Comprehension of belowground competition between plant species is a central part in understanding the complex interactions in intercropped agricultural systems, between crops and weeds as well as in natural ecosystems. So far, no simple and rapid method for species discrimination of roots in the soil exists. We will be developing a method for root discrimination of various species based on Fourier Transform Infrared (FTIR)-Attenuated Total Reflexion (ATR) Spectroscopy and expanding its application to the field. The absorbance patterns of FTIR-ATR spectra represent the chemical sample composition like an individual fingerprint. By means of multivariate methods, spectra will be grouped according to spectral and chemical similarity in order to achieve species discrimination. We will investigate pea and oat roots as well as maize and barnyard grass roots using various cultivars/proveniences grown in the greenhouse. Pea and oat are recommendable species for intercropping to achieve superior grain and protein yields in an environmentally sustainable manner. To evaluate the effects of intercropping on root distribution in the field, root segments will be measured directly at the soil profile wall using a mobile FTIR spectrometer. By extracting the main root compounds (lipids, proteins, carbohydrates) and recording their FTIR-ATR spectra as references, we will elucidate the chemical basis of species-specific differences.
In structured soils, the interaction of percolating water and reactive solutes with the soil matrix is mostly restricted to the surfaces of preferential flow paths. Flow paths, i.e., macropores, are formed by worm burrows, decayed root channels, cracks, and inter-aggregate spaces. While biopores are covered by earthworm casts and mucilage or by root residues, aggregates and cracks are often coated by soil organic matter (SOM), oxides, and clay minerals especially in the clay illuviation horizons of Luvisols. The SOM as well as the clay mineral composition and concentration strongly determine the wettability and sorption capacity of the coatings and thus control water and solute movement as well as the mass exchange between the preferential flow paths and the soil matrix. The objective of this proposal is the quantitative description of the small-scale distribution of physicochemical properties of intact structural surfaces and flow path surfaces and of their distribution in the soil volume. Samples of Bt horizons of Luvisols from Loess will be compared with those from glacial till. At intact structural surfaces prepared from soil clods, the spatial distribution (mm-scale) of SOM and clay mineral composition will be characterized with DRIFT (Diffuse reflectance infrared Fourier transform) spectroscopy using a self-developed mapping technique. For samples manually separated from coated surfaces and biopore walls, the contents of organic carbon (Corg) and the cation exchange capacity (CEC) will be analyzed and related to the intensities of specific signals in DRIFT spectra using Partial Least Square Regression (PLSR) analysis. The signal intensities of the DRIFT mapping spectra will be used to quantify the spatial distribution of Corg and CEC at these structural surfaces. The DRIFT mapping data will also be used for qualitatively characterizing the small scale distribution of the recalcitrance, humification, and microbial activity of the SOM from structural surfaces. The clay mineral composition of defined surface regions will be characterized by combining DRIFT spectroscopic with X-ray diffractometric analysis of manually separated samples. Subsequently, the spatial distribution of the clay mineral composition at structural surfaces will be determined from the intensities of clay mineral-specific signals in the DRIFT mapping spectra and exemplarily compared to scanning electron microscopic and infrared microscopic analysis of thin sections and thin polished micro-sections. The three-dimensional spatial distribution of the total structural surfaces in the volume of the Bt horizons will be quantified using X-ray computed tomography (CT) analysis of soil cores. The active preferential flow paths will be visualized and quantified by field tracer experiments. These CT and tracer data will be used to transfer the properties of the structural surfaces characterized by DRIFT mapping onto the active preferential flow paths in the Bt horizons.
Soil structure determines a large part of the spatial heterogeneity in water storage and fluxes from the plot to the hillslope scale. In recent decades important progress in hydrological research has been achieved by including soil structure in hydrological models. One of the main problems herein remains the difficulty of measuring soil structure and quantifying its influence on hydrological processes. As soil structure is very often of biogenic origin (macropores), the main objective of this project is to use the influence of bioactivity and resulting soil structures to describe and support modelling of hydrological processes at different scales. Therefore, local scale bioactivity will be linked to local infiltration patterns under varying catchment conditions. At hillslope scale, the spatial distribution of bioactivity patterns will be linked to connectivity of subsurface structures to explain subsurface stormflow generation. Then we will apply species distribution modelling of key organisms in order to extrapolate the gained knowledge to the catchment scale. As on one hand, bioactivity influences the hydrological processes, but on the other hand the species distribution also depends on soil moisture contents, including the feedbacks between bioactivity and soil hydrology is pivotal for getting reliable predictions of catchment scale hydrological behavior under land use change and climate change.
