specialized niche. Hexaploids and spatially isolated cytotype pairs differed morphologically, including allopatric tetraploids. While leaf and shoot morphology were influenced by environmental conditions and polyploidy, flower morphology depended exclusively on the cytotype.

CONCLUSIONS

Reproductive isolation mechanisms vary between cytotypes. While diploids and polyploids are isolated postzygotically, the environmental niche shift is essential between higher polyploids. The impact of polyploidy and the environment on plant morphology implies the adaptive potential of polyploids, while the exclusive relationship between flower morphology and cytotype highlights the role of polyploidy in reproductive isolation.

Perishing rich, expanding poor: Demography and population genetic patterns in two congeneric butterflies

In human-altered landscapes, specialist butterflies typically form spatially restricted populations, genetically differentiated due to dispersal restrictions. Generalists, in contrast, display minimum differentiation but high genetic diversity. While local-level actions suffice to conserve specialists and landscape-level actions are necessary for generalists, minimum information exists regarding conservation of species with intermediate features. We targeted two congeneric butterflies, the recently re-expanding Argynnis adippe and the strongly declining A. niobe, co-occurring in the pastoral landscape of the Carpathian Mountains, Czech Republic. We integrated species distribution models, mark-recapture and microsatellite analysis to compare their habitat requirements, adult demography, dispersal and genetic patterns, and expanded the genetic analysis across the Carpathian Arc and beyond to delimit spatial conservation units. In two mountain valleys, both species formed interconnected populations numbering thousands of individuals. Mobility patterns suggested the populations' interconnection across the Czech Carpathians. Genetic diversity was extremely poor in the nonthreatened A. adippe and moderate in the declining A. niobe. No population differentiation was detected within the Czech Carpathians (~1500 km² ). Low genetic diversity and no differentiation was preserved in A. adippe across East Central Europe, whereas in A. niobe, populations from Serbia were differentiated from the Carpathian Arc + Alps. The high adult mobility linked to low differentiation probably reflects the distribution of larval resources, historically widespread but sparse and currently declining for A. niobe (grazing-disturbed grounds), while currently increasing for A. adippe (abandonment scrub, disturbed woodlands). Units as large as entire mountain systems define population boundaries, and hence conservation management units, for both species.

Phylogeography and colonization pattern of subendemic round-leaved oxeye daisy from the Dinarides to the Carpathians

The Carpathians are an important biodiversity hotspot and a link between mountain ranges on the European continent. This study investigated the phylogeography of one the Carpathian subendemics, Leucanthemum rotundifolium, which is distributed throughout the range and in one isolated population outside it. Range-wide sampling was used to examine phylogeographic patterns by sequencing uniparentally inherited chloroplast markers that exemplify seed dispersal. Reconstruct Ancestral State in Phylogenies (RASP) software, Bayesian binary Markov Chain Monte Carlo (BBM) analysis, and ecological niche modeling based on concatenated results of five algorithms were used to infer migration routes and examine links with other species through phylogeny. The round-leaved oxeye daisy is an example of organisms that reached the Carpathians through a southern "Dacian" migration route, most probably through long-distance dispersal. Dating placed the events in the Pleistocene and supported migrations during cooler periods and stasis/isolation followed by separation in the interglacials. Haplotype diversification indicated that after L. rotundifolium reached the area around the Fagaras Mountains, several migration events occurred leading to colonization of the Southern Carpathians followed by migration to the Apuseni Mountains, the Eastern Carpathians, and finally the Western Carpathians. The results are consistent with previous phylogeographic studies in this region and indicate several novel patterns.

First records of Calamagrostis purpurea (Poaceae) in the Carpathians, a relict species new to the flora of Slovakia, Ukraine, and Romania

The first records of Calamagrostis purpurea, an apomictic wetland grass species with a Euro-Siberian, predominantly boreal distribution, are reported for the Carpathians. This significantly expands the species’ range in Central Europe eastwards from the known localities in Austria and Czechia. Due to in situ finds and revision of the herbarium vouchers, C. purpurea was discovered in the Western Carpathians in Slovakia (the Nízke Tatry Mts) as well as in the Eastern Carpathians in Ukraine (the Chornohora Mts) and Romania (Dorna Depression, the Harghita, Bodoc Mts, Intorsura Buzaului Depression) at 6 sites in total. All these newly found localities are situated within 870–1570 m a.s.l. The locality in the Nízke Tatry Mts is at the highest elevation, while those in the Romanian Carpathians are the southeasternmost in Central Europe. In the Carpathians, C. purpurea is confined to undisturbed wetland habitats, which implies its relict origin in the region. A distribution map, habitat characteristics, morphological description, and images of the plants from the Carpatians are provided. Carpathian populations tested with flow cytometry are DNA-octoploid (the predominant ploidy level of the species in Europe). Because of the species’ rarity and vulnerability, it is suggested to include C. purpurea in the next editions of the Red Data Books and/or Red Lists of the corresponding countries.

