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  • 1
    Language: English
    In: Molecular Phylogenetics and Evolution, March 2013, Vol.66(3), pp.617-627
    Description: ► We provide the first exhaustive phylogeny of crocuses based on nuclear sequences. ► We reconstruct chromosome number evolution and polyploidization in . ► 8 out of 15 series of are monophyletic, as well as probably both sections. ► Chromosome numbers increased multiple times independently by polyploidization. ► Supernumerary B chromosomes evolved at least five times independently within consists of about 100 species distributed from western Europe and northern Africa to western China, with the center of diversity on the Balkan Peninsula and in Asia Minor. Our study focuses on clarifying phylogenetic relationships and chromosome number evolution within the genus using sequences of the chloroplast L-F region, the nuclear ribosomal DNA internal transcribed spacer (ITS) region, and a part of the nuclear single-copy gene . In a combined dataset of ITS and L-F sequences, 115 individuals representing 110 taxa from both subgenera and all sections and series of were analyzed with Bayesian phylogenetic inference. For 79 individuals representing 74 taxa were included, and for the majority of them PCR amplicons were cloned and up to eight clones per individual were sequenced to detect allopolyploidization events. species were included as outgroup in both analyses. Characteristics of seed surface structures were evaluated by scanning electron microscopy. Phylogenetic analysis of ITS/ L-F data resulted in a monophyletic genus , probably monophyletic sections and , and inferred monophyly for eight of the 15 series of the genus. The aggregate, thought to be consisting of closely related subspecies, was found to be polyphyletic, the taxa occurring within three major clades in the phylogenetic tree. Cloning of resulted in the detection of homoeologous copies in about one third of the taxa of section , indicating an allotetraploid origin of this section. Reconstruction of chromosome number evolution along the phylogenetic tree using a probabilistic and a parsimony approach arrived at partly contradictory results. Both analyses agreed however on the occurrence of multiple polyploidization and dysploidy events. B chromosomes evolved at least five times independently within the genus, preferentially in clades characterized by karyotype changes.
    Keywords: B Chromosome ; Chromosome Number ; Crocus ; Evolution ; Internal Transcribed Spacer (Its) ; Pcosat103 ; Phylogeny ; Trnl-F ; Seed Testa ; Whole Genome Duplication ; Biology
    ISSN: 1055-7903
    E-ISSN: 1095-9513
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  • 2
    Language: English
    In: Ecological indicators, 2016, Vol.65, pp.44-54
    Description: Succession is a key ecological process that supports our understanding of community assembly and biotic interactions. Dispersal potential and dispersal strategies, such as wind- or animal-dispersal, have been assumed to be highly relevant for the success of plant species during succession. However, research yielded varying results on changes in dispersal modes between successional stages. Here, we test the hypotheses that (a) vascular plant species that use a number of dispersal modes dominate in early stages of succession while species specialized on one/few dispersal modes increase in abundance towards later stages of succession; (b) species well adapted to wind-dispersal (anemochory) will peak in abundance in early successional stages and (c) species well adapted to adhesive dispersal (epizoochory) will increase with proceeding succession. We test these hypotheses in four sites within agriculturally dominated landscapes in Germany. Agricultural use in these sites was abandoned 20–28 years ago, leaving them to secondary succession. Sites have been monitored for plant biodiversity ever since. We analyze changes in plant species richness and abundance, number of dispersal modes and two ranking indices for wind- and adhesive dispersal by applying generalized linear mixed-effect models. We used both abundance-weighted and unweighted dispersal traits in order to gain a comprehensive picture of successional developments. Hypothesis (a) was supported by unweighted but not abundance-weighted data. Anemochory showed no consistent changes across sites. In contrast, epizoochory (especially when not weighted by abundance) turned out to be an indicator of the transition from early to mid-successional stages. It increased for the first 9–16 years of succession but declined afterwards. Species richness showed an opposing pattern, while species abundance increased asymptotically. We suggest that plant-animal interactions play a key role in mediating these processes: By importing seeds of highly competitive plant species, animals are likely to promote the increasing abundance of a few dominant, highly epizoochorous species. These species outcompete weak competitors and species richness decreases. However, animals should as well promote the subsequent increase of species richness by disturbing the sites and creating small open patches. These patches are colonized by weaker competitors that are not necessarily dispersed by animals. The changes in the presence of epizoochorous species indicate the importance of plant traits and related plant–animal interactions in the succession of plant communities. ; p. 44-54.
