(Dept. 1) Ecohydrology and Biogeochemistry
The interactions within and between green water (in terrestrial systems) and blue water (lakes, rivers, and subsurface aquifers) affect in complex ways the habitats for organisms and the reactive transport of abiotic components. Aquatic and terrestrial systems are coupled at multiple spatio-temporal scales. The overall goal of the Department of Ecohydrology and Biogeochemistry is to understand the ecohydrological and biogeochemical processes of these connected land- and waterscapes in natural, rural and urban environments. Therefore, our research projects focus on the following core topics:
- Interactions of landscape-freshwater ecosystems
- Physical and biogeochemical drivers under global change
- Water security in disturbed and urban systems
In our research, we integrate different modelling approaches with data collected in field studies, in large-scale manipulation studies, by long-term monitoring and in laboratory experiments. We study ecohydrological and biogeochemical processes using a variety of tracer techniques, particularly stable isotopes, and by measuring naturally dissolved solutes, conservative geogenic ions, trace organic matter, and nutrients. In doing so, we combine basic research with application aspects and aim to record and model the effects of climate and land use changes. With its laboratory infrastructure and expertise in the fields of inorganic and organic analysis as well as isotope measurement, the department performs a central function for the entire institute. To achieve our research goal, we combine our professional expertise from the research disciplines of hydrology, geochemistry, aquatic physics, ecology, environmental engineering, and geography.
Unravelling the role of sulphate in reed development in urban freshwater lakes
The authors analysed data from 14 lakes in the Berlin catchment area for the period 2000 to 2020. They found that if sulphate concentrations had not increased, there would be about 20 per cent more reeds in the sulphate-polluted lakes today.
Upscaling Tracer-Aided Ecohydrological Modeling to Larger Catchments: implications for Process Representation and Heterogeneity in Landscape Organization
The authors adapted a tracer-aided ecohydrological model to upscale tracer-informed process representation to larger catchments scales. The modeling unravelled spatio-temporally varying patterns of water storage-flux-age interactions and their interplay under drought. Insights into ecohydrological functioning at scales relevant to management decision-making are important for guiding interventions.
Worldwide moderate-resolution mapping of lake surface chl-a reveals variable responses to global change (1997–2020)
Whether a lake appears blue or green is also related to its chlorophyll-a content. Researchers led by IGB used satellite data to draw conclusions about the concentrations of the green pigment produced by algae.
Enhancing urban runoff modelling using water stable isotopes and ages in complex catchments
Hydrological and water stable isotope datasets within a modelling framework were utilized to evaluate the water flow paths and ages in the heavily urbanized Panke catchment in Berlin. Groundwater was the primary flow component in reaches with less urbanisation. Wastewater effluent dominated the mid-reaches with direct storm runoff and shallow subsurface contributions in the urbanized reaches.
Using stable water isotopes to understand ecohydrological partitioning under contrasting land uses in a drought-sensitive rural, lowland catchment
To analyse the influence of vegetation on water partitioning under land management strategies, the authors used stable water isotopes with contrasting land covers and soil types in the Demnitzer Millcreek. The study underlined the need for long-term observations of land use changes and drought-sensitive vegetation to evolve a drought resilient land management considering time lags.