- Department:(Dept. 1) Ecohydrology and Biogeochemistry
Towards the outwelling hypothesis in a Patagonian estuary: first support from lipid markers and bacterial communities
Fatty acid markers, stable isotopes of C and N, and bacterial communities were investigated in a mesotidal estuary of the Patagonia to assess the Odum’s outwelling hypothesis. Rhodobacterales were likely early colonizers of the outwelled organic matter and the exportation of nutrients and organisms and their essential fatty acids from the wetland was inferred, supporting the findings of Odum.
Evaluating satellite-derived soil moisture data for improving the internal consistency of process-based ecohydrological modelling
The authors investigated whether satellite-derived soil moisture products of high spatio-temporal resolution are useful for calibrating a process-based ecohydrological model. Including soil moisture data for calibration improved process-consistency of the model. At this scale, the temporal dynamics of the satellite-derived data were more helpful for model calibration than the spatial patterns.
The role of boundary mixing for diapycnal oxygen fluxes in a stratified marine system
The research team investigated the vertical oxygen flux through the halocline in the Baltic Sea using high-resolution temperature and oxygen profiles during different seasons. Oxygen transport showed a strong seasonality and was higher in autumn compared to summer and winter. The shoreline regions were responsible for >80% of the total oxygen transport through the halocline.
Formation of vivianite in digested sludge and its controlling factors in municipal wastewater treatment
Phosphorus as scare raw material can be recovered from municipal wastewater treatment as iron phosphate mineral vivianite. Vivianite formation increased with higher iron and lower sulphur content. The study suggests that the use of sulphur-free precipitants for chemical P elimination may enhance vivianite formation. The new insights are also of high relevance for the research on aquatic sediments.
Fate of trace organic compounds in the hyporheic zone: influence of microbial metabolism
The authors investigated the influence of microbial processes on the fate of trace organic compounds in stream sediments. The study demonstrates the usefulness of the fluorescent tracer system resazurin-resorufin for determining microbial metabolism and disentangling specific reactive properties and ultimately their influence on the fate of contaminants in natural hyporheic zones.
Spatial and temporal dynamics of water isotopes in the riverine-marine mixing zone along the German Baltic Sea coast
The spatial and temporal variability of stable water isotopes were investigated in the Schlei and in the Baltic Sea boddens. The data improve the understanding of hydrological processes behind those dynamics. Further they will be a helpful contribution to multiple IGB projects, e.g. in context of migration studies of pike and analysis of biochemical processes in macrophytes
Organizational principles of hyporheic exchange flow and biogeochemical cycling in river networks across scales
Understanding organizational principles of hyporheic exchange flow and biogeochemical cycling in landscapes is key for generalizing process knowledge.
Dynamics of greenhouse gases (CH4 and CO2) in meromictic Lake Burgsee, Germany
At its deepest point, Lake Burgsee has one of the highest methane concentrations ever measured in a natural freshwater lake.
The potential of large floodplains to remove nitrate in river basins: the Danube case
Based on the modelling of nutrient fluxes in the Danube River Basin, the authors estimated the (potential) contribution of the large floodplains to remove nitrate from the Danube and major tributaries. The active floodplains retain 33000 tons per year, or 6.5% of the total nitrogen emissions, which can be increased by 5000 tons if floodplains and water bodies are reconnected.
A hybrid empirical and parametric approach for managing ecosystem complexity: water quality in Lake Geneva under nonstationary futures
A hybrid model which combines a classical 1D lake model with data-driven machine learning was used to predict changes in deepwater oxygen concentrations under varying climatic conditions and nutrient concentrations. The model predicted deepwater oxygen concentrations of Lake Geneva more precisely than a classical approach. Increasing air temperatures have similar effects as phosphorus inputs.