Closing the Carbon Cycle in River Networks across Climate and Terrestrial Productivity Gradients

Large amounts of carbon (C) are exported from terrestrial ecosystems into rivers, where C can be processed and emitted as CO2 to the atmosphere.

Current estimates of riverine CO2 emissions to the atmosphere are high, enough to substantially affect regional C budgets.

However, my past research has showed that those global estimates are very uncertain because of extreme spatial variability in CO2 concentrations, with local topography strongly shaping stream CO2 emissions.

In this project, I will use my background in modelling to develop a CO2 reaction-transport model in stream networks, anchored by catchment topography to capture the fine-scale processes that govern stream CO2 dynamics.

This will allow to accurately quantify and understand CO2 emissions from stream networks, as a first step to understand the broader controls of C losses from land.

The model will be first developed and implemented in virtual landscapes (WP1) across temperature and precipitation gradients, to provide a mechanistic understanding of stream CO2 emissions.

Then, the model will be blended with empirical data from six catchments (in Sweden, Switzerland and Spain) across gradients in climate and terrestrial productivity (WP2).

And finally, the model will be explored across multiple temporal scales in a boreal catchment to predict future C biogeochemical regimes (WP3).

This project will reveal the connection between CO2 emissions from stream networks with climate and landscape productivity.