59 research outputs found

    Differential effects of plant diversity on functional trait variation of grass species

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    Background and Aims Functional trait differences and trait adjustment in response to influences of the biotic environment could reflect niche partitioning among species. In this study, we tested how variation in above-ground plant traits, chosen as indicators for light and nitrogen acquisition and use, differs among taxonomically closely related species (Poaceae) to assess their potential for niche segregation at increasing plant diversity. Methods Traits of 12 grass species were measured in experimental grasslands (Jena Experiment) of varying species richness (from 1 to 60) and presence of particular functional groups (grasses, legumes, tall herbs and small herbs). Key Results Grass species increased shoot and leaf length, investment into supporting tissue (stem mass fraction) and specific leaf area as well as reduced foliar δ13C values with increasing species richness, indicating higher efforts for light acquisition. These species-richness effects could in part be explained by a higher probability of legume presence in more diverse communities. Leaf nitrogen concentrations increased and biomas s : N ratios in shoots decreased when grasses grew with legumes, indicating an improved nitrogen nutrition. Foliar δ15N values of grasses decreased when growing with legumes suggesting the use of depleted legume-derived N, while decreasing δ15N values with increasing species richness indicated a shift in the uptake of different N sources. However, efforts to optimize light and nitrogen acquisition by plastic adjustment of traits in response to species richness and legume presence, varied significantly among grass species. It was possible to show further that trait adjustment of grass species increased niche segregation in more diverse plant communities but that complementarity through niche separation may differ between light and nutrient acquisition. Conclusions The results suggest that even among closely related species such as grasses different strategies are used to cope with neighbours. This lack in redundancy in turn may facilitate complementary resource use and coexistenc

    Optimierung der Beanspruchungen durch eine neue Arbeitsorganisation bei Call-Center-Arbeitsplätzen

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    aus der Zusammenfassung: "Call-Center sind eine schnell wachsende Branche innerhalb der Informationstechnologien, die an den Schnittstellen von Organisationen konflikthaltige, vermittelnde und beratende Interaktionsarbeiten zwischen multiplen Auftraggebern und Kunden ausführen. Wie bei der Einführung jeder neuen Technologie, treten auch hierbei typische Formen tayloristischer Arbeitsteilung auf.

    Digital dashboards visualizing public health data: a systematic review

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    IntroductionPublic health is not only threatened by diseases, pandemics, or epidemics. It is also challenged by deficits in the communication of health information. The current COVID-19 pandemic demonstrates that impressively. One way to deliver scientific data such as epidemiological findings and forecasts on disease spread are dashboards. Considering the current relevance of dashboards for public risk and crisis communication, this systematic review examines the state of research on dashboards in the context of public health risks and diseases.MethodNine electronic databases where searched for peer-reviewed journal articles and conference proceedings. Included articles (n = 65) were screened and assessed by three independent reviewers. Through a methodological informed differentiation between descriptive studies and user studies, the review also assessed the quality of included user studies (n = 18) by use of the Mixed Methods Appraisal Tool (MMAT).Results65 articles were assessed in regards to the public health issues addressed by the respective dashboards, as well as the data sources, functions and information visualizations employed by the different dashboards. Furthermore, the literature review sheds light on public health challenges and objectives and analyzes the extent to which user needs play a role in the development and evaluation of a dashboard. Overall, the literature review shows that studies that do not only describe the construction of a specific dashboard, but also evaluate its content in terms of different risk communication models or constructs (e.g., risk perception or health literacy) are comparatively rare. Furthermore, while some of the studies evaluate usability and corresponding metrics from the perspective of potential users, many of the studies are limited to a purely functionalistic evaluation of the dashboard by the respective development teams.ConclusionThe results suggest that applied research on public health intervention tools like dashboards would gain in complexity through a theory-based integration of user-specific risk information needs.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=200178, identifier: CRD42020200178

    Trait means, trait plasticity and trait differences to other species jointly explain species performances in grasslands of varying diversity

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    Functional traits may help to explain the great variety of species performances in plant communities, but it is not clear whether the magnitude of trait values of a focal species or trait differences to co‐occurring species are key for trait‐based predictions. In addition, trait expression within species is often plastic, but this variation has been widely neglected in trait‐based analyses. We studied functional traits and plant biomass of 59 species in 66 experimental grassland mixtures of varying species richness (Jena Experiment). We related mean species performances (species biomass and relative yield RY) and their plasticities along the diversity gradient to trait‐based pedictors involving mean species traits (Tmean), trait plasticities along the diversity gradient (Tslope), extents of trait variation across communities (TCV; coefficient of variation) and hierarchical differences (Tdiff) and trait distances (absolute values of trait differences Tdist) between focal and co‐occurring species. Tmean (30–55%) and Tdiff (30–33%) explained most variation in mean species performances and their plasticities, but Tslope (20–25%) was also important in explaining mean species performances. The mean species traits and the trait differences between focal species and neighbors with the greatest explanatory power were related to plant size and stature (shoot length, mass:height ratios) and leaf photosynthetic capacity (specific leaf area, stable carbon isotopes and leaf nitrogen concentration). The contribution of trait plasticities in explaining species performances varied in direction (positive or negative) and involved traits related to photosynthetic capacity, nitrogen acquisition (nitrogen concentrations and stable isotopes) as well as structural stability (shoot carbon concentrations). Our results suggest that incorporating plasticity in trait expression as well as trait differences to co‐occurring species is critical for extending trait‐based analyses to understand the assembly of plant communities and the contribution of individual species in structuring plant communities

