Organic carbon transfer in mountain catchments

Woody debris plays an important role in stream dynamics and morphology in the Vogelbach, Alptal (Picture: D. Rickenmann)

Carbon dioxide is a green house gas and a pollutant of the atmosphere. The global carbon cycle has long been established, whereby carbon is outgassed in volcanos and drawn down in chemical reactions with siliceous rocks (silicate weathering). A second way to remove carbon from the atmosphere is only incompletely understood: living biomass (plants, trees) bind carbon. If plant material gets into a stream and is transported into an environment, where it can be buried, this carbon is removed from the atmosphere and is locked into the geological record. Recent research has shown that the global potential for carbon removal of this process is a factor ten of silicate weathering and thus could be very important (see the study by Hilton and others in Global Biochemical Cycles 2009).

In this project we try to better understand this, and in particular the processes by which biogenic carbon is transferred from the terrain near the streams into the water flow. The project is led by Niels Hovius at the University of Cambridge, whereby Jo Smith will do the bulk of data analysis in her doctoral dissertation. Additional collaborations exist with Albert Galy (Univ. Cambridge) and Bob Hilton (Univ. Durham).

In three study streams and some sub-catchments in the Alptal near Einsiedeln (canton Schwyz) we take regular water samples to localise the sources of carbon and make a carbon budget for the streams. In additional field work we will try to characterise the transport behaviour of individual flood events in detail and study landsliding and soil production. The Erlenbach, in particular, is an ideal site for this study. Sediment transport behaviour and hydrology have been monitored for around 30 years and long-term observations on biomass, forest ecology and forest chemistry are available.

Links

• Hydrological experimental catchments
• Long-term bedload monitoring
• Soil carbon
• Swiss canopy project
• Nutrient fluxes, nutrient status of the stand and ground vegetation on the LWF plots

Participants

• Patrick Schleppi
• Frank Hagedorn
• Kim Krause
• Dieter Rickenmann
• Karl Steiner
• Manfred Stähli
  

Contact

• Jens Martin Turowski