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  • 51.
    Schmiede, Ralf
    et al.
    Justus-Liebig-University, Giessen, Germany.
    Ruprecht, Eszter
    Babeş-Bolyai University, Romania.
    Eckstein, Rolf Lutz
    Justus-Liebig-University, Giessen, Germany.
    Otte, Annette
    Justus-Liebig University, Giessen, Germany.
    Donath, Tobias W.
    Justus-Liebig-University, Giessen, Germany.
    Establishment of rare flood meadow species by plant material transfer: Experimental tests of threshold amounts and the effect of sowing position2013In: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 159, p. 222-229Article in journal (Refereed)
    Abstract [en]

    The transfer of freshly cut seed-containing plant material is a widely applied method to re-establish grassland of high biodiversity. Still, the amount of plant material applied varies greatly across restoration projects. Therefore, we set up a two-year common garden experiment where we assessed the effect of plant material amount (0, 400, 800, 1600, 3200 g m2 and relative seed position (on top and beneath a litter layer) on seedling establishment, seedling fate and seedling fitness of eight target species for restoration of alluvial meadows. Most seedlings (85.6%) emerged within the first year. Cumulative seedling emergence and final seedling establishment across all species were highest on control plots and low litter plots but were very low or failed completely, at 1600 and 3200 g m2, respectively. In general, large-seeded species were significantly more successful than smaller seeded species. Relative seed position had only a small impact on seedling emergence and establishment but was decisive for seedling survival at high litter quantities. Across all species, seedlings that died had a significantly lower relative height than surviving seedlings. Interestingly, co-occurring resident grassland vegetation had a neutral rather than negative impact on the response variables. Our results suggest an upper threshold of 1000 g m2 for the amount of plant material applied in grassland restoration, since higher amounts will inhibit seedling establishment. The prompt emergence of most seedlings during the first vegetation period highlights the importance of creating optimal conditions for seedling establishment already in the early phase of vegetation development on restoration sites.

  • 52.
    Schulz, Benjamin
    et al.
    Justus Liebig University Giessen, Germany.
    Durka, Walter
    Helmholtz Centre for Environmental Research-UFZ, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Germany..
    Danihelka, Jiri
    Masaryk University, Czech Republic; The Czech Academy of Sciences, Czech Republic..
    Eckstein, Rolf Lutz
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Differential role of a persistent seed bank for genetic variation in early vs. late successional stages2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 12, article id e0209840Article in journal (Refereed)
    Abstract [en]

    Persistent seed banks are predicted to have an important impact on population genetic processes by increasing effective population size and storing past genetic diversity. Accordingly, persistent seed banks may buffer genetic effects of disturbance, fragmentation and/or selection. However, empirical studies surveying the relationship between aboveground and seed bank genetics under changing environments are scarce. Here, we compared genetic variation of aboveground and seed bank cohorts in 15 populations of the partially cleistogamous Viola elatior in two contrasting early and late successional habitats characterized by strong differences in light-availability and declining population size. Using AFLP markers, we found significantly higher aboveground than seed bank genetic diversity in early successional meadow but not in late successional woodland habitats. Moreover, individually, three of eight woodland populations even showed higher seed bank than aboveground diversity. Genetic differentiation among populations was very strong ((ST) = 0.8), but overall no significant differentiation could be detected between above ground and seed bank cohorts. Small scale spatial genetic structure was generally pronounced but was much stronger in meadow (Sp-statistic: aboveground: 0.60, seed bank: 0.32) than in woodland habitats (aboveground: 0.11; seed bank: 0.03). Our findings indicate that relative seed bank diversity (i.e. compared to aboveground diversity) increases with ongoing succession and despite decreasing population size. As corroborated by markedly lower small-scale genetic structure in late successional habitats, we suggest that the observed changes in relative seed bank diversity are driven by an increase of outcrossing rates. Persistent seed banks in Viola elatior hence will counteract effects of drift and selection, and assure a higher chance for the species' long term persistence, particularly maintaining genetic variation in declining populations of late successional habitats and thus enhancing success rates of population recovery after disturbance events.

