159 research outputs found
Spatial and temporal patterns of Ellenberg nutrient values in forests of Germany and adjacent regions - a survey based on phytosociological databases
Within the last 30 years the role of nitrogen in Central European forests has changed fundamentally from limiting resource to environmental problem. As the retrospective tracking of nutrient availability by soil chemical and biogeochemical measurements faces serious problems, bioindication based on understorey species composition is indispensable for monitoring broad-scale eutrophication. Based on a broad survey of more than 100,000 forest vegetation plots accessible in electronic data-bases from Germany and adjacent countries, we calculated unweighted average Ellenberg nutrient values (mN) as a proxy of plant-available macronutrients. Based on the quantiles of the frequency distribution of mN in a regionally stratified sample, we define five trophic classes, which can be used to compare dimensionless mN values. We studied spatial patterns of average nutrient values within 17 regions and compared the periods from 1899 to 1975 and 1976 to 2006. After 1975 eutrophic (mN > 5.67) and hypertrophic (mN > 6.28) conditions were common everywhere except in the Alps and Saxony-Anhalt, but very oligotrophic conditions (mN <3.44) were still widespread in regions with nutrient-poor bedrock. Before 1975 mN of plots had been lower than after 1975 in all but the southeastern regions. Between the pre- and post-1975 data the proportion of hypertrophic plots increased from 5.7 to 11.8%, and that of very oligo-trophic plots decreased from 14.6 to 8.3%. To remove bias resulting from uneven distribution, the dataset was stratified by five tree layer dom-inance types, period and region and resampled. In pre-1975 plots medians of mN increased in the order Pinus sylvestris, Quercus spp., Picea abies, Fagus sylvatica and Alnus spp, whereas the increase of mN was highest in forest types with historically low nutrient values. Therefore, the widespread change in mN must be attributed to the pronounced vegetation changes in Quercus and Pinus stands, indicating the importance of land-use change, i.e. recovery of nutrient cycles after hundreds of years of exploita-tion through coppicing, grazing and litter use. The analysis confirms eutrophication as a megatrend of modern vegetation change and demonstrates the high research potential of linking vegetation plot databases across large regions. Keywords: bioindication, Central Europe, Ellenberg indicator values, eutrophication, nitrogen deposi-tion, soil nutrients, vegetation-plot dat
On Scottish sawflies, with results of the 14th International Sawfly Workshop, in the southern Highlands, 2010 (Hymenoptera, Symphyta).
Die Ergebnisse der Feldarbeit aus dem 14. Internationalen Sawfly Workshop werden vorgestellt. Dies fand im sĂŒdlichen schottischen Hochland, ĂŒberwiegend in Perthshire, statt. Einige Nachweise von Pflanzenwespen aus anderen Teilen von Schottland sind enthalten. Erstnachweise fĂŒr die Britischen Inseln werden fĂŒr acht tenthredinide Arten erbracht: Amauronematus mimus, Phyllocolpa alienata, P.âŻerythropyga, P.âŻplicalapponum, P.âŻplicaphylicifolia,âŻP. prussica, Pristiphora thalictri und Tenthredo ignobilis. A.âŻmimus ist auch aus Irland nachgewiesen. Amauronematus stenogaster ist aus der Liste der Symphyta der Britischen Inseln zu entfernen. Erstmalig sind in Schottland eine Cephiden-Art (Hartigia xanthostoma) und zehn Tenthrediniden gefunden worden (Claremontia uncta, Dolerus brevicornis, Empria basalis, Empria parvula, Parna apicalis, Pristiphora decipiens, Pristiphora leucopus, Pristiphora testacea, Tenthredo mandibularis und Tenthredopsis ornata). Merkmale fĂŒr die Unterscheidung einzelner Arten werden dargestellt. Der Locus typicus von Nematus herbaceae Cameron, 1876 ist geklĂ€rt. Geranium pratense ist als Wirtspflanze von Macrophya albipuncta bestĂ€tigt. Salix reticulata ist eine Wirtspflanze von Amauronematus mcluckieae. Sedum rosea kann eine Wirtspflanze von Tenthredo ignobilis sein. Allgemeine Schlussfolgerungen: hoher Artenreichtum der Pflanzenwespenfauna von Perthshire im Vergleich zu anderen Regionen in Schottland, darunter mehrere Arten, die auf den Britischen Inseln nur von dort bekannt sind; die Wichtigkeit der Erhaltung der LebensrĂ€ume von Felssimsen; groĂe Defizite in unseren Kenntnissen bei vielen Arten, insbesondere zu Wirtspflanzen, PhĂ€nologie und Verbreitung; hoher Wert der Malaise-Falle in faunistischen Untersuchungen von Symphyta, weil das Spektrum von erfassten Taxa sich unterscheidet von dem was mit Streifnetz erfasst wird; Zusammensetzung des 'fall-outâ auf Schneeresten deutet darauf hin, dass Pflanzenwespen in einem gröĂeren AusmaĂ als bisher angenommen, aktiver Dispersion innerhalb von Landmassen unterliegen.StichwörterBritish Isles, Cephidae, Pamphiliidae, Tenthredinoidea, hosts, phenology, distribution.Results of fieldwork are presented from the 14th International Sawfly Workshop, held in the southern Highlands of Scotland, mostly in Perthshire. Some records of Symphyta from other parts of Scotland are included. First records in the British Isles are given for eight tenthredinid species: Amauronematus mimus, Phyllocolpa alienata, P.