European Distribution Range Research Articles

The hemiparasite Pedicularis palustris: ‘Ecosystem engineer’ for fen-meadow restoration

‘Ecosystem engineers’ have a critical role in the structure and function of natural communities and need to be considered as focal species to enable successful conservation or restoration of ecosystems. Through introduction and/or managing a single species, an entire community can be influenced. In our study we show that Pedicularis palustris, an endangered hemiparasite in large parts of Europe, can act as an ‘ecosystem engineer,’ speeding up the restoration of undrained fen-meadow ecosystems colonised by species-poor and resistant Carex acuta vegetation. The parasitic behavior of Pedicularis palustris on tall sedges significantly alters local plant diversity, biomass production and soil characteristics. Our experiments show that, under the right hydrological conditions and mowing management practice, several target species for nature conservation can benefit from the gaps it creates in above-ground Carex acuta vegetation and its dense below-ground root system. The more prominent presence of mosses and lower density of the topsoil stimulates the recovery of mesotrophic transition mire with active peat formation. Since this habitat type is specifically protected under the European Habitat Directive, (re)introduction of Pedicularis palustris in similar sites within its geographical distribution range in Europe may be a helpful tool to achieve the imposed obligations for appropriate management and restoration.

European phylogeography of the epiphytic lichen fungusLobaria pulmonariaand its green algal symbiont

In lichen symbiosis, fungal and algal partners form close associations, often codispersed by vegetative propagules. Due to the particular interdependence, processes such as colonization, dispersal or genetic drift are expected to result in congruent patterns of genetic structure in the symbionts. To study the population structure of an obligate symbiotic system in Europe, we genotyped the fungal and algal symbionts of the epiphytic lichen Lobaria pulmonaria at eight and seven microsatellite loci, respectively, and analysed about 4300 L.pulmonaria thalli from 142 populations from the species' European distribution range. Based on a centroid approach, which localizes centres of genetic differentiation with a high frequency of geographically restricted alleles, we identified the South Italy-Balkan region as the primary glacial refugial area of the lichen symbiosis. Procrustean rotation analysis and a distance congruence test between the fungal and algal population graphs indicated general concordance between the phylogeographies of the symbionts. The incongruent patterns found in areas of postglacial recolonization may show the presence of an additional refugial area for the fungal symbiont, and the impact that horizontal photobiont transmission and different mutation rates of the symbionts have on their genotypic associations at a continental scale.

Deep phylogeographic divergence and cytonuclear discordance in the grasshopper Oedaleus decorus

The grasshopper Oedaleus decorus is a thermophilic insect with a large, mostly south-Palaearctic distribution range, stretching from the Mediterranean regions in Europe to Central-Asia and China. In this study, we analyzed the extent of phylogenetic divergence and the recent evolutionary history of the species based on 274 specimens from 26 localities across the distribution range in Europe. Phylogenetic relationships were determined using sequences of two mitochondrial loci (ctr, ND2) with neighbour-joining and Bayesian methods. Additionally, genetic differentiation was analyzed based on mitochondrial DNA and 11 microsatellite markers using F-statistics, model-free multivariate and model-based Bayesian clustering approaches. Phylogenetic analyses detected consistently two highly divergent, allopatrically distributed lineages within O. decorus. The divergence among these Western and Eastern lineages meeting in the region of the Alps was similar to the divergence of each lineage to the sister species O. asiaticus. Genetic differentiation for ctr was extremely high between Western and Eastern grasshopper populations (Fct=0.95). Microsatellite markers detected much lower but nevertheless very significant genetic structure among population samples. The nuclear data also demonstrated a case of cytonuclear discordance because the affiliation with mitochondrial lineages was incongruent in Northern Italy. Taken together these results provide evidence of an ancient separation within Oedaleus and either historical introgression of mtDNA among lineages and/or ongoing sex-specific gene flow in this grasshopper. Our study stresses the importance of multilocus approaches for unravelling the history and status of taxa of uncertain evolutionary divergence.

