Background and Objectives: The project area is located in the Ashanti Region of Ghana / West Africa in the transition zone of the moist semideciduous forest and tropical savannah zone. Main land use in this region is subsistence agriculture with large fallow areas. As an alternative land-use, forest plantations are under development by the Ghanaian wood processing company DuPaul Wood Treatment Ltd. Labourers from the surrounding villages are employed as permanent or casual plantation workers. Within three forest plantation projects of approximately 6,000 ha, DuPaul offers an area of 164 ha (referred to as Papasi Plantation) - which is mainly planted with Teak (Tectona grandis) - for research purposes. In return, the company expects consultations to improve the management for sustainable timber and pole production with exotic and native tree species. Results: In a first research approach, the Papasi Plantation was assessed in terms of vegetation classification, timber resources (in qualitative and quantitative terms) and soil and site conditions. A permanent sampling plot system was established to enable long-term monitoring of stand dynamics including observation of stand response to silvicultural treatments. Site conditions are ideally suited for Teak and some stands show exceptionally good growth performances. However, poor weed management and a lack of fire control and silvicultural management led to high mortality and poor growth performance of some stands, resulting in relative low overall growth averages. In a second step, a social baseline study was carried out in the surrounding villages and identified landowner conflicts between some villagers and DuPaul, which could be one reason for the fire damages. However, the study also revealed a general interest for collaboration in agroforestry on DuPaul land on both sides. Thirdly, a silvicultural management concept was elaborated and an improved integration of the rural population into DuPaul's forest plantation projects is already initiated. If landowner conflicts can be solved, the development of forest plantations can contribute significantly to the economic income of rural households while environmental benefits provide long-term opportunities for sustainable development of the region. Funding: GTZ supported PPP-Measure, Foundation
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.
The overarching goal of our proposal is to understand the regulation of organic carbon (OC) transfor-mation across terrestrial-aquatic interfaces from soil, to lotic and lentic waters, with emphasis on ephemeral streams. These systems considerably expand the terrestrial-aquatic interface and are thus potential sites for intensive OC-transformation. Despite the different environmental conditions of ter-restrial, semi-aquatic and aquatic sites, likely major factors for the transformation of OC at all sites are the quality of the organic matter, the supply with oxygen and nutrients and the water regime. We will target the effects of (1) OC quality and priming, (2) stream sediment properties that control the advective supply of hyporheic sediments with oxygen and nutrients, and (3) the water regime. The responses of sediment associated metabolic activities, C turn-over, C-flow in the microbial food web, and the combined transformations of terrestrial and aquatic OC will be quantified and characterized in complementary laboratory and field experiments. Analogous mesocosm experiments in terrestrial soil, ephemeral and perennial streams and pond shore will be conducted in the experimental Chicken Creek catchment. This research site is ideal due to a wide but well-defined terrestrial-aquatic transition zone and due to low background concentrations of labile organic carbon. The studies will benefit from new methodologies and techniques, including development of hyporheic flow path tubes and comparative assessment of soil and stream sediment respiration with methods from soil and aquatic sciences. We will combine tracer techniques to assess advective supply of sediments, respiration measurements, greenhouse gas flux measurements, isotope labeling, and isotope natural abundance studies. Our studies will contribute to the understanding of OC mineralization and thus CO2 emissions across terrestrial and aquatic systems. A deeper knowledge of OC-transformation in the terrestrial-aquatic interface is of high relevance for the modelling of carbon flow through landscapes and for the understanding of the global C cycle.
The South Atlantic passive margin around the landfall of the Walvis Ridge hotspot track is a unique example of continental extension, breakup and oceanic basin development, assisted or dominated by hotspot-related magmatism. There is a prime opportunity to study the variation of the magmatic signal in space and time, and investigate the interrelation with rift-related deformation. A globally significant problem to be addressed here by observation of lithospheric structure, velocity and conductivity is whether magmatism drives continental deformation and breakup, or whether even rifting with copious hot-spot related magmatism is principally in response to crustal and lithospheric stretching. The approach is to quantify thickness and extent of dipping reflector sequences and interleaved sediments, identify deep fault zones, and characterize underplated magmatic rocks near the continent-ocean transition zone from a set of new set of wide angle seismic, magnetotelluric (MT), and supplementary gravity data. The funding requested is intended to support marine surveys of the Namibian margin where it is intersected by the Walvis Ridge, and to carry out post-cruise data processing. Our new integrated approach is geared towards achieving imaging of large magmatic bodies, of sediments interleaved in dipping reflector sequences, and large, potentially fluid filled fault zones. Data integration will be achieved through joint inversion of wide angle seismic, gravity and MT data. The project is part of a coordinated amphibian geophysical campaign within the SAMPLE program.
