The aim of P2 within the Research Unit 'The Forgotten Part of Carbon Cycling: Organic Matter Storage and Turnover in Subsoils (SUBSOM)' is to contribute to the understanding of the different sources and stabilization processes of subsoil organic matter. This will be achieved by the analysis of the soil organic matter composition in topsoil versus subsoil by 13C NMR spectroscopy in bulk soils as well as organo-mineral associations. This will be done on a number of soil profiles differing in parent material and mineralogy and therefore also in the relevance of organo-mineral associations for subsoil C stabilization. In addition, a specific sampling approach will allow to differentiate three zones associated with the dominating effect of (1) leaching of DOC (the 'bulk soil' between trees), (2) root litter decomposition (the 'root-affected zone'), and (3) direct rhizodeposition of root exudates (the 'rhizosphere' sensu strictu). The contribution of above-ground versus below-ground litter is differentiated by the analysis of cutin and suberin biomarkers. Organic matter derived from microbial sources will be identified by the microbial signature of polysaccharides in the subsoil through the analysis of neutral sugars and amino sugars. Organo-mineral associations will be further characterized by N2-BET analyses to delineate the coverage of the mineral phase with organic matter. With these analyses and our specific analytical expertise at the submicron scale (nanoSIMS) we will participate in selected joint experiments of the research unit.
The present-day configuration of Indonesia and SE Asia is the results of a long history of tectonic movements, volcanisms and global eustatic sea-level changes. Not indifferent to these dynamics, fauna and flora have been evolving and dispersing following a complicate pattern of continent-sea changes to form what are today defined as Sundaland and Wallacea biogeographical regions. The modern intraannual climate of Indonesia is generally described as tropical, seasonally wet with seasonal reversals of prevailing low-level winds (Asian-Australian monsoon). However at the interannual scale a range of influences operating over varying time scales affect the local climate in respect of temporal and spatial distribution of rainfall. Vegetation generally reflects climate and to simplify it is possible to distinguish three main ecological elements in the flora of Malaysia: everwet tropical, seasonally dry tropical (monsoon) and montane. Within those major ecological groups, a wide range of specific local conditions caused a complex biogeography which has and still attract the attention of botanists and biogeographers worldwide. Being one of the richest regions in the Worlds in terms of species endemism and biodiversity, Indonesia has recently gone through intensive transformation of previously rural/natural lands for intensive agriculture (oil palm, rubber, cocoa plantations and rice fields). Climate change represents an additional stress. Projected climate changes in the region include strengthening of monsoon circulation and increase in the frequency and magnitude of extreme rainfall and drought events. The ecological consequences of these scenarios are hard to predict. Within the context of sustainable management of conservation areas and agro-landscapes, Holocene palaeoecological and palynological studies provide a valuable contribution by showing how the natural vegetation present at the location has changed as a consequence of climate variability in the long-term (e.g. the Mid-Holocene moisture maximum, the modern ENSO onset, Little Ice Age etc.). The final aim of my PhD research is to compare the Holocene history of Jambi province and Central Sulawesi. In particular: - Reconstructing past vegetation, plant diversity and climate dynamics in the two study areas Jambi (Sumatra) and Lore Lindu National Park (Sulawesi) - Comparing the ecological responses of lowland monsoon swampy rainforest (Sumatra) and everwet montane rainforests (Sulawesi) to environmental variability (vulnerability/resilience) - Investigating the history of human impact on the landscape (shifting cultivation, slash and burn, crop cultivation, rubber and palm oil plantation) - Assessing the impact and role of droughts (El Niño) and fires - Adding a historical perspective to the evaluation of current and future changes.
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.
Objectives: Sustainable management of tropical moist forests through private forest owners will become increasingly important. Media report that in Brazil, particularly in Amazonia, approx. 80 percent of the timber harvested is from illegal sources. Private management of forests according to internationally acknowledged standards offers an opportunity to significantly lower the portion of illegally cut timber. Moreover, it contributes significantly to the conservation of the Amazon forest. Private forest owners show a clear long-term commitment towards the implementation of management standards according that is ecologically compatible, socially acceptable and economically viable. The project area, a pristine forest in legal Amazonia in the transition zone between moist tropical forests and savannas (cerrado), is extremely diverse in floristic and faunistic terms. The institute cooperates with the private forest owner. Main tasks are to document the faunistic and floristic diversity, to calculate the Annual Allowable Cut and to elaborate concepts for site-specific silviculture. Results: To date (Oct. 2006) the following activities were started: - a comprehensive inventory system for planning at the FMU-level has been successfully introduced; - the inventory system for the annual coupe area has been designed and data for the first coupe are being processed; - the annual allowable cut is currently calculated based on the results of the above described inventories; - two fauna surveys are completed; one focusing on large mammals and one on the avi-fauna. A long-term monitoring concept to assess the influence of forest management on the faunistic diversity is currently under development; - forest zoning is completed applying terrestrial surveys and interpreting high-resolution satellite images; - a study on the use of Bethollethia excelsa-fruits (Brazil nuts) is currently implemented; - a study on timber properties of lesser known species is currently implemented.