DNA barcodes evidence the contact zone of eastern and western caddisfly lineages in the Western Carpathians

The region of the Western Carpathians is, among other aspects, very important for survival and diversity of European freshwater fauna due to the presence of a large number of (sub)mountain springs and streams. However, these ecologically and faunistically diversified habitats are still understudied in the context of genetic diversity and population structure of their inhabitants. This study focuses on genetic diversity and distribution patterns of the caddisfly Rhyacophila tristis, common and widespread representative of mountain freshwater fauna. Analysis of the COI mitochondrial marker revealed presence of the western and eastern lineages, with samples from both lineages being grouped in BOLD (Barcode of Life Data System) into separate BINs (Barcode Index Numbers). Our data indicates that eastern lineage (BIN_E) is more closely related to the Balkan populations than to co-occurring western lineage (BIN_W), and that the contact zone of the lineages passes through the W Carpathians. The study revealed phylogeographic and demographic differences between lineages, supporting hypothesis of their evolutionary independence and specific ecological preferences. The obtained genetic data of the R. tristis population from W Carpathians improved our knowledge about population genetics of this aquatic species and can contribute to understanding the state and evolution of biodiversity of freshwater ecosystems in Europe.

Fuzzy species borders of glacial survivalists in the Carpathian biodiversity hotspot revealed using a multimarker approach

The Carpathians are one of the key biodiversity hotspots in Europe. The mountain chain uplifted during Alpine orogenesis and is characterised by a complex geological history. Its current biodiversity was highly influenced by Pleistocene glaciations. The goal of the current study was to examine the phylogenetic and demographic history of Gammarus balcanicus species complex in the Carpathians using multiple markers as well as to delimit, using an integrative approach, and describe new species hidden so far under the name G. balcanicus. Results showed that divergence of the studied lineages reaches back to the Miocene, which supports the hypothesis of their survival in multiple micro refugia. Moreover, the increase of their diversification rate in the Pleistocene suggests that glaciation was the driving force of their speciation. The climatic changes during and after the Pleistocene also played a major role in the demography of the local Carpathian lineages. Comparison of diversity patterns and phylogenetic relationships of both, the mitochondrial and nuclear markers, provide evidence of putative hybridisation and retention of ancient polymorphism (i.e., incomplete lineage sorting). The morphological examination supported the existence of two morphological types; one we describe as a G. stasiuki sp. nov. and another we redescribe as a G. tatrensis (S. Karaman, 1931).

Greater reproductive assurance of asexual plant compared with sexual relative in a low-density sympatric population: Experimental evidence for pollen limitation

High reproductive assurance is regarded as a key advantage of uniparentally reproducing organisms for establishing a new population. This demographic benefit should especially be relevant for plants with autonomous apomixis, that is those which produce seeds completely independently from mates and pollinators. Indeed, many autonomous apomicts occupy larger distributional ranges when compared to their sexual relatives, showing geographical parthenogenesis patterns. However, uniparental reproduction advantage has only rarely been quantified in natural populations and results provided a mixed support, partly because allopatric sexual and asexual populations were exposed to different environmental and pollination conditions causing considerable between-population variation in the level of reproductive assurance. Here, we compared the level and stability of reproductive assurance between sexual self-incompatible and asexual autonomously apomictic plants of Hieracium alpinum (Asteraceae) cultivated in a sympatric low-density population with two levels of spatial clumping of sexual plants. Overall, we found that the realized seed set (i.e. proportion of well-developed seeds per capitulum) of asexuals was ca. 3 times greater than that of sexuals (83% vs. 27%), whereas the variance of this trait expressed as coefficient of variation was ca. 4 times smaller in asexuals compared with sexuals (19% vs. 83%). Solitary sexual plants had more than 2 times lower realized seed set when compared to clumps composed of two spatially close (20-30 cm) sexual plants (13% vs. 34%). Our study provides experimental evidence for benefit of uniparental reproduction of asexuals in a sympatric situation when the availability of mates is limited. This, together with unpredictability of pollinator environment could provide autonomous apomicts with an ultimate demographic superiority during colonization reflected in geographical parthenogenesis observed in this species.