Life-history traits controlling the survival of Tillaea aquatica: a threatened wetland plant species in intensively managed fishpond landscapes of the Czech Republic

Tillaea aquatica (Crassulaceae) is considered as annual wetland species threatened by changes in land use and progressing eutrophication in large part of its European distribution range. We summarised the historical and recent data on this species, and analysed its distribution and associated habitat changes in the Czech Republic. We used permanent plots as well as seed bank and seed dispersal studies to obtain better insight into the plant’s survival strategy. During the second half of the twentieth century T. aquatica disappeared from most historical localities situated mainly in large fishponds. After 1999, altogether 18 new populations were found in small fry ponds and other fish-farming ponds. The largest populations of Tillaea were found in ponds with long-term bottom exposure where the vegetation of perennial herbs was eliminated by herbicides or grazing. Propagules easily dispersible by water, on gumboots or tyres of vehicles, and long-term soil seed bank also might contribute to persistence of the species in the habitats, diminishing the chance of extinction. As the fishpond management has changed, and so have done the original habitats of Tillaea, the species could survive in habitats different from those in the past. In this article, we suggest management measures aimed at promoting survival of Tillaea under new circumstances.

Usnea flavocardia Found in Germany

OTTE, V. 2011. Usnea flavocardia found in Germany. — Herzogia 24: 151-154. Usnea flavocardia was found in Lower Lusatia, Brandenburg, far northeast of its known Western and Southern European distribution range. There is no doubt that it is a recent colonisation in this area that was heavily influenced by S02 pollution during the 20th century. The appearance of U. flavocardia could be the result of milder winters of the last few years, but the possibility that the species was previously overlooked in Brandenburg cannot be ruled out.

Spatial genetic structure of Campanula thyrsoides across the European Alps: Indications for glaciation-driven allopatric subspeciation

Abstract Quaternary climate change had profound impacts on the geographical distribution and genetic structure of plant species which is hypothesized to have triggered allopatric speciation due to spatial isolation. However, evidence is scarce despite recent advances that indicate glacial history and substrate requirements as main drivers of spatial genetic structures. Here we built upon these studies to test the role of glaciations on the morphological and ecological differentiation within the calcicolous Campanula thyrsoides across its European Alpine distribution range. We collected samples from 51 populations (1173 plants), used five microsatellite markers, estimated diversity ( N a , H E ) and differentiation ( D est , G ST_est , F ST ) and applied Bayesian clustering analysis and tessellation methods. We found support for four genetically distinct groups of populations, arranged from West to East: (i) France and Western Switzerland, (ii) Central and most of Eastern Switzerland, (iii) parts of Eastern Switzerland and Central Austria, and (iv) Southeastern Austria, Slovenia and Northeastern Italy. Among-subspecies variance was 8.4% and each subspecies was highly differentiated ( C.*thyrsoides : D est = 0.47; C.*carniolica : D est = 0.58). Geographic structuring of within-population diversity was not related to refugia outside of previously-glaciated terrain but to subspecies: the more thermophilic C.*carniolica showed significantly lower levels of within-population diversity and higher numbers of private alleles. The location of the genetic break lines between these four groups of populations corresponds to well-known biogeographic barriers. However, the phylogeographic pattern has elements formerly found in both calcicolous and silicicolous species and thus questions the generality of substrate-related patterns. Within C.*thyrsoides , population admixture upon secondary contact may have led to high genetic diversity across the distribution range. Given the geographic and genetic differences of the subspecies we conclude that differentiation between C.*thyrsoides and C.*carniolica represents a case of glaciation-driven allopatric subspeciation reinforced by missing secondary contact due to incomplete post-glacial recolonization of potential habitats.

Conservation priorities differ at opposing species borders of a European orchid

How populations from different regions within the distribution of a species contribute to the adaptive potential and survival of that species has important implications for formulating conservation actions. We test assumptions of concepts on geographic population structure (e.g. central-marginal concept and ‘rear edge versus leading edge’ model) that could be used to inform conservation of plant species under climatic changes. We analyze a comprehensive dataset of demographic traits (e.g. population size, flowering, δ 13C of plant leaves) of up to 32 sites of Himantoglossum hircinum (L.) Spreng. (Orchidaceae) located within six sub-regions of its European distribution range. Soil and climate parameters are employed as environmental predictors of variation in measured population traits. Climate is the main driver of demographic variability overriding central-marginal gradients that might be present. Warming of the climate at high latitudes paves the way for northward range expansion of species. Populations at the north and north-eastern range peripheries partly show exponential population growth and high genetic diversity and are likely to be the source of immigrants for colonization of newly suitable habitats as the climate continues to change. In recent times, populations at the southern range periphery have suffered from intensification of land use and decreasing rainfall, but in the case of Southern Italy are important because they contain genetically unique traits. Populations at both, ‘leading’ and ‘rear’, edges ought to be at the focus of conservation planning. Different conservation strategies are proposed at opposing species borders taking into account spatial variation in population needs on a geographic scale, projected population response to expected environmental changes and genetic characteristics.

