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Impact of long-term exposure to elevated pCO2 on activity and populations of free living N2 fixing organisms in a temperate grassland system

Das Projekt "Impact of long-term exposure to elevated pCO2 on activity and populations of free living N2 fixing organisms in a temperate grassland system" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Tropische Agrarwissenschaften (Hans-Ruthenberg-Institut), Fachgebiet Pflanzenbau in den Tropen und Subtropen (490e) durchgeführt. The project aims at achieving a better understanding of the processes that drive or limit the response of grassland systems in a world of increasing atmospheric pCO2. We will test the hypothesis that the previously shown increase in below-ground allocation of C under elevated pCO2 provides the necessary energy excess and will stimulate free-living N2 fixers in a low N grassland environment. The project thus aims at assessing the occurrence and importance of free-living N2 fixers under elevated pCO2 and identify the associated microbial communities involved in order to better understand ecosystems response and sustainability of grassland systems. This project had the last opportunity to obtain soil samples from a grassland ecosystem adapted to long-term (10 year) elevated atmospheric pCO2 as the Swiss FACE experiment. The project aims to identify the relevant components of free-living diazotrophs of the microbial community using 15N stable isotope - DNA probing.

B 2.3: Transport of agrochemicals in a watershed in Northern Thailand - Phase 3

Das Projekt "B 2.3: Transport of agrochemicals in a watershed in Northern Thailand - Phase 3" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Bodenkunde und Standortslehre, Fachgebiet Biogeophysik durchgeführt. Land use changes of the last decades in the mountainous regions of Northern Thailand have been accompanied by an increased input of agrochemicals, which might be transferred to rivers by surface and/or subsurface flow. Where the river water is used for household consumption, irrigation and other purposes, agrochemical losses pose a serious risk to the environment and food safety. In the first and the second phase, subproject B2 collected data on and gained knowledge of the vertical and lateral transport processes that govern the environmental fate of selected agrochemicals at the plot and the hillslope scale (Ciglasch et al., 2005; Kahl et al., 2006). In the third phase, B2.3 will turn from the hillslope to the watershed scale. For simulation of water flow and pesticide transport the SWAT model (Neitsch et al., 2002b) will be adapted and used. The study area will be the Mae Sa watershed (138 km2), which includes the Mae Sa Noi subcatchment where B2 carried out detailed investigations during the last two phases. The specific focus of the subproject will be the parameterization and calibration of the SWAT model and its integration into the model network of the SFB. The SFB database has been established and can be used for model parameterization. In addition, high-quality geo-data are available from the Geoinformatic and Space Technology Development Agency (GISTDA) in Chiang Mai. For model calibration, discharge measurements are available for the Mae Sa Noi subcatchment (12 km2) and for the neighboring Mae Nai subcatchment (18 km2). To collect data on the Mae Sa watershed discharge, at the very beginning of the third phase gauging stations will be established in a midstream position and at the outlet of the watershed. Pesticide fluxes will be measured at each gauging station as well as in the Mae Sa Noi subcatchment, where B2.2 has operated two flumes equipped with automatic discharge-proportional water samplers since 2004. Rainfall distribution and intensity will be monitored with a net of automatic rain gauges. Hydrograph separation will be performed using soil and river temperatures (Kobayashi et al., 1999). Within the watershed temperature loggers will be installed at different soil depths to measure the temperature of the different discharge components. Already at the beginning of the second year of the third phase we will start to couple the SWAT model with land use and farm household models of the SFB and to use the model to assess the effect of land use and land management changes on the loss of pesticides to surface waters.