Mitochondrial DNA diversity of the alpine newt (Ichthyosaura alpestris) in the Carpathian Basin: evidence for multiple cryptic lineages associated with Pleistocene refugia

The phylogeography and molecular taxonomy of the Alpine newt, Ichthyosaura alpestris, has been intensively studied in the past. However, previous studies did not include a comprehensive sampling from the Carpathian Basin, possibly a key region in the evolution of the species. We used a 1251 bp long fragment of the mitochondrial genome to infer the species’ evolutionary history in central-eastern Europe by assigning isolated Carpathian Basin populations from 6 regions to previously defined mtDNA lineages. We also revised the morphology-based intraspecific taxonomy of the species in the light of new genetic data. Alpine newt populations from the Carpathian Basin represented two different mitochondrial lineages. The Mátra, Bükk and Zemplén Mts populations can be assigned to the Western lineage of the nominotypical subspecies. Bakony and Őrség populations showed high haplotype diversity and formed a separate clade within the Western lineage, suggesting that the Carpathian Basin might have provided cryptic refugia for Alpine newt populations in their cold-continental forest-steppe landscapes during the younger Pleistocene. Newts from Apuseni Mts were related to the Eastern lineage but formed a distinct clade within this lineage. Considering the morphological and genetic differentiation of the Bakony and Őrség populations, consistent with a long independent evolutionary history, we propose these populations be referred to as Ichthyosaura alpestris bakonyiensis (Dely, 1964). We provide a redescription of this poorly known subspecies.

Borders as Crossroads: The Diverging Routes of Herbal Knowledge of Romanians Living on the Romanian and Ukrainian Sides of Bukovina

Cross-border and cross-cultural ethnomedicine are novel ways to address the evolution of local ecological knowledge. As is widely acknowledged, ethnomedicinal knowledge is not static, but evolves according to several factors, including changes in ecological availability and socioeconomic conditions, and yet the effect of the political context on medicinal knowledge remains largely underexplored. Bukovina, a small region of Eastern Europe that has been divided by a border since the 1940s and is currently part of both Romania and Ukraine, represents a unique case study in which to address the impact of political contexts on ethnomedicinal knowledge. The aim of this study was to compare plant-based medicinal uses among Romanians living on the two sides of the Romanian-Ukrainian border. In addition, we performed cross-cultural and cross-border analysis with published data on the ethnomedicine of the neighboring ethnolinguistic group of Hutsuls. We conducted 59 semistructured interviews with conveniently selected Romanians living in both Romanian and Ukrainian Bukovina. We elicited preparations for treating different ailments and disorders by naming each part of the body. We also asked about the sources of this medicinal knowledge. We documented the medicinal use of 108 plant taxa belonging to 45 families. Fifty-four taxa were common to both Romanian communities; 20 were only found among Romanians living in Romania and 34 only among Romanians living in Ukraine. However, the number of recorded uses was higher among Romanians living in Romania, revealing that they make consistent use of local medicinal plants, and Romanians living in Ukrainian Bukovina use more taxa but less consistently. Comparison with the data published in our study on neighboring Hutsuls shows that medicinal knowledge is more homogeneous among Hutsuls and Romanians living in Ukraine, yet many similar uses were found among Romanian communities across the border. We argue that the 50 years during which Ukrainian Bukovina was part of the USSR resulted in the integration of standard pan-Soviet elements as evidenced by several plant uses common among the groups living in Ukraine yet not among Hutsuls and Romanians living in Romania.