âŻerythropyga, P.âŻplicalapponum, P.âŻplicaphylicifolia, P.âŻprussica, Pristiphora thalictri and Tenthredo ignobilis. A.âŻmimus is also recorded from Ireland. Amauronematus stenogaster is removed from the list of British Isles Symphyta. Recorded for the first time in Scotland are one cephid (Hartigia xanthostoma) and ten tenthredinids (Claremontia uncta, Dolerus brevicornis, Empria basalis, Empria parvula, Parna apicalis, Pristiphora decipiens, Pristiphora leucopus, Pristiphora testacea, Tenthredo mandibularis and Tenthredopsis ornata). Characters useful for the distinction of some species are illustrated. The type locality of Nematus herbaceae Cameron, 1876 is clarified. Geranium pratense is confirmed as a host of Macrophya albipuncta. Salix reticulata is a host of Amauronematus mcluckieae [mandatory correction of spelling of species name]. Sedum rosea may be a host of Tenthredo ignobilis. General conclusions: high species richness of Perthshire sawfly fauna compared to other regions of Scotland, including several species only known in British Isles from there; importance to conservation of rock-ledge habitats; large data deficits for many species, particularly on hosts, phenology and distribution; high value of Malaise traps in faunal survey of Symphyta, because spectrum of taxa captured differs from that recorded by hand-netting; as indicated by species and sex composition of âfall-outâ on snow patches, adult sawflies undertake active dispersal, within landmasses, to a greater extent than is often assumed.KeywordsBritish Isles, Cephidae, Pamphiliidae, Tenthredinoidea, hosts, phenology, distribution
EUNIS Habitat Classification: Expert system, characteristic species combinations and distribution maps of European habitats
Aim: The EUNIS Habitat Classification is a widely used reference framework for European habitat types (habitats), but it lacks formal definitions of individual habitats that would enable their unequivocal identification. Our goal was to develop a tool for assigning vegetationâplot records to the habitats of the EUNIS system, use it to classify a European vegetationâplot database, and compile statisticallyâderived characteristic species combinations and distribution maps for these habitats. Location: Europe. Methods: We developed the classification expert system EUNISâESy, which contains definitions of individual EUNIS habitats based on their species composition and geographic location. Each habitat was formally defined as a formula in a computer language combining algebraic and setâtheoretic concepts with formal logical operators. We applied this expert system to classify 1,261,373 vegetation plots from the European Vegetation Archive (EVA) and other databases. Then we determined diagnostic, constant and dominant species for each habitat by calculating speciesâtoâhabitat fidelity and constancy (occurrence frequency) in the classified data set. Finally, we mapped the plot locations for each habitat. Results: Formal definitions were developed for 199 habitats at Level 3 of the EUNIS hierarchy, including 25 coastal, 18 wetland, 55 grassland, 43 shrubland, 46 forest and 12 manâmade habitats. The expert system classified 1,125,121 vegetation plots to these habitat groups and 73,188 to other habitats, while 63,064 plots remained unclassified or were classified to more than one habitat. Data on each habitat were summarized in factsheets containing habitat description, distribution map, corresponding syntaxa and characteristic species combination. Conclusions: EUNIS habitats were characterized for the first time in terms of their species composition and distribution, based on a classification of a European database of vegetation plots using the newly developed electronic expert system EUNISâESy. The data provided and the expert system have considerable potential for future use in European nature conservation planning, monitoring and assessment
Using incomplete floristic monitoring data from habitat mapping programmes to detect species trends
Aim: The loss of biodiversity has raised serious concerns about the entailing losses of ecosystem services. Here, we explore the potential of repeated habitat mapping data to identify floristic changes over time. Using one German federal state as a case study, we assessed floristic changes between the 1980s and 2010s. These habitat data have great potential for analysis because of their high spatial coverage while also posing methodological challenges such as incomplete observation data. We developed a modelling approach that accounts for incomplete observations and explored the ability to detect temporal trends.
