Grégoire Freschet joins TULIP to explore the relationship between biodiversity and ecosystem functioning

Grégoire Freschet recently obtained a "Junior" package from TULIP, an attractiveness project prepared for many months by the LabEx team and the Moulis Theoretical and Experimental Ecology Station (UMR 5321 CNRS / UPS). We take this opportunity to talk about his research on the role of plant diversity and their symbionts in the stability of ecosystem functioning at the interface between plant functional biology and ecology.

What are your research activities on?

My research focuses on the dynamic relationships between plants and their environment, including soil. I am particularly interested in the effects of plants and their symbionts on ecosystem functioning and stability. Through their functional traits and diversity, plant-symbiotic associations strongly influence biogeochemical cycles in ecosystems (for example, primary productivity, the nutritional quality of plants, their resistance to herbivores or litter decomposition, soil carbon storage, and large cycles of nutrients), and play a major role in the context of land use change, particularly with the arrival of new agro-ecological practices that profoundly modify ecosystem and agrosystem functioning. In this context, I wish to highlight the mechanisms by which plant-symbiont associations can improve ecosystem stability, in order to determine under what conditions plant-symbiont diversity can improve ecosystem functioning.

Why to come to SETE and TULIP?

The scientific and technical environment of SETE within the LabEx favors interdisciplinary collaborations on biodiversity and plant-soil-microorganism interactions. Clearly, my project is at the interface of TULIP’s main themes, between biology and ecology, plants and microorganisms, while linking the two scales of organisms and communities.

However, leaving a well-established research group and efficient collaborations is never easy. When I discovered the LabEx Tulip Packages, I quickly realized that it was the ideal tool to quickly create a new group of research. In the current context of public research, this kind of tool is exceptional.

How did the package help you to come and settle?

The rapid implementation of my research and their interdisciplinary development depended on the kind of financial support that I could get, in terms of technical equipment and scientific environment. I am fortunate to work in both soil science and plant physiology, but this also implies that I have rather large needs in terms of space, equipment and analyses... The TULIP financial support will allow me to set the conditions to start my new projects in the coming months and years, and to perpetuate good working conditions.

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Experimental manipulation of the diversity of herbaceous plants © G. Freschet

Speaking of your projects, what are they?

My biggest ambition is an experimental ecology project coupling plant ecophysiology, root ecology and symbiotic interactions in order to explore the mechanistic aspect of Biodiversity-Ecosystem Functioning relationships. Several recent reviews, as well as my own work, have highlighted the lack of knowledge about root mechanisms and their symbioses underlying the relationships between plant biