PhD about the decoupling of photosynthesis and stomatal conductance, INRAE Nancy, France (3 years)
INRAE - French national Research Institute for Agriculture, Food and Environment
The French National Research Institute for Agriculture, Food, and the Environment (INRAE) is a public research establishment. It is a community of 12,000 people with more than 200 research units and 42 experimental units located throughout France. The institute is among the world leaders in agricultural and food sciences, in plant and animal sciences, and is 11th in the world in ecology and environment. INRAE’s main goal is to be a key player in the transitions necessary to address major global challenges. In the face of the increase in population, climate change, scarcity of resources and decline in biodiversity, the institute develops solutions for multiperformance agriculture, high quality food and sustainable management of resources and ecosystems.
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By joining our teams, you benefit from (depending on the type of contract and its duration):
- up to 30 days of annual leave + 15 days “Reduction of Working Time” (for a full time);
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The exchange of water and CO2 between the biosphere and the atmosphere takes place mainly through the stomata. They open and close so that plants can maximise the CO2 input necessary for photosynthesis, while minimising water loss through transpiration. While photosynthesis can adapt to environmental changes in seconds, stomata respond more slowly. The response time of stomatal conductance varies from a few minutes to nearly an hour, depending on the species and the variations in environmental variables. Photosynthesis and stomatal conductance are not fully coupled during this lag time, leading to sub-optimal water use. This phenomenon is well known in the laboratory, but has not been studied at the ecosystem scale.
Objectives & Methods
The proposed thesis will focus on characterising the importance of the decoupling between photosynthesis and stomatal conductance on the dynamics of water and carbon fluxes at the scale of a forest ecosystem. The student will rely on kinetic data measured at the leaf scale as well as on flux data, representative of an ecosystem.
The thesis will therefore include several campaigns of stomatal conductance measurements: we envisage a first campaign under controlled conditions in a greenhouse to characterise the dynamics of stomatal conductance and photosynthesis under different environmental conditions in order to model daily kinetics at the leaf level. This will be followed by a second measurement campaign in the forest, at the FR-Hes experimental site, which is part of the international network ICOS. The flux data acquired at FR-Hes will also be analysed by the thesis student, in collaboration with a post-doctoral fellow who will process these data at high resolution using wavelet decomposition techniques. The thesis will eventually include a modelling component by taking into account the importance of the decoupling of photosynthesis/stomata, in a surface model, in order to estimate the importance of this process on larger scale.
- Master in ecophysiology or plant physiology or other relevant fields, or engineering school
- Motivated, dynamic and curious student who appreciates teamwork and is able to work independently
- Skills in data analysis and programming (R, Python) are a plus
- Good command of English (writing scientific articles, oral communication)
The thesis will take place at the UMR Silva (INRAE) Grand Est on the campus near Nancy (54280 Champenoux) from October 2022 onwards. Attendance of several conferences (national and international) is planned.
To apply, please send a cover letter to the thesis co-directors below, a CV, the transcript of grades of the master (or of the 3 years of engineering school), two letters of recommendation, as well as a synthetic description (300 words) of the master topic (or of the end-of-study internship).
Do not hesitate to ask for any further information.