Das Projekt "Fate of 17-ethinylestradiol in the aqueous environment and the associated effects on organisms" wird vom Umweltbundesamt gefördert und von RWTH Aachen University, Institut für Umweltforschung, Biologie V, Lehrstuhl für Umweltbiologie und -chemodynamik durchgeführt. Introduction: In aquatic systems, the bioavailability of a compound is dependent on numerous factors such as partitioning between water, different organisms and solids, biotransformation and food web transfer. This project dealt with the fate of an important environmental xeno-estrogen, 17-ethinylestradiol (EE2), in the aquatic environment. Therefore, the kinetics of EE2 in indicator species representing the different trophic levels of an ecosystem were assessed. As primary producers, green algae (Desmodesmus suspicatus) were selected. The water flea Daphnia magna and larvae of the midge Chironomus riparius were introduced as primary consumers of the water phase and the sediment, respectively. Finally, water as well as dietary uptake of EE2 were investigated in a target species and secondary consumer: zebrafish (Danio rerio). Methodology: In a first series of experiments, uptake of 14C-labelled EE2 (14C-EE2) from the water phase and elimination by the different organisms were investigated over time. In a second test series, both primary consumers were fed 14C-EE2 spiked algae in order to study bioaccumulation. Uptake of 14C-EE2 by chironomid larvae after water and sediment spiking was compared, including sediments of different composition. In a third series of experiments, male fish were short term (48 h) exposed to 14C-EE2 through different routes: by water exposure (WE) and by dietary exposure (DE) via both contaminated daphnids and chironomid larvae. Distribution of 14C-EE2 in the fish was studied by measuring the amount of radioactivity (RA) in the different fish tissues. Additionally, the effect of EE2 on the vitellogenin (Vtg) induction in male fish was compared after WE and DE in a long term (14 d) experiment. The RA in liquid samples was quantified by means of liquid scintillation counting (LSC). Solid samples were subjected to combustion in a biological oxidiser, trapping (14)CO2, measured with LSC. Water and organism extracts were analysed by means of HPLC with a radiodetector, except for algae extracts that were subjected to TLC. Metabolites were identified with GC-MS, high resolution LC-MS and enzymatic hydrolysis followed by HPLC with radiodetection. Metabolites, detected in the water phase, were tested for estrogenic activity by means of YES and ER-CALUX assays. Results: Accumulation and effects: Of the four organisms mentioned above, bioconcentration of 14C-EE2 was highest in the algae. Whereas the growth rate of D. subspicatus was significantly affected at high EE2 concentrations compared to unexposed algae, EE2 had no acute effects on D. magna and C. riparius. Daphnids showed a higher bioaccumulation potential after exposure via spiked algae. For chironomids, water exposure was the predominant uptake route. The presence of sediment lowered the bioavailability of 14C-EE2 to the larvae after both water and sediment spiking. Nevertheless, uptake was higher when the nutritional quality of the sediment was better. Etc.
Das Projekt "Highly-resolved imaging in artificial and natural soils to yield dynamics and structure of interfaces from oxygen, pH and water content" wird vom Umweltbundesamt gefördert und von Universität Potsdam, Institut für Erd- und Umweltwissenschaften durchgeführt. In soils and sediments there is a strong coupling between local biogeochemical processes and the distribution of water, electron acceptors, acids, nutrients and pollutants. Both sides are closely related and affect each other from small scale to larger scale. Soil structures such as aggregates, roots, layers, macropores and wettability differences occurring in natural soils enhance the patchiness of these distributions. At the same time the spatial distribution and temporal dynamics of these important parameters is difficult to access. By applying non-destructive measurements it is possible to overcome these limitations. Our non-invasive fluorescence imaging technique can directly quantity distribution and changes of oxygen and pH. Similarly, the water content distribution can be visualized in situ also by optical imaging, but more precisely by neutron radiography. By applying a combined approach we will clarify the formation and architecture of interfaces induces by oxygen consumption, pH changes and water distribution. We will map and model the effects of microbial and plant root respiration for restricted oxygen supply due to locally high water saturation, in natural as well as artificial soils. Further aspects will be biologically induced pH changes, influence on fate of chemicals, and oxygen delivery from trapped gas phase.