Efectos de la estructura forestal sobre la ab undancia del topillo rojo Myodes glareolus (Schreber, 1780) en un encinar de la Garrotxa (NE Catalunya)

The bank vole Myodes glareolus (Schreber, 1780) is a small Eurosiberian forest rodent that lives in the northern third of the Iberian Peninsula. Within its European distribution range, the bank vole is known to prefer forested areas with extensive plant cover (i.e., herbs and shrubs) that provide refuge and food. However, there is a lack of data on its environmental requirements in the Mediterranean, which constitutes the southernmost limit of its distribution. This study analyzed the influence of forest structure on bank vole abundance in a holm-oak forest in La Garrotxa (NE Catalonia, Spain). A total of 34 rectangular plots each containing 8 Sherman traps (4 x 2) were constructed in zones with different structures within the same forest patch. These plots were sampled for 3 consecutive days in winter 1999. The forest structure enabled the definition of two groups of plots based on cluster analysis: 1) one group of 17 plots (type 1) with large oaks and a smaller density of trunks, with a great amount of herbaceous vegetation and shrubs; and 2) a group of 10 plots (type 2), with small oaks and a high density of trunks, with very poor undercover. A third experimental group was added (n = 7 plots), consisting of plots with a structure similar to the type 2 plots, and that were cleared by removing bushes and small trees. A total of 32 different individuals were captured, and analysis of variance demonstrated that the density of bank voles was 9 times higher in type 1 plots than in type 2 plots, whereas there were no captures in type 3 plots. These results indicate microhabitat preferences that are similar to those already known in more northern populations, and that lead to the selection of forest patches with extensive shrub and herbaceous cover.

Phylogeography and genetic structure of the orchid Himantoglossum hircinum (L.) Spreng. across its European central–marginal gradient

AbstractAim This study aims to link demographic traits and post‐glacial recolonization processes with genetic traits in Himantoglossum hircinum (L.) Spreng (Orchidaceae), and to test the implications of the central–marginal concept (CMC) in Europe.Location Twenty sites covering the entire European distribution range of this species.Methods We employed amplified fragment length polymorphism (AFLP) markers and performed a plastid microsatellite survey to assess genetic variation in 20 populations of H. hircinum located along central–marginal gradients. We measured demographic traits to assess population fitness along geographical gradients and to test for correlations between demographic traits and genetic diversity. We used genetic diversity indices and analyses of molecular variance (AMOVA) to test hypotheses of reduced genetic diversity and increased genetic differentiation and isolation from central to peripheral sites. We used Bayesian simulations to analyse genetic relationships among populations.Results Genetic diversity decreased significantly with increasing latitudinal and longitudinal distance from the distribution centre when excluding outlying populations. The AMOVA revealed significant genetic differentiation among populations (FST = 0.146) and an increase in genetic differentiation from the centre of the geographical range to the margins (except for the Atlantic group). Population fitness, expressed as the ratio NR/N, decreased significantly with increasing latitudinal distance from the distribution centre. Flower production was lower in most eastern peripheral sites. The geographical distribution of microsatellite haplotypes suggests post‐glacial range expansion along three major migratory pathways, as also supported by individual membership fractions in six ancestral genetic clusters (C1–C6). No correlations between genetic diversity (e.g. diversity indices, haplotype frequency) and population demographic traits were detected.Main conclusions Reduced genetic diversity and haplotype frequency in H. hircinum at marginal sites reflect historical range expansions. Spatial variation in demographic traits could not explain genetic diversity patterns. For those sites that did not fit into the CMC, the genetic pattern is probably masked by other factors directly affecting either demography or population genetic structure. These include post‐glacial recolonization patterns and changes in habitat suitability due to climate change at the northern periphery. Our findings emphasize the importance of distinguishing historical effects from those caused by geographical variation in population demography of species when studying evolutionary and ecological processes at the range margins under global change.

