Arriving at D-USYS: Prof. Sebastian Dötterl

Why tropical regions are important to us

Deforestation, crop cultivation and soil degradation can have serious consequences for ecosystems. The way in which biogeochemical cycles in soils react to erosion is one of the greatest uncertainties when it comes to gauging the fluxes of greenhouse gases from soils to the atmosphere. «This is largely due to the lack of data in areas such as tropical Africa,» explains Dötterl, «but it's also a result of inadequate knowledge transfer from smaller to larger scales.» During the course of his ongoing projects Dötterl therefore repeatedly visits the Congo Basin with the aim of gaining a better understanding of the biogeochemical cycles in tropical soils, which are often much older and lower in nutrients than soils in the temperate zones. For example, it is unclear how carbon dynamics in the tropics differ from temperate climatic zones. A major portion of our knowledge of mechanistic processes is derived from temperate regions where a comparatively large amount of research is carried out. «It is important to close this gap in our knowledge,» emphasises Dötterl, «because tropical ecosystems are of key importance on a global level.» When investigating plant and soil carbon sequestration we are ultimately concerned with soil fertility, plant productivity and food supply.

Projects in Switzerland and the high latitudes

Ecosystems in tropical Africa are frequently geared towards quickly recycling dead organic material and assimilating them into the nutrient cycle. Conversely, nutrients are often leached directly out of the rocks in mountainous regions and the high northern and southern latitudes that have poorly developed and young soils. This is leading Dötterl to further research projects that attract keywords such as «Alpine greening» and «Antarctic Greening», in which he and his team are investigating how warming in these areas affects plant growth and how biogeochemical processes, in line with increasingly intensive soil weathering, interact with a changing climate.

Opportunities at ETH Zurich

«In order to be able to comprehensively investigate complex environmental processes – from experimentation through to modelling – and to do so on various scales, there are only very few places on Earth where such research is possible under one roof», says Dötterl appreciatively. One of them is ETH Zurich. Here, Dötterl benefits enormously from opportunities for collaboration. For instance, his post-doctoral students are already working closely with Prof. Tim Eglinton's biogeosciences group. He is also in discussion with other professors at D-USYS and D-ERDW (Department of Earth Sciences). During the course of the year his group will be expanded by several postdocs and doctoral students.