Intricate Distribution Patterns of Six Cytotypes of Allium oleraceum at a Continental Scale: Niche Expansion and Innovation Followed by Niche Contraction With Increasing Ploidy Level

The establishment and success of polyploids are thought to often be facilitated by ecological niche differentiation from diploids. Unfortunately, most studies compared diploids and polyploids, ignoring variation in ploidy level in polyploids. To fill this gap, we performed a large-scale study of 11,163 samples from 1,283 populations of the polyploid perennial geophyte Allium oleraceum with reported mixed-ploidy populations, revealed distribution ranges of cytotypes, assessed their niches and explored the pattern of niche change with increasing ploidy level. Altogether, six ploidy levels (3x-8x) were identified. The most common were pentaploids (53.6%) followed by hexaploids (22.7%) and tetraploids (21.6%). Higher cytotype diversity was found at lower latitudes than at higher latitudes (>52° N), where only tetraploids and pentaploids occurred. We detected 17.4% of mixed-ploidy populations, usually as a combination of two, rarely of three, cytotypes. The majority of mixed-ploidy populations were found in zones of sympatry of the participating cytotypes, suggesting they have arisen through migration (secondary contact zone). Using coarse-grained variables (climate, soil), we found evidence of both niche expansion and innovation in tetraploids related to triploids, whereas higher ploidy levels showed almost zero niche expansion, but a trend of increased niche unfilling of tetraploids. Niche unfilling in higher ploidy levels was caused by a contraction of niche envelopes toward lower continentality of the climate and resulted in a gradual decrease of niche breadth and a gradual shift in niche optima. Field-recorded data indicated wide habitat breadth of tetraploids and pentaploids, but also a pattern of increasing synanthropy in higher ploidy levels. Wide niche breadth of tetra- and pentaploids might be related to their multiple origins from different environmental conditions, higher "age", and retained sexuality, which likely preserve their adaptive potential. In contrast, other cytotypes with narrower niches are mostly asexual, probably originating from a limited range of contrasting environments. Persistence of local ploidy mixtures could be enabled by the perenniality of A. oleraceum and its prevalence of vegetative reproduction, facilitating the establishment and decreasing exclusion of minority cytotype due to its reproductive costs. Vegetative reproduction might also significantly accelerate colonization of new areas, including recolonization of previously glaciated areas.

Parallel Alpine Differentiation in Arabidopsis arenosa

Parallel evolution provides powerful natural experiments for studying repeatability of evolution and genomic basis of adaptation. Well-documented examples from plants are, however, still rare, as are inquiries of mechanisms driving convergence in some traits while divergence in others. Arabidopsis arenosa, a predominantly foothill species with scattered morphologically distinct alpine occurrences is a promising candidate. Yet, the hypothesis of parallelism remained untested. We sampled foothill and alpine populations in all regions known to harbor the alpine ecotype and used SNP genotyping to test for repeated alpine colonization. Then, we combined field surveys and a common garden experiment to quantify phenotypic parallelism. Genetic clustering by region but not elevation and coalescent simulations demonstrated parallel origin of alpine ecotype in four mountain regions. Alpine populations exhibited parallelism in height and floral traits which persisted after two generations in cultivation. In contrast, leaf traits were distinctive only in certain region(s), reflecting a mixture of plasticity and genetically determined non-parallelism. We demonstrate varying degrees and causes of parallelism and non-parallelism across populations and traits within a plant species. Parallel divergence along a sharp elevation gradient makes A. arenosa a promising candidate for studying genomic basis of adaptation.

Direct and indirect effects of land-use intensity on plant communities across elevation in semi-natural grasslands

Grassland biodiversity is vulnerable to land use change. How to best manage semi-natural grasslands for maintaining biodiversity is still unclear in many cases because land-use processes may depend on environmental conditions and the indirect effects of land-use on biodiversity mediated by altered abiotic and biotic factors are rarely considered. Here we evaluate the relative importance of the direct and indirect effects of grazing intensity on plant communities along an elevational gradient on a large topographic scale in the Eastern Carpathians in Ukraine. We sampled for two years 31 semi-natural grasslands exposed to cattle grazing. Within each grassland site we measured plant community properties such as the number of species, functional groups, and the proportion of species undesirable for grazing. In addition, we recorded cattle density (as a proxy for grazing intensity), soil properties (bare soil exposure, soil organic carbon, and soil pH) and densities of soil decomposers (earthworms and soil microorganisms). We used structural equation modelling to explore the direct and indirect effects of grazing intensity on plant communities along the elevation gradient. We found that cattle density decreased plant species and functional diversity but increased the proportion of undesirable species. Some of these effects were directly linked to grazing intensity (i.e., species richness), while others (i.e., functional diversity and proportion of undesirable species) were mediated via bare soil exposure. Although grazing intensity decreased with elevation, the effects of grazing on the plant community did not change along the elevation gradient. Generally, elevation had a strong positive direct effect on plant species richness as well as a negative indirect effect, mediated via altered soil acidity and decreased decomposer density. Our results indicate that plant diversity and composition are controlled by the complex interplay among grazing intensity and changing environmental conditions along an elevation gradient. Furthermore, we found lower soil pH, organic carbon and decomposer density with elevation, indicating that the effects of grazing on soil and related ecosystem functions and services in semi-natural grasslands may be more pronounced with elevation. This demonstrates that we need to account for environmental gradients when attempting to generalize effects of land-use intensity on biodiversity.