    Origin context of trait data matters for predictions of community performance in a grassland biodiversity experiment

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    Plant functional traits may explain the positive relationship between species richness and ecosystem functioning, but species‐level trait variation in response to growth conditions is often ignored in trait‐based predictions of community performance. In a large grassland biodiversity experiment (Jena Experiment), we measured traits on plants grown as solitary individuals, in monocultures or in mixtures. We calculated two measures of community‐level trait composition, i.e., community‐weighted mean traits (CWM) and trait diversity (Rao's quadratic entropy; FD) based on different contexts in which traits were measured (trait origins). CWM and FD values of the different measurement origins were then compared regarding their power to predict community biomass production and biodiversity effects quantified with the additive partitioning method. Irrespective of trait origin, models combining CWM and FD values as predictors best explained community biomass and biodiversity effects. CWM values based on monoculture, mixture‐mean or community‐specific trait data were similarly powerful predictors, but predictions became worse when trait values originated from solitary‐grown individuals. FD values based on monoculture traits were the best predictors of community biomass and net biodiversity effects, while FD values based on community‐specific traits were the best predictors for complementarity and selection effects. Traits chosen as best CWM predictors were not strongly affected by trait origin but traits chosen as best FD predictors varied strongly dependent on trait origin and altered the predictability of community performance. We conclude that by adjusting their functional traits to species richness and even specific community compositions, plants can change community‐level trait compositions, thereby also changing community biomass production and biodiversity effects. Incorporation of these plastic trait adjustments of plants in trait‐based ecology can improve its predictive power in explaining biodiversity–ecosystem functioning relationships

    Optimierung der Risiko- und Krisenkommunikation von Regierungen, Behörden und Organisationen der Gesundheitssicherung – Herausforderungen in lang anhaltenden Krisen am Beispiel der COVID-19-Pandemie [Optimisation of risk and crisis communication of governments, authorities and public health institutions—challenges in long-lasting crises illustrated by the COVID-19 pandemic]

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    Die COVID-19-Pandemie illustriert die besondere Bedeutung von Risiko- und Krisenkommunikation. Behörden und Politik stehen vor der Herausforderung, in einer dynamischen Lage mit einer Vielzahl von Daten umzugehen, diese zu überprüfen und zielgruppengerecht zu kommunizieren. Verständliche und eindeutige Informationen zu Risiken und Handlungsoptionen tragen maßgeblich zu einer Steigerung der objektiven und subjektiven Sicherheit der Bevölkerung bei. Es besteht daher ein großer Bedarf, die Erfahrungen aus der Pandemie in die Optimierung der Risiko- und Krisenkommunikation einfließen zu lassen. Die Digitalisierung ermöglicht multimodale Arrangements – also die Kombination aus Text, Abbildungen, Grafik, Icons und z. T. Bewegtbilder, Animationen und Ton. Diese spielen auch in der digitalen Risiko- und Krisenkommunikation eine zunehmend wichtigere Rolle. Von Interesse ist, inwiefern das kommunikative Zusammenspiel von Behörden, Medien und weiteren Öffentlichkeitsakteur/-innen in Vorbereitung auf und zur Bewältigung von Krisen angesichts einer komplexen Öffentlichkeit mit Hilfe zielgruppenspezifischer Kommunikation verbessert und wie Rechtssicherheit für die behördliche und mediale Praxis gewährleistet werden kann. Dementsprechend verfolgt der Beitrag 3 Ziele: 1. Er beschreibt die Herausforderungen, vor denen Behörden und mediale Akteur/-innen in der Pandemiekommunikation stehen. 2. Er zeigt, welche Rolle multimodale Arrangements spielen und welcher Forschungsperspektiven es bedarf, um die Komplexität des kommunikativen Krisenhandelns im föderalen System zu erfassen. 3. Er begründet, wie ein interdisziplinärer Forschungsverbund aus Medien‑, Kommunikations- und Rechtswissenschaft Erkenntnisse zum evidenzbasierten Einsatz multimodaler Kommunikation gewinnen kann

