Project Details
Projekt
Carbon and energy use efficiency of soil microorganisms unfolding over time
Applicant
Dr. Sergey Blagodatskiy
Subject Area
Soil Sciences
Microbial Ecology and Applied Microbiology
Microbial Ecology and Applied Microbiology
Term
since 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 465124939
The incomplete understanding of soil carbon cycle reflects itself in uncertain prediction of the general system reaction, which is often mysterious and cannot be reliably captured by model approaches excluding soil microorganisms. The idea of C-timing project is that developing in time soil microbial community induces the cascade of events either reducing/stabilizing or intensifying decomposition process. The routes of decomposition cascade are restricted by the energy input and shaped by the energy distribution through the foodwebs channels. The stabilization level and number of active cascades at each time point is regulated by microbial competition for C and nutrients, by efficiency of microbial metabolism and by oxygen availability. Biological processes influencing the carbon use efficiency will be considered and modelled in this project. They include substrate uptake by microorganisms, microbial growth, maintenance, CO2 emission, recycling of microbial biomass, and microbial death due to predation by grazers. Several models of increasing complexity with different representation of the listed processes will be built and analyzed in respect of i) equilibrium ratios of main soil C pools (stabilized, dissolved and microbial OM) at steady state, ii) transient dynamics of main pools either in response to substrate input or to stress impact suppressing microbial growth and causing microbial die-off.The metabolic efficiency of microorganisms in soil is strongly affected by a prevailing electron acceptor that controls energy and carbon conversion in soil microhabitats. Due to soil heterogeneity, aerobic and anaerobic conditions co-occur within the same soil volume but their relative fractions are changing in time. Therefore, modeling of microbial growth and turnover considering anaerobic soil volume will be a specific task of C-timing. The aim of the project is to develop a microbial-explicit model of soil organic matter turnover describing in parsimonious way the dynamics of carbon and energy use efficiency, constrained by biotic interactions and soil boundary conditions. To do that, complementary model versions will be developed, compared, and fused, (if necessary), aiming to find the main driver of temporal changes in CUE as determined by microbial thermodynamics and dynamics of functional structure of soil microbial community. Simulation results will be validated using experimental data gathered in the core experiments and collaborative projects of SPP 2322 Soil Systems. Final selection of the simplified model version based on holistic principle and approved by SPP consortium will be done in accordance with other modeling groups in the Priority Program.
DFG Programme
Priority Programmes