Biogeographical connections between the Maghreb and the Mediterranean peninsulas of southern Europe

The glacial–interglacial cycles have caused severe range modifications of species' distributions. In Europe, thermophilic species had to retreat into geographically distinct southern refugia during glaciations. This process produced strong genetic imprints, which are still detectable by the present pattern of genetic differentiation and the distribution of regional diversity. To reveal the biogeographical imprints in the western Mediterranean, we analysed 26 populations of the butterfly Maniola jurtina spread over large areas of its European and North African distribution range. The samples were analysed using allozyme electrophoresis. We detected three genetic groups, divided into Western Europe, Central/Eastern Europe, and Italy with the Maghreb. The North African samples randomly cluster within the Italian samples. Even the population sampled in Morocco is genetically closely related to these samples and not to the geographically neighbouring Iberian ones. Parameters of genetic diversity showed similar values over the whole study area. The observed genetic pattern reflects possible glacial refugia in Europe located in the Iberian Peninsula and the Balkans. For North Africa and Italy, our data reveal a colonization of Africa originating from Italy.

Phylogeography and host race differentiation in the European mistletoe (Viscum album L.)

Mistletoes are bird dispersed, hemi-parasitic shrubs infecting a large number of woody host plants. Chloroplast fragment length polymorphisms were used to study genetic differentiation among presumed host races, population genetic structure, and to elucidate the postglacial migration history of mistletoe (Viscum album) across the entire natural distribution range in Europe. The populations sampled belong to four closely related taxa, three of which are widely distributed and differ in their host trees, whereas a fourth taxon is rare and endemic to the Island of Crete. The molecular analysis of chloroplast DNA variation supported the distinction of these four taxa. We further found evidence for phylogeographical structure in each of the three widely distributed host races. Independent of host race, mistletoe haplotypes from Turkey were distinct and distant from those found elsewhere in Europe, suggesting that highly differentiated populations, and possibly new taxa, exist at the range limit of the species.

Population genetic structure of the caddisfly Rhyacophila pubescens, Pictet 1834, north of the Alps

In this study we analyse the genetic population structure of the caddisfly Rhyacophila pubescens, a montane aquatic insect with a Central European distribution range. The species exhibits an insular distribution pattern due to its strong binding to unimpaired tufa streams and thus to mountain ranges with calcareous geology. We examined sequence data (mtCOI) of 197 individuals from 33 sites of the northern part of the distribution range to elucidate whether genetic population structure reflects this insular distribution. 28 haplotypes were identified, one of which was central in the median-joining haplotype network, occurred all across the study area, and seemed to be ancestral to others. In almost every mountain we also found closely related, private haplotypes indicating recent differentiation processes. Exact tests of population differentiation and pairwise F ST values showed that most mountain ranges that were studied are significantly differentiated from one another, indicating limited gene flow between mountain ranges. Analysis of Molecular Variance (AMOVA) revealed that most variation was within (68.54 %) and among mountains (30.48 %, for both p < 0.0001), but not among major mountain ranges (0.98 %, p = 0.31). Analysis of demographic history inferred recent demographic expansion in every region of the study area and the entire data set. Together these results provide evidence that limited extant gene flow and isolation between populations are currently structuring the populations north of the Alps. We present different hypotheses how the present-day genetic pattern of R. pubescens could have developed from its contrasting pattern in the past.

Eurasian badger habitat selection in Mediterranean environments: Does scale really matter?

It is widely believed that spatial scale affects habitat selection, and should influence management options, especially for species with wide geographic distribution or large territories. Eurasian badger habitat selection has been well studied throughout most of its European distribution range, but never at multiple spatial scales. We used compositional analysis to assess habitat selection of Eurasian badgers in southern Portugal at four spatial scales (1, 4, 25, and 100 km 2). We assessed habitat use from setts, latrines and footprints presence, and road kills. Oak woodlands with understorey were selected at all scales, being the most preferred habitat at 3 scales (1, 4, and 100 km 2). Pastures were most selected at the scale of the 25 km 2 cell, but their use was not significantly different from oak woodland with understorey. Shrubs and pastures were also secondly important at the majority of scales. Contrary to findings at northern latitudes, deciduous forests decreased in importance as cell size increased. In the highly humanized and fragmented landscape of southern Portugal, Eurasian badgers are selecting the matrix of oak woodlands interspersed with patches of pastures, shrubs and riparian vegetation. In these oak woodlands, scale does not have a marked effect. Management for badgers should provide, for at least, 30% of oak woodland cover at all scales. Our study illustrates the across-scale importance of maintaining the historically human altered, sustainable and unique landscape and land use system – the montado.

