Reliability characteristics of natural functional group interaction webs

ABSTRACT We compare the reliability of interaction webs for functional groups derived from extensive field data. Reliability is the probability of a web continuing to function despite the failure of one or more functional groups. Interaction webs are diagrams of all the trophic and non-trophic relationships between groups. Functional groups are suites of species with similar roles in an ecosystem and, importantly, mediate the relationship between biodiversity and the functioning of ecosystems. How they interact will thus have major ecological consequences. We reveal interactions between groups by simple and partial Mantel tests and determine link type by applying sets of logical rules to the Mantel test results. We then calculate the reliability of the resulting interaction webs. We also derive the reliabilities for webs of different link types because web topology affects reliability, not just the number of groups and links. Using the qualities of sink webs derived from these interaction webs, we illustrate the overall patterns in the relationships between reliability and other web characteristics. We compare these with the relationships in food-webs. We demonstrate the relation of reliability to principal components representing the information common to web characteristics other than reliability. We show that reliabilities for webs of interactions between functional groups are very high, at least as high as those for food-webs, and that they show similar relationships to other web characteristics. Nevertheless, in our natural setting, it is the number of groups and the number of links a web has that most affects reliabilities. However, they also differ more between webs of different link types, where topology differs, than between sites. Thus, in nature, the reliability of webs of interactions between functional groups will depend on both web size and topology. This means that their contribution to mediating the relationship between biodiversity and ecosystem function will also depend on both web and topology

Automated Indirect Immunofluorescence Evaluation of Antinuclear Autoantibodies on HEp-2 Cells

Indirect immunofluorescence (IIF) on human epithelial (HEp-2) cells is considered as the gold standard screening method for the detection of antinuclear autoantibodies (ANA). However, in terms of automation and standardization, it has not been able to keep pace with most other analytical techniques used in diagnostic laboratories. Although there are already some automation solutions for IIF incubation in the market, the automation of result evaluation is still in its infancy. Therefore, the EUROPattern Suite has been developed as a comprehensive automated processing and interpretation system for standardized and efficient ANA detection by HEp-2 cell-based IIF. In this study, the automated pattern recognition was compared to conventional visual interpretation in a total of 351 sera. In the discrimination of positive from negative samples, concordant results between visual and automated evaluation were obtained for 349 sera (99.4%, kappa = 0.984). The system missed out none of the 272 antibody-positive samples and identified 77 out of 79 visually negative samples (analytical sensitivity/specificity: 100%/97.5%). Moreover, 94.0% of all main antibody patterns were recognized correctly by the software. Owing to its performance characteristics, EUROPattern enables fast, objective, and economic IIF ANA analysis and has the potential to reduce intra- and interlaboratory variability

ReSurveyGermany: Vegetation-plot time-series over the past hundred years in Germany

Vegetation-plot resurvey data are a main source of information on terrestrial biodiversity change, with records reaching back more than one century. Although more and more data from re-sampled plots have been published, there is not yet a comprehensive open-access dataset available for analysis. Here, we compiled and harmonised vegetation-plot resurvey data from Germany covering almost 100 years. We show the distribution of the plot data in space, time and across habitat types of the European Nature Information System (EUNIS). In addition, we include metadata on geographic location, plot size and vegetation structure. The data allow temporal biodiversity change to be assessed at the community scale, reaching back further into the past than most comparable data yet available. They also enable tracking changes in the incidence and distribution of individual species across Germany. In summary, the data come at a level of detail that holds promise for broadening our understanding of the mechanisms and drivers behind plant diversity change over the last century

Bottom-up effects of plant diversity on multitrophic interactions in a biodiversity experiment

Biodiversity is rapidly declining1, and this may negatively affect ecosystem processes, including economically important ecosystem services. Previous studies have shown that biodiversity has positive effects on organisms and processes4 across trophic levels. However, only a few studies have so far incorporated an explicit food-web perspective. In an eight-year biodiversity experiment, we studied an unprecedented range of above- and below-ground organisms and multitrophic interactions. A multitrophic data set originating from a single long-term experiment allows mechanistic insights that would not be gained from meta-analysis of different experiments. Here we show that plant diversity effects dampen with increasing trophic level and degree of omnivory. This was true both for abundance and species richness of organisms. Furthermore, we present comprehensive above-ground/below-ground biodiversity food webs. Both above ground and below ground, herbivores responded more strongly to changes in plant diversity than did carnivores or omnivores. Density and richness of carnivorous taxa was independent of vegetation structure. Below-ground responses to plant diversity were consistently weaker than above-ground responses. Responses to increasing plant diversity were generally positive, but were negative for biological invasion, pathogen infestation and hyperparasitism. Our results suggest that plant diversity has strong bottom-up effects on multitrophic interaction networks, with particularly strong effects on lower trophic levels. Effects on higher trophic levels are indirectly mediated through bottom-up trophic cascades

Diversity Promotes Temporal Stability across Levels of Ecosystem Organization in Experimental Grasslands

The diversity–stability hypothesis states that current losses of biodiversity can impair the ability of an ecosystem to dampen the effect of environmental perturbations on its functioning. Using data from a long-term and comprehensive biodiversity experiment, we quantified the temporal stability of 42 variables characterizing twelve ecological functions in managed grassland plots varying in plant species richness. We demonstrate that diversity increases stability i) across trophic levels (producer, consumer), ii) at both the system (community, ecosystem) and the component levels (population, functional group, phylogenetic clade), and iii) primarily for aboveground rather than belowground processes. Temporal synchronization across studied variables was mostly unaffected with increasing species richness. This study provides the strongest empirical support so far that diversity promotes stability across different ecological functions and levels of ecosystem organization in grasslands