This project is aimed at the characterization of the systemic reprogramming in barley, which modulates the compatible interaction with the biotrophic leaf pathogen Blumeria graminis f.sp. hordei upon root infestation with the mutualistic endophyte Piriformospora indica. We have recently shown that the basidiomycete P. indica - upon successful establishment in the roots - reprograms barley to salt stress tolerance, resistance to root diseases and higher yield (Waller et al., 2005). Successful powdery mildew infections in barley leaves are also disturbed by the mutualistic fungus. These processes are associated with a strong change in plant metabolism, especially with a drastic alteration of leaf and root antioxidants. On the basis of these findings we will perform an in-depth analysis of the barley metabolome (B6) and transcriptome (B7) with two specific foci: First, to elucidate the process of establishment of the mutualistic fungus within the barley roots; second, to characterize elements of the systemic response in leaves leading to an interruption or failure of compatibility processes required for successful establishment of biotrophic leaf pathogens like Blumeria. New gene candidates will be pre-selected systematically for their regulatory role in compatibility by means of transiently transformed barley leaves upon Blumeria inoculation. Stable transgenic barley and maize lines (B3) generated with verified gene candidates and genes identified by other projects (A1, A2, B5, B6) will be tested with Blumeria and P. indica. By comparing candidate genes in the different plant - microbe systems, we will identify common regulatory processes, metabolites and metabolic networks implicated in compatibility including those required for successful interactions with mutualistic fungi.
The biogeochemical interface (BGI) in this project is defined as the organo-mineral surface of soil particles colonized by microorganisms. In the preceding project it was demonstrated that the different soil particle size fractions were associated with specifically structured microbial communities, a characteristic amount of soil organic carbon, and a specific capacity for adsorption of the organic chemicals phenol and 2,4-dichlorophenol, respectively. While the diversity of the microbial community was responsive to fertilization-determined additional organic soil carbon in the larger particle size fractions, it was unaffected in clay. Stable isotope probing with 13C-labelled phenol and 2,4-dichlorophenol revealed that the soil organic carbon in the BGIs also affected the diversity of microorganisms involved in the degradation of these chemicals. All these results are yet only based on studying one soil with three organic carbon variants (Bad Lauchstädt) and only two organic compounds. The objective of this 2nd phase project is to apply the innovative technology developed in the 1st phase for studying the BGI processes with soil organic carbon variants from another soil (Ultuna, SPP 1315 site) and with the chiralic anilide Fungicide metalaxyl as an additional compound. This 2nd phase SPP 1315 project will also, in a collaborative effort with two other SPP 1315 partners, investigate (1) the importance of BGIs for the entantio-selective degradation of metalaxyl and (2) the role of soil microorganisms in the formation of bound residues, respectively. Furthermore, the project will utilize stable isotope probing and next-generation DNA sequencing to link the structural and functional diversity of the microbial communities responsible for metabolism of organic chemicals in the different BGIs determined by particle size fractions and soil organic carbon variants.
Die temperatur- und feuchteabhängige Eisnukleationseffizlenz von verschiedenen Aerosolen kann in Laborexperimenten genau charakterisiert und für die Beschreibung von primärer Eisbildung in numerischen Modellen auf verschiedensten Skalen parametrisiert werden. Wenn diese Effizienten als bekannt vorausgesetzt werden, unter welchen Bedingungen und wie oft tritt heterogene Eisnukleation in den verschiedenen Nukleationsmoden tatsächlich in typischen Mischphasenwolken auf? Dieser Frage wird in diesem Projekt mit dem Modell ICON-LES (der Large Eddy Version des neuen icosahedrischen nichthydrostatischen Modells, welches zurzeit am Deutschen Wetterdienst und dem Max-Planck-Institut für Meteorologie in Hamburg entwickelt wird) nachgegangen. Dieses Modell enthält ein Zwei-Momenten-Wolkenphysikschema und wird durch aerosolspezifische Eisnukleationsparameterisierungen ergänzt werden. Zusätzlich wird eine einfache Diagnostik von Aerosolen in Wolkentropfen eingeführt, um zwischen potentiellen Immersionseiskeimen und interstitiellen eisnukleierenden Partikeln, die als Kontakt- oder Depositionseiskeime dienen können, zu unterscheiden. In idealisierten Simulationen von verschiedenen Mischphasenwolkentypen, die in Europa häufig auftreten (Winternebel, Altostratus, orographische Wolken, hochreichende Konvektion) und unter Benutzung von klimatologischen Aerosolfeldern wird das Auftreten von Immersions-, Depositions- und Kontaktgefrieren und die Werte der Eiskeimkonzentrationen statistisch ausgewertet und mit den Sensitivitätsbereichen der INUIT Labor- und Feldmessgeräten verglichen. Zusätzlich wird das bevorzugte räumliche Auftreten dieser Prozesse (z. B. Kontaktgefrieren in den Einmischbereichen an den Wolkenrändern) analysiert und quantifiziert werden. Das Modellsetup für die Fallstudie der konvektiven Wolke wird mit RP3 abgestimmt, so dass ein Vergleich zwischen dem spektralen und dem Zwei-Momenten- Mikrophysikschema möglich ist. Außerdem wird in diesem Projekt zusammen mit WP-F und WP-L eine Schließungsstudie für die Messungen in der Mittelmeerkampagne durchgeführt. Dabei wird untersucht, welche Parameter zu den größten Unsicherheiten in der Vorwärtsberechnung von potentiellen Eiskeimen führen.