Protein loci in diploid tissue of Norway spruce (Piceu abies K.): description and interpretation of electrophoretic variability patterns

An increasing interest has focused on the patterns for distribution of genetic vaniation in coniferous species, but difficulties in using diploid tissue for electrophoretic analyses have placed obvious limitations on the scale of studies aimed at delineating the genetic population structure of conifers. We describe electrophoretic procedures for analysis of enzyme loci in diploid tissue of Norway spruce (Picea abies K.). Using bud extracts, a total of 25 loci (coding for 12 enzymes) considered usable in population surveys have been identified. All these loci are also expressed in endosperm tissue, but only 15 of them can be scored in needle extracts. The electrophoretic expressions of a total of 65 alleles observed after scoring some 5000 trees from most of the species' European distribution range are also described.

Increase of heterozygosity in a growing population of lesser kestrels

The lesser kestrel (Falco naumanni) suffered a sharp population decline over much of its European distribution range in the middle of the twentieth century. Still declining in some areas, the species has recently experienced a notable population recovery in certain regions. We examined the genetic diversity variation in a growing population of lesser kestrels from Central Spain over a 6-year period (2000-2005). The population studied showed a rapid demographic expansion, increasing in the number of both breeding pairs and colonies. Annual average heterozygosity and allelic diversity increased and genetic similarity between potential mates decreased over the study period. Several immigrants regularly arrived in the study area and introduced new alleles into the local population, pointing to immigration as the main cause contributing to the observed genetic recovery.

Mitochondrial DNA phylogeography of the three-spined stickleback ( Gasterosteus aculeatus) in Europe—Evidence for multiple glacial refugia

An analysis of mitochondrial DNA sequence variation in 172 three-spined sticklebacks ( Gasterosteus aculeatus) sampled across the European distribution range revealed three major evolutionary lineages occupying relatively large and separate geographic areas. The trans-Atlantic lineage comprised of populations spanning from the East Coast of USA to the continental Europe and was basal group to the other European lineages in the phylogeny. The European lineage included populations located in the Western and Eastern Europe, British Isles, Scandinavia as well as some parts of the Mediterranean region. The third lineage was specific to the Black Sea drainages. The within lineage structure was characterized by significant excess of low frequency haplotypes and star-like mtDNA genealogies, which suggest a recent population expansions to the formerly glaciated marine and freshwater environments. A coalescent-based method dated the splits between the major lineages to have occurred during the Saalian and Weichselian glaciations in the late Pleistocene, depending on the molecular clock calibration. The coalescent simulations further indicate high degree of genetic diversity within the lineages and a substantial increase in the genetic diversity in the European lineage relative to the ancestral level. In addition to the three major lineages, the freshwater populations in R. Neretva and L. Skadar in the Adriatic Sea coast region harboured unique and highly divergent haplotypes suggesting long independent histories of these populations. Evidence from mtDNA analyses suggests that these populations deserve a status of an evolutionary significant unit.

Genetic structure and evidence for recent population decline in Eurasian otter populations in the Czech and Slovak Republics: implications for conservation

AbstractOver the latter part of the 20th century, Eurasian otter Lutra lutra populations suffered dramatic declines, resulting in extinction or fragmentation of populations in many western and central European countries. Part of the Czech otter population became totally isolated while the Slovak population remained partly connected to the relatively continuous central and eastern European otter distribution range. This paper examines the genetic structure and past demographic history of otters in the Czech and Slovak Republics, using microsatellite nuclear markers amplified from DNA extracted from tissue and faecal samples. A relatively high level of genetic differentiation was found between the Czech and Slovak populations (FST=0.154, P=0.0002), supported by a perfect assignment in Bayesian cluster analysis. Both the Czech and Slovak populations showed significant heterozygosity excess (assuming an infinite allele model), indicating recent population bottlenecks. A very recent population decline was also suggested by coalescent analysis, inferring a drop to c. 25% of past effective population size in both populations. The timing of the decline was in accordance with published data from otter surveys, suggesting that the strongest decline probably occurred between the 1970s and the mid‐1990s. The results of this study confirm that otter populations remain vulnerable to any violent demographic change and, despite the claims of fish‐farmers and anglers for legal culls, it is highly desirable that they remain a strongly protected species in both countries. The spreading and re‐connection of otter populations observed recently is essential for the future health of the populations, and should be supported through habitat conservation.