Dairy farming across Germany displays diverse production systems. Factor endowment, management, technology adoption as well as competitive dynamics in the local or regional land, agribusiness and dairy processing sectors contribute to this differentiation on farm level. These differences impact on the ability of dairy farms and regional dairy production systems to successfully respond to pressures arising from future market and policy changes. The overall objective of the research activities of which this project is a part of, is to develop a thorough understanding of the processes that govern the spatial dynamics of dairy farm development in different regions in Germany. The central hypothesis of this research project is that management system and technological choices differ systematically across local production and market conditions. The empirical approach will focus on the estimation of farm specific nonparametric cost functions for dairy farms located in across Germany differentiated by time and location. A spatially differentiated data base with information on input use, resource availability, as well as local market conditions for land and output markets will be compiled. The nonparametric approach is specifically suited to disclose a more accurate representation of dairy production system heterogeneity across locations and time compared to parametric concepts as it provides the necessary flexibility to accommodate non-linearities relevant for a wide domain of explanatory variables. The methodology employed goes beyond the state of the art of the literature as it combines kernel density estimation with a Bayesian sampling approach to provide theory consistent parameters for each farm in the data sample.The specific methodological hypothesis is that the nonparametric approach is superior to current parametric techniques and this hypothesis is tested using statistical model evaluation. Regarding the farm management and technological choices, we hypothesize that land suitability for feed production determines the farm intensity of dairy production and thus management and technological choices. With respect to the ability of farms to successfully respond to market pressures we hypothesize that farms at the upper and lower tail of the intensity distribution both can generate positive returns from dairy production. These last two hypotheses will be tested using the estimated spatially differentiated farm specific costs and marginal costs.The expected outcomes are of relevance for the agricultural sector and the food supply chain economy as a whole as fundamental market structure changes in the dairy sector are ongoing due to the abolition of the quota regulation in the years 2014/2015. Thus, exact knowledge about differences and development of dairy cost heterogeneity of farms within and between regions are an important factor for the actors involved in the market as well as the political support of this process.
Populations of P. fortinii from allover Europe are examined using microsatellites to construct gene genealogies and infer evolutionary history. The tree-root endophyte Phialocephala fortinii s.l. (mitosporic Ascomycota) is the dominant colonizer of conifer root systems in forests in the northern hemisphere. P. fortinii s.l. is genetically highly diverse and forms a complex of several cryptic species. Recombination occurs or has occurred within cryptic species and to some extent also among them (introgression). Cryptic species occur sympatrically and they can form large thalli, but it remains unclear whether the observed patterns of spatial distribution reflect local climax situations or are the results of recent gene and genotype flow. One of the key objectives will be to estimate population genetic parameters (eg. migration rates, genotype flow, recombination) within and among populations of cryptic species in forests where man-mediated genotype flow can be excluded. Other key objectives are the determination of the number, frequency, distribution and evolutionary history of the cryptic species in Europe and to identify the driving forces for speciation. The approach will be multidisciplinary and will include standard mycological and microbiological methods as well as molecular genetic techniques such as microsatellite fingerprinting and DNA sequencing. The evolutionary history of haplotypes at both the population and species level will be reconstructed and the results will be compared with known patterns of pleistocenic glaciations and postglacial recolonization of host trees. The project will be a significant contribution to the understanding of the population and evolutionary genetics of a versatile and ecologically extremely successful fungal genus and it will shed light on the effects of pleistocenic and postglacial climatic changes on fungal speciation.
