Department of Geography

PhD position in soil organic matter cycling: Deep soil root biomass a key driver in the carbon cycle?
60 %

Our world is warming rapidly, and so do deep soil temperatures. But how will the largest terrestrial stock of actively cycling carbon, soil organic matter, respond to a warmer climate? Globally, several field experiments simulate a +4° C warming including the deep soil. First results show that experimental warming accelerated soil respiration significantly, accompanied by changing soil microbial communities and accelerated decomposition of biomass. And surprisingly, surface soil and subsoil respond very differently (see below: publications no. 1 & 2).

Your responsibilities

Project
Here we ask the question: Will warming accelerate the turnover of belowground biomass? One potential outcome could be that subsoil produce more greenhouse gases and thus could accelerate warming. We will investigate temperate forest and grassland, and tropical rainforest. The methodological approach is to follow isotopically labelled plant biomass incubated in deep soil for several years, supported by laboratory incubation experiments. We combine isotopic analysis and molecular markers to detect proxies for cell membranes of active microbes (and distinguish the presence of above- and belowground plant biomass (see below: publication no. 3). The ultimate aim of this project is to quantify underlying mechanisms of how deep soil responds to a warming world, and integrate this urgently needed understanding in the soil modules of evolving Earth System Models.

1 Soong, J. L. et al. Five years of whole-soil warming led to loss of subsoil carbon stocks and increased CO2 efflux. Sci Adv accepted (2021).

2 Ofiti, N. O. E. et al. Warming promotes loss of subsoil carbon through accelerated degradation of plant-derived organic matter. Soil Biolgy and Biochemistry in press (2021).

3 Jansen, B. & Wiesenberg, G. L. B. Opportunities and limitations related to the application of plant-derived lipid molecular proxies in soil science. Soil 3, 211-234 (2017).

Your profile

The ideal candidate will be experienced in experimental work, interested in operating high-end equipment in the lab, able to analyze comprehensive datasets, and will be a good team player. Responsibilities include supervision of students, presentations of results at conferences and publication in international refereed journals.
Requirements include a MSc-degree in soil biogeochemistry or a related discipline, such as physical geography, geo-ecology, environmental sciences, and some work experience in analytical methods. Good knowledge of English as working language is essential.

What we offer

The position is part of a SNF-funded research project "DeepC". The work involves field and lab work, data analysis, in collaboration with colleagues from the Lawrence Berkeley Laboratory. The position will also provide the opportunity to acquire teaching, communication, management and outreach experiences.
We offer varied and interesting work in an inspiring and socially relevant environment.
Diversity and inclusion are important to us.

Place of work

Irchel Campus

Start of employment

Start upon mutual agreement. Evaluation will start in March 2021 and will continue until the position is filled.
Send a letter of application, CV, a statement of your motivation and your research interests and addresses of two potential referees (e.g. former advisers)

Further information

For further details contact Prof. Dr. Michael W. I. Schmidt