7. Workshop der Arbeitsgruppe Vegetationsdatenbanken zum Thema "Plant-Trait-Environment-Linkages" in Oldenburg

The German Working Group on Vegetation Databanks has held annual meetings since 2002 with financial support by the German Federal Agency for Nature Conservation. Ca. 215 members are regularly informed through a mailing-list. The 2008 meeting was hosted by University of Oldenburg’s Landscape Ecology Group and was attended by 72 participants from 15 countries. Software demonstrations of vegetation databanks Turboveg and VegetWeb as well as plant trait databanks LEDA and BiolFlor opened the workshop. There were lecture sessions on trait databanks, recalibration of ecological indicator values and new developments in the field of vegetation databanks. Working groups were devoted to an initiative to build a meta-databank of existing vegetation databanks in Germany and to mathematical modelling of species habitats. In 2009 the 8th workshop will be held on "Vegetation Databanks and Biodindication" at the University of Greifswald.Die Arbeitsgruppe Vegetationsdatenbanken trifft sich seit 2002 jährlich zu bundesweiten, vom Bundesamt für Naturschutz geförderten Workshops. Über einen E-Mail-Verteiler, der derzeit 215 Adressen in Deutschland und angrenzenden Ländern umfasst, wird regelmäßig über einschlägige Aktivitäten informiert - Bitten um Aufnahme in den Verteiler sind per E-Mail an J. Ewald zu richten. Das 7. Arbeitstreffen fand vom 5.-7. März 2008 auf Einladung von Cord Peppler-Lisbach und Michael Kleyer an der Universität Oldenburg, Arbeitsgruppe Landschaftsökologie, statt, und wurde von 72 TeilnehmerInnen besucht. ..

Experimental salt marsh islands: a model system for novel metacommunity experiments

Shallow tidal coasts are characterised by shifting tidal flats and emerging or eroding islands above the high tide line. Salt marsh vegetation colonising new habitats distant from existing marshes are an ideal model to investigate metacommunity theory. We installed a set of 12 experimental salt marsh islands made from metal cages on a tidal flat in the German Wadden Sea to study the assembly of salt marsh communities in a metacommunity context. Experimental plots at the same elevation were established within the adjacent salt marsh on the island of Spiekeroog. For both, experimental islands and salt marsh enclosed plots, the same three elevational levels were realised while creating bare patches open for colonisation and vegetated patches with a defined transplanted community. One year into the experiment, the bare islands were colonised by plant species with high fecundity although with a lower frequency compared to the salt marsh enclosed bare plots. Initial plant community variations due to species sorting along the inundation gradient were evident in the transplanted vegetation. Competitive exclusion was not observed and is only expected to unfold in the coming years. Our study highlights that spatially and temporally explicit metacommunity dynamics should be considered in salt marsh plant community assembly and disassembly

Bestimmung biogeomorphologischer Rückkopplung zwischen Pflanzen und Sedimentation

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A global analysis of the seaward salt marsh extent: the importance of tidal range

Despite the growing interest in ecosystem services provided by intertidal wetlands, we lack sufficient understanding of the processes that determine the seaward extent of salt marsh vegetation on tidal flats. With the present study, we aim to establish a globally valid demarcation between tidal flats and salt marsh vegetation in relation to tidal range. By comparing results from a regional GIS study with a global literature search on the salt marsh- tidal flat border, we are able to define the global critical elevation, above which salt marsh plants can grow in the intertidal zone. Moreover, we calculate inundation characteristics from global tide gauge records to determine inundation duration and frequency at this predicted salt marsh - tidal flat border depending on tidal range. Our study shows that the height difference between the lowest elevation of salt-marsh pioneer vegetation and mean high water increases logarithmically with tidal range when including macrotidal salt marshes. Hence, the potentially vegetated section of the tidal frame below mean high water does not proportionally increase with tidal range. The data analysis suggests that inundation frequency rather than duration defines the global lower elevational limit of vascular salt marsh plants on tidal flats. This is critical information to better estimate sea level rise and coastal change effects on lateral marsh development

Spatial and temporal patterns of initial plant establishment in salt marsh communities