B 2: Lateral water flow and transport of agrochemicals - Phase 1

Das Projekt "B 2: Lateral water flow and transport of agrochemicals - Phase 1" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Bodenkunde und Standortslehre durchgeführt. The project aims at developing a model of the dynamics of agrochemicals (fertilisers, pesticides) and selected heavy metals on a regional scale as a function of cropping intensity in the highland areas of Northern Thailand. The model shall predict the effects of cropping intensity on mobility and leaching of agrochemicals in the agriculturally used system itself but also on the chemical status of neighbouring ecosystems including downstream areas. The methods for measuring and estimating the fluxes of agrochemicals in soils will be adapted to the conditions of the soils and sites in Northern Thailand. Fluxes of agrochemicals will be measured in fruit tree orchards on the experimental sites established together with projects B1, C1 and D1. Also, processes governing the dynamics of agrochemicals will be studied. The objectives for the first phase are as follows: - To identify suitable study sites - To establish the methods for measuring the fluxes of agrochemicals in the study sites - To adopt the analytical procedures for pesticides - To identify and parametrise the processes governing the mobility of agrochemicals - To identify the major chemical transformation processes for agrochemicals in the soils of the project area - To establish models of the fate of agrochemicals an the plot scale. Dynamics of agrochemicals include processes of mobilisation/immobilisation, degradation and transport. Both, experiments and field inventories are needed to elucidate the complex interaction of the various processes. Field measurements of the fluxes of nutrient elements (N, P, K, Ca, Mg, Mn, Zn, Cu), pesticides and some heavy metals will be conducted at different regional scales (plot, agricultural system, small catchment, region). Laboratory and field experiments consider chemical, physicochemical and biological processes. Biological processes and degradation of pesticides will not be considered in the first phase of the project, however, they should be included later on. The project as a whole is broken down into three essential parts, which consecutively follow each other. The subproject is methods- and processes-orientated. Methods, which were developed in Hohenheim to quantify the fluxes of chemicals in soils have to be adapted to meet the requirements of the specific conditions in the study area. Recently, these methods are already under development in tropical environments (Vietnam, Costa Rica). After adaptation the methods will be used to yield flux data on the plot scale. These data are needed to help deciding which of the hypothesised processes are of major importance for modelling the dynamics of agrochemicals. The final outcome of this project phase are models of the fate of agrochemicals as a function of management intensity on the plot scale.

Forest management in the Earth system

Das Projekt "Forest management in the Earth system" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für Meteorologie durchgeführt. The majority of the worlds forests has undergone some form of management, such as clear-cut or thinning. This management has direct relevance for global climate: Studies estimate that forest management emissions add a third to those from deforestation, while enhanced productivity in managed forests increases the capacity of the terrestrial biosphere to act as a sink for carbon dioxide emissions. However, uncertainties in the assessment of these fluxes are large. Moreover, forests influence climate also by altering the energy and water balance of the land surface. In many regions of historical deforestation, such biogeophysical effects have substantially counteracted warming due to carbon dioxide emissions. However, the effect of management on biogeophysical effects is largely unknown beyond local case studies. While the effects of climate on forest productivity is well established in forestry models, the effects of forest management on climate is less understood. Closing this feedback cycle is crucial to understand the driving forces behind past climate changes to be able to predict future climate responses and thus the required effort to adapt to it or avert it. To investigate the role of forest management in the climate system I propose to integrate a forest management module into a comprehensive Earth system model. The resulting model will be able to simultaneously address both directions of the interactions between climate and the managed land surface. My proposed work includes model development and implementation for key forest management processes, determining the growth and stock of living biomass, soil carbon cycle, and biophysical land surface properties. With this unique tool I will be able to improve estimates of terrestrial carbon source and sink terms and to assess the susceptibility of past and future climate to combined carbon cycle and biophysical effects of forest management. Furthermore, representing feedbacks between forest management and climate in a global climate model could advance efforts to combat climate change. Changes in forest management are inevitable to adapt to future climate change. In this process, is it possible to identify win-win strategies for which local management changes do not only help adaptation, but at the same time mitigate global warming by presenting favorable effects on climate? The proposed work opens a range of long-term research paths, with the aim of strengthening the climate perspective in the economic considerations of forest management and helping to improve local decisionmaking with respect to adaptation and mitigation.

