Das Projekt "Element cycles in mountain regions under various land use" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Geowissenschaften, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Agrarökosystemforschung durchgeführt. Research question: What is the role of agricultural land use in changes of nutrient cycles and losses dependingon surface slope and climate? Approach: Annual balance of main nutrients for 3-4 main agricultural farms based on fertilizer input, partitioning of nutrients in above and below ground plant parts, output with harvest, losses with DOM and erosion (in collaboration with other TP). The balances will be done depending on agricultural practices in Eger and Haean Catchment and will be compared with adjacent grassland and forest. Obtained element cycles will be upscaled from farm area to the level of both catchments basins depending on specific land use, surface slope and climate. Research question: Can we reconstruct previous erosion and nutrient losses and separate them under forest and under agricultural use? Approach: Undisturbed sediment cores (7 for Eger and 7 for Haean) will be taken from the lakes and soils of landscapes subordinated to agricultural fields. Three radiocarbon data of wood particles at increasing depth for each sediment core will be used as references. The age of the bottom sediment layer should be less than 1000 years. The total content of C, N, P, K, Mg, Ca, Si will be analyzed in individual laminae or sediment layers. Conclusions will be drawn based on the thickness of the laminae, their elements content and the ratio between nutrients and Si. The conclusions will be proven by 13C (vegetation change) and 15N (N input by fertilizers) of individual laminae. Research question: What are the best management practices for sloping uplands? Approach: Measured element cycles and losses under various agriculture practice will be analysed and practices with the least nutrient losses and erosion will be selected. The best management practices for landscapes with different slopes will be elaborated.
Das Projekt "C 4.1: Impact of land-use intensification on land -use dynamics and environmental services of tropical mountainous watersheds" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Tropische Agrarwissenschaften (Hans-Ruthenberg-Institut), Fachgebiet Pflanzenbau in den Tropen und Subtropen (490e) durchgeführt. Changing socio-economic conditions and the introduction of new technologies are rapidly altering land use in Vietnam and Thailand. In both countries farmland is often characterized by relatively steep slopes and is thus highly susceptible to land degradation by soil erosion. Intensification of agricultural systems has led to higher systems productivity but with associated increased resource use and degradation/pollution risks. The goal of this subproject is to comprehend the biophysical linkages and drivers of land-use changes in upland areas of Vietnam and Thailand and their impact on systems productivity, sustainability and environmental services. This can be only assessed by an approach, integrating the various systems and processes at stake and looking at their interconnectivity at landscape level. Of special interest is thus quantification and modelling of the interrelationships and feedback mechanisms between agricultural components within these complex ecosystems. Subproject C4.1 will develop a spatially explicit, integrated dynamic biophysical model for land use change impact assessment (LUCIA) to understand systems relationships at the landscape level and subsequently link this landscape model to the multi-agent-system (MAS) model of G1.2 (Innovations and Sustainability Strategies). In Vietnam, subproject C4.1 will investigate how nutrient and carbon losses and associated soil degradation in uplands will impact on lowland paddy rice and fish production systems. In North Thailand, an existing crop/tree model will be improved to assist in assessing the impact off-season fruit production technologies or management options on plant productivity, resource use and carbon sequestration and its modules integrated in the MAS model. The integrated biophysical and MAS models will allow assessing alternative options so that policy-relevant conclusions can then be drawn regarding the promotion of improved conservation and management systems, adapted to both the local populations and systems of governance in tropical humid mountainous watersheds from Thailand and Vietnam.