The W-Bohemia/Vogtland region is characterized by spatially clustered swarm earthquake activity with a typical source depth of 6-12 km. Degassing of upper mantle derived fluids, correlating with seismicity, is observed as well as temporal variations in the amount and composition of the emitted gas, isotope composition, and in earthquake source processes. Evidence for fluid-controlled earthquake triggering was found from earthquake source studies and inter-event relationships. Fluid reservoirs have been proposed for the upper crust as well as for the crust-mantle transition zone, but their direct observation is still missing. Epicentres and gas springs are spatially separated and the pathways of fluids to the surface remain unresolved as are their relations to the crustal seismic structure. These features make the Eger Rift/Vogtland area a prime site for scientific drilling. In this project spatial and temporal imaging of crustal seismic structures and fluid dynamics will be achieved by various approaches. We will test the hypothetical existence of a fluid reservoir and estimate its spatial extent using seismic velocity and attenuation tomography as well as coda studies. We will measure the temporal evolution of stress and fluid dynamics giving information about changes in the upper crust during a swarm earthquake cycle. The 3D and 4D seismological models delivered by this project will constrain the decision for an optimal ICDP drilling location in the Eger Rift system.
Im Projekt soll aus Analysen des Zustandes und zu erwartender zukünftiger Herausforderungen (z.B. GAP, EEG) in Biosphärenreservaten Handlungspotenziale und Empfehlungen zu ihrer Anwendung und Umsetzung erarbeitet werden. Der Schwerpunkt sind dabei die Entwicklungszonen (EZ) und ihre beiden Schlüsselfunktionen: die Entwicklungsfunktion mit der Etablierung einer nachhaltigen Wirtschaftsweise, und die Puffer- und Vernetzungsfunktion, mit ihrer Bedeutung für die biologische Vielfalt. Dies soll beispielhaft für ökologisch, ökonomisch und soziokulturell nachhaltige flächenrelevante Landnutzungsformen für die EZ von BR durchgeführt werden und zu bundesweit verallgemeinerbaren Empfehlungen für diese Gebiete führen. Der Fokus liegt auf nachhaltigen Formen der Land- und Forstwirtschaft und der Gewässerbewirtschaftung. Die Bearbeitung erfolgt in zwei Arbeitspaketen (A: Integrierte Folgenabschätzung von Landnutzungsstrategien auf die nachhaltige Entwicklung in BR, B: Raumanalyse und indikatorenbasierte Ableitung von Handlungserfordernissen flächenrelevanter Landnutzungen (Landwirtschaft, Forstwirtschaft, Gewässerbewirtschaftung). Sie erfolgt jeweils schrittweise: auf einer übergeordneten Ebene (für alle 16 BR in Deutschland) und genauer für fünf Fallbeispiele werden der Zustand analysiert, Handlungserfordernisse und Umsetzungsmöglichkeiten ermittelt. Abschließend wird ein Empfehlungskatalog für die 16 BR zur zielgerichteten nachhaltigen Entwicklung der EZ erstellt.
Bioavailable nitrogen (N) from anthropogenic sources is an important driver of lacustrine eutrophication. However, N loading in lakes is partially mitigated by microbially mediated processes that take place in redox transition zones (RTZ) within the water column and in sediments. RTZ are also sites of methane (CH4) and nitrous oxide (N2O) production and consumption. As a result of anthropogenic activities, emissions of these greenhouse gases to the atmosphere have significantly increased over the past decades. Lake Lugano is an excellent model system for an anthropogenically impacted lake that represents a hot-spot of quantitative redox-driven transformations involving the green house gases CH4 and N2O, as well as other N species acting as important macro nutrients. Previous studies have revealed that this lake represents an important sink for fixed N and that the anoxic deep-waters and sediments contain high concentrations of CH4. Through the application of stable isotopic, molecular ecological and geochemical techniques, laboratory cultivation and (radio-) tracer studies, the project will try (i) to understand the metabolic pathway involved in N and CH4 elimination in Lake Lugano, (ii) to assess the metabolic rates, at which the respective elimination processes take place, as well as their variability in time and space, (iii) to constrain the isotope effects associated with specific N and CH4 transformations, and (iv) to provide information about the microorganisms involved in these transformations. Thereby, a particularly focus is put on reactions that have essentially been neglected in lacustrine studies thus far, namely the anarobic oxidation of ammonium (anammox) and the anaerobic oxidation of methane (AOM). The project will provide the first comprehensive characterization of early diagenetic reactions in Lake Lugano. Moreover, it may allow insights into novel modes of autotrophic life in lakes. Finally, quantitative estimates of N and CH4 elimination in both the water column and sedimentary RTZ of Lake Lugano will be a prerequisite for ecosystem-scale N and C budgets. Thus, the project will provide important information that is directly pertinent to the health of Lake Lugano in particular, and eutrophied south alpine lakes in general.