Questions: How are dispersal processes, abiotic and biotic interactions determining the initial salt marsh plant community establishment and development when connectivity is different? We aim to answer this question by analysing the spatial and temporal patterns of plant establishment along the environmental gradient at two connectivity settings. Location: Back‐barrier salt marsh and tidal flats of Spiekeroog, northwest Germany Methods: We established an experiment along the salt marsh elevation gradient with bare sediment open for spontaneous colonisation on the natural salt marsh and on the experimental salt marsh islands built on the tidal flats approximately 500 m from the natural salt marsh for low connectivity. Plant establishment was identified from georeferenced photos at least monthly. Results: Experimental islands as low connectivity plots had limited colonisation by annual halophytes that produce large number of small seeds. Number of individuals increased with higher connectivity at salt marsh enclosed patches. Number of individuals was highest at the mid elevations whereas peak species richness was at the upper salt marsh. Temporal patterns of seedling emergence showed increasing plant numbers until end of April followed by gradual incline over the season at the pioneer and lower salt marsh zones. Upper elevations on the other hand had a stable number of low individual counts over time. Spatial clustering of plant individuals indicating possible facilitation was important at the initial stages of salt marsh development at pioneer and lower salt marsh elevation, but only early in the season. Conclusions: Stochastic patterns of early salt marsh colonisation indicated that success of species colonisation was determined by seed properties, seed availability and environmental conditions mediated by elevation. We found indications, that further colonisation was supported by already colonised plants at initial stages, but shifted to avoidance later in the season

Disease interception with interleukin-17 inhibition in high-risk psoriasis patients with subclinical joint inflammation—data from the prospective IVEPSA study

Background A specific subset of psoriasis patients is characterized by subclinical inflammatory changes. These patients frequently present with arthralgia and have a higher risk to develop psoriatic arthritis (PsA). We hypothesized that IL-17A inhibition in this subset of patients can intercept the link between skin and joint disease and resolves pain and inflammatory changes. Methods Psoriasis, but no PsA, patients were included in the open prospective exploratory Interception in very early PsA (IVEPSA) study. Patients had to have nail or scalp involvement or a high psoriasis area severity index (PASI) (> 6) as well as inflammatory or erosive changes in MRI or CT. Patients received treatment with the anti-interleukin (IL)-17A antibody secukinumab over 24 weeks. Clinical assessments of skin and joint disease were done at baseline and after 12 and 24 weeks, MRI and CT at baseline and after 24 weeks. Results Twenty patients were included, 85% of them reporting arthralgia and 40% had tender joints at the examination. Eighty-three percent had at least one inflammatory lesion in the MRI, most of them synovitis/enthesitis. Skin disease (PASI: p < 0.002; BSA: p < 0.003) and arthralgia (VAS pain: p < 0.003) significantly improved after 24 weeks. Total PsAMRIS (p = 0.005) and synovitis subscore (p = 0.008) also significantly improved. Erosions and enthesiophytes did not progress, while bone mass in the distal radius significantly (p = 0.020) increased after 24 weeks. Conclusions These data suggest that very early disease interception in PsA is possible leading to a comprehensive decline in skin symptoms, pain, and subclinical inflammation. IVEPSA therefore provides rationale for future early interventions with the concept to prevent the onset of PsA in high-risk individuals. Trial registration Trial registry name PSARTROS; trial registry number: NCT02483234; June 26, 2015

Praxisnahes Küstenlabor zur Entwicklung von kurz- und langfristigen Strategien zum Schutz und zur Bewahrung der schleswig-holsteinischen Halligen (Living CoastLab Halligen)

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Plant traits poorly predict winner and loser shrub species in a warming tundra biome

Climate change is leading to species redistributions. In the tundra biome, shrubs are generally expanding, but not all tundra shrub species will benefit from warming. Winner and loser species, and the characteristics that may determine success or failure, have not yet been fully identified. Here, we investigate whether past abundance changes, current range sizes and projected range shifts derived from species distribution models are related to plant trait values and intraspecific trait variation. We combined 17,921 trait records with observed past and modelled future distributions from 62 tundra shrub species across three continents. We found that species with greater variation in seed mass and specific leaf area had larger projected range shifts, and projected winner species had greater seed mass values. However, trait values and variation were not consistently related to current and projected ranges, nor to past abundance change. Overall, our findings indicate that abundance change and range shifts will not lead to directional modifications in shrub trait composition, since winner and loser species share relatively similar trait spaces