Das Projekt "Effectiveness of low emission zones: Large scale analysis of changes in environmental NO2, NO and NOx concentrations in 17 German cities" wird vom Umweltbundesamt gefördert und von Evonik Industries AG durchgeführt. Background: Low Emission Zones (LEZs) are areas or roads where the most polluting vehicles are restricted from entering. The effectiveness of LEZs to lower ambient exposures is under debate. This study focused on LEZs that restricted cars of Euro 1 standard without appropriate retrofitting systems from entering and estimated LEZ effects on NO2, NO, and NOx (=NO2+NO) concentrations. Methods: Continuous half-hour and diffuse sampler 4-week average NO2, NO, and NOx concentrations measured inside and outside LEZs in 17 German cities of 6 federal states (2005-2009) were analysed as matched quadruplets (two pairs of simultaneously measured index values inside LEZ and reference values outside LEZ, one pair measured before and one after introducing LEZs with time differences that equal multiples of 364 days) by multiple linear and log-linear fixed-effects regression modelling (covariables: e.g., wind velocity, amount of precipitation, height of inversion base, school holidays, truck-free periods). Additionally, the continuous half-hour data was collapsed into 4-week averages and pooled with the diffuse sampler data to perform joint analysis. Results: More than 3,000,000 quadruplets of continuous measurements (half-hour averages) were identified at 38 index and 45 reference stations. Pooling with diffuse sampler data from 15 index and 10 reference stations lead to more than 4,000 quadruplets for joint analyses of 4-week averages. Mean LEZ effects on NO2, NO, and NOx concentrations (reductions) were estimated to be at most - 2 microgram/m3 (or - 4 percent). The 4-week averages of NO2 concentrations at index stations after LEZ introduction were 55 microgram/m3 (median and mean values) or 82 microgram/m3 (95th percentile). Conclusion: This is the first study investigating comprehensively the effectiveness of LEZs to reduce NO2, NO, and NOx concentrations controlling for most relevant potential confounders. Our analyses indicate that there is a significant, but rather small reduction of NO2, NO, and NOx concentrations associated with LEZs. Key words: air quality, low emission zone, NO2, NO and NOx, air pollution
Das Projekt "Sub project: Temperature chaos and microbial food web dynamics" wird vom Umweltbundesamt gefördert und von Universität Köln, Institut für Zoologie, Biozentrum Köln, Arbeitsgruppe Allgemeine Ökologie durchgeführt. Microbial food webs dominate the functioning of marine and freshwater ecosystems. Conclusions on the impact of climatic changes on aquatic ecosystems have generally been based on studies of constant increases in experimental temperatures. However, since the invention of deterministic chaos in the 60ies of the last century, it is known that organisms are confronted with non-linear dynamics of external temperatures. One important forecast for climate changes is the increase of weather (e.g. temperature) variability especially in the middle of Europe. Thus, we would like to contribute to the studies of the current consortia working in the frame of AQUASHIFT with a model study on the dynamic behaviour of experimental food webs. Organisms are not only faced with external irregularities but also with internal (intrinsic) fluctuations of population dynamic parameters. Here we would like to investigate the interaction between non-linear dynamic behaviours of extrinsic and intrinsic factors. We have developed an exceptional model systems consisting of a microbial two-preyone-predator-systems that allows for a detailed analysis of dynamic behaviour under defined chemostat conditions. We will analyze match/mismatches occurring due to the interference of non-linear dynamics of extrinsic (temperature) and intrinsic (population sizes) parameters on different trophic levels and would like to contribute to create a theoretical basis for the understanding of the impact of global changes on aquatic communities.
Das Projekt "TRENCH (Tree-Ring Environmental Network for Climate Change Monitoring): Developing a tree-based indicator system for environmental change impacts on forest ecosystems in southern Ecuador" wird vom Umweltbundesamt gefördert und von Universität Erlangen-Nürnberg, Institut für Geographie durchgeführt. The suggested project aims at the development of a tree-ring based indicator system on climate and environmental change impacts on forest ecosystems in Southern Ecuador. We follow a multiparameter approach that shallintegrate various information sources in wood into one indicator system by modelling approaches. We will measure quantitative variations of wood anatomical parameters in relation to climate soil and soil factors. Long- erm growth rates of trees and diurnal amplitudes of stem diameter variations shall be measured with high-resolution electronic dendrometers. In addition, interannual variations and long-term trends of various stable isotope species over the past 30 years shall be analyzed. By combining of growth data and stable carbon and oxygen isotope analyses it is possible to distinguish if changes in intrinsic water use efficiency are caused by changes of assimilation or stomatal conductance. Analyses of stable nitrogen isotopes in wood allow conclusions about changes of soil nutrient cycling that is expected with worldwide increasing rates of nitrogen input in tropical forest ecosystems. The project will work anelevation gradient, including tropical dry forests, perhumid mountain rainforests and very wet treeline ecotones towards the paramo. The nutrient manipulation experiment NUMEX simulates the impact of increasing atmospheric nutrient input so that reactions of intrinsic water use efficiency and other growth parameters of specific tree species of all forest ecosystems can be studied. To detect nutrient-triggered species-specific changes in the reaction pattern on short-term drought events, intra-annual variations of stable carbon and oxygen isotopes shall be carried out for the past six years.
