Salinity reduces the productivity of cucumber (Cucumis sativus L.) through osmotic and ionic effects. For given atmospheric conditions we hypothesize the existence of an optimal canopy structure at which water use efficiency is maximal and salt accumulation per unit of dry matter production is minimal. This canopy structure optimum can be predicted by integrating physiological processes over the canopy using a functional-structural plant model (FSPM). This model needs to represent the influence of osmotic stress on plant morphology and stomatal conductance, the accumulation of toxic ions and their dynamics in the different compartments of the system, and their toxic effects in the leaf. Experiments will be conducted to parameterize an extended cucumber FSPM. In in-silico experiments with the FSPM we attempt to identify which canopy structure could lead to maximum long-term water use efficiency with minimum ionic stress. The results from in-silico experiments will be evaluated by comparing different canopy structures in greenhouses. Finally, the FSPM will be used to investigate to which extent the improvement of individual mechanisms of salt tolerance like reduced sensitivity of stomatal conductance or leaf expansion can contribute to whole-plant salt tolerance.
In the last decades agricultural policy has gained increasingly in complexity. Nowadays it influences the food and agricultural sector from the global market down to the farm level. Widespread research questions, like the impact of the WTO negotiations on the farm structure, most often require comprehensive modeling frameworks. Thus, different types of models are utilized according to their comparative advantages and combined in a strategically useful way to more accurately represent micro and macro aspects of the food and agricultural sector. Consequently, in recent years we have seen an increase in the development and application of model linkages. Given this background, the overall objective of this subproject is a systematic sensitivity analysis of model linkages that gradually involves more and more characteristics of the linkage and the corresponding transfer of results between models. In addition, the project aims to answer the following specific question: How does structural change at the farm level influence aggregate supply and technical progress? Under which conditions is it possible to derive macro-relationships from micro-relationships? How does the aggregation level influence the model results and how can possible problems be overcome? This procedure is used to quantify the effects and to derive conditions for optimal interaction of the connected models. The analysis is based on the general equilibrium model GTAP (Global Trade Analysis Project) and the farm group model FARMIS (Farm Modelling Information System) which are employed in conjunction to analyze the effects of WTO negotiations on the farm level.
Organotin and especially butyltin compounds are used for a variety of applications, e.g. as biocides, stabilizers, catalysts and intermediates in chemical syntheses. Tributyltin (TBT) compounds exhibit the greatest toxicity of all organotins and have even been characterized as one of the most toxic groups of xenobiotics ever produced and deliberately introduced into the environment. TBT is not only used as an active biocidal compound in antifouling paints, which are designed to prevent marine and freshwater biota from settlement on ship hulls, harbour and offshore installations, but also as a biocide in wood preservatives, textiles, dispersion paints and agricultural pesticides. Additionally, it occurs as a by-product of mono- (MBT) and dibutyltin (DBT) compounds, which are used as UV stabilizer in many plastics and for other applications. Triphenyltin (TPT) compounds are also used as the active biocide in antifouling paints outside Europe and furthermore as an agricultural fungicide since the early 1960s to combat a range of fungal diseases in various crops, particularly potato blight, leaf spot and powdery mildew on sugar beet, peanuts and celery, other fungi on hop, brown rust on beans, grey moulds on onions, rice blast and coffee leaf rust. Although the use of TBT and TPT was regulated in many countries world-wide from restrictions for certain applications to a total ban, these compounds are still present in the environment. In the early 1970s the impact of TBT on nontarget organisms became apparent. Among the broad variety of malformations caused by TBT in aquatic animals, molluscs have been found to be an extremely sensitive group of invertebrates and no other pathological condition produced by TBT at relative low concentrations rivals that of the imposex phenomenon in prosobranch gastropods speaking in terms of sensitivity. TBT induces imposex in marine prosobranchs at concentrations as low as 0,5 ng TBT-Sn/L. Since 1993, for the littorinid snail Littorina littorea a second virilisation phenomenon, termed intersex, is known. In female specimens affected by intersex the pallial oviduct is transformed of towards a male morphology with a final supplanting of female organs by the corresponding male formations. Imposex and intersex are morphological alterations caused by a chronic exposure to ultra-trace concentrations of TBT. A biological effect monitoring offers the possibility to determine the degree of contamination with organotin compounds in the aquatic environment and especially in coastal waters without using any expensive analytical methods. Furthermore, the biological effect monitoring allows an assessment of the existing TBT pollution on the basis of biological effects. Such results are normally more relevant for the ecosystem than pure analytical data. usw.