    Keywords: Functional Traits ; Animals ; Secondary Succession ; Vegetation ; Models ; Long-Term Ecological Research ; Plant Communities ; Community Assembly ; Seeds ; Landscapes ; Species Diversity ; Anemochory Ranking Index ; Epizoochory Ranking Index
    ISSN: 1470-160X
    Source: AGRIS (Food and Agriculture Organization of the United Nations)
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  • 3
    In: Journal of Applied Ecology, April 2016, Vol.53(2), pp.501-510
    Description: The rapid expansion of systematic monitoring schemes necessitates robust methods to reliably assess species' status and trends. Insect monitoring poses a challenge where there are strong seasonal patterns, requiring repeated counts to reliably assess abundance. Butterfly monitoring schemes (BMSs) operate in an increasing number of countries with broadly the same methodology, yet they differ in their observation frequency and in the methods used to compute annual abundance indices. Using simulated and observed data, we performed an extensive comparison of two approaches used to derive abundance indices from count data collected via BMS, under a range of sampling frequencies. Linear interpolation is most commonly used to estimate abundance indices from seasonal count series. A second method, hereafter the regional generalized additive model (GAM), fits a GAM to repeated counts within sites across a climatic region. For the two methods, we estimated bias in abundance indices and the statistical power for detecting trends, given different proportions of missing counts. We also compared the accuracy of trend estimates using systematically degraded observed counts of the Gatekeeper Pyronia tithonus (Linnaeus 1767). The regional GAM method generally outperforms the linear interpolation method. When the proportion of missing counts increased beyond 50%, indices derived via the linear interpolation method showed substantially higher estimation error as well as clear biases, in comparison to the regional GAM method. The regional GAM method also showed higher power to detect trends when the proportion of missing counts was substantial. Synthesis and applications. Monitoring offers invaluable data to support conservation policy and management, but requires robust analysis approaches and guidance for new and expanding schemes. Based on our findings, we recommend the regional generalized additive model approach when conducting integrative analyses across schemes, or when analysing scheme data with reduced sampling efforts. This method enables existing schemes to be expanded or new schemes to be developed with reduced within‐year sampling frequency, as well as affording options to adapt protocols to more efficiently assess species status and trends across large geographical scales. Monitoring offers invaluable data to support conservation policy and management, but requires robust analysis approaches and guidance for new and expanding schemes. Based on our findings, we recommend the regional generalized additive model approach when conducting integrative analyses across schemes, or when analysing scheme data with reduced sampling efforts. This method enables existing schemes to be expanded or new schemes to be developed with reduced within‐year sampling frequency, as well as affording options to adapt protocols to more efficiently assess species status and trends across large geographical scales.
    Keywords: Abundance Indices ; Butterfly Monitoring Scheme ; Butterfly Count ; Citizen Science ; Flight Period ; Insect Conservation ; Missing Data ; Pollard Walk ; Sampling Effort ; Seasonal Pattern
    ISSN: 0021-8901
    E-ISSN: 1365-2664
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  • 4
    Language: German
    In: Archiv fuer Acker- und Pflanzenbau und Bodenkunde, 1990, Vol.(3), pp.205-212
    Description: Nach eine Einfuehrung zu D- und G-optimalen Versuchsplaenen fuer die Regressionsschaetzung werden Probleme der Anwendung im Feldversuchswesen diskutiert. Dazu werden am Beispiel der Schaetzung der optimalen Duengermenge mit Hilfe von Stickstoffsteigerungsversuchen Ergebnisse von Simulationsrechnungen vorgestellt, welche die Moeglichkeiten und Grenzen der Anwendung dieser Plaene in praktischen Faellen aufzeigen ; 2 ill., 1 table; 3 refs. Summaries (De, En, Ru)
    Keywords: Simulation ; Models ; Trials/ Statistical Analysis ; Planning ; Simulation ; Modele ; Essai/ Analyse Statistique ; Planification ; Simulacion ; Modelos ; Pruebas/ Analisis Estadistico ; Planificacion
    ISSN: 0365-0340
    Source: AGRIS (Food and Agriculture Organization of the United Nations)
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  • 5
    In: Diversity and Distributions, December 2017, Vol.23(12), pp.1393-1407
