Student Projects

Student Projects
Sensor networks for stream metabolism and CO2 outgassing
Streams play a hitherto underestimated role in carbon cycling. To better constrain regional estimates of ecosystem gross primary production, respiration and CO2 outgassing from streams to the atmosphere, we are designing novel sensor systems. The aim of this Master Thesis would be to assemble, test and calibrate a pilot sensor system. An engineering background with skills in electronics or communication technology would be most welcome.

Quantifying gas exchange in Alpine streams
A key component to quantifying CO2 outgassing and ecosystem metabolism is to quantify the exchange of gasses across the air-water interface. Reaeration depends on differences in partial pressure of gases in the atmosphere and the streamwater but also on turbulence. The aim of this Master Thesis would be to test and compare various methods from modelling to field approaches of quantifying reaeration in an Alpine stream catchment. A background in environmental engineering and more specifically in hydrology would be most welcome.

CO2 fluxes and organic carbon biogeochemistry in Alpine streams
While it is becoming increasingly recognized that streams emit large amounts of CO2 to the atmosphere, the source of the CO2 and its temporal and spatial dynamics remain largely elusive. Elucidating these CO2 dynamics is critical to fully understand and predict the boundless carbon cycle across the terrestrial-aquatic interface. The aim of this Master Thesis is to work on hydrodynamic exchange between groundwater and streamwater to establish its relevance for CO2 outgassing from streams. A background in general environmental engineering with a focus on hydrology and/or geomorphology would be most welcome.

Microbial diversity dynamics and scaling in the porous space of streambeds
The hyporheic zone of streams is a major site of microbial biodiversity and biogeochemical cycling. As such, the hyporheic zone greatly contributes to stream ecosystem processes. Currently we do not well understand how fine-scale processes in the hyporheic zone may contribute to the ecosystem processes. The aim of this Master Thesis would be to explore and relate fine-scale hydrodynamics to the microbial ecology in the porous space of the hyporheic zone. A background in environmental engineering with a focus on fluid mechanics and/or environmental microbiology would be most welcome.

Tacking of predators on biofilm landscapes using automated image analysis
In streams and rivers, microbial assemblages form matrix-enclosed and surface-attached structures called biofilms. Biofilms are composed of diverse communities of bacteria and algae and form complex architectures, comparable to landscapes. Predators feed on these biofilms, affecting biofilm structure and function. We are interested in monitoring the behaviour of individual predators (different unicellular eukaryotic organisms) on biofilm landscapes using microscopy and automated image analysis. The aim of the Master project would be to establish the image analysis tools in order to track predators on biofilm landscapes and to use mathematical modelling to describe this behaviour. A background in environmental engineering, image analysis and mathematical modelling would be most welcome.