Dorothee Kinkel

Profile

Project title: Temperature and nitrogen modulated nitrous oxide cycling

Summary: A novel sink for the greenhouse gas nitrous oxide (N₂O) may have been found in pristine, nitrogen limited streams in Iceland and the same could also be true for regions of the cold, Southern Ocean. This sink seems to be temperature regulated, with N₂O being consumed at colder temperatures. In the cold it is more energy efficient to break the bond of N₂O than it is to break the triple bond of N₂. N₂O could therefore be used as an alternative nitrogen source in cold, pristine ecosystems. This opens up a few interesting questions:

Is N-fixation in cold temperatures more dependent on N₂O?
Is the fixation of N₂O a physiological response of diazotrophs that normally fix N₂O?
Are cold and N-limited ponds, streams, and their adjacent soils characteristically under saturated with N₂O?

By examining the nitrogen cycle in the controlled setting of long-term experimentally warmed ponds, in a gradient of geothermally heated streams in Iceland, and/or the Southern Ocean, and in low N impacted sites in UK uplands, these questions will be addressed.

Supervisor

• Professor Mark Trimmer

Research