Das Projekt "Absatzanalyse für regionale und fair gehandelte Öko-Lebensmittel (Fair und regional)" wird vom Umweltbundesamt gefördert und von Universität Kassel, Fachbereich 11 Ökologische Agrarwissenschaften, Fachgebiet Agrar-und Lebensmittelmarketing durchgeführt. Zielsetzung des beantragten Projekts ist eine umfassende Analyse des Absatzerfolgs für die im Rahmen von zwei anderen BLE-Projekten (siehe Kooperation) entwickelten und verkauften Testprodukte. Die Analyse des Absatzerfolgs basiert auf einer Analyse von Absatzmengen und -preisen und Umsätzen der Testprodukte sowie von deren engsten Substituten im Sortiment der Testgeschäfte. Darüber hinaus werden Verkaufsförderungsmaßnahmen, die im Rahmen der BLE-Projekte durchgeführt werden, im Hinblick auf deren kurz- und mittelfristigen Absatzerfolg analysiert. Die Analyseergebnisse sollen Entscheidungsträgern bei Herstellern und Händlern Informationen liefern, die für eine Listung der regionalen und fairen Öko-Lebensmittel in Naturkostläden essentiell sind.
Das Projekt "Fuzzy-Based Sediment Transport Simulation Using Contemporary Modeling Concepts and Measurement Methods as Validation" wird vom Umweltbundesamt gefördert und von Universität Stuttgart, Institut für Wasser- und Umweltsystemmodellierung durchgeführt. An estimate of sediment transport rates in alluvial rivers is important in the context of erosion, sedimentation, flood control, long-term morphological assessment, etc. Extensive research during the last decades has produced a plethora of sediment transport models. Sediment transport is complex and often subject to semi-empirical or empirical treatment. Most of the sediment transport functions are based on simplified assumptions that the rate of sediment transport could be determined by one or two dominant factors, such as water discharge, average flow velocity, energy slope, and shear stress (Yang, 1996). In many practical situations prediction errors of these models are observed to be high.An alternative approach is to use data driven modelling, which is especially attractive for modelling processes about which adequate knowledge of the physics is limited, like in the case of sediment transport. Over the last decade fuzzy rule-based models have been introduced in engineering as a powerful alternative modelling tool. The fuzzy rule-based approach introduced by Zadeh (1965) is being widely utilized in various fields of engineering. It is a qualitative modelling scheme in which the system behaviour is described using a natural language (Sugeno & Yasukawa, 1993). This research focuses on the applicability of a data-driven fuzzy rule-based modelling approach in estimating sediment transport rates. It also aims at the comparison of the results of the fuzzy rule-based model with the results of other commonly utilized sediment transport functions.A number of variables play important roles in determining sediment transport capacity. These variables are: flow depth, particle fall velocity, particle diameter, flow velocity, energy or water surface slope, shear velocity, shear stress, fluid density, sediment density, stream power, unit stream power, and discharge. Additionally; size, shape, and unit weight of bed composition; morphology of bed forms and availability of sediment from source area affect sediment transport capacity. The most significant factors affecting sediment transport capacity will be identified and used for constructing a fuzzy model. The fuzzy model identification is usually carried out in two steps: (1) determining the number of fuzzy rules and their associated membership functions and (2) optimizing the fuzzy model. The fuzzy logic toolbox in MATLAB will be used for performing the fuzzy modelling.A general fuzzy system has the components of fuzzification, fuzzy rule base, fuzzy output engine, and defuzzification. Fuzzification converts each piece of input data to degrees of membership by a look-up in one or more several membership functions. Intuition, fuzzy clustering, neural networks, genetic algorithms, and inductive reasoning can be among many ways to assign membership values or functions to fuzzy variables...