Location: The Federal State of SchleswigâHolstein (Germany)
Methods: We compiled plant species lists from the earliest (1980s) and most recent (2010s) habitat mapping survey and aligned differing habitat definitions across mapping campaigns. A total of 5,503 mapped polygons, each with a list of species records, intersected the two surveys. We accounted for underrecorded species by assigning occurrence probabilities, based on species coâoccurrence information across all surveys, using Beals' index and tested the robustness of this approach by simulation experiments. For those species with significant increases and decreases in occurrence probability, we linked these trends to the species' functional characteristics.
Results: We found a systematic loss of species that are moderately threatened. Species that indicate low nitrogen supply and high soil moisture declined, suggesting a shift towards a more eutrophic and drier landscape. Importantly, assessing specific plant traits associated with losses, we also detected a decrease in species with reddish and blueish flowers and species providing nectar, pointing to a decrease of insectâpollinated taxa.
Main conclusions: The identified changes raise concerns that plant biodiversity has fundamentally changed over the last three decades, with concomitant consequences for ecosystem services, especially pollination. Given the general lack of historical standardized data, our approach for trend analyses using incomplete observation data may be widely applicable to assess longâterm biodiversity change
Targeting a Subpocket in Trypanosoma brucei Phosphodiesterase B1 (TbrPDEB1) Enables the Structure-Based Discovery of Selective Inhibitors with Trypanocidal Activity
Several trypanosomatid cyclic nucleotide phosphodiesterases (PDEs) possess a unique, parasite-specific cavity near the ligand-binding region that is referred to as the P-pocket.
One of these enzymes, Trypanosoma brucei PDE B1 (TbrPDEB1), is considered a drug target for the treatment of African sleeping sickness. Here, we elucidate the molecular
determinants of inhibitor binding and reveal that the P-pocket is amenable to directed design. By iterative cycles of design, synthesis, and pharmacological evaluation and by elucidating the structures of inhibitor-bound TbrPDEB1, hPDE4B, and hPDE4D complexes, we have developed 4a,5,8,8a-tetrahydrophthalazinones as the first selective TbrPDEB1 inhibitor series. Two of these, 8 (NPD-008) and 9 (NPD-039), were potent (Ki = 100 nM) TbrPDEB1 inhibitors with antitrypanosomal effects (IC50 = 5.5 and 6.7 ?M, respectively). Treatment of parasites with 8 caused an increase in intracellular cyclic adenosine monophosphate (cAMP) levels and severe disruption of T. brucei cellular organization, chemically validating trypanosomal PDEs as therapeutic targets in trypanosomiasis
European Vegetation Archive (EVA): An integrated database of European vegetation plots
© 2016 International Association for Vegetation Science. The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and regional vegetation- plot databases on a single software platform. Data storage in EVA does not affect on-going independent development of the contributing databases, which remain the property of the data contributors. EVA uses a prototype of the database management software TURBOVEG 3 developed for joint management of multiple databases that use different species lists. This is facilitated by the SynBioSys Taxon Database, a system of taxon names and concepts used in the individual European databases and their corresponding names on a unified list of European flora. TURBOVEG 3 also includes procedures for handling data requests, selections and provisions according to the approved EVA Data Property and Governance Rules. By 30 June 2015, 61 databases from all European regions have joined EVA, contributing in total 1 027 376 vegetation plots, 82% of them with geographic coordinates, from 57 countries. EVA provides a unique data source for large-scale analyses of European vegetation diversity both for fundamental research and nature conservation applications. Updated information on EVA is available online at http://euroveg.org/eva-database
A Range of Earth Observation Techniques for Assessing Plant Diversity
AbstractVegetation diversity and health is multidimensional and only partially understood due to its complexity. So far there is no single monitoring approach that can sufficiently assess and predict vegetation health and resilience. To gain a better understanding of the different remote sensing (RS) approaches that are available, this chapter reviews the range of Earth observation (EO) platforms, sensors, and techniques for assessing vegetation diversity. Platforms include close-range EO platforms, spectral laboratories, plant phenomics facilities, ecotrons, wireless sensor networks (WSNs), towers, air- and spaceborne EO platforms, and unmanned aerial systems (UAS). Sensors include spectrometers, optical imaging systems, Light Detection and Ranging (LiDAR), and radar. Applications and approaches to vegetation diversity modeling and mapping with air- and spaceborne EO data are also presented. The chapter concludes with recommendations for the future direction of monitoring vegetation diversity using RS
EURECâŽA
