Lead
Export of carbon produced by the terrestrial biosphere by rivers and its subsequent burial in ocean sediments represents a key component of the global carbon cycle, and regulates atmospheric CO2 and O2 concentrations over a range of timescales. Terrestrial organic carbon buried in marine sedimentary sequences also provides a window into past variations in terrestrial ecosystems and their response to natural (e.g., climate) and human-induced environmental variations. While there have been considerable advances in our understanding of carbon transport within river basins, major gaps in our understanding of underlying processes persist which limit our ability to predict future responses to natural and anthropogenically-driven change, and to accurately interpret sedimentary records.

Lay summary

Objectives

The objectives of this project are to (a) explore links between carbon and mineral particle dynamics in eroding terrestrial landscapes, (b) assess the evolution of organic matter-mineral associations along the land-to-ocean continuum, and (c) derive global-scale perspectives on coupled terrestrial-marine carbon cycle processes. We place particular emphasis on interactions between organic matter and minerals as this is hypothesized to strongly influence of organic matter reactivity and stability in terrestrial and aquatic systems, its transport in rivers and its dispersal in the ocean. Information obtained from this study will be incorporated into new databases in order to place information on carbon signatures in rivers and adjacent continental margins in a global context.

Scientific and Social Context of the Research Project

River have been focal points of human civilization for millennia due to their importance as sources of water, fertile soils and transportation. River systems also form a key component the global carbon cycle, linking terrestrial and marine carbon pools, and integrating processes occurring within their watersheds.  Studies of the processes that influence carbon processing and transport in rivers are therefore essential to understand carbon cycling on large portions of the earth surface.  Equipped with this understanding, we are in a better position to assess the influence of natural processes and human activity on this aspect of carbon cycle, as well as on land-ocean interactions.