Post-doc position in Paris in microbial ecology

Context and scientific objectives
The ANR NitroAfrica project aims to study the effects of the increase in atmospheric nitrogen deposition currently observed worldwide, and particularly in Africa, on soil functioning and associated greenhouse gas emissions (CO2, N2O, CH4) and reactive gases (NO). Permanent plots have been set up since April 2023 in Lamto (Côte d’Ivoire, wet tropical climate), Korhogo (Côte d’Ivoire, more marked dry season) and Dahra (Senegal, dry tropical climate), with plots in agricultural and natural vegetation zones at each site. The plots received different fertilisation treatments (a control, and three treatments with an increase in nitrogen deposits with contrasting ammonium-nitrate ratios). Gas emission measurements have been carried out every month of the wet season in situ at Lamto since April 2023, and during intensive campaigns at Korhogo and Dahra in 2024, soil and biomass samples were collected at all 3 sites. The LAERO laboratory in Toulouse, which runs the project (https://www.aero.obs-mip.fr/), is responsible for modelling these gas emissions and using the model to predict feedbacks on the regional climate.

The objective of the postdoctoral work is to describe soil microbial communities using classical molecular biology methods, focusing in particular on genes related to the nitrogen cycle (e.g. amoA-AOB and amoA-AOA for nitrification). The aim will be to test to what extent fertilization treatments, vegetation type and site impact these communities. These data can also be statistically linked to gas emissions, soil physicochemical and biomass analyses (plant and total microbial abundances).

Scientific team
The work will be carried out under the supervision of S. Barot (DR IRD), J.-C. Lata (PR SU) and Yoan Marcangeli (AI CNRS) in the “Ecosystem Functioning in the Anthropocene” team of the Institute of Ecology and Environmental Sciences-Paris (https://iees-paris.fr/).

Selected publications of the scientific team
Srikanthasamy, T., J. Leloup, A. B. N’Dri, S. Barot, J. Gervaix, A. W. Koné, K. F. Koffi, X. Le Roux, X. Raynaud, and J.-C. Lata. 2018. Contrasting effects of grasses and trees on microbial N-cycling in an African humid savanna. Soil Biology and Biochemistry 117:153-163.
Srikanthasamy, T., Barot, S., Koffi, F.K., Tambosco, K., Marcangeli, Y., Carmignac, D., N’Dri, A.B., Gervaix, J., Leloup, J., Le Roux, X., Lata, J.-C., 2022. Effects of vegetation cover and season on soil nitrifiers in an African savanna: Evidence of archaeal nitrifier inhibition by grasses. Geoderma 115775.
Yé, L., Lata, J.-C., Nacro, H.B., Masse, D., Barot, S., 2021. Effects of livestock on nitrogen and carbon cycling in a savanna in Burkina Faso. Acta Oecologica 110, 103694.
Lata, J.-C., Le Roux, X., Koffi, K.F., Yé, L., Srikanthasamy, T., Konaré, S., Barot, S., 2022. The causes of the selection of biological nitrification Inhibition (BNI) in relation to ecosystem functioning, and a research agenda to explore them. Biology Fertil. Soils 58, 207–224.
Konaré, S., Koffi, K.F., Boudsocq, S., Gignoux, J., Lata, J.C., Raynaud, X., Barot, S., 2024. Spatial heterogeneity of nitrification contributes to tree–grass coexistence in West African savannas. J. Ecol. 112, 86–97.

Candidate profile
The postdoc must have skills in soil and ecosystem ecology and the ability to carry out the quantification of different genes as autonomously as possible (extraction and purification of nucleic acids from the soil, amplification of certain genes, quantification). She/he must be able to statistically analyse the data obtained. The postdoc will have completed a doctorate in soil microbial ecology or a related field.
The work can be carried out in French or English. A good knowledge of English will be essential for writing articles for international journals and communication in international conferences.

Location
The postdoc will be carried out at the IEES-Paris Laboratory (Sorbonne University, 4 place Jussieu, 75005 Paris, France) in the “Ecosystem Functioning in the Anthropocene” team.

Duration and salary
From 19 to 24 months (ideally from September 2025) and net salary between 2000 euros and 2500 euros per month (depending on experience).

How to apply
Send a CV and covering letter to sebastien.barot@ird.fr before 10 May 2025