Das Projekt "Root distribution and dynamics and their contribution to subsoil C-fluxes" wird vom Umweltbundesamt gefördert und von Universität Göttingen, Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Abteilung Pflanzenökologie und Ökosystemforschung durchgeführt. It has been suggested that dying and decaying fine roots and root exudation represent important, if not the most important, sources of soil organic carbon (SOC) in forest soils. This may be especially true for deep-reaching roots in the subsoil, but precise data to prove this assumption are lacking. This subproject (1) examines the distribution and abundance of fine roots (greater than 2 mm diameter) and coarse roots (greater than 2 mm) in the subsoil to 240 cm depth of the three subsoil observatories in a mature European beech (Fagus sylvatica) stand, (2) quantifies the turnover of beech fine roots by direct observation (mini-rhizotron approach), (3) measures the decomposition of dead fine root mass in different soil depths, and (4) quantifies root exudation and the N-uptake potential with novel techniques under in situ conditions with the aim (i) to quantify the C flux to the SOC pool upon root death in the subsoil, (ii) to obtain a quantitative estimate of root exudation in the subsoil, and (iii) to assess the uptake activity of fine roots in the subsoil as compared to roots in the topsoil. Key methods applied are (a) the microscopic distinction between live and dead fine root mass, (b) the estimation of fine and coarse root age by the 14C bomb approach and annual ring counting in roots, (c) the direct observation of the formation and disappearance of fine roots in rhizotron tubes by sequential root imaging (CI-600 system, CID) and the calculation of root turnover, (d) the measurement of root litter decomposition using litter bags under field and controlled laboratory conditions, (e) the estimation of root N-uptake capacity by exposing intact fine roots to 15NH4+ and 15NO3- solutions, and (f) the measurement of root exudation by exposing intact fine root branches to trap solutions in cuvettes in the field and analysing for carbohydrates and amino acids by HPLC and Py-FIMS (cooperation with Prof. A. Fischer, University of Trier). The obtained data will be analysed for differences in root abundance and activity between subsoil (100-200 cm) and topsoil (0-20 cm) and will be related to soil chemical and soil biological data collected by the partner projects that may control root turnover and exudation in the subsoil. In a supplementary study, fine root biomass distribution and root turnover will also be studied at the four additional beech sites for examining root-borne C fluxes in the subsoil of beech forests under contrasting soil conditions of different geological substrates (Triassic limestone and sandstone, Quaternary sand and loess deposits).
Das Projekt "Biodiversity and trophic interactions in agricultural mosaic landscapes, comparing bees, wasps and their natural enemies" wird vom Umweltbundesamt gefördert und von Universität Göttingen, Department für Nutzpflanzenwissenschaften, Abteilung Agrarökologie durchgeführt. Global biodiversity is declining at an alarming rate and traditional conservation areas are no longer sufficient to slow this decline, so the potential contribution of managed land for conservation is increasingly acknowledged. This includes a broadening of the perspective from the field and farm to the landscape level, considering the often neglected spatial and temporal turnover in anthropogenic mosaic landscapes. Here we will use a highly replicated study design with the experimental exposure of standardized nesting resources to examine the relative importance of habitat type to landscape diversity using trap-nesting bees, wasps and their natural enemies. We will analyze the scale-dependence of partitioned biodiversity and quantify host-parasitoid and prey-predator interactions, as well as make food web statistics with a fully quantified interaction web (following Tylianakis et al. 2007, Nature 445: 2002-5). We will show how the major habitat types in our mosaic landscapes (and different years) contribute to overall species richness, comparing wheat, oilseed rape, grassland, field margin strips, fallows and forest margins, which represent a gradient of anthropogenic disturbance. We will examine how landscape composition influences the relative contribution of the six habitat types to species richness by focusing on a gradient of simple to complex structured landscapes. Further, we expect enemy richness to be related to host/prey mortality, so we will contribute to this highly debated topic. The mosaic structure of agricultural landscapes allow to study little known effects of landscape configuration, including spillover effects across habitats, inhibition of dispersal (by hostile cereal fields) and facilitation (by grassy corridors). Experiments with marked bee and wasp individuals allow to describe foraging behaviour and resource use across habitats.
Das Projekt "Auswirkungen von Klima und Landnutzung auf die Diversität und Funktion von Bestäubern, Zersetzern und Herbivoren" wird vom Umweltbundesamt gefördert und von Julius-Maximilians-Universität Würzburg, Theodor-Boveri-Institut für Biowissenschaften, Biozentrum, Lehrstuhl für Zoologie III (Tierökologie und Tropenbiologie) durchgeführt. SP7 analyses two important ecosystem processes: pollination and decomposition. Species richness and abundance of pollinators sampled with coloured UV-reflecting pan traps will be related to floral diversity (SP4, SP5), vegetation type, altitude and climate (SP1 to SP3). Plant-pollinator interaction webs will be quantified to estimate specialization and connectance in relation to climatic variables (SP1), land use and biodiversity (SP4, SP5, SP8). Fruit and seed set of five abundant flowering plant species will be measured for open, hand-pollinated and exclosure treatments to evaluate pollinator limitation in relation to climate, land use and biodiversity. Transplant and pollination experiments with an endemic and a wide-spread Impatiens species will be performed to analyse the importance of pollinator-mediated gene flow (SP4). From combined litter and soil samples the meso- and macrofauna will be extracted. Furthermore the epigaeic fauna is sampled using pitfall traps. Identification to morphospecies, measuring of body size and DNA-barcoding will be applied to estimate biodiversity and size structure (SP 8). Diversity, abundance and size structure of soil fauna taxa will be related to floral diversity, climate, land use, biogeochemical processes (SP1-3) and aboveground diversity (SP4-8). Decomposition rates and the contribution of size classes of decomposers will be measured using litter bags differing in mesh size. Experiments with litter mixtures will be performed to test for adaptations of decomposers to local conditions as well as the effect of litter diversity on decomposition rates along altitudinal gradients.
Das Projekt "Processes determining biodiversity in both managed and unmanaged forest stands analysed in the Bavarian Forest, Germany" wird vom Umweltbundesamt gefördert und von Technische Universität München, Fachgebiet Geobotanik durchgeführt. In this study important processes determining the compositional biodiversity of forest stands are investigated. The central goal is to find out the mechanisms leading to a certain biodiversity after natural and management disturbances. In the national park Bayerischer Wald experimental plots in forest stands with different disturbance regime are selected: - untouched for a long time, - Norway Spruce killed by bark beetle, - single tree selection silviculture - clearcut on small areas (up to 1 ha). Three important organismic groups are under study: beetles, fungi and plants. The first group is investigated by the Chair of Applied Zoology, the second by the Division of Systematic Botany. In the teaching unit Geobotany the effect of small scale soil disturbances on diversity of the ground vegetation is examined. Experimental plots of 0,5 m2 are digged up and the reaction of the vegetation is monitored for two years. Exposed mineral soil is a favourable site for germination and establishment for many species of the species pool. Thus soil disturbances may have a positive effect on species richness. The soil seed bank plays an important role for vegetation regeneration after disturbance. Therefore soil samples are taken and cultivated in a greenhouse. It is hypothesised that the soil seed bank is richer in seed and species number in managed forests than in those forests without direct human influence. To monitor seed rain we expose seed traps in the summer season. Light is an important trigger for the germination of species. Linking the reaction to soil disturbances under different light conditions to the biodiversity of the community helps to widen our understanding of the effect of disturbance regime on biological diversity. The comparison of unmanaged to managed forests enables us to contribute important aspects to the discussion on the effect of forest management on biological diversity.
Das Projekt "Diversification of Andean crop systems at local and landscape scales: enhancing biological control of potato pests" wird vom Umweltbundesamt gefördert und von Universität Göttingen, Department für Nutzpflanzenwissenschaften, Abteilung Agrarökologie durchgeführt. Current agricultural practices have caused serious ecological problems that affect agricultural sustainability by reducing ecological functions and biodiversity. There is evidence that the density of natural enemies of crop pests is related to high biodiversity. This has been shown for landscape-scale management practices (augmenting landscape complexity) and for intercropping systems (augmenting biodiversity at a local scale). However, the relative importance of local and landscape management and the mechanisms through which biodiversity may enhance biological control are still unknown. In this project we will investigate how increased plant diversity at different spatial scales affects biological control of herbivores in potato fields in the Andes. By (1) increasing plant diversity at the field scale and (2) choosing fields along a gradient in landscape complexity, the single and combined effects of these variables on biological control will be analyzed. Furthermore, we will examine whether an increase in plant functional group diversity (trap plants, repellent plants and flowering plants) enhances biological control. The introduction of trap, repellent and flowering plant species to potato fields is expected to reduce the density of the potato moth (Phthorimaea operculella, Lepidoptera: Gelechiidae), a pest able to destroy 100Prozent of the potato crop. The role of constitutively emitted volatile organic compounds (VOCs), from selected weed species and potato, as signals for herbivores and their natural enemies in these interactions will be shown. The results of the project are expected to contribute to the development of sustainable and ecologically sound management methods for potato cultivation in the Andes. Therefore, the requirements and restrictions of management scales, local cropping practices and landscape management are considered.
Das Projekt "Teilvorhaben: Isotopenmethoden und Modellierung (ISOMOD)" wird vom Umweltbundesamt gefördert und von Technische Hochschule Lübeck, Fachbereich Bauwesen, Labor für Hydrologie und Wasserwirtschaft durchgeführt. Das Ziel des Projektes MEDSAL ist es, die Ursachen der Grundwasserversalzung, das Risikopotential und geeignete Bewirtschaftungsmaßnahmen zur Wiederherstellung und Erhaltung des guten Zustandes von Küstenaquiferen im Mittelmeerraum zu identifizieren. Das Labor für Hydrologie der TH Lübeck liefert zu diesem übergeordneten Projektziel drei wichtige Beiträge: Mit stabilen Isotopenmethoden und hydrochemischen Modellen sollen die Ursachen der Versalzung identifiziert werden (Ziel Z1). Es gibt mindestens vier verschiedene mögliche Ursachen der Versalzung von Küstenaquiferen. Durch Übernutzung kann es zum direkten Eindringen von Meerwasser kommen (intrusion), durch zu tiefe Wasserstände kann der Stofftransport vom Inland zum Meer unterbrochen werden (trapping), Versalzung kann durch Bodenversalzung (leaching) oder durch aufsteigendes Tiefenwasser verursacht werden (upconing). Das Labor für Hydrologie entwickelt in den Forschungsprojekt ein Verfahren, mit dem mit wenigen Beprobungen oder an Hand vorhandener Isotopen- und wasserschemischer Daten die Ursache eindeutig erkannt und identifiziert werden kann. Das zweite Arbeitsziel besteht darin, innovative Modellverfahren zu entwickeln, mit denen das Voranschreiten Versalzung von Küstenaquiferen und die Prozesse bei der Sanierung quantitativ beschrieben werden können (Ziel Z2). Neben den verbreiteten Verfahren der numerischen Modellierung entwickelt die TH Lübeck sowohl thermodynamische Reaktionsmodelle (Phase Reaction Equilibrium, PhREq) als auch hocheffiziente Kompartmentmodelle, mit denen die Zeit einer Sanierung realistisch abgeschätzt werden können. Diese Modelle sollen ebenfalls mit Isotopendaten zur Beschreibung der Verweilzeiten kalibriert werden. Schließlich trägt die TH Lübeck zu dem gemeinsamen Projektziel der Erstellung einer Datenbank von versalzten Küstenaquiferen im Mittelmeerraum bei, indem das Untersuchungsgebiet Samos (Griechenland) untersucht wird (Ziel Z3).
Das Projekt "Quantification of active interfaces with respect to dissolved chemicals in unsaturated structured soil" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum für Umweltforschung GmbH - UFZ, Department Bodenphysik durchgeführt. During the first project period we developed a general approach to quantify soil pore structure based on X-ray micro-tomography Vogel et al. (2010) which is applicable at various scales to cover soil pores larger that 0.05 mm in a representative way. Based on this method we generated equivalent network models to numerically simulate flow and transport of dissolved chemicals. The existing network model was extended to handle reactive transport and infiltration processes which are especially critical for matter flux in soil. The results were compared to experimental findings. The original research question 'what does a particle see on its way through soil' could be answered quantitatively for various boundary conditions including steady state flux and infiltration. However, we identified various critical aspects of the proposed modeling concept which will be in the focus of the second period. This includes 1) the spatial arrangement of interfaces having different quality which is crucial for chemical interactions and pore scale water dynamics, 2) the realistic multiphase dynamics at the pore scale which need to reflect the dynamic pressure and movement of trapped non-wetting phase and 3) the parametrization of structural complexity which need to be developed beyond the measurement of continuous Minkowski functions to allow the development of quantitative relations between structure and function. These aspects will be explored in a joint experiments in cooperation with partners within the SPP.
Das Projekt "Biozönologische Gradientenanalyse von Wald-, Hecken- und Parkstandorten der Stadt Aachen: Verteilungsmuster von Phyto-, Carabido- und Araneozönose" wird vom Umweltbundesamt gefördert und von RWTH Aachen University, Institut für Umweltforschung, Lehr- und Forschungsgebiet Ökosystemanalyse (ESA) durchgeführt. Die Biozönosen städtischer Lebensräume wurden am Beispiel von Gehölzbeständen der Stadt Aachen untersucht. Die Artkombination wird dabei im Sinne von Braun-Blanquet als vieldimensionaler Abdruck des Standortes, als 'biozönotischer Fingerprint aufgefasst. Die Biozönose wird als höhere Organisationsstufe begriffen, die mehr ist als die Summe ihrer Teile. Da in Städten oft Gradienten der Umweltbedingungen auftreten wurde eine Gradientenanalyse durchgeführt, deren grundlegende Methode die Ordination (Ordnung durch Anordnung) ist. 37 Wald-, Hecken- und Parkstandorte im Stadtgebiet von Aachen wurden untersucht. Damit liegt eine repräsentative Mischung sowohl für den Naturraum als auch für den Gradienten Umland/Stadt vor. Fragestellungen: Wie sehen Standorttypen aus, die über die Artkombinationen von Pflanzen-, Carabiden- und Spinnenartengruppen festgelegt sind? Lassen sich mathematisch standardisierbare Kriterien zur Bildung ökologischer Gruppen bei Carabiden und Araneen finden? Gibt es typisch städtische Biozönosen; wenn ja, wie sehen sie aus? Führt die Analyse innerhalb einzelner Taxa zu den gleichen Ergebnissen wie eine Synthese, die auf der Synopsis aller Daten beruht? Welche Gradienten treten in den Gehölzstrukturen der Stadt Aachen auf, gibt es in diesen Gradienten besonders empfindliche Bereiche? Folgende Zusammenhänge und Ergebnisse konnten erarbeitet werden: Am Beispiel eines Standorttranssektes ausgewählter Standorte zeigte sich, dass die hier erstmals entwickelte Bindungswertanalyse als Verknüpfung von Repräsentanz und Präsenz (Stetigkeit) ein geeignetes mathematisches Maß zur Klassifizierung von Artengruppen entlang eines Gradienten ist. Dies gilt sowohl für Carabiden als auch für Araneen. Zur Klärung der Frage, ob die Lage oder Anbindung an Waldstandorte die Verbreitung von Waldarten mit geringerer Ausbreitungfähigkeit limitiert, wurde für ausgewählte Arten die Phänologie als Ausdruck der Populationsdynamik untersucht. Auch die Verbreitung der Larven und der frisch geschlüpften Tiere dieser Arten wurde berücksichtigt. Anbindungseffekte konnten auf Individuen-Ebene nur in sehr geringem Maße nachgewiesen werden. Es zeigte sich im Gegenteil, dass auch bei niedriger Aktivitätsdichte der adulten Käfer noch Larven und frisch geschlüpfte Tiere gefangen wurden. Bei den Spinnen wurden auch bei erheblich niedrigerer Aktivitätsdichte der Männchen Weibchen im gleichen Maße nachgewiesen. Es wurde eine Klassifikation aller untersuchten Standorte für die Vegetation, für die Carabiden und die Araneen durch Bildung ökologischer Gruppen (Grundarten- und Differentialartengruppen) erstellt. Dabei werden alle Arten mit gleichen ökologischen Amplituden im Gesamtgradienten zu einer Gruppe zusammengefasst. Daraus ergibt sich die Anordnung der Arten hinsichtlich ihrer diagnostischen Wertigkeit und der Lage der einzelnen Standorte im Gesamtgradienten. In einer Synthese werden die Ergebnisse, die innerhalb der einzelnen Taxa gefunden wurden, neu zusammenges U.s.w.
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