    Description: To purchase or authenticate to the full-text of this article, please visit this link: http://onlinelibrary.wiley.com/doi/10.1111/ddi.12634/abstract Byline: Nicolas Titeux,Dirk Maes,Toon Van Daele,Thierry Onkelinx, Risto K. Heikkinen,Helena Romo,Enrique Garcia-Barros,Miguel L. Munguira,Wilfried Thuiller,Chris A. M. van Swaay,Oliver Schweiger,Josef Settele, Alexander Harpke, Martin Wiemers,Lluis Brotons,Miska Luoto Keywords: bioclimatic models; butterflies; climate envelopes; climatic niche; local approaches; species distribution modelling Abstract Aim Species distribution models built with geographically restricted data often fail to capture the full range of conditions experienced by species across their entire distribution area. Using such models to predict distribution shifts under future environmental change may, therefore, produce biased projections. However, restricted-scale models have the potential to include a larger sample of taxa for which distribution data are available and to provide finer-resolution projections that are better applied to conservation planning than the forecasts of broad-scale models. We examine the circumstances under which the projected shifts in species richness patterns derived from restricted-scale and broad-scale models are most likely to be similar. Location Europe. Methods The distribution of butterflies in Finland, Belgium/Netherlands and Spain was modelled based on restricted-scale (local) and broad-scale (continental) distribution and climate data. Both types of models were projected under future climate change scenarios to assess potential changes in species richness. Results In Finland, species richness was projected to increase strongly based on restricted-scale models and to decrease slightly with broad-scale models. In Belgium/Netherlands, restricted-scale models projected a larger decrease in richness than broad-scale models. In Spain, both models projected a slight decrease in richness. We obtained similar projections based on restricted-scale and broad-scale models only in Spain because the climatic conditions available here covered the warm part of the distributions of butterflies better than in Finland and Belgium/Netherlands. Main conclusions Restricted-scale models that fail to capture the warm part of species distributions produce biased estimates of future changes in species richness when projected under climatic conditions with no modern analogue in the study area. We recommend the use of distribution data beyond the boundaries of the study area to capture the part of the species response curves reflecting the climatic conditions that will prevail within that area in the future. Article Note: Funding information European Commission Framework Programmes (FP6 and FP7) via the Integrated Project ALARM, Grant/Award Number: 506675; Integrated Project SCALES, Grant/Award Number: 226852; Collaborative Project STEP, Grant/Award Number: 244090; BiodivERsA Eranet Project CLIMIT; Collaborative Project EU BON, Grant/Award Number: 308454; ERC Starting Grant TEEMBIO, Grant/Award Number: 281422; Structuring the European Research Area Program, Lapland Atmosphere-Biosphere Facility, Grant/Award Number: 025969 CAPTION(S):
    Keywords: Bioclimatic Models ; Butterflies ; Climate Envelopes ; Climatic Niche ; Local Approaches ; Species Distribution Modelling
    ISSN: 1366-9516
    E-ISSN: 1472-4642
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  • 6
    In: Diversity and Distributions, July 2019, Vol.25(7), pp.1088-1100
    Description: Byline: Thomas Lecocq, Alexander Harpke, Pierre Rasmont,Oliver Schweiger, Janine Bolliger Keywords: bumblebee; climate change; evolutionary significant unit; intraspecific variability; model performance; species distribution model Abstract Aim Conventional species distribution models (SDMs) usually focus on the species level but disregard intraspecific variability. Phylogeographic structure and evolutionary significant units (ESU) have been proposed as pragmatic proxies to incorporate intraspecific differentiation in SDMs. Nevertheless, the efficiency of using these proxies in SDMs has been poorly investigated. We analysed how the projections of current and future climatically suitable areas can be affected when using ESU-based or lineage-based models compared to a species-level model. Location West-Palaearctic region. Methods As examples, we used three bumblebee species (133,787 observations). We assessed potential climatic niche differentiation between species level, lineages and ESUs, by determining the niche position and niche breadth for each classification level by outlying mean index analyses. Subsequently, we developed SDMs for each species and classification level separately using boosted regression trees prior to a comparison of their performances. Finally, we used the alternative models to project the extent of climatically suitable areas in 2070. Results We found that in spite of highly similar overall model accuracy, integrating intraspecific variability significantly increases model sensitivity (i.e., better predicting presences) while decreased model specificity (i.e., over-predicting the range). Consequently, both predictions of current and projections of future suitable conditions differed among the three approaches. Main conclusions We showed that although integrating lineage or ESU information did not improve the accuracy of conventional species-level SDMs, it led to considerably different conclusions. As SDM-based climatic risk assessments are increasingly used to help and improve conservation plans, divergences and limitations of each modelling approach should be taken into account for developing efficient biodiversity management strategies. Lineage and ESU-based SDMs offer the advantage to draw attention to species in which allopatric populations could display physiologically different responses to climate change when they lead to different results than species-based models. CAPTION(S):
    Keywords: Bumblebee ; Climate Change ; Evolutionary Significant Unit ; Intraspecific Variability ; Model Performance ; Species Distribution Model
    ISSN: 1366-9516
    E-ISSN: 1472-4642
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