As highlighted in several lectures, Soil Organic Matter (SOM) matters a lot as a fundamental part of soil carbon storage and ecosystem health. SOM is a mixture of organic substance, created by decomposition of plant and animal remains and the syntheses of new biomolecules by soil microbes. The composition reflects the conditions under which it has been formed and stored and how vulnerable it is for decomposition. Therefore, by describing the SOM composition we expect  to understand better how soil management effects how labile or stabile this SOM pool is. 

We have several sets of soils, from agricultural fields in Canada and Norway to more tropical sites in Ghana available for your thesis. In your thesis you will use the novel density-thermal fractionation scheme in the laboratory, based on Stoner et al. (2023) and improved by Johanna Zimmermann, to answer the question how land use change or soil management has affected the SOM stability. 

Supervisors: Dr. Jeroen H. T. Zethof, Johanna Maria Zimmermann, Prof. Dr. Hermann Jungkunst

Contact: jeroen.zethof(at)rptu.de

Tropical forests are dominated by deeply weathered soils, often limited in plant necessary nutrients. Under natural forests ecosystems, the vegetation is adapted to recycle nutrients in the upper soil or obtain them from deep (younger) soil layers. Upon clearing of the forests, this closed system is changed by the different root system of the pasture vegetation. Very little is known about the effects on plant available nutrients, most notably phosphor and sulphur. Therefore, deep soil samples have been taken in Acre (Brasil) to study this further.

The main question we hope to answer with your thesis is how much of the plant essential nutrients are lost under the pasture vegetation over time. In your thesis you will use a subset of these deep profile to extract and quantify plant available nutrients in the laboratory. 

Supervisors: Dr. Jeroen H. T. Zethof, Johanna Maria Zimmermann, Dr. Klaus Schützenmeister Rex, Prof. Dr. Hermann Jungkunst

Contact: jeroen.zethof(at)rptu.de

We have further ideas for Bachelor’s or Master’s thesis topics, such as investigating white-sand ecosystems or carrying out modelling exercises.

In addition, we would also like to encourage your own ideas, provided they relate to biogeochemistry, soil, or land use—for example, the effect of invasive plants on soil functions.

Please feel free to contact us.

Contact: hermann.jungkunst(at)rptu.de