Naturally occurring arsenic (As) in groundwater aquifers is widely recognized as a threat to water resources. An estimated 100 million people worldwide are exposed to hazardous levels of As in their drinking water, predominately in South and Southeast Asia. Biologically-driven reductive dissolution of As-bearing Fe(III)-(hydr)oxides and As(V) are generally accepted to be the dominant mode of As release, resulted from microbial degradation of organic matter (OM) under limited oxygenation within soils/sediments. As the release process is governed by OM and its decomposition mechanisms and rates, it is crucial to understand the nature and reactivity of OM. Within the Mekong Delta of Cambodia, As release to groundwater was recently identified to occur mainly in the shallow clay layers of permanently saturated wetlands. In contrast, lesser amounts of As are released in the surficial clay layers below seasonally saturated wetlands. The two locations therefore provide an ideal opportunity to study the nature of OM and compare its reactivity during decomposition in similar environments under different redox conditions. Accordingly, we seek to determine how different geomorphic features result in different quantities and type of OM, and to link the characteristics of OM to the quantity of As release. During a field trip in July 2010 two 1 m deep soil profiles from two different locations (permanently and seasonally saturated wetlands), were sampled for OM characterization. Visual inspection of the seasonally saturated wetlands profile showed two different OM morphologies with leaf-type OM in the upper and amorphous OM in the lower part of the profile, while no leaf-type OM was found in the permanently saturated wetlands. ATR-FTIR spectroscopy revealed significant differences between the two materials, especially in the areas of C=O vibrations of carboxylates and of CH and NH (amide II) bending motions. Two high-resolution sediment sequences up to 6 m depth in both seasonally and permanently saturated wetlands are presently being examined by ATR-FTIR spectroscopy. Further, synchrotron-based FTIR spectra of transition zones and of the organic matter-mineral assemblages are being investigated. The specific chemical states are then be related to reactivity through incubation studies. Collectively, the results of this study will provide valuable insights into the role and heterogeneity of OM driving As liberation.
The project 'Modeling the role of the last ice age for the present and future sea-level contribution from Antarctica' will encompass the numerical simulation of at least four glacial cycles of the Antarctic sheet-shelf system using the Parallel Ice Sheet Model (PISM). The objective of the research plan is to determine the role of the past development of the Antarctic Ice Sheet for its sea-level contribution of the past and future century. To this end we investigate the influence of past climate evolution, especially the last deglaciation, on its present dynamic state: The ongoing changes in terms of mass balance, disregarding anthropogenic climate change, during the 20th and 21st centuries are influenced by the history of the advance and retreat of the ice during the last glacial cycles. Instead of aiming at a best-guess simulation, we will work on providing an ensemble of model simulations that incorporates uncertainties from climate boundary conditions and internal process-modeling and ice parameter choices. Apart from answering the above mentioned research question concerning the influence of the history of the ice sheet on its present day dynamics, we will also take an important step towards a new generation of projections of future ice discharge from Antarctica: It is important to know how much sea-level contribution, if any, is not caused by anthropogenic climate change. The program encompasses the development and short-term testing of physical improvements to the model that are needed in order to perform four glacial cycles (4GC) simulations and to provide a comprehensive ensemble. The currently implemented climate boundary conditions, both for the upper surface of the ice sheet and the underside of the ice shelves in contact with the ocean, will be examined and expanded to be suitable for 4GC-simulations. Process-based model components, concerning the numerical representation of the transition zone between ice sheet and ice shelf will be evaluated and improved. High-resolution nested simulation approaches will be developed for PISM in order to better resolve these crucial zones in order the further close the gap between finite differences models like PISM using shallow approximations of the stress balance and higher-order models. Sensitivity tests within 4GC-simulations will shed light on how the above mentioned new methods, climate boundary conditions in general and internal model parameters, influence the 4GC-simulation and ultimately the modeled present day state. An ensemble selection process will take place, excluding those parameter and climate-boundary combinations that are not conform to available geologic data for the past and observations of the present day state of the Antarctic ice sheet. This can be thought of as a 'blind selection' of the dynamic present-day state of the ice sheet...
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