Biogeochemistry seeks to understand the composition of and changes to ecosystems. It focuses in particular on the cycles of important elements such as carbon (C) and nitrogen ( N), as well as their interactions with other substances and organisms - in the atmosphere, hydrosphere, biosphere and lithosphere.
These chemical cycles (in addition to C and N, also oxygen, sulphur, phosphorus or mercury) are either driven by microbiological activity themselves or influence it. Biogeochemical studies therefore traditionally include analytical-chemical, (micro-)biological and statistical methods
Ecosystem "functions" of a landscape, such as its role as a source or sink in the carbon cycle, can only be understood by integrating hydrological, geological and soil-ecological processes. Our research projects aim to analyse current ecosystem functions, but also to predict how they will react to future disturbances. To this end, we conduct research in a collaborative, interdisciplinary and cross-scale manner. In addition, we draw on freely available global datasets as often as possible in our biogeochemical analyses and modelling.
The Earth's ecosystems are constantly changing and the most important current trends include warming, increased nutrient availability (eutrophication), dam construction and decreasing regional rainfall. What they have in common is that they change the chemical and physical properties of the systems. Warmer lakes and reservoirs, for example, are more stably stratified, which can have an impact on the amount of greenhouse gases emitted, but also influences how the key nutrient phosphorus moves through the system. Less water in the landscape (e.g. due to less precipitation or longer warm periods) can also favour the depletion of oxygen in water and soil, where oxygen-free ("anoxic") zones can form. Our research therefore focuses on turnover processes (of C, N, O, S and Fe) in anthropogenically influenced ecosystems, with the aim of predicting their long-term effects on, for example, drinking water supplies, greenhouse gas emissions and the condition of terrestrial and aquatic habitats.