  • 53.
    Schulz, Benjamin
    et al.
    Justus-Liebig-University, Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University, Giessen, Germany.
    Durka, Walter
    Justus-Liebig-University, Giessen, Germany.
    Epigenetic variation reflects dynamic habitat conditions in a rare floodplain herb2014In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 23, no 14, p. 3523-3537Article in journal (Refereed)
    Abstract [en]

    Variation of DNA methylation is thought to play an important role for rapid adjustments of plant populations to dynamic environmental conditions, thus compensating for the relatively slow response time of genetic adaptations. However, genetic and epigenetic variation of wild plant populations has not yet been directly compared in fast changing environments. Here, we surveyed populations of Viola elatior from two adjacent habitat types along a successional gradient characterized by strong differences in light availability. Using amplified fragment length polymorphisms (AFLP) and methylation-sensitive amplification polymorphisms (MSAP) analyses, we found relatively low levels of genetic (H-gen' = 0.19) and epigenetic (H-epi' = 0.23) diversity and high genetic (phi(ST) = 0.72) and epigenetic (phi(ST) = 0.51) population differentiation. Diversity and differentiation were significantly correlated, suggesting that epigenetic variation partly depends on the same driving forces as genetic variation. Correlation-based genome scans detected comparable levels of genetic (17.0%) and epigenetic (14.2%) outlier markers associated with site specific light availability. However, as revealed by separate differentiation-based genome scans for AFLP, only few genetic markers seemed to be actually under positive selection (0-4.5%). Moreover, principal coordinates analyses and Mantel tests showed that overall epigenetic variation was more closely related to habitat conditions, indicating that environmentally induced methylation changes may lead to convergence of populations experiencing similar habitat conditions and thus may play a major role for the transient and/or heritable adjustment to changing environments. Additionally, using a new MSAP-scoring approach, we found that mainly the unmethylated (phi(ST) = 0.60) and CG-methylated states (phi(ST) = 0.46) of epiloci contributed to population differentiation and putative habitat-related adaptation, whereas CHG-hemimethylated states (phi(ST) = 0.21) only played a marginal role.

  • 54.
    Schulz, Benjamin
    et al.
    Justus-Liebig-University Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University Giessen, Germany.
    Durka, Walter
    Helmholtz Centre for Environmental Research.
    Scoring and analysis of methylation-sensitive amplification polymorphisms for epigenetic population studies2013In: Molecular Ecology Resources, ISSN 1755-098X, E-ISSN 1755-0998, Vol. 13, no 4, p. 642-653Article in journal (Refereed)
    Abstract [en]

    DNA methylation is an important, heritable epigenetic modification in most eukaryotic organisms that is connected with numerous biological processes. To study the impact of natural epigenetic variation in an ecological or evolutionary context, epigenetic studies are increasingly using methylation-sensitive amplification polymorphism (MSAP) for surveys at the population or species level. However, no consensus exists on how to interpret and score the multistate information obtained from the MSAP banding patterns. Here, we review the previously used scoring approaches for population epigenetic studies and develop new alternatives. To assess effects of the different approaches on parameters of epigenetic diversity and differentiation, we applied eight scoring schemes to a case study of three populations of the plant species Viola elatior. For a total number of 168 detected polymorphic MSAP fragments, the number of ultimately scored polymorphic epiloci ranged between 78 and 286 depending on the particular scoring scheme. Both, estimates of epigenetic diversity and differentiation varied strongly between scoring approaches. However, linear regression and PCoA revealed qualitatively similar patterns, suggesting that the scoring approaches are largely consistent. For single-locus analyses of MSAP data, for example the search for loci under selection, we advocate a new scoring approach that separately takes into account different methylation types and thus seems appropriate for drawing more detailed conclusions in ecological or evolutionary contexts. An R script (MSAP_score.r) for scoring and basic data analysis is provided.

  • 55.
    Shakeri, Zahed
    et al.
    Iran.
    Mohadjer, Mohammad Reza Marvie
    Iran.
    Simberloff, Daniel
    USA.
    Etemad, Vahid
    Iran.
    Assadi, Mostafa
    Iran.
    Donath, Tobias W.
    Germany.
    Otte, Annette
    Germany.
    Eckstein, Rolf Lutz
    Germany.
    Plant community composition and disturbance in Caspian Fagus orientalis forests: which are the main driving factors?2012In: Phytocoenologia, ISSN 0340-269X, Vol. 41, no 4, p. 247-263Article in journal (Refereed)
    Abstract [en]

    The oriental beech forests along the southern Caspian Sea shores of Iran are characterized by high biodiversity and high ecological value. However, there is little information concerning factors governing community composition and the presence and abundance of invasive plants. In the present study we aimed to evaluate the main drivers of community composition, diversity, and establishment of invasive plants in disturbed and undisturbed Fagus orientalis communities. We sampled 104 vegetation releves in undisturbed and disturbed sites of the "Kheiroud Investigation Forest" in northern Iran and collected data on a large number of environmental variables concerning soil properties, light conditions, and topography. Data analysis consisted of a forward selection of significant explanatory variables followed by partial CCA analyses. Additionally, we carried out indicator species analysis of groups of releves affected by different disturbance types and analyzed effects of disturbance on species richness, diversity, and evenness using general linear models. CCA results showed that disturbance, soil properties, light conditions and elevation explained 22.6% of the total variation in floristic composition. Gap and gap + grazing were the most important disturbance types affecting community composition. Disturbance had significant but rather weak effects on species richness, evenness, and the Shannon index. The most obvious effect of disturbance was on species composition, as revealed by significant groups of indicator species for different disturbance types. Most of the indicator species in grazed sites were unpalatable, poisonous, and creeping species, which are avoided by cattle. Grazing led to decreased abundance of indicator species and species characteristic of old-growth Fagus forests. The most intensive disturbance type "harvesting + gap + grazing" was associated with invasion by native vascular plant species not typically found in beech forests (apophytes).