Magnetic properties of ferrimagnetic minerals depend on their crystal lattice, anisotropy, chemical composition and grain size. The latter parameter is strongly controlled by microstructures, which are significant for the interpretation of the magnetic properties of shocked magnetic minerals. Fracturing and lattice defects are the main causes for magnetic domain size reduction and generate an increase in coercivity and the suppression of magnetic transitions (e.g. 34 K transition in pyrrhotite, Verwey transition in magnetite).Especially for an adequate investigation of shock-induced modifications in ferromagnetic minerals, a combination of microstructural and magnetic measurements is therefore essential.This project focusses on two significant aspects of extreme conditions - the consequence of shock waves on natural material on Earth and on the magnetic mineralogy of exotic magnetic minerals in iron meteorites. In order to obtain general correlations between deformation structures and magnetic properties, the specific magnetic properties and carriers as well as microstructures of samples from two impact structures in marine targets (Lockne and Chesapeake Bay) will be compared with shocked magnetite ore and magnetite-bearing target lithologies from outside the crater (Lockne) as well as from undeformed megablocks within the crater (Chesapeake Bay). We will test the hypothesis if shock-related microstructures and associated magnetic properties can significantly be overprinted by postshock hydrothermal alteration. We especially want to focus on the Verwey transition (TV) as lower TVs are described for shocked impact lithologies. Hence, the main focus of this study lies on magneto-mineralogical investigations which combine low- and high-temperature magnetic susceptibility and saturation isothermal remanent magnetization with mineralogical and microstructural investigations. The same methods will then be used for the investigation of iron meteorites, whose magnetic properties are often controled by exotic magnetic minerals like cohenite, schreibersite and daubreelite in addition to the metal phases. Magnetic transition temperatures of those phases are poorly documented in relation to their chemical composition as well as to their crystallographic and microstructural configuration. For a general understanding of shock-related magnetization processes in extraterrestrial and terrestrial material, however, it is crucial to obtain a general correlation between the initial 'unshocked' state and the subsequent shock- and alteration-related overprints.
The classical point wise Cornell-McGuire probabilistic seismic hazard assessment (PSHA), which is widely used for seismic hazard mapping and development of design codes, does not allow direct estimation of multiple-location hazard for distributed structures and facilities: what is the (annual) probability that specific level of ground motion will be exceeded simultaneously in several sites? It is possible to extent the classical methodology to the multiple sites problem considering also ground-motion correlation. We study multiple-location PSHA, as compared with the classical point wise PSHA, using Monte Carlo simulation. Specific items are:(1) Development of the algorithms for multiple-location PSHA;(2) Analysis of the role of the geometry of multiple sites, correlation of ground motion, and evel of seimicity for multiple-location PSHA;(3) Study of correspondence and differences between multiple-location PSHA and classical point wise PSHA and analysis of possibility of utilization of classical PSHA procedures for simplified multiple-location hazard assessment.The project is innovative because only few attempts have been made so far regarding our research questions.
Changes in agroecosystem management (e.g. landscape diversity, management intensity) affect the natural control of pests. The effects of agricultural change on this ecosystem service, however, are not universal and the mechanisms affecting it remain to be understood. As biological control is effectively the product of networks of interactions between pests and their natural enemies, food web analysis provides a versatile tool to address this gap of knowledge. The proposed project will utilize a molecular food web approach and examine, for the first time, how changes in plant fertilisation and landscape complexity affect quantitative aphid-parasitoid-hyperparasitoid food webs on a species-specific level to unravel how changes in food web interactions affect parasitoid aphid control. Based on the fieldderived data, cage experiments will be conducted to assess how parasitoid diversity and identity affect parasitoid interactions and pest control, complementing the field results. The work proposed here will take research on parasitoid aphid control one step further, as it will provide a clearer understanding of how plant fertilization affects whole aphid-parasitoid food webs in both simple and complex landscapes, allowing for further improvements in natural pest control.
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