M. Sc. Project

Viruses, Carbon Cycling and Climate Change

Soils store more carbon than the atmosphere and vegetation combined, and understanding what controls carbon losses from soil is essential for predicting climate change. Microbes play a central role in breaking down plant litter, and recent studies suggest that viruses infecting these microbes may strongly influence how much carbon is released as CO₂ or dissolved organic carbon (DOC). However, these ideas have never been tested in agricultural soils, where management practices strongly shape microbial communities and soil health.

This Master project will investigate how natural soil viral communities affect carbon release during the early stages of plant litter decomposition. We will use soils from four contrasting agricultural management systems (conventional vs. organic; intensive tillage vs. reduced/no tillage; and additional grassland and woodland as controls). For each soil, a microbial community will be exposed to three treatments: (1) no added virus, (2) killed-virus material (a control for organic matter addition), and (3) live viral particles extracted from the same soil.

The student will set up controlled microcosms with buried plant litter and monitor carbon dynamics by measuring CO₂ production and dissolved organic carbon. At the end of the experiment, we will assess microbial biomass and basic nitrogen pools and examine how microbial communities changed using DNA sequencing. Viral communities from the original soils will also be characterized by collaborators to understand how management practices influence viral diversity.

The project provides training in experimental design, scientific reporting, statistical analysis, soil biogeochemistry, microbial ecology, and modern molecular techniques. It offers a unique opportunity to explore an emerging topic in soil ecology with direct relevance to carbon cycling, climate change and sustainable agriculture.

Further information & daily supervision: 

Daniel Müller (daniel.mueller9@uzh.ch, +41 78 721 01 50) & Stefanie Lutz (stefanie.lutz@uzh.ch, +41 76 250 77 86)

Responsible Professor: Marcel van der Heijden

The Agroecology & Plant-Microbiome Interactions group is a dynamic, engaging, international research group at Irchel Campus with approx. 25 members, including between 3-7 Master and Bachelor students.