La foresta come habitat del Gallo cedrone: ricerca applicata e nuove esperienze di gestione

Capercaillie (Tetrao urogallus L.) is considered as an indicator species for naturally open coniferous forests, with high proportions of old and open stands. At present, Capercaillie conservation status is threatened in all its central European distribution range: the species has narrow habitat preferences and large spatial requirements and it is particularly susceptible to changes in landscape and habitat use. Forestry practices are commonly considered as the major factor influencing Capercaillie’s population dynamics, though direct human disturbance is another threat of considerable impact. Increasing loss and fragmentation of suitable habitats have resulted in small populations with different levels of connectivity, up to complete isolation. Preservation, restoration and improvement of the habitat are the most important conservation measures to ensure the long-term survival of Capercaillie populations. Integrating silvicultural practices with specific environmental requirements of this forest grouse is therefore of crucial importance. Some results of recent research and conservation efforts carried out in central-eastern Alpine Arc of Switzerland and Italy are presented here, based on different research approaches. Preliminary experiences of management guidelines applied to conservation strategy of such a symbolic species are also commented. A conservation strategy recently developed by Regione Lombardia is discussed. Secondly, two studies developed in the frame of a research project concerning “A metapopulation model of Capercaillie in the Swiss Alps” are presented, referring to different spatial scale (forest stand and landscape). A specific Action Plan at Swiss national level will be developed based on the main results of this project. Finally implementation of Special Forest Reserves is described, as a possible long-term tool for protecting and conserving Capercaillie populations.

Breeding Habitat Selection of Salamandra salamandra (Linnaeus, 1758) in the Most Arid Zone of its European Distribution Range: Application to Conservation Management

The influence of environmental variables on the selection of a water body as breeding habitat by Salamandra salamandra was studied in an arid zone located in the southwestern part of its distribution range. From November 2002 to October 2003, 50 water bodies were monitored in the south east of the Iberian Peninsula. Environmental data were submitted to a stepwise logistic regression analysis at macrohabitat, water body typology and microhabitat scales in order to establish the main factors influencing the use of a given water body as breeding habitat by this species. A significant degree of dependence between the reproduction of Salamandra salamandra and environmental variables was observed at all of these levels. These results should be taken into account when populations of this species are subjected to management and/or recovery programmes in arid areas.

Genetic relationships among marine and freshwater populations of the European three‐spined stickleback (Gasterosteus aculeatus) revealed by microsatellites

To assess the population genetic structure of the three-spined stickleback, Gasterosteus aculeatus, variability at 18 microsatellite loci was examined in 1724 individuals from 74 locations covering most of the species distribution range in Europe. The results revealed high overall degree of differentiation (F(ST) = 0.21) but contrasting level of divergence and genetic variability between habitat types. Marine populations were genetically relatively uniform even across great geographical distances as compared to substantial differentiation among freshwater populations. Analysis of molecular variance indicated low but significant (2.7%) variation in allele frequencies between geographical regions, but a negligible effect of habitat type (0.2%). The phylogenetic pattern was not explained by habitat type, but a weak signal of populations clustering according to geographical or water system origin was found. The results support the view that three-spined stickleback marine ancestors colonized northern European fresh waters during the postglacial marine submergence c. 10,000 years ago, whereas in the Mediterranean region colonization probably dates back to the Pleistocene. The independent origins of river and lake populations indicate that they originate from multiple colonizations rather than sharing common ancestry. In the continuous marine environment, the low degree of differentiation among populations can be explained by gene flow among subpopulations and large effective population size buffering divergence in neutral markers. In contrast, among postglacially established freshwater populations differentiation appears to be driven by genetic drift and isolation. The stepwise mutations appear to have contributed to the population differentiation in the southern part of the three-spined stickleback distribution range.