#10 Louis: Soil microbial responses to land use change

How do changes in land use and plant community affect the activity of soil microbes and their carbon use efficiency?

Louis Dufour is a PhD student at the Swedish University of Agricultural Science (SLU). He conducts field experiments to see how microbial communities in the soil respond to changes in plant communities in terms of their activity and carbon turn-over.

Department & Group: Department of Soil and Environment, Group of Nutrient Cycling, SLU

Supervisors: Anke M. Herrmann, Johanna Wetterlind, Martin Weih, Stefano Manzoni, Naoise Nunan

Dissertation title (as for now 😀)

Responses of microbial physiology to changes in land management: a bioenergetics approach

Topic – in brief

Testing whether changes in plant community affect the activity of microorganisms. Changes in plant community that occur during changes in land use refer to types of vegetation like grassland, wood land or cover crops in fields. Louis wants to gain understanding of how land management influences the composition of organic matter in the soil and how these different compositions influence microbial activity in the soil and the effect of this activity in terms of releases of heat and CO2.


Microbial physiology refers to the adaptation or behavioural changes of a community of microorganisms as a respond to changes in their environment.

Louis’ approach:

Bioenergetics approach

  • Determine the composition of soil microbial communities through DNA sequencing and organic molecules present in the soil through ultra-high resolution mass spectrometry, infrared spectroscopy, and pyrolysis GC-MS with reference to above-ground plant communities.
  • Study the interaction of molecules and microbes: What are the microbes ‘doing’ in presence of a given “cocktail” of organic molecules? E.g. converting the molecules into smaller ones such as CO2, converting them into exoenzymes, incorporating them into their own biomass or producing heat.

Way forward:

  • Ultimately, Louis’ findings can help to improved carbon models, which predict carbon dynamics in soil as a respond to land use changes.
  • Through such models one might be able to give recommendations for land-use changes that can enhance carbon sequestration


Potential energetic return on investment positively correlated with overall soil microbial activity

Louis’ joys & struggles

Joys: the development of scientific skills like critical thinking, asking questions, formulating and testing hypothesis.

Struggles: finding that some paradigms or narratives in science might not be as straightforward as they are sometimes presented – and learning how to read or find the sometimes hidden biased in science.

If you would like to get in touch with Louis: louis.dufour@slu.se

Louis’ funding: Agence Nationale de la Recherche (ANR-14-CE22-0021) ; the Swedish Research Council Formas (22836000 and OPTUS 22551000) ; Financial support from the French FT-ICR network (FR3624CNRS) ; co-funding from EJP SOIL and NJ faculty at SLU.)

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