  • 56.
    Voss, Nicole
    et al.
    Justus-Liebig-University Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University Giessen, Germany.
    Durka, Walter
    UFZ, Halle, Germany.
    Range expansion of a selfing polyploid plant despite widespread genetic uniformity2012In: Annals of Botany, ISSN 0305-7364, E-ISSN 1095-8290, Vol. 110, no 3, p. 585-593Article in journal (Refereed)
    Abstract [en]

    Ongoing and previous range expansions have a strong influence on population genetic structure of plants. In turn, genetic variation in the new range may affect the population dynamics and the expansion process. The annual Ceratocapnos claviculata (Papaveraceae) has expanded its Atlantic European range in recent decades towards the north and east. Patterns of genetic diversity were investigated across the native range to assess current population structure and phylogeographical patterns. A test was then made as to whether genetic diversity is reduced in the neophytic range and an attempt was made to identify source regions of the expansion. Samples were taken from 55 populations in the native and 34 populations in the neophytic range (Sweden, north-east Germany). Using amplified fragment length polymorphism markers an analysis was made of genetic variation and population structure (Bayesian statistical modelling) and population differentiation was quantified. Pollen/ovule ratio was analysed as a proxy for the breeding system. Genetic diversity at population level was very low (mean H-e 0004) and two multilocus genotypes dominated large parts of the new range. Population differentiation was strong (F-ST 0812). These results and a low pollen/ovule ratio are consistent with an autogamous breeding system. Genetic variation decreased from the native to the neophytic range. Within the native range, H-e decreased towards the north-east, whereas population size increased. According to the Bayesian cluster analysis, the putative source regions of the neophytic range are situated in north-west Germany and adjacent regions. Ceratocapnos claviculata shows a cline of genetic variation due to postglacial recolonization from putative Pleistocene refugia in south-west Europe. Nevertheless, the species has expanded successfully during the past 40 years to southern Sweden and north-east Germany where it occurs as an opportunistic neophyte. Recent expansion was mainly human-mediated by single long-distance diaspore transport and was facilitated by habitat modification.

  • 57. Voss, Nicole
    et al.
    Simmering, Dietmar
    Peppler-Lisbach, Cord
    Carl von Ossietzky University Oldenburg.
    Durka, Walter
    Helmholtz Centre for Environmental Research, Halle, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University Giessen, Germany.
    Vegetation databases as a tool to analyse factors affecting the range expansion of the forest understory herb Ceratocapnos claviculata2011In: Journal of Vegetation Science, ISSN 1100-9233, E-ISSN 1654-1103, Vol. 22, no 4, p. 726-740Article in journal (Refereed)
    Abstract [en]

    Question: The eu-atlantic forest herb Ceratocapnos claviculata showed a recent increase in frequency within its native range and an eastward and northward range expansion in Central Europe. To gain deeper understanding of factors affecting the range expansion of the species, we analyzed vegetation releves at three different scales and asked the following questions: As the species occurs in a wide range of vegetation types, is variation in community composition across the entire range related to climatic environmental zones and tree cover? Are there differences in species composition and habitat characteristics between the native range and the two invaded regions (S Sweden and NE Germany)? Did community composition and habitat characteristics within the native range (The Netherlands) change between 'before 1970' and '1990 to 2006'? Location: W, C and N Europe. Methods: We analysed vegetation-plot data with C. claviculata from various databases and own surveys using partial CCA, partial DCA, Indicator Species Analysis, MANCOVA and multiple regression. Results: Using vegetation plots from the entire distribution range, climatic environmental zones explained 68.9% of the total canonical Eigenvalue. Differences in floristic composition and habitat characteristics between the two invaded regions were as large as between native and invaded range sites. However, releves from the invaded range were generally characterized by anthropogenic disturbance. Accordingly, abundance of C. claviculata was positively linked to silvicultural intensity. New releves from 1990 to 2006 were characterized by higher Ellenberg nutrient indicator values, lower species diversity, higher proportions of neophytic and hemerobic species and showed a lower cover of the study species than old releves from before 1970. Conclusions: Across the range of C. claviculata, climatic environmental zones determine vegetation composition. Accordingly, the species is characterized by a broad macroclimatic amplitude. Vegetation composition and structure differ significantly between the two regions of the new range. Thus, the species has successfully established under various biotic and abiotic environmental conditions. Beyond potential positive effects of soil eutrophication and mild winters, anthropogenic impact may directly facilitate seed dispersal and provide sites and resource conditions suitable for germination and establishment of C. claviculata, whereas a decrease of forest management may constrain the species.

