Water and matter cycles
Rivers, lakes and wetlands connect the land to the sea, they are directly linked to groundwater, and regulate the global nutrient and carbon balance. Their sediments are also highly active zones that can extract nutrients and contaminants from the surface water. We explore these complex physical, hydrological, biological and chemical processes and interactions. We then use the knowledge gained to develop concepts for sustainable water management and for enhancing water quality. For example, we focus on the wetland rehydration of bogs, interactions between groundwater and surface water, the significance of riparian zones, and matter conversion in sediments.
Related News
Selected publications
Ecohydrological resilience and the landscape water storage continuum in droughts
A better understanding of water storage dynamics at medium scales, i.e. areas between 10 and 100 square kilometres, could help to better predict and ensure the availability of water resources, even in times of climate change. To this end, the researchers here synthesised findings from several long-term studies and introduced the concept of ecohydrological resilience.
Electrical conductivity fluctuations as a tracer to determine time-dependent transport characteristics in hyporheic sediments
The paper presents a modeling approach to estimate time-varying travel times from the stream water to the streambed. The modeling is based on fluctuations in electrical conductivity in the surface water and in the porewater. Given the high temporal dynamics of transport in streambed sediments, the model will be a valuable tool for the assessment of reactive transport in streambed sediments.
Multiple-stressor effects on leaf litter decomposition in freshwater ecosystems: A meta-analysis
By using a meta analytical technique, the authors investigated the effect of multiple-stressors on leaf litter decomposition in freshwaters. The overall interaction between multiple stressors was antagonistic and the magnitude and direction of multiple-stressor interactions depends on factors such as the involvement of macroinvertebrates, habitat type and available resources.
Linking terrestrial biogeochemical processes and water ages to catchment water quality: A new Damköhler analysis based on coupled modeling of isotope tracers and nitrate dynamics
Catchment-scale nitrate dynamics involve complex coupling of hydrological transport and biogeochemical transformations, imposing challenges for source control of diffuse pollution. Coupled modeling of isotope tracers and nitrate dynamics revealed that upland arable areas impose pollution risks under drought while the river-connected lowlands are processing hotspots and more resilient to drought.
Temperatures and hypolimnetic oxygen in German lakes: Observations, future trends and adaptation potential
A study of oxygen and temperature trends in 46 German lakes showed that temperatures have risen mainly at the surface, but not in the deep water. This led to increased stratification and lower oxygen concentrations. Scenarios showed that these effects of climate change on oxygen content could be compensated by reducing nutrients.