Controls on the persistence of organic carbon in soils from single profiles to the globe

Earth Surface Science Institute seminar. Speaker Dr Marion Schrumpf, Max-Planck-Institut für Biogeochemie, Jena, Germany.

 

Abstract

Soils are the largest terrestrial carbon pool and changes of C-fluxes into and out of the soil have the potential to significantly alter atmospheric CO2 concentrations. In my group we are therefore studying the persistence of organic carbon (OC) in soils and its sensitivity to land use and global changes using both, experimental and modelling approaches. In first part of the presentation I will therefore show experimental results from three main research foci we have: the controls of carbon stabilization on mineral surfaces, interactions between carbon and nutrient cycling, and plant-soil-interactions under elevated CO2. In the second part, I will demonstrate how we implemented our current process understanding into a new soil profile model, and identify the main drivers of top- and subsoil carbon ages in the model. Finally, I will show results of global model runs and how well our model is able to represent patterns of soil carbon stocks and radiocarbon depth profiles from global databases.