  • 58.
    Voss, Nicole
    et al.
    Justus-Liebig-University, Giessen, Germany.
    Welk, Erik
    Martin Luther Univerity, Halle, Germany.
    Durka, Walter
    UFZ, Halle, Germany.
    Eckstein, Rolf Lutz
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences. Justus-Liebig-University Giessen, Germany.
    Biological flora of Central Europe: Ceratocapnos claviculata (L.) Liden2012In: Perspectives in plant ecology, evolution and systematics, ISSN 1433-8319, E-ISSN 1618-0437, Vol. 14, no 1, p. 61-77Article in journal (Refereed)
    Abstract [en]

    The eu-oceanic therophytic woodland herb Ceratocapnos claviculata has been expanding north- and eastwards into north temperate and subcontinental regions during the past decades. The rapid range expansion of the species may be an example of a species which is strongly profiting from global change. Against this background, in the present paper we review the taxonomy, morphology, distribution, habitat requirements, life cycle and biology of the species. (C) 2011 Elsevier GmbH. All rights reserved.

  • 59.
    Winter, Silvia
    et al.
    University of Natural Resources and Life Sciences Vienna, Austria.
    Jung, Linda S.
    Justus-Liebig-University, Giessen, Germany.
    Eckstein, Rolf Lutz
    Justus-Liebig-University, Giessen, Germany.
    Otte, Annette
    Justus-Liebig-University, Giessen, Germany.
    Donath, Tobias W.
    Justus-Liebig-University, Giessen, Germany.
    Kriechbaum, Monika
    University of Natural Resources and Life Sciences Vienna, Austria.
    Control of the toxic plant Colchicum autumnale in semi- natural grasslands: Effects of cutting treatments on demography and diversity2014In: Journal of Applied Ecology, ISSN 0021-8901, E-ISSN 1365-2664, Vol. 51, no 2, p. 524-533Article in journal (Refereed)
    Abstract [en]

    Semi-natural grasslands are important habitats for the conservation of biodiversity in Europe. High population densities of toxic Colchicum autumnale in these grasslands may cause problems for livestock and the marketing of hay. Consequently, farmers may either intensify grassland management to reduce C. autumnale in the fodder or abandon the land; both practices will lead to a loss of biodiversity. Previous studies suggesting early cutting to control C. autumnale did not consider population dynamics and the effects on plant diversity. We conducted a four-year experiment in six regions within Austria and Germany, applying five cutting treatments in 16 C. autumnale populations to test the effects of cutting date and frequency on C. autumnale and co-occurring vegetation. Demographic data were evaluated with matrix population models, life-table response experiment (LTRE), anova and manova. Vegetation data were analysed with multiresponse permutation procedures (MRPP), anova and manova. Population growth rate was significantly reduced in plots cut in early and late May compared to plots cut in June (control). Plants cut in late April or early May showed the lowest survival probability. Significantly fewer large vegetative plants developed capsules in the following year when cut in early or late May. LTRE analysis showed that differences in the population growth rate between the control and early cut treatments were mainly the result of a reduced survival and growth and an increased retrogression to smaller stages. Multiresponse permutation procedures revealed no differences in vegetation composition between treatments except for one site in 2011. There were no differences in Shannon index, evenness or species turnover rate within any year. Synthesis and applications. The greatest reduction in vitality of Colchicum autumnale was observed in grasslands cut in late April or early May. After three years of early cutting, no reduction in plant species diversity was observed. The second cut should be postponed to July to enable seed shed of plants. Grassland management decisions to control toxic C. autumnale must be made in close cooperation with nature conservation authorities to consider site characteristics and requirements of endangered species. The greatest reduction in vitality of Colchicum autumnale was observed in grasslands cut in late April or early May. After three years of early cutting, no reduction in plant species diversity was observed. The second cut should be postponed to July to enable seed shed of plants. Grassland management decisions to control toxic C. autumnale must be made in close cooperation with nature conservation authorities to consider site characteristics and requirements of endangered species.

12 51 - 59 of 59
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