Spatial modelling of microbial interactions and carbon dynamics in soils

Soil hosts a large diversity of microorganisms, that are responsible for the transformation, storage in the soil and release of carbon (C) to the atmosphere. These transformations of C are realized by individual cells that all belong to a metabolic interaction network, i.e. a network of interactions within which cells from different species compete for, transform and exchange resources. Soil C respiration, soil C storage and soil Carbon Use Efficiency are all outcomes of the functioning of this metabolic interaction network. Understand the functioning of metabolic interaction networks is thus essential to understand the cycling of C in soils. We present a spatially explicit, individual based, model of microbial interactions in which cells are able to take up some resources, transform them into other products, which are released into the environment. Each cell is assumed to have a spatially limited impact on their environment. In this contribution, using different model parametrizations, we explore the interplay between spatial distribution of cells, resource diversity and microbial diversity, and show how the spatial distribution of cells can be a strong modulator of the functioning of metabolic networks in soils.