Quantifying biogeochemical links between land and ocean: closing a major gap in the global carbon cycle

Each year a significant fraction of all the carbon taken up by terrestrial ecosystems is exported to fluvial systems as dissolved and particulate organic matter; approximately 2 Gt of carbon are exported annually from the UK landmass alone. Only a fraction of this is thought to reach the open ocean, but our understanding of where, how and when organic matter is lost along the land-ocean continuum remains incomplete. This hampers our ability to understand how changing land management strategies and climate change will influence the fate of terrigenous organic matter and hence global biogeochemical cycles. We seek a highly motivated student that is interested in studying biogeochemical cycling along the land-ocean continuum, an exciting and emerging area of research. This project will combine novel incubation experiments and state-of-the-art stable isotope techniques to quantify the biological removal of terrigenous organic matter in contrasting locations, from headwater streams to coastal seas, at different times of the year. It will also investigate how an increase in the export of bioavailable dissolved organic matter influences the fate of biological unreactive carbon, so-called "priming effects". The outcome of this project will help inform Earth System Models and the development of future IPCC assessments.