Ecological corridors for the amphibians and reptiles in the Natura 2000 sites of Romania

Landscape heterogeneity and fragmentation are key challenges for biodiversity conservation. As Earth’s landscape is increasingly dominated by anthropogenic land use, it is clear that broad-scale systems of nature reserves connected by corridors are needed to enable the dispersal of flora and fauna. The European Union currently supports a continent-wide network of protected areas, the Natura 2000 program, but this program lacks the necessary connectivity component. To examine whether a comprehensive network could be built in order to protect amphibians and reptiles, two taxonomic groups sensitive to environmental changes due to their physiological constrains and low dispersal capacity, we used species’ distribution maps, the sites of community interest (SCIs) in Romania, and landscape resistance rasters. Except Vipera ursinii rakosiensis, all amphibians and reptiles had corridors mapped that, when assembled, provided linkages for up to 27 species. Natura 2000 species were not good candidates for umbrella species as these linkages covered only 17% of the corridors for all species. Important Areas for Connectivity were identified in the Carpathian Mountains and along the Danube River, further confirming these regions as hot spots for biodiversity in Europe, where successful linkages are most likely. In the end, while such corridors may not be created just for amphibians and reptiles, they can easily be incorporated into more complex linkages with corridors for more charismatic species, therefore enhancing the corridors’ value in terms of quality and structure.

Genetic diversity, phylogenetic position and morphometric analysis of Astacus colchicus (Decapoda, Astacidae): a new insight into Eastern European crayfish fauna

The phylogeny of European crayfish fauna, especially with respect to Eastern European species, is still far from being completely resolved. To fill this gap, we analyzed most of the European crayfish species focusing on the phylogenetic position of the endemic crayfish Astacus colchicus, inhabiting Georgia. Three mitochondrial and one nuclear marker were used to study evolutionary relationships among European crayfish species, resulting in the unique phylogenetic position of A. colchicus indicating independent species status to A. astacus. Phylogenetic analyses revealed a deep molecular divergence of A. colchicus in comparison to A. astacus (6.5-10.9% in mtDNA and 1.1% in nDNA) as well as to Pontastacus leptodactylus and P. pachypus (5.5-10.0% in mtDNA and 1.4-2.4% in nDNA). Absent ventral process on second male pleopod and abdominal somites II and III with pleura rounded lacking prominent spines clearly indicate taxonomic assignment to the genus Astacus; however, the species is distributed almost in the middle of Ponto-Caspian area typical by occurrence of the genus Pontastacus. Several morphological indices linked to head length, carapace, and total body length and width were found to demonstrate apparent differences between A. colchicus and A. astacus. Although this study provides a novel insight into European crayfish phylogeography, we also point out the gaps in comprehensive study of the P. leptodactylus species complex, which could reveal details about the potential species status of particular species and subspecies within this genus.

The tale of springs and streams: how different aquatic ecosystems impacted the mtDNA population structure of two riffle beetles in the Western Carpathians

The Western Carpathians are a particularly interesting part of the Carpathian Arc. According to recent molecular data upon aquatic and terrestrial taxa, this mountain area is an important biodiversity hotspot of Europe. Moreover, the W Carpathians include rich systems of karst springs inhabited by specific fauna, where molecular diversity and phylogeographic patterns are yet to be fully explored. Our study aims to compare population genetic structure and molecular diversity of two related and commonly co-occurring riffle beetles, Elmis aenea (PWJ Müller, 1806) and Limnius perrisi (Dufour, 1843) in the springs and streams of the W Carpathians using the mitochondrial DNA barcoding fragment of the cytochrome c oxidase subunit I gene (COI). The relatively stable thermal and chemical conditions of springs throughout unfavourable climatic settings make these highly specific lotic systems potentially ideal for a long-term survival of some aquatic biota. Populations of both elmid species were relatively homogeneous genetically, with a single dominant haplotype. However, we revealed that E. aenea significantly dominated in the springs, while L. perrisi preferred streams. Relative isolation of the springs and their stable conditions were reflected in significantly higher molecular diversity of the E. aenea population in comparison to L. perrisi. The results of Bayesian Skyline Plot analysis also indicated the exceptional position of springs regarding maintaining the population size of E. aenea. On the other hand, it seems that streams in the W Carpathians provide more effective dispersal channels for L. perrisi, whose population expanded much earlier compared to E. aenea. Present study points out that different demographic histories of these two closely related elmid species are manifested by their different habitat preference and molecular diversity.

