M. Sc. Johanna Schwarzer
Research Interests:
- Plant-mediated effects on soil microbial carbon cycling
- Biogeochemistry and ecology of wetlands
- DNA - stable isotope probing
- Data science and biostatistics
Career:
Professional employment
- since 2023: PhD student in the Rhizosphere Biogeochemistry research group at the iLÖK in Münster, with GFZ Potsdam as the main workplace.
- 2022: Research assistant, AWI Potsdam, Helmholtz Centre for Polar and Marine Research.
Expeditions and field campaigns
- 06/2022: AWI expedition to Inari, Finland. PeCHEc Project.
- 08/2021: AWI expedition to Kenai Peninsula, Alaska, USA. P2C2 Arctic Coastal Wetlands Project.
- 06/2021: AWI expedition to Siikaneva, Finland. FluxWIN Project.
- 09/2018: International Moor Excursion to Northern Poland.
Education:
- M.Sc. Environmental Earth Science, FU Berlin, 2022. Master thesis title: A Theoretical Model for CO2 Fluxes of High Resolution Incubation Measurements.
- B.Sc. Landscape Ecology, University of Münster, 2017.
- B.Sc. Life Science, University of Münster, 2014.
Projects:
RELATE - Rhizosphere Mediation of Biosphere-Climate Feedbacks
The RELATE Project is led by Peter Mueller at the iLÖK in Münster and is funded through the DFG Emmy Noether Programme. The goal of this project is to advance the mechanistic understanding of biosphere-climate feedbacks by investigating the carbon cycle of wetland rhizospheres. To achieve this goal, following groups cooperate:
- the ecohydrology and biogeochemistry research group, led by Klaus-Holger Knorr (ILÖK, Münster)
- the microbial carbon dynamics in the climate system research group, led by Susanne Liebner (GFZ Potsdam)
- the biogeochemistry lab, led by Pat Megonigal (Smithsonian)
- the applied plant ecology lab, led by Kai Jensen (Universität Hamburg)
Global soil organic carbon (SOC) stocks can potentially be mobilized under global warming and lead to alterations in greenhouse gas fluxes. This process is mediated by soil conditions, microbial community functioning, and plant responses. In wetland soils, conditions are strongly influenced by water saturation, leading to the scarcity of oxygen as a terminal electron acceptor (TEA). In coastal wetlands, seawater influence further alters soil redox conditions. In these systems, plants not only control substrate supply to microbial communities through root exudates but also regulate the availability of oxygen. As wetland soils have sequestered large SOC stocks, their potential to emit large amounts of greenhouse gases poses a significant risk for positive climate feedbacks. The RELATE project aims to develop a comprehensive understanding of plant traits controlling soil microbial processes under varying redox conditions.
At the GFZ, we are using traditional techniques of molecular biology together with DNA stable isotope probing (DNA-SIP) to gain insights into specific microbial processes and interactions involved in carbon cycling in wetlands. This approach will help us elucidate the interactions and carbon fluxes between plants and microbial communities in wetlands under varying redox conditions and lead to a better understanding of biosphere-climate feedbacks.