My PhD focuses on oxidative ratios (OR) of various terrestrial ecosystems in Germany, different biomes across the globe and also Indonesia, where land has been and is transformed from natural forest to oil palm and rubber plantations. Using the already existing infrastructure, I am collecting plant material and soil of those 3 ecosystem types.
Through the elemental analysis of the chemical elements carbon, nitrogen, hydrogen and oxygen of the organic matter, I calculate the oxidative ratio (see e. g. Worrall, et al. (2013). Biogeochemistry 115: 23-32 and Masiello, et al. (2008). Journal of Geophysical Research – Biogeosciences 113: G3, G03010), which is the amount of carbon dioxide sequestered in the terrestrial biosphere for each mol of oxygen produced and indicates the O2 production efficiency and thus can be a tool to determine the carbon sink ability of ecosystems.
Both for soils with changed carbon content and for vegetation, as OR varies more between plant species than between different parts of a plant, significant differences are expected.
The results will be connected to past, present and future flux measurements from the same area.

Project: OXYFLUX (funding: ERC Consolidator Grant)

Supervisors: Prof. Dr. Alexander Knohl, Dr. Jens Dyckmans and Prof. Dr. Dirk Hölscher

Indonesian counterpart: Dr. Aiyen Tjoa