Integrating Multiple Lines of Evidence to Explore Intraspecific Variability in a Rare Endemic Alpine Plant and Implications for Its Conservation

We studied the ecology, distribution, and phylogeography of Tephroseris balbisiana, a rare plant whose range is centered to the South-Western Alps. Our aim was to assess the extent of intraspecific variability within the nominal species and the conservation status of isolated populations. We studied genetic diversity across the whole species range. We analyzed leaf traits, which are distinctive morphological characters within the Tephroseris genus. A clear pattern of genetic variation was found among populations of T. balbisiana, which clustered according to their geographic position. On the contrary, there was a strong overlap in the morphological space of individuals across the species' range, with few peripheral populations diverging in their leaf morphology. Studying habitat suitability by means of species distribution models, we observed that T. balbisiana range is primarily explained by solar radiation and precipitation seasonality. Environmental requirements could explain the genetic and morphological uniformity of T. balbisiana in its core distribution area and justify genetic, morphological, and ecological divergences found among the isolated populations of the Apennines. Our findings emphasize the need to account for the whole diversity of a species, comprising peripheral populations, in order to better estimate its status and to prioritize areas for its conservation.

Quantitative biogeography of Orthoptera does not support classical qualitative regionalization of the Carpathian Mountains

The first biogeographical division of the Carpathians, the second largest mountain range in Europe, was based on qualitative observational floristic data > 100 years ago and has also been applied for the regional zoogeography. In this study, the recent availability of detailed quantitative data allowed us to perform a more powerful evaluation of the classical biogeographical regions of the area. Thus, we analysed updated distribution patterns of 137 Orthoptera species native to the Carpathian Mountains and, by using published species range maps, we compiled data on species presence or absence within 2576 cells of a 10 km × 10 km universal transverse mercator grid in the area. Pattern analysis of the data was based on non-metric multidimensional scaling and clustering using six different algorithms applied to a β sim dissimilarity matrix. The unweighted pair-group method using arithmetic averages, which gave the best performance in the analysis of species turnover, delineated four regions. Environmental variables and species richness were used in logistic regression as predictors of delineated clusters, and indicator species were identified for each of the inferred regions. The pattern can be explained, in part, by environmental variables and species richness (34.2%) and was also influenced by connections with the orthopterofauna from adjacent areas. The observed discrepancy between regionalization based on expert knowledge and the pattern revealed using quantitative data provides a warning that the biogeography of the Carpathians might also have been revised in other taxa, where only classical qualitative regionalization exists.

Diversification and independent polyploid origins in the disjunct species Alyssum repens from the Southeastern Alps and the Carpathians

PREMISE

Disjunct distributions have been commonly observed in mountain plant species and have stimulated phylogeographic and phylogenetic research. Here we studied Alyssum repens, a member of the polyploid species complex A. montanum-A. repens, which exhibits SE Alpine-Carpathian disjunctions with a large elevational span and consists of diploid and tetraploid populations. We aimed to investigate the species' genetic and cytotype structure in the context of its distribution patterns, to elucidate the polyploid origins and to propose an appropriate taxonomic treatment.

METHODS

We combined AFLP fingerprinting markers, sequence variation of the highly repetitive ITS region of rDNA and the low-copy DET1 nuclear gene, genome size, and morphometric data.

RESULTS

We identified four geographically structured genetic lineages. One consisted of diploid populations from the foothills of the Southeastern Alps and neighboring regions, and the three others were allopatric montane to alpine groups comprising diploids and tetraploids growing in the Southeastern Carpathians and the Apuseni Mts. in Romania.

CONCLUSIONS

We inferred a vicariance scenario associated with Quaternary climatic oscillations, accompanied by one auto- and two allopolyploidization events most likely involving a northern Balkan relative. Whereas genetic differentiation and allopatric distribution would favor the taxonomic splitting of this species, the genetic lineages largely lack morphological distinguishability, and their ecological, cytotype and genome size divergence is only partial. Even though we probably face here a case of incipient speciation, we propose to maintain the current taxonomic treatment of Alyssum repens as a single, albeit variable, species.