The science guiding the EURECâŽA campaign and its measurements is presented. EURECâŽA comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic â eastward and southeastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EURECâŽA marked a turning point in our ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or the life cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso- (200âkm) and larger (500âkm) scales, roughly 400âh of flight time by four heavily instrumented research aircraft; four global-class research vessels; an advanced ground-based cloud observatory; scores of autonomous observing platforms operating in the upper ocean (nearly 10â000 profiles), lower atmosphere (continuous profiling), and along the airâsea interface; a network of water stable isotopologue measurements; targeted tasking of satellite remote sensing; and modeling with a new generation of weather and climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that EURECâŽA explored â from North Brazil Current rings to turbulence-induced clustering of cloud droplets and its influence on warm-rain formation â are presented along with an overview of EURECâŽA's outreach activities, environmental impact, and guidelines for scientific practice. Track data for all platforms are standardized and accessible at https://doi.org/10.25326/165 (Stevens, 2021), and a film documenting the campaign is provided as a video supplement
EURECâŽA
The science guiding the EURECâŽA campaign and its measurements is presented. EURECâŽA comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic â eastward and southeastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EURECâŽA marked a turning point in our ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or the life cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso- (200âkm) and larger (500âkm) scales, roughly 400âh of flight time by four heavily instrumented research aircraft; four global-class research vessels; an advanced ground-based cloud observatory; scores of autonomous observing platforms operating in the upper ocean (nearly 10â000 profiles), lower atmosphere (continuous profiling), and along the airâsea interface; a network of water stable isotopologue measurements; targeted tasking of satellite remote sensing; and modeling with a new generation of weather and climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that EURECâŽA explored â from North Brazil Current rings to turbulence-induced clustering of cloud droplets and its influence on warm-rain formation â are presented along with an overview of EURECâŽA's outreach activities, environmental impact, and guidelines for scientific practice. Track data for all platforms are standardized and accessible at https://doi.org/10.25326/165 (Stevens, 2021), and a film documenting the campaign is provided as a video supplement
In memory of Bruno Peter: fresh insights on the Swiss sawfly fauna (Hymenoptera, Symphyta): With 18 figures and 1 table
Bruno Peter-Sager (1943â2018) war ein Schweizer Entomologe, der Pflanzenwespen sammelte und studierte und unter dem Namen Bruno Peter darĂŒber publizierte. Seine groĂe Sammlung ist im Senckenberg Deutschen Entomologischen Institut, MĂŒncheberg, Deutschland, deponiert. Nach einer kurzen Biographie werden bemerkenswerte Exemplare aus der Schweiz kommentiert und einige allgemeine und spezifische Merkmale der Schweizer Pflanzenwespenfauna vorgestellt, die auf seiner Sammlung und Datenbank basieren. Zwanzig Pflanzenwespenarten werden zum ersten Mal fĂŒr die Schweiz gemeldet: Aprosthema bifurca, Arge fuscipennis, Cladardis hartigi, Dolerus altivolus, D. brevicornis, D. zhelochovtsevi, Empria fletcheri, Euura amentorum, E. cyrnea, E. longiserra, E. scotonota, Nescianeura noblecourti, Pristiphora depressa, P. luteipes, P. nigricans, Rhogogaster polaris, Taxonus alboscutellatus, Tenthredo semicolon, Tenthredopsis tischbeinii und Calameuta idolon. Drei Arten werden von der nationalen Liste gestrichen: Cladardis bordonii, Taxonus sticticus und Tomostethus melanopygius. Die Nachweise von sieben wenig bekannten oder seltenen Arten aus der Schweiz werden ebenfalls diskutiert. Die Daten der meisten von B. Peter gesammelten Exemplare beinhalten die Höhenlage, so dass die Ergebnisse einiger Analysen des Artenreichtums in AbhĂ€ngigkeit von der Höhenlage sowie Beispiele von Mustern der HöhenhĂ€ufigkeit fĂŒr ausgewĂ€hlte Arten prĂ€sentiert werden können.Bruno Peter-Sager (1943â2018) was a Swiss entomologist who collected and studied sawflies, and published on these under the name Bruno Peter. His large collection is deposited in the Senckenberg Deutsches Entomologisches Institut, MĂŒncheberg, Germany. Following a short biography, we present commentaries on noteworthy specimens from Switzerland and some general and specific characteristics of the Swiss sawfly fauna, based on his collection and database. Twenty sawfly species are recorded for the first time in Switzerland: Aprosthema bifurca, Arge fuscipennis, Cladardis hartigi, Dolerus altivolus, D. brevicornis, D. zhelochovtsevi, Empria fletcheri, Euura amentorum, E. cyrnea, E. longiserra, E. scotonota, Nescianeura noblecourti, Pristiphora depressa, P. luteipes, P. nigricans, Rhogogaster polaris, Taxonus alboscutellatus, Tenthredo semicolon, Tenthredopsis tischbeinii and Calameuta idolon. Three species are removed from the national list: Cladardis bordonii, Taxonus sticticus and Tomostethus melanopygius. Records from Switzerland of seven little-known or rarely recorded species are also discussed. Data for most specimens collected by B. Peter include altitude, enabling presentation of results of some analyses of species richness related to altitude, as well as examples of patterns of altitudinal abundance for selected species
- âŠ