Manganese (Mn) is involved in the decomposition of soil organic matter (SOM) via redox reactions,
which gives it a significant role in the terrestrial carbon cycle. It is also strongly recycled by vegetation
in forest ecosystems, but the influence of tree species, as well as climate and soil, on Mn fluxes to the
soil remains poorly characterised. The evolution of the distribution of forest species, induced among
other things by climate change or silvicultural practices, could therefore modify the recycling of Mn
and thus the dynamics of the SOM. The objective of this project is therefore to better constrain the
influence of different forest species by considering environmental variables (climate and soil) on Mn
fluxes. To this end, we are working on the European forest monitoring network (ICP Forests), which
gathers qualitative (species, location, soil type, etc.) and quantitative (volumes and composition of the
various fluxes, physico-chemical properties of the soils, etc.) data for nearly 1,000 forest plots across
Europe. The first stage of this work consists of filling in the missing data for soils and climate, in
particular via the LUCAS (Land Use and Coverage Area frame Survey), SGDBE (Soil Geographical
Database of Eurasia) and Copernicus (European meteorological database) databases. This different
information will make it possible to isolate the role played by the forest species, under different
climatic and soil conditions, on Mn fluxes in order to quantify the evolution of the SOM under different
scenarios.