Recent Deforestation Pattern Changes (2000–2017) in the Central Carpathians: A Gray-Level Co-Occurrence Matrix and Fractal Analysis Approach

The paper explores the distribution of tree cover and deforested areas in the Central Carpathians in the central-east part of Romania, in the context of the anthropogenic forest disturbances and sustainable forest management. The study aims to evaluate the spatiotemporal changes in deforested areas due to human pressure in the Carpathian Mountains, a sensitive biodiverse European ecosystem. We used an analysis of satellite imagery with Landsat-7 Enhanced Thematic Mapper Plus (Landsat-7 ETM+) from the University of Maryland (UMD) Global Forest Change (GFC) dataset. The workflow started with the determination of tree cover and deforested areas from 2000–2017, with an overall accuracy of 97%. For the monitoring of forest dynamics, a Gray-Level Co-occurrence Matrix analysis (Entropy) and fractal analysis (Fractal Fragmentation-Compaction Index and Tug-of-War Lacunarity) were utilized. The increased fragmentation of tree cover (annually 2000–2017) was demonstrated by the highest values of the Fractal Fragmentation-Compaction Index, a measure of the degree of disorder (Entropy) and heterogeneity (Lacunarity). The principal outcome of the research reveals the dynamics of disturbance of tree cover and deforested areas expressed by the textural and fractal analysis. The results obtained can be used in the future development and adaptation of forestry management policies to ensure sustainable management of exploited forest areas.

A journey on plate tectonics sheds light on European crayfish phylogeography

Crayfish can be used as model organisms in phylogeographic and divergence time studies if reliable calibrations are available. This study presents a comprehensive investigation into the phylogeography of the European stone crayfish (Austropotamobius torrentium) and includes samples from previously unstudied sites. Two mitochondrial markers were used to reveal evolutionary relationships among haplogroups throughout the species' distributional range and to estimate the divergence time by employing both substitution rates and geological calibration methods. Our haplotype network reconstruction and phylogenetic analyses revealed the existence of a previously unknown haplogroup distributed in Romania's Apuseni Mountains. This haplogroup is closely related to others that are endemic in the Dinarides, despite their vast geographical separation (~600 km). The separation is best explained by the well-dated tectonic displacement of the Tisza-Dacia microplate, which started in the Miocene (~16 Ma) and possibly carried part of the A. torrentium population to the current location of the Apuseni Mountains. This population may thus have been isolated from the Dinarides for a period of ca. 11 m.y. by marine and lacustrine phases of the Pannonian Basin. The inclusion of this geological event as a calibration point in divergence time analyses challenges currently accepted crayfish evolutionary time frames for the region, constraining the evolution of this area's crayfish to a much earlier date. We discuss why molecular clock calibrations previously employed to date European crayfish species divergences should therefore be reconsidered.

Contrasting evolutionary origins of two mountain endemics: Saxifraga wahlenbergii (Western Carpathians) and S. styriaca (Eastern Alps)

BACKGROUND

The Carpathians and the Alps are the largest mountain ranges of the European Alpine System and important centres of endemism. Among the distinctive endemic species of this area is Saxifraga wahlenbergii, a Western Carpathians member of the speciose genus Saxifraga. It was frequently considered a taxonomically isolated Tertiary palaeopolyploid and palaeoendemic, for which the closest relatives could not yet be traced. A recently described narrow endemic of the Eastern Alps, S. styriaca, was hypothesized to be closely related to S. wahlenbergii based on shared presence of peculiar glandular hairs. To elucidate the origin and phylogenetic relationships of both species we studied nuclear and plastid DNA markers based on multiple accessions and analysed the data in a wide taxonomic context. We applied Sanger sequencing, followed by targeted next-generation sequencing (NGS) for a refined analysis of nrITS variants to detect signatures of ancient hybridization. The ITS data were used to estimate divergence times of different lineages using a relaxed molecular clock.

RESULTS

We demonstrate divergent evolutionary histories for the two mountain endemics. For S. wahlenbergii we revealed a complicated hybrid origin. Its maternal parent belongs to a Western Eurasian lineage of high mountain taxa grouped in subsect. Androsaceae and is most likely the widespread S. androsacea. The putative second parent was most likely S. adscendens, which belongs to the distantly related subsect. Tridactylites. While Sanger sequencing of nrITS only showed S. adscendens-related variants in S. wahlenbergii, our NGS screening revealed presence of sequences from both lineages with clear predominance of the paternal over the maternal lineage.

