Structure and composition of soil organic matter-mineral aggregates in organic surface layers of forest soils after one year of litter bag f

Soil organic matter (SOM) in organic surface layers of forest soils (forest floors; FF) is susceptible to P losses and conversion of soil carbon into atmospheric CO2 by global warming. Formation of SOM-mineral associations and aggregates stabilizes forest floor SOM against decomposition and reduces undesired ecosystem C and P losses; The mechanisms involved in this process and the microspatial structure of the formed SOM-mineral associations are largely unknown. We aim to reduce this knowledge deficit by conducting µ-XRF and P µ-XANES analyses on FF samples obtained from a field litter bag experiment with FF material after one year of SOM decomposition with vs. without prior addition of soil-typical minerals. The experiment shall be conducted at ID 21 of ESRF. Combined with results from mass and element analysis, NanoSIMS and NMR studiesconducted on the same samples, the results of our experiment will provide clues on key processes of SOM-mineral association formation in forest soils.