2-P5: MICROHEAT II

Carbon and energy turnover for complex substrates and intact soils

The goal of this project is to explore how the efficiency of carbon turnover in soil depends on the initial substrate and on soil conditions, which together control the metabolic pathways and result in characteristic carbon and energy use efficiency. By a broad selection of substrates with the same C content (6 C atoms; glucose, cellobiose, lysine, phenol) but varying combustion enthalpies and Gibbs energies we explore the influence of these substrate characteristics on the C and energy turnover, as well as enzyme activities and microbial communities in comparative incubations. In addition, we conduct experiments with mixed substrates to investigate the influence of the stoichiometry of available nutrients in the soil, specifically the availability of nitrogen, on C and energy turnover during the utilization of C6 substrates.  

The other project focus is on experiments with intact soil cores instead of homogenized soil. It is known that the position of the substrate in the pore space controls the accessibility for the microbiome as well as the supply of oxygen and nutrients and thus the turnover kinetics of the substrate. The project aims to investigate the influence of natural substrate distribution on C and energy turnover during the rewetting of dry soils. Although the initial substrates are unknown in intact soil, comparisons with repacked reference samples of the same storage, moisture, and labile C quantity are possible. With X-ray CT, the spatial heterogeneity can be detected and associated with differences in the turnover kinetics.

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Link to English scientific abstract
Link to German scientific abstract

Link to project in the 1^st phase

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Research Team