Introduction: In Malaysia, excessive nutrients from livestock waste management systems are currently released to the environment. Particularly, large amounts of manure from intensive pig production areas are being excreted daily and are not being fully utilised. Alternatively, the excess manure can be applied as an organic fertiliser source in neighbouring cropping systems on the small landholdings of the pig farms to improve soil fertility so that its nutrients will be available for crop uptake instead of being discharged into water streams. Thus, there is a need for better tools to analyse the present situation, to evaluate and monitor alternative livestock production systems and manure management scenarios, and to support farmers in the proper management of manure and fertiliser application. Such tools are essential to quantify, and assess nutrient fluxes, manure quality and content, manure storage and application rate to the land as well as its environmental effects. Several computer models of animal waste management systems to assist producers and authorities are now available. However, it is felt that more development is needed to adopt such models to the humid tropics and conditions of Malaysia and other developing countries in the region. Objectives: The aim is to develop a novel model to evaluate nutrient emission scenarios and the impact of livestock waste at the landscape or regional level in humid tropics. The study will link and improve existing models to evaluate emission of N to the atmosphere, and leaching of nutrients to groundwater and surface water. The simulation outputs of the models will be integrated with a GIS spatial analysis to model the distribution of nutrient emission, leaching and appropriate manure application on neighbouring crop lands and as an information and decision support tool for the relevant users.
Neue Befunde zeigen, dass die Umsetzung von organischem Material durch Bakterioneuston in marinen Oberflächenfilmen (engl. sea-surface microlayer, SML) eine Rolle spielen, bei der Kontrolle des Flusses von klimarelevanten Spurengasen, sowie bei der Speicherung von anthropogenen Ablagerungen aus der Atmosphäre. Unsere früheren Untersuchungen weisen auf die Bedeutung der bakteriellen Aktivität bzgl. des Kohlenstoffzyklus in der SML hin, heben aber auch die vielen unbekannten Einflüsse des Bakterioneuston in der SML hervor. Besonders photochemische Umwandlung von organischem Material, in Verbindung mit schädlichen Effekten durch Sonnenstrahlung auf die Bakterien in der SML, wurden bisher nicht detailliert untersucht. Demzufolge besteht unsere Motivation für das vorgeschlagene Projekt darin, das Wissen über Stoffwechselprozesse und Anpassungen von Bakterien in der SML in ihrer Gesamtheit, aber auch auf Einzelzell- und Stammebene, in Bezug auf physikalische und chemische Variabilität in dieser Grenzschicht zu untersuchen. Des Weiteren ist das Zooplankton eine wichtige Komponente für die Verbindung zwischen Phytoplankton, Bakterien und den höheren Ebenen des Nahrungsnetzes in der SML, wobei auch hier für das Verständnis relevante Daten fehlen. Daher werden wir im Rahmen des Projektes zum ersten Mal Studien zur Verbreitung des Zooplanktons sowie zu dessen Fressverhalten in der SML der Nordsee durchführen.
Ziel des Projektes ist eine Bestandsaufnahme der Wassermassenverteilung und der Zirkulation im Arktischen Ozean. Stabile Sauerstoffisotopen (delta18O) des Wassers ist ein konservativer Tracer und werden zusammen mit hydrochemischen Daten dazu verwendet das vom Schelf stammende Süßwasser (Flusswasser und Meereis-Schmelze oder Bildung) und die aus dem Pazifik stammende Komponente zu untersuchen. Auf diese Weise wird der Einfluss dieser Wassermassen in der arktischen Salzgehaltsschichtung (Halokline), dem Atlantischen Zwischenwasser und dem Tiefen- und Bodenwasser des Arktischen Ozeans quantifiziert werden. Es ist bekannt, dass die Verteilung der Pazifischen Komponente starken Veränderungen auf dekadischen Zeitskalen unterliegt aber auch in den Süßwasserverteilungen im Transpolaren Drift Strom wurden 2007 starke Variationen beobachtet welche somit auf zusätzliche jährliche Variationen hinweisen. Es ist nicht bekannt ob die 2007 beobachteten Variationen ein permanentes Phänomen sind und ob diese mit dem weitgehenden Fehlen des Pazifischen Wassers in diesem Zeitraum zusammenhängen. Die geplante flächendeckende und quantitative Erfassung der Süßwasserverteilung und des Pazifischen Wassers werden daher dazu beitragen, den Einfluss und die möglichen Rückkopplungsmechanismen der arktischen Hydrographie auf den arktischen und globalen Klimawandel weitergehend zu verstehen.