Das Projekt "Untersuchungen zur Mikrostruktur und zum Setzungsverhalten von Lössböden" wird vom Umweltbundesamt gefördert und von Universität der Bundeswehr München, Institut für Bodenmechanik und Grundbau durchgeführt. Forschungstätigkeiten auf dem Gebiet der Sackungsanfälligkeit von Lössböden waren insbesondere zwischen den 30er und 80er Jahren des 20. Jahrhunderts von nationaler Individualität gekennzeichnet. Erst seit Anfang der 80er Jahre, mit Aufstellung der Arbeitsgruppe 'Geotechnical Properties of Loess' der International Union for Quarternary Research (INQUA), ist eine international referenzierende Forschung auf dem Gebiet der Erfassung bodenmechanischer Eigenschaften von Lössböden zu verzeichnen. Der Schwerpunkt bisheriger Forschungsarbeiten lag auf der Erarbeitung sogenannter Kollapskriterien zur qualitativen Abschätzung des Sackungspotentials bei einem Anstieg des Wassergehalts. Bisher durchgeführten geochemischen Untersuchungen von Lössböden beschreiben zwar die mineralische Zusammensetzung, geben jedoch nur eingeschränkt Aufschluss über die Löslichkeit dieser Bestandteile in Wasser oder deren Einfluss auf das Sackungsverhalten. Sämtliche bis dato veranlassten Untersuchungen zum Kollapsverhalten der metastabilen Bodenstruktur von Lössböden wurden für den statischen Lastfall angestellt. Das Verformungsverhalten von Lössböden unter zyklischer Lasteinwirkung hingegen bedarf einer intensiveren wissenschaftlichen Betrachtung. In der vorliegenden Arbeit wird erstmals der Anteil leicht wasserlöslicher mineralischer Bestandteile eines afghanischen Lössbodens ermittelt und anhand von Parameterstudien der Einfluss des Ton- und Kalkgehalts auf das Hydrokonsolidationsverhalten untersucht. Betrachtungen der makro- und mikroskopischen Bodenstruktur ermöglichen belastbare Aussagen über das Verhalten und die Bedeutung des Porenraumes beim Übergang einer metastabilen Bodenstruktur in eine dichtere und somit stabilere Lagerung. Die aus den eigenen Untersuchungen gewonnenen Erkenntnisse dienen als Grundlage für die Formulierung einer neuen, empirisch-deduktiven Prognosemethode zur qualitativen Abschätzung der infolge Hydrokonsolidation zu erwartenden kollapsartigen Verformung (Kollapsverformung). Neben der Vorstellung der Prognosemethode für den statischen Lastfall wurden dynamische Triaxialversuche zur vergleichenden Untersuchung der dynamischen Stabilität metastabiler und idealverdichteter Lössböden angestellt. Sämtliche bodenmechanischen und bodenphysikalischen sowie physiko- und geochemischen Untersuchungen erfolgten an geologisch rezent gebildeten, alluvial und fluvial abgelagerten afghanischen Lössböden der Regionen BALKH und KUNDUZ.