AURORa - Investigation of the Radar Backscatter of Rain Impinging on the Ocean Surface

Das Projekt "AURORa - Investigation of the Radar Backscatter of Rain Impinging on the Ocean Surface" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Zentrum für Meeres- und Klimaforschung, Institut für Meereskunde (IfM) durchgeführt. Over land, observations of rain rates are more or less operational. To obtain information about precipitation at the coastal zones, weather radars are used. However, over the oceans, especially away from the main shipping routes, no direct precipitation measurements are performed. In these regions, satellite data can provide information about precipitation events. Satellites deploying passive and active microwave sensors can operate independently of cloud cover and time of day. Passive microwave sensors give crude estimates of rain rates over large areas but cannot resolve small-scale rain events of short duration as are often observed in the tropics, for example. Active microwave sensors with high resolutions, such as synthetic aperture radars can provide more reliable information. Though the effect of rain on the atmosphere is a very topical area of research, the radar backscattering mechanisms at the water surface during rain events combined with wind are still not well understood. The purpose of this project is to investigate the radar backscattering from the water surface in the presence of rain and wind in order to interpret satellite radar data produced by active microwave sensors. Furthermore, the results should be embedded into models of the radar backscattering from the water surface to allow for estimating rain rates by using satellite data. Research topics: Rain impinging on a water surfaces generates splash products including crowns, cavities, stalks and secondary drops, which do not propagate, and ring waves and subsurface turbulence. We are investigating this phenomena at the wind-wave tank of the University of Hamburg. The tank is fitted with an artificial rain simulator of 2.3 m2 area mounted 4.5 m over the water surface. Rain drops of 2.1 and 2.9 mm in diameter with rain rates up to 100 mm/h have been produced. Wind with speeds 10 m/s and monomolecular slicks act on the water surface. The influence of the rain on the water surface is measured with a resistance type wire gauge, a two dimensional laser slope gauge and an coherent 9.8 GHz (x band) continuous wave scatterometer operating at VV-, HH- and HV-polarization. The influence of rain below the water surface is measured with colored raindrops which are observed with a video camera to investigate the turbulent motion and the depth of the mixed layer. At the North Sea Port of Buesum in Germany, a scatterometer operating at all polarizations and five frequencies will be mounted during summer of this year. The radar backscatter of the sea surface during rain events will be measured in combination with meteorological observations. With help of these measurements, existing radar backscatter models of the water surface will be improved for the presence of rain events. To validate the improved models, ERS-2 SAR-images will be compared with weather radar data.

C3: Market inclusion of ecosystem services: A viable option to achieve sustainable land use in the tropics?

Das Projekt "C3: Market inclusion of ecosystem services: A viable option to achieve sustainable land use in the tropics?" wird vom Umweltbundesamt gefördert und von Technische Universität München, Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt, Fachgebiet für Waldinventur und nachhaltige Nutzung durchgeführt. The concept of ecosystem services (ES) links ecosystem functioning and human wel-fare to achieve sustainable land use. However, the success of this concept will critically depend on sources to finance the provision of ES (possibly mobilized by means of markets for ES), on credibility of ES values and on willingness of ES providers to ac-cept financial compensation. Our proposal addresses these aspects: The first part investigates how the land use in Ecuador would change if ES were actually acknowl-edged as economic values. We will use and develop a risk sensitive economic modeling approach to integrate the uncertainty of expected economic values for ES. The aim is to explore how the uncertainty of ES values would affect investments into specific ecosystem types and the connected conversion processes from tropical forest lands to other land use types and vice versa. The second proposal part investigates the willing-ness to accept financial compensation for providing ES. In this part we adapt a risk-sensitive bioeconomic farm model that combines various productive but sustainable land management options to real farm situations. The farm level modeling builds upon the effects of risk compensation from diversified land use by means of a land use port-folio approach. It will be used to derive acceptable individual and thus effective conser-vation payments.