CONCLUSIONS

Saxifraga styriaca was unambiguously assigned to subsect. Androsaceae and is not the sister taxon of S. wahlenbergii. Accordingly, the similarity of the glandular hairs observed in both taxa rests on parallelism and both species do not constitute an example of a close evolutionary link between the floras of the Western Carpathians and Eastern Alps. With the origin of its paternal, S. adscendens-like ITS DNA estimated to ca. 4.7 Ma, S. wahlenbergii is not a relict of the mid-Tertiary climate optimum. Its hybrid origin is much younger and most likely took place in the Pleistocene.

A new, morphologically cryptic bush-cricket discovered on the basis of its song in the Carpathian Mountains (Insecta, Orthoptera, Tettigoniidae)

A new, morphologically cryptic species of phaneropterine bush-crickets is described from the grasslands of the Romanian Eastern Carpathians. Despite the morphological and acoustic similarities with the recently described Isophyanagyi Szövényi, Puskás & Orci, I.bucovinensissp. n. is characterized by a peculiar male calling song, with faster syllable repetition rate (160–220 syllables per minute, at 22–27°C) and less complex syllable structure (composed of only two elements instead of three observable in I.nagyi). The morphological description of the new species is supplemented with an oscillographic and spectrographic analysis of the male calling song and male–female pair-forming acoustic duet. An acoustic signal-based identification key is provided for all the presently known species of the Isophyacamptoxypha species group, including the new species.

Epigean gammarids survived millions of years of severe climatic fluctuations in high latitude refugia throughout the Western Carpathians

Isolated glacial refugia have been documented in Central Europe for a number of taxa, but conclusive evidence for epigean aquatic species has remained elusive. Using molecular data (mitochondrial and nuclear markers), we compared the spatial patterns of lineage diversity of the widely distributed Gammarus fossarum species complex between two adjacent biogeographically and geomorphologically distinct Central European regions: the Bohemian Massif and the Western Carpathians. We investigated if the observed patterns of spatial diversity are more likely to stem from historical or present-day factors. Phylogenetic and phylogeographic analyses revealed eight phylogenetically diverse lineages: two exhibiting local signatures of recent demographic expansion inhabit both regions, while the other six display a relict distributional pattern and are found only in the Western Carpathians. Molecular dating indicates that these lineages are old and probably diverged throughout the Miocene (7-18Ma). Furthermore, their distribution does not seem to be constrained by the present boundaries of river catchments or topography. The contrasting spatial patterns of diversity observed between the two regions thus more likely result from historical rather than contemporaneous or recent factors. Our results indicate that despite the high latitude and proximity to the Pleistocene ice sheets, the Western Carpathians functioned as long-term glacial refugia for permanent freshwater fauna, allowing the uninterrupted survival of ancient lineages through millions of years of drastic climatic fluctuations.

Between the Balkans and the Baltic: Phylogeography of a Common Vole Mitochondrial DNA Lineage Limited to Central Europe

The common vole (Microtus arvalis) has been a model species of small mammal for studying end-glacial colonization history. In the present study we expanded the sampling from central and eastern Europe, analyzing contemporary genetic structure to identify the role of a potential 'northern glacial refugium', i.e. a refugium at a higher latitude than the traditional Mediterranean refugia. Altogether we analyzed 786 cytochrome b (cytb) sequences (representing mitochondrial DNA; mtDNA) from the whole of Europe, adding 177 new sequences from central and eastern Europe, and we conducted analyses on eight microsatellite loci for 499 individuals (representing nuclear DNA) from central and eastern Europe, adding data on 311 new specimens. Our new data fill gaps in the vicinity of the Carpathian Mountains, the potential northern refugium, such that there is now dense sampling from the Balkans to the Baltic Sea. Here we present evidence that the Eastern mtDNA lineage of the common vole was present in the vicinity of this Carpathian refugium during the Last Glacial Maximum and the Younger Dryas. The Eastern lineage expanded from this refugium to the Baltic and shows low cytb nucleotide diversity in those most northerly parts of the distribution. Analyses of microsatellites revealed a similar pattern but also showed little differentiation between all of the populations sampled in central and eastern Europe.