Das Projekt "Cell wall hemicelluloses as mobile carbon stores in plants" wird vom Umweltbundesamt gefördert und von Universität Basel, Philosophisch-Naturwissenschaftliche Fakultät durchgeführt. Non-structural carbohydrates (NSC) are the most important carbon reserves in most tissues and species. Beside NSC, cell wall hemicelluloses as the second most abundant polysaccharides in plants have often been discussed to serve as additional carbon reserves during periods of enhanced carbon-sink activity. By using a refined extraction method hemicelluloses were quantitatively and qualitatively determined in tissues of different plant functional groups and the ecophysiological importance of hemicelluloses as mobile carbon pools was investigated in two studies. In the first study hemicelluloses were investigated in newly synthesized tissues of 16 species of four different plant functional groups that were grown under extremely low (140 ppm), medium (280 ppm) or high (560 ppm) CO2 concentrations inducing a massive carbon-under or -oversupply. The changed carbon source-sink activities were evidenced by significant increments of biomass and NSC under elevated CO2 concentrations in tissues of all species. In contrast, hemicellulose concentrations remained remarkably stable with varying CO2 supply. Nevertheless, the monosaccharide spectrum of hemicelluloses showed a significant increase in glucose monomers in leaves of woody species as carbon supply increased. In contrast to the growing tissues of the first experiment the second study investigated the potential carbon reserve function of hemicelluloses by using the naturally occurring fluctuation in carbon-sink activity during bud break in mature forest trees (two deciduous species Carpinus betulus L., Fagus sylvatica L. and two evergreen species Picea abies L., Pinus sylvestris L.). NSC concentrations in branch sapwood of the deciduous trees declined strongly immediately before bud break and increased after bud break. Previous seasons' needles exhibited a significant increase in NSC concentrations shortly before bud break which declined again after flushing. Short-term fluctuations in hemicellulose concentrations were found in branch sapwood of Carpinus and previous seasons' needles of Picea and Pinus and correlated with those of NSC suggesting a mobile reserve function of hemicelluloses. The observed variations in hemicellulose concentrations in previous seasons' needles were due to variations in hemicellulose-bound glucose. In conclusion, this thesis showed that during 'de-novo' synthesis of cell-walls, hemicellulose concentrations do not vary strongly with changing carbon supply. Hemicelluloses are therefore unlikely to play a significant role as additional carbon sinks at future elevated atmospheric CO2 concentrations. On the other hand, apart from their predominant structural function, hemicelluloses can serve as additional carbon reserves in mature tissues during times of exceptionally high carbon demand.
Das Projekt "Functional morphology and productivity of a tussock grassland in the Bolivian Altiplano" wird vom Umweltbundesamt gefördert und von Universität Basel, Philosophisch-Naturwissenschaftliche Fakultät durchgeführt. Tropical and subtropical high elevation grasslands are generally dominated by tall tussock grasses, a life form that seems to dominante in year round cold climates but otherwise quite different soil moisture regimes, from very wet (New Guinea, New Zealand, Ecuador) to rather dry, even semi-arid, as is the case in the NW-Argentinan and Bolivian Altiplano. The biomass production of these vast areas is largely unknown, since the classical harvesting technique cannot be applied in perennial vegetation without affecting growth. Given the steady increase in land use intensity, such information is needed to estimate the carrying capacity of these vast rangelands. In this thesis, I developed the needed non-destructive tools and applied them for a 30-month productivity analysis in the Bolivian Altiplano. The work was conducted in Sajama National Park at 4250 m elevation. The study plant, Festuca orthophylla, is a tall (up to 1 m, mostly around 60 cm) tussock forming grass that represents more than 90Prozent of all biomass in many parts of the Altiplano, including the study area. Forming clones of initially compact, but later fragmented shape, persisting many decades, this species is characteristic for the appearance of the semi-arid, Andean landscape over thousands of square kilometers at elevations between 3600 and 4600 m a.s.l. As a first step, I analysed the clonal structure, the morphology and biomass allocation in representative tussocks. The core of the theses is related to the tussock biomass production using a demographic approach and land cover data (Chapter 3), followed by an assessment of seasonal leaf dynamics (Chapter 4). In conclusion, our data provide a quantitative characterisation of the architecture and dry matter investment of this dominant Altiplano species, the first year-round productivity estimation for a high-elevation tropical, grassland, and a detailed assessment of leaf dynamics for the rainy and the dry season. In a number of ways the traits exhibited, contrast Festuca orthophylla from other, non-woody, high elevation taxa. In particular, the foliage of these tussocks operates at temperature close to that of the free atmosphere, while at the same time, providing shelter to below-ground shoot meristems. The large amount of dead plant material constrains photosynthetic light interception, and reflects slow rates of decomposition, a likely trade-off of generally poor nutrional quality (Patty et al., 2010), which, in turn, relates to the heavy herbivory pressure. The rates of biomass accumulation per unit of tussock area are quite high, much higher than one would expect in such a semi-arid rangeland. The most plausible explanation is that these tussocks are utilizing a far greater land area for water and nutrient acquisition than represented by their projected canopy area. The space in-between tussocks is, thus, a most likely mechanism explaining these high rates of productivity.
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