Energy Storage for Direct Steam Solar Power Plants (DISTOR)

Das Projekt "Energy Storage for Direct Steam Solar Power Plants (DISTOR)" wird vom Umweltbundesamt gefördert und von Deutsches Zentrum für Luft- und Raumfahrt e.V., Institut für Technische Thermodynamik durchgeführt. Objective: Solar thermal power plants represent today's most economic systems to generate electricity from solar insulation in them-range in regions like the Mediterranean area. By demonstrating the feasibility of direct steam generation in the absorber pipes European industry and research institutions have gained a leading position in this technology area. A key element foray successful market penetration is the availability of storage systems to reduce the dependence on the course of solarinsolation. The most important benefits result from -reduced internal costs due to increased efficiency and extended utilisation of the power block-facilitating the integration of a solar power plant into an electrical grid-adoption of electricity production to the demand thus increasing revenues Efficient storage systems for steam power plants demand transfer of energy during the charging/discharging process at constant temperatures. The DISTOR project focuses on the development of systems using phase change materials (PCM) as storage media. In order to accelerate the development, the DISTOR project is based on parallel research on three different storage concepts. These concepts include innovative aspects like encapsulated PCM, evaporation heat transfer and new design concepts. This parallel approach takes advantage of synergy effects and will enable the identification of the most promising storage concept. A consortium covering the various aspects of design and manufacturing has been formed from manufacturers, engineering companies and research institutions experienced in solar thermal power plants and PCM technology. The project will provide advanced storage material based on PCM for the temperature range of 200-300 C adapted to the needs of Direct Steam generation thus expanding Europe's strong position in solar thermal power plants.

Is the immune system required to adapt to flowering time change?

Das Projekt "Is the immune system required to adapt to flowering time change?" wird vom Umweltbundesamt gefördert und von Universität Köln, Biozentrum, Botanisches Institut durchgeführt. For effective crop improvement, breeders must be able to select on relevant phenotypic traits without compromising yield. This project proposes to investigate the evolutionary consequences of flowering time modifications on a second trait of major importance for plant breeding: immunity. This will have implications both for understanding cross-talks between flowering time and defense network and for developing efficient breeding strategies. There is clear evidence that plant maturity influences levels and effectiveness of defense. Theoretical models actually predict that changes in life-history can modulate the balance between costs and benefits of immunity. Simultaneously, actors of the immune system have often been observed to alter flowering time. Two alternative and possibly complementary hypotheses can explain this link: genetic constraints due to the pleiotropic action of players in either systems, or co-evolution, if flowering-time changes modulate the cost-benefit balance of immunity. We will conduct field assays in Arabidopsis thaliana, using constructed lines as well as recombinant inbred lines and natural accessions, to differentiate the action of the two explanatory hypotheses. Using transcriptome analyses, we will identify defense genes associating with flowering time modification (f-t-a defense genes). We will quantify their expression along the assay and test whether it varies with both flowering time and fitness. We will further test whether flowering time and immunity interact to determine yield in tomato and potato.

E 1.2: Multi-layer drying models for optimising high value crop drying in small scale food industries

