Most soil biogeochemical models represent soil carbon (C) and nutrients as pools and fluxed at the ‚bulk soil‘ level (f.e. soil C and N stocks, microbial biomass, respiration, N mineralisation). Model parameters that control transformations between these pools are however often derived from physiological concepts of microbial cells (e.g. microbial carbon use efficiency, enzyme and uptake kinetics). Thus, this approach implicitely ‚scales up‘ microbial processes from the cell level to bulk soil and beyond.

In this interactive PICO session we want to challenge and discuss this common simplification by taking a closer look on how microscale interactions among microbes, as well as between microbes and their physical micro-habitat (soil aggregates, roots), influence biogeochemical cycling at the macroscale. Can accounting for possible self-regulating and organising behaviour emerging from microscale interactions improve our understanding of the system soil? Do we need to integrate ecological concepts (as known from macro-ecology) into soil microbial models? Can insights from these types of models be used to improve predictions of large-scale biogeochemical models?

We welcome contributions on novel approaches in soil modelling, in particular those accounting for feedbacks between soil microbes and the soil microarchitecture, as well as those on upscaling of microscale dynamics to macroscale fluxes. We also welcome experimental or conceptual studies focusing on soil microbial and organic matter dynamics across scales.