A comparison of the strength of biodiversity effects across multiple functions

In order to predict which ecosystem functions are most at risk from biodiversity loss, meta-analyses have generalised results from biodiversity experiments over different sites and ecosystem types. In contrast, comparing the strength of biodiversity effects across a large number of ecosystem processes measured in a single experiment permits more direct comparisons. Here, we present an analysis of 418 separate measures of 38 ecosystem processes. Overall, 45% of processes were significantly affected by plant species richness, suggesting that, while diversity affects a large number of processes not all respond to biodiversity. We therefore compared the strength of plant diversity effects between different categories of ecosystem processes, grouping processes according to the year of measurement, their biogeochemical cycle, trophic level and compartment (above- or belowground) and according to whether they were measures of biodiversity or other ecosystem processes, biotic or abiotic and static or dynamic. Overall, and for several individual processes, we found that biodiversity effects became stronger over time. Measures of the carbon cycle were also affected more strongly by plant species richness than were the measures associated with the nitrogen cycle. Further, we found greater plant species richness effects on measures of biodiversity than on other processes. The differential effects of plant diversity on the various types of ecosystem processes indicate that future research and political effort should shift from a general debate about whether biodiversity loss impairs ecosystem functions to focussing on the specific functions of interest and ways to preserve them individually or in combinatio

Is a Federal European Constitution for an Enlarged European Union Necessary? Some Preliminary Suggestions Using Public Choice Analysis

In order to guarantee a further successful functioning of the enlarged European Union a Federal European Constitution is proposed. Six basic elements of a future European federal constitution are developed: the European commission should be turned into an European government and the European legislation should consist of a two chamber system with full responsibility over all federal items. Three further key elements are the subsidiarity principle, federalism and the secession right, which are best suited to limiting the domain of the central European authority to which certain tasks are given, such as defense, foreign and environmental policy. Another important feature is direct democracy, which provides the possibility for European voters to participate actively in the political decision making, to break political and interest group cartels, and to prevent an unwanted shifting of responsibilities from EU member states to the European federal level

<scp>ReSurveyEurope</scp>: A database of resurveyed vegetation plots in Europe

AbstractAimsWe introduce ReSurveyEurope — a new data source of resurveyed vegetation plots in Europe, compiled by a collaborative network of vegetation scientists. We describe the scope of this initiative, provide an overview of currently available data, governance, data contribution rules, and accessibility. In addition, we outline further steps, including potential research questions.ResultsReSurveyEurope includes resurveyed vegetation plots from all habitats. Version 1.0 of ReSurveyEurope contains 283,135 observations (i.e., individual surveys of each plot) from 79,190 plots sampled in 449 independent resurvey projects. Of these, 62,139 (78%) are permanent plots, that is, marked in situ, or located with GPS, which allow for high spatial accuracy in resurvey. The remaining 17,051 (22%) plots are from studies in which plots from the initial survey could not be exactly relocated. Four data sets, which together account for 28,470 (36%) plots, provide only presence/absence information on plant species, while the remaining 50,720 (64%) plots contain abundance information (e.g., percentage cover or cover–abundance classes such as variants of the Braun‐Blanquet scale). The oldest plots were sampled in 1911 in the Swiss Alps, while most plots were sampled between 1950 and 2020.ConclusionsReSurveyEurope is a new resource to address a wide range of research questions on fine‐scale changes in European vegetation. The initiative is devoted to an inclusive and transparent governance and data usage approach, based on slightly adapted rules of the well‐established European Vegetation Archive (EVA). ReSurveyEurope data are ready for use, and proposals for analyses of the data set can be submitted at any time to the coordinators. Still, further data contributions are highly welcome.</jats:sec

Chemical footprints of anthropogenic nitrogen deposition on recent soil C:N ratios in Europe

Long-term human interactions with landscape and nature produced a plethora of trends and patterns of environmental disturbances in time and space. Nitrogen deposition, closely tracking energy and land use, is known to be among the main pollution drivers, affecting both freshwater as terrestrial ecosystems. We investigated the geographical distribution of nitrogen deposition and the impacts of accumulation on recent soil carbon to nitrogen ratios over Europe. After the Second Industrial Revolution (1880–2010), large landscape stretches characterized by different atmospheric deposition caused either by industrialized areas or by intensive agriculture emerged. Nitrogen deposition affects in a still recognizable way recent soil C:N ratios despite the emission abatement of oxidized and reduced nitrogen during the last two decades. Given the seemingly disparate land-use history, we focused on ~10,000 unmanaged ecosystems, providing evidence for a rapid response of nature to chronic nitrogen supply by atmospheric deposition.JRC.H.5-Land Resources Managemen

Enge Nachbarn

Burgen, die sich in unmittelbarer Nachbarschaft befinden, werfen die Frage auf, ob zwischen ihnen einst ein engerer Zusammenhang bestanden hat. Man spricht von Mehrfachburgen, wenn mindestens zwei separate, aber benachbarte und zur gleichen Zeit genutzte Burganlagen eine funktionale Einheit darstellten. Die bronzezeitlichen Burgwälle von Lossow und Lebus an der Oder bilden den Ausgangspunkt für eine Untersuchung dieses aus der Bronzezeit und dem Mittelalter bekannten Phänomens. Ein Überblick zu metallzeitlichen Befestigungsanlagen liefert den Kontext, in den sich die konkreten Fallstudien bronzezeitlicher Mehrfachburgen einbinden lassen. Diesen Anlagen werden wiederum mittelalterliche Mehrfachburgen und Doppelstädte in einer Reihe regionaler Untersuchungen gegenübergestellt. So trägt der Band zu einem tieferen Verständnis und einer klareren Terminologie des Phänomens eng benachbarter Burg- und Stadtanlagen bei