Das Projekt "E 1.2: Multi-layer drying models for optimising high value crop drying in small scale food industries" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Agrartechnik, Fachgebiet Agrartechnik in den Tropen und Subtropen durchgeführt. Fruit tree cultivation is a suitable option for erosion control in mountainous regions of Southeast Asia. However, seasonal overproduction and insufficient access to markets can cause economic losses. The possibility of processing fruits locally could contribute considerably to increase and stabilize farm income. Currently, fruit drying methods in these areas are yielding products of inferior quality. Pre-treatments such as sulphurizing are commonly used, but can make the product undesirable for international markets. In addition, high energy requirements increase production costs significantly. Therefore, the objective of subproject E1.2 is to optimize the drying process of small-scale fruit processing industries in terms of dryer capacity, energy consumption and efficiency and end product quality. During SFB-phase II in E1.1, drying fundamentals for the key fruits mango, litchi and longan were established. In laboratory experiments, impacts of drying parameters on quality were investigated and numerical single-layer models for simulation of drying kinetics have been designed. In SFB-phase III this knowledge will be expanded with the aim of optimizing practical drying processes. Therefore, the single-layer models will be extended to multi-layer models for simulating bulk-drying conditions. The Finite Element Method (FEM) will be adapted to calculate heat and mass transfer processes. Thermodynamic behavior of batch and tray dryers will be simulated using Computational Fluid Dynamics (CFD) software. Drying facilities will be optimized by systematic parameter variation. For reduction of energy costs, the potential of solar energy and biomass will be investigated in particular. Further research approaches are resulting from cooperation with other subprojects. A mechanic-enzymatic peeling method will be jointly used with E2.3 for studying the drying behavior of peeled litchi and longan fruits. Furthermore, a fruit maturity sensor based on Acoustic Resonance Spectroscopy (ARS) will be developed in cooperation with E2.3 and B3.2. Finally, an internet platform will be built for exchange of farmer-processor information about harvest time and quantities to increase utilization of the processing facilities.

B 3.1: Efficient water use of mixed cropping systems in watersheds of Northern Thailand highlands

Das Projekt "B 3.1: Efficient water use of mixed cropping systems in watersheds of Northern Thailand highlands" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Kulturpflanzenwissenschaften (340), Fachgebiet Düngung und Bodenstoffhaushalt (340i) durchgeführt. Worldwide an important part of agricultural added value is produced under irrigation. By irrigation unproductive areas can be cultivated, additional harvests can be obtained or different crops can be planted. Since its introduction into Northern Thailand lychee has developed as one of the dominating cash crops. Lychee is produced in the hillside areas and has to be irrigated during the dry season, which is the main yield-forming period. Water therefore is mainly taken from sources or streams in the mountain forests. As nowadays all the available resources are being used do to increased production, a further increase in production can only be achieved by increasing the water use efficiency. In recent years, partial root-zone drying has become a well-established irrigation technique in wine growing areas. In a ten to fifteen days rhythm one part of the root system is irrigated while the other dries out and produces abscisic acid (ABA) a drought stress hormone. While the vegetative growth and thus labor for pruning is reduced, the generative growth remains widely unaffected. Thereby water-use efficiency can be increased by more than 40Prozent. In this sub-project the PRD-technique as well as other deficit irrigation strategies shall be applied in lychee and mango orchards and its effects on plant growth and yield shall be analyzed. Especially effects of this water-saving technology on the nutrient balance shall be considered, in order to develop an optimized fertigation strategy with respect to yield and fruit quality. As shown in preliminary studies, the nutrient supply is low in soils and fruit trees in Northern Thailand (e.g. phosphate) and even deficient for both micronutrients boron (B) and zinc (Zn). Additionally, non-adapted supply of nitrogen (mineralization, fertilization) can induce uneven flowering and fruit set. Therefore, improvement is necessary. For a better understanding of possible influence of low B and Zn supply on flowering and fruit set, mobility and retranslocation of both micronutrients shall be investigated for mango and lychee. Finally, the intended system of partial root-zone fertigation (PRF) shall guarantee an even flowering and a better yield formation under improved use of the limited resource water. As this modern technique, which requires a higher level of irrigation-technology, cannot be immediately spread among the farmers in the region, in a parallel approach potential users shall be integrated in a participative process for adaptation and development. Water transport and irrigation shall be considered, as both factors offer a tremendous potential for water saving. Local knowledge shall be integrated in the participatory process (supported by subproject A1.2, Participatory Research) in order to finally offer adapted technologies for application within PRF systems for the different conditions of farmers in the hillsides of Northern Thailand.

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