PhD project offered by the IMPRS-gBGC in July 2025

Fast Microbial Processes and the Long-Term Soil Carbon-Climate Feedback

Bernhard Ahrens, Alexander J. Winkler, Thomas Wutzler, Markus Reichstein

Project description

Fast microbial processes, such as microbial acclimation or substrate depletion may play a crucial role in how soils respond to climate change. These processes could provide a self-regulating feedback controlling soil carbon losses in a warmer world - but they are often poorly explored in current soil carbon models, in part due to limited integration of experimental data from soil warming studies and global soil carbon databases.

At the same time, increased vegetation productivity due to the CO₂ fertilization effect may increase carbon inputs to the soil. While this could offset soil carbon losses due to climate change via increased carbon inputs, it might also stimulate priming effects, accelerating the microbial decomposition of existing soil carbon. Understanding these competing mechanisms is essential for improving predictions of how soil carbon contributes to the global carbon-climate feedback.

In this project we aim to understand how fast microbial processes affect the long-term soil carbon-climate feedback by combining soil microbial models and vegetation models with machine learning from large-scale soil warming datasets and global soil carbon databases.

Your profile

We welcome applications from curious and motivated students from any country who have

A master degree in geoecology, environmental sciences, hydrology, mathematics, physics, physical geography, data science, or related fields
A strong background in at least one of the following: soil biogeochemistry, numerical modelling, or machine learning
A broad interest in soil processes and curiosity to deepen our understanding of soil organic carbon decomposition and formation.
Very good oral and written communication skills in English

The Max Planck Society (MPS) strives for gender equality and diversity. The MPS aims to increase the proportion of women in areas where they are underrepresented. Women are therefore explicitly encouraged to apply. We welcome applications from all fields. The Max Planck Society has set itself the goal of employing more severely disabled people. Applications from severely disabled persons are expressly encouraged.

Working group and planned collaborations

The Max Planck Institute for Biogeochemistry in Jena offers an exceptionally dynamic, creative, international, and multidisciplinary working environment. You will join the Modeling Interactions in Soil Systems Group, focusing on the persistence and sensitivity of organic carbon in soils and interactions between biogeochemical cycles of carbon, nutrients, and water. The project is embedded in the MC3 4 Earth Max Planck Center - a collaboration between:

Max Planck Institute of Biogeochemistry
Max Planck Institute for Chemistry
California Institute of Technology
Carnegie Institution for Science (Department of Global Ecology)
Columbia University.

A confirmed collaboration partner is Alexis Renchon.

For further information, please contact
Bernhard Ahrens
Alexander Winkler
Thomas Wutzler
Markus Reichstein