    The biogeochemical impact of glacial meltwater from Southwest Greenland

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    Biogeochemical cycling in high-latitude regions has a disproportionate impact on global nutrient budgets. Here, we introduce a holistic, multi-disciplinary framework for elucidating the influence of glacial meltwaters, shelf currents, and biological production on biogeochemical cycling in high-latitude continental margins, with a focus on the silica cycle. Our findings highlight the impact of significant glacial discharge on nutrient supply to shelf and slope waters, as well as surface and benthic production in these regions, over a range of timescales from days to thousands of years. Whilst biological uptake in fjords and strong diatom activity in coastal waters maintains low dissolved silicon concentrations in surface waters, we find important but spatially heterogeneous additions of particulates into the system, which are transported rapidly away from the shore. We expect the glacially-derived particles – together with biogenic silica tests – to be cycled rapidly through shallow sediments, resulting in a strong benthic flux of dissolved silicon. Entrainment of this benthic silicon into boundary currents may supply an important source of this key nutrient into the Labrador Sea, and is also likely to recirculate back into the deep fjords inshore. This study illustrates how geochemical and oceanographic analyses can be used together to probe further into modern nutrient cycling in this region, as well as the palaeoclimatological approaches to investigating changes in glacial meltwater discharge through time, especially during periods of rapid climatic change in the Late Quaternary

    Using Plant Functional Traits to Explain Diversity–Productivity Relationships

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    Background: The different hypotheses proposed to explain positive species richness–productivity relationships, i.e. selection effect and complementarity effect, imply that plant functional characteristics are at the core of a mechanistic understanding of biodiversity effects. Methodology/Principal Findings: We used two community-wide measures of plant functional composition, (1) community- weighted means of trait values (CWM) and (2) functional trait diversity based on Rao’s quadratic diversity (FDQ) to predict biomass production and measures of biodiversity effects in experimental grasslands (Jena Experiment) with different species richness (2, 4, 8, 16 and 60) and different functional group number and composition (1 to 4; legumes, grasses, small herbs, tall herbs) four years after establishment. Functional trait composition had a larger predictive power for community biomass and measures of biodiversitity effects (40–82% of explained variation) than species richness per se (,1–13% of explained variation). CWM explained a larger amount of variation in community biomass (80%) and net biodiversity effects (70%) than FDQ (36 and 38% of explained variation respectively). FDQ explained similar proportions of variation in complementarity effects (24%, positive relationship) and selection effects (28%, negative relationship) as CWM (27% of explained variation for both complementarity and selection effects), but for all response variables the combination of CWM and FDQ led to significant model improvement compared to a separate consideration of different components of functional trait composition. Effects of FDQ were mainly attributable to diversity in nutrient acquisition and life-history strategies. The large spectrum of traits contributing to positive effects of CWM on biomass production and net biodiversity effects indicated that effects of dominant species were associated with different trait combinations. Conclusions/Significance: Our results suggest that the identification of relevant traits and the relative impacts of functional identity of dominant species and functional diversity are essential for a mechanistic understanding of the role of plant diversity for ecosystem processes such as aboveground biomass production

    Review of: Hildegard Maria Nickel, Andreas Heilmann, Hasko Hüning, Max Lill: Geschlechterpolitik in Krisenzeiten. Eine Fallstudie im Bankensektor. Berlin: edition sigma 2015.

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    Am Beispiel der LandesBank Berlin zeigen die Autor/-innen konkrete Auswirkungen der Bankenkrise auf in Unternehmen agierende betriebliche Akteur/-innen. Inwiefern diese eigene Handlungsspielräume entwickeln (können) und welche Kontinuitäten betriebliche Vergeschlechtlichungsprozesse aufweisen, belegt die Studie eindrücklich. Der mit dem Wandel von Erwerbsarbeit verknüpfte Eigensinn zeigt sich in den Vorstellungen von Zuständigkeiten der weiblichen Angestellten und in den veränderten Antworten auf Work-Life-Balance-Fragen ─ bei jungen männlichen Angestellten und bei älteren Führungskräften, die jungen Vätern einen Mentalitätswandel unterstellen. So könnten sich neue Kollektivierungen jenseits von Geschlecht bilden, insofern an geteilte Interessen in Krisensituationen angeknüpft werden würde.Using the LandesBank Berlin as an example, the authors illustrate specific effects of the banking crisis on persons operating in companies. The study provides clear evidence of the extent to which these persons (are able to) develop their own rooms for maneuver and of the consistencies exhibited by the company’s gendering processes. The waywardness related to the alteration of gainful employment becomes apparent in the notions of responsibilities of the female employees and in the altered responses towards work-life-balance questions – both in the case of young male employees and older managers, who accuse the young fathers of a change in mentality. Thus, new collectivizations beyond gender could be established if shared interests in critical situations would be built on
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