Methane (CH4) is a major greenhouse gas of which the atmospheric concentration has more than doubled since pre-industrial times. Soils can act as both, source and sink for atmospheric CH4, while upland forest soils generally act as CH4 consumers. Oxidation rates depend on factors influenced by the climate like soil temperature and soil moisture but also on soil properties like soil structure, texture and chemical properties. Many of these parameters directly influence soil aeration. CH4 oxidation in soils seems to be controlled by the supply with atmospheric CH4, and thus soil aeration is a key factor. We aim to investigate the importance of soil-gas transport-processes for CH4 oxidation in forest soils from the variability the intra-site level, down to small-scale (0.1 m), using new approaches of field measurements. Further we will investigate the temporal evolution of soil CH4 consumption and the influence of environmental factors during the season. Based on previous results, we hypothesize that turbulence-driven pressure-pumping modifies the transport of CH4 into the soil, and thus, also CH4 consumption. To improve the understanding of horizontal patterns of CH4 oxidation we want to integrate the vertical dimension on the different scales using an enhanced gradient flux method. To overcome the constraints of the classical gradient method we will apply gas-diffusivity measurements in-situ using tracer gases and Finite-Element-Modeling. Similar to the geophysical technique of Electrical Resistivity Tomography we want to develop a Gas Diffusivity Tomography. This will allow to derive the three-dimensional distribution of soil gas diffusivity and methane oxidation.
Water is an intrinsic component of ecosystems acting as a key agent of lateral transport for particulate and dissolved nutrients, forcing energy transfers, triggering erosion, and driving biodiversity patterns. Given the drastic impact of land use and climate change on any of these components and the vulnerability of Ecuadorian ecosystems with regard to this global change, indicators are required that not merely describe the structural condition of ecosystems, but rather capture the functional relations and processes. This project aims at investigating a set of such functional indicators from the fields of hydrology and biogeochemistry. In particular we will investigate (1) flow regime and timing, (2) nutrient cycling and flux rates, and (3) sediment fluxes as likely indicators. For assessing flow regime and timing we will concentrate on studying stable water isotopes to estimate mean transit time distributions that are likely to be impacted by changes in rainfall patterns and land use. Hysteresis loops of nitrate concentrations and calculated flux rates will be used as functional indicators for nutrient fluxes, most likely to be altered by changes in temperature as well as by land use and management. Finally, sediment fluxes will be measured to indicate surface runoff contribution to total discharge, mainly influenced by intensity of rainfall as well as land use. Monitoring of (1) will be based on intensive sampling campaigns of stable water isotopes in stream water and precipitation, while for (2) and (3) we plan to install automatic, high temporal-resolution field analytical instruments. Based on the data obtained by this intensive, bust cost effective monitoring, we will develop the functional indicators. This also provides a solid database for process-based model development. Models that are able to simulate these indicators are needed to enable projections into the future and to investigate the resilience of Ecuadorian landscape to global change. For the intended model set up we will couple the Catchment Modeling Framework, the biogeochemical LandscapeDNDC model and semi-empirical models for aquatic diversity. Global change scenarios will then be analyzed to capture the likely reaction of functional indicators. Finally, we will contribute to the written guidelines for developing a comprehensive monitoring program for biodiversity and ecosystem functions. Right from the beginning we will cooperate with four SENESCYT companion projects and three local non-university partners to ensure that the developed monitoring program will be appreciated by locals and stakeholders. Monitoring and modelling will focus on all three research areas in the Páramo (Cajas National Park), the dry forest (Reserva Laipuna) and the tropical montane cloud forest (Reserva Biologica San Francisco).
| Organisation | Count |
|---|---|
| Bund | 245 |
| Europa | 35 |
| Land | 7 |
| Wissenschaft | 143 |
| Zivilgesellschaft | 1 |
| Type | Count |
|---|---|
| Förderprogramm | 235 |
| unbekannt | 10 |
| License | Count |
|---|---|
| Geschlossen | 1 |
| Offen | 240 |
| Unbekannt | 4 |
| Language | Count |
|---|---|
| Deutsch | 61 |
| Englisch | 221 |
| Resource type | Count |
|---|---|
| Archiv | 1 |
| Datei | 1 |
| Keine | 169 |
| Webdienst | 8 |
| Webseite | 70 |
| Topic | Count |
|---|---|
| Boden | 212 |
| Lebewesen und Lebensräume | 237 |
| Luft | 181 |
| Mensch und Umwelt | 243 |
| Wasser | 188 |
| Weitere | 245 |