In Vivo und in vitro Verabreichung von Nahrungsmittelzusatzstoffen (Tartrazin, Gelborange, Amaranth, Benzoesaeure, Sorbinsaeure, Na-Disulfit, K-Disulfit, Glutamat) und von Nahrungsmitteln (Ei, Milch, Nuesse, Fisch, Rohkost, Fleisch, Mehlsorten) an Patienten mit Verdacht auf entsprechende Unvertraeglichkeiten. Symptome: Kopf- und Bauchschmerzen, Asthma, Rhinitis, Diarrhoe, Urticaria, anaphylaktischer Schock. Mit Hilfe der in vitro Provokationen werden Korrelationen zwischen Mediatorenprofilen und der klinischen Symptomatologie hergestellt. Ziel der Untersuchung: Etablierung eines validen, nicht invarsiven, den Patienten nicht gefaehrdenden diagnostischen Verfahrens zur Objektivierung der nahrungsmittelinduzierten pseudoallergischen Reaktionen.
Our long term activities aim at a functional understanding of alpine plant life. Overall our research shifted gradually from studying resource acquisition (e.g. photosynthesis) toward resource investment and questions of developement. As with treeline, sink activity seems to be the major determinant of growth. A common misconception associated with alpine plant life finds its expression in the use of the terms 'stress' and 'limitation'. See the critique in: Körner C (1998) Alpine plants: stressed or adapted? In: Press MC, Scholes JD, Barker MG (eds.) Physiological Plant Ecology. Blackwell Science , 297-311. Ongoing experimental work: The influence of photoperiod on growth and development in high elevation taxa (Ph.D. by Franziska Keller in cooperation with the Dept. of Geography, University of Fribourg). We test, whether and which species are responsive to earlier snow melt. It appears there exists a suite of different sensitivities, suggesting biodiversity shifts. We also tested the influence of nutrient addition on high elevation pioneer plants and run a longer term project on the interactive effect on sheep tramplng, nitrogen deposition and warming as part of the Swiss National Project NFP 48. A Europe-wide assessment of ground temperatures in alpine grassland is part of ALPNET (see associated organisations). The assessment provides a basis for comparing biodiversity in alpine biota from 69 to 37 degree of northern latitude. (Nagy et al. (2003) Ecological Studies, Vol. 167. 577 p. Springer, Berlin). A synthesis of research in functional ecology of alpine plants over the past 100 years was published in 1999.
Current and future global warming will cause the degradation of mountain permafrost, which may strongly influence the stability of permafrost slopes or rock walls with potentially hazardous consequences. Due to the strong heterogeneity of both the thermal regime and the ground composition of mountain permafrost, its response to atmospheric forcing can however be highly variable for different landforms and within short distances. The spatial distribution of ice and liquid water is important for determining the sensitivity of a specific permafrost occurrence to climate change because of their large influence on the pace of temperature changes (by effects of latent heat) and their importance for geotechnical properties of the ground. Detailed knowledge of the material properties and internal structures of frozen ground is therefore an important prerequisite to determine the sensitivity of permafrost to climate change. Except for the active layer ice and water contents and their temporal and spatial variability usually cannot be measured directly. Geophysical methods are sensitive for the ice and liquid water content in the ground. With the proposed collaboration, two similar but complementary approaches to quantify the composition of the ground based on 2D sections of geophysical data will be combined for an improved determination of ice and water contents in permafrost regions. The so-called 4-phase model (4PM) is based on two simple petrophysical relationships for electrical resistivity and seismic velocity and estimates volumetric fractions of ice, water, and air within the pore volume of a rock matrix by jointly using complementary data sets from electric and seismic measurements. Due to inherent ambiguities in the model it is still restricted to specific cases and often allows only a rough estimation of the phase fractions. Major drawbacks of the current 4PM comprise the unsatisfactory discrimination between rock and ice and its under-determinedness, requiring the prescription of the porosity and further parameters. The so-called RSANN model (developed and used by the host institution) uses the technique of simulated annealing (a Monte-Carlo-type stochastic simulation approach) as an optimization tool for the integration of electrical resistivity and P-wave velocity to derive 2D sections of porosity, water saturation and volumetric water content. The simulated annealing technique allows - due to its iterative procedure - more parameters to be predicted instead of being prescribed as in the 4PM. The objective of the proposed collaboration is to combine the advantages of the two algorithms (4PM and RSANN) to overcome the shortcomings of the 4PM in order to improve the reliability of the determined ice and liquid water contents. (...)
In den zurückliegenden 1.5 Jahren des Projektes konzentrierten sich die Arbeiten auf das erste bereits fertiggestellte vertikale Seismometer-Array des ICDP-GONAF-Observatoriums auf der Tuzla Halbinsel im Südosten Istanbuls. Aufgrund des verbesserten Signal-Rausch-Verhältnisses an den Bohrlochseismometern im Vergleich zu den Oberflächenstationen war es möglich, deutlich mehr M kleiner als 0 Mikrobeben zu detektieren. Diese Messdaten stellten die Grundlage für die bereits durchgeführten seismologischen Studien dar. In der hier beantragten Verlängerung werden wir unsere Erdbebendatenbank für das östliche Marmarameer fortlaufend erweitern, indem wir die im Sommer 2014 fertig gestellten Seismometer-Arrays auf der Armutlu-Halbinsel in die Detektionsalgorithmen integrieren, sowie dann auch weitere vier GONAF-Bohrlocharrays, deren Fertigstellung bis Frühjahr 2015 geplant ist. Es wurden verschiedene Methoden zur Bestimmung oberflächennaher Eigenschaften des Tuzla-Standortes, wie z.B. seismische Geschwindigkeiten und Dämpfung, angewendet und angepasst. Dieselben Methoden werden auf die neuen GONAF-Stationen übertragen, um zu verifizieren, ob die Beobachtungen in Tuzla standortspezifisch, oder auch für andere geologische Formationen repräsentativ sind. Die dann erstmals durchgeführte vergleichende Analyse unterschiedlicher Standorte in der Region wird neue Einblicke geben, um die Auswerteverfahren für die Korrektur von Standort-Effekten weiterzuentwickeln. Dies ist z.B. für eine genaue Abschätzung von Erdbeben-Quellparametern essentiell. Darüber hinaus planen wir, Processing-Methoden des Vertical-Seismic Profiling einzusetzen, um die Zweige der Nordanatolischen Verwerfungszone unterhalb des östlichen Marmarameeres abzubilden (passive fault-zone imaging). Dabei wird die lokale Seismizität genutzt, die in kleiner als 20 km Epizentralentfernung von den GONAF-Stationen in Tiefen von 5 bis 20 km auftritt und an den verschiedenen Tiefenstockwerken der GONAF-Arrays registriert wird. Schließlich werden Wellenformen-Registrierungen von erstmals in 300m Tiefe eingesetzten 3-Komponenten 1Hz MARK Seismometern ausgewertet, unter Anderem um verstärkt S-Wellen-Eigenschaften der Region zu untersuchen.
Climate models predict more frequent and more severe extreme events in Europe during the next decades. The potential impact of extended drought periods on agricultural production represents a key aspect in this context. Drought causes metabolic changes in cereals related to protein metabolism (alterations in protein synthesis and adaptation of the protein pattern, protein degradation). The relation of these changes to yield quantity and quality is not yet well understood. Plant exposure to various environmental stresses often leads to the synthesis of stress-inducible proteins with chaperonine functions, dehydrins or proteases. The relationship among the stress-inducible proteins is very important for the survival of plants during drought stress and for the subsequent recovery phase. One of the major signals to be considered during drought stress is the plant hormone abscisic acid (ABA). Drought triggers the production of ABA which induces various genes involved in a signaling cascade for the regulation of downstream biochemical protective mechanisms. Wheat (Triticum aestivum L.) is a widely cultivated crop plant with high sensitivity to water deprivation. In view of this, it is important for agricultural practice to understand the relation between the stress-inducible proteins and the growth of wheat varieties differing in their drought sensitivity. The comparison of selected wheat genotypes may be relevant for basic research on one hand (identification of mechanisms and of potentials in wheat lines differing in their drought tolerance) and may be relevant for agronomy on the other hand (selection of wheat lines for agronomic use in a changing climate). A team from the Bulgarian Academy of Sciences (leader: Professor Klimentina Demirevska-Kepova) and a team from the Institute of Plant Sciences of the University of Bern (leader: Prof. Urs Feller) will collaborate in this project. Successful interactions between the two institutions started several years ago. Initially the contacts were restricted to correspondence and the exchange of reprints. In 2002 a direct collaboration started, when Prof. Klimentina Demirevska-Kepova was as a guest researcher for three months at the Institute of Plant Sciences of the University of Bern. Antibodies previously raised by her team in Bulgaria were helpful tools for the joint experiments. This project will allow to intensify the interactions between the two institutions and to involve more scientists from the Bulgarian Academy of Sciences in this collaboration.
The main objective of the project is to determine growth sensitivity, elasticity, and resilience of Douglas-fir provenances to climatic alterations, in particular drought events. To differentiate between the impact of site and genetics, samples from experiments will be analyzed, where identical provenances are planted at different sites. Major research scopes are: Investigating the impact of weather on intra-annual growth patterns We will determine how weather variations affect the provenances' growth. The focus will be on intra-annual variations in wood anatomy and density. A dendrometer study will complement the retrospective analyses to monitor changes in stem hydraulic status and to trace the seasonal timing of growth processes. Fitting genotype- and climate-sensitive growth models for a growth simulation system Retrospective inter-annual growth address long-term trends as well as the effect of distinct climate events on inter-annual growth responses. The goal is to build provenance- and climate-sensitive growth models that can be integrated into a growth simulation system. The assessment of growth responses to drought will be tested and interpreted against the results of the partner projects within the general research concept 'adaptation of forest trees to climatic change - diversity of drought responses in Douglas-fir provenances': P1 (genes), P2 (stable isotopes), and P4 (isoprenoids). A major contribution of our project is to provide the partner projects with research opportunities in the adult stands of the provenance experiments.
Lakes can be considered as sentinels and thus indicators and integrators of environmental pressures such as climate change. To maintain lakes in a healthy ecological state is nowadays a major task for water management authorities, and will be increasingly so under climate change which is believed to negatively affect lake ecosystem functioning. Phytoplankton plays a key role in lake dynamics as it is at the base of the food web, and changes in its community have potential to affect the entire lake ecosystem. In addition, Cyanobacteria, the only freshwater phytoplankton group that is able to produce cyanotoxins, are capable of inflicting considerable harm to lake ecosystems and to human health through contamination of drinking water supply and toxin accumulation in fishes. Phytoplankton is thus a common indicator to assess the ecological status of lakes. Without understanding the complex mechanisms and processes that underlay a lake ecosystem in a changing climate, planning for future lake management and adaptation will be compromised. Numerical deterministic modelling is today the most appropriate approach to address these global and complex mechanistic features of lake ecosystems. Modeling studies play a key role in exploring the processes responsible for changes since they can be used to test the sensitivity of lakes to both observed and projected changes in climate. The aim of this project is to apply an ecological model to Lake Geneva, which has not been undertaken yet. Lake Geneva, a deep sub-Alpine lake, is the largest lake in central Europe and an essential source of drinking water, having not only a high ecological value, but also economic and social values. Due to its considerable environmental importance, it is crucial to assess, through numerical modeling techniques applied, how the Lakes water quality may be impaired; especially in view of the fact the observed rate of warming since 1900 is more than double that of the observed global average. Moreover, the hydrodynamic characteristics of Lake Geneva, the watershed of its most important inflow river Rhône, as well as the regional climate, have already been modeled. In coupling these models together, we will close the essential gaps, through which we will be able to understand the links between climate, watersheds, and lakes and provide a whole, integrated ecosystem perspective. This integrative model will provide an accurate predictive management tool to help take decisions and response strategies in a timely manner. It is generally recognized that future climate change will have an important impact on Lake Geneva, with a likely deterioration of its water quality. This will be manifested by high phosphorus concentrations, by phytoplankton biomass increase, by a change in phytoplankton composition, by an asynchronous phenology and by an emergence of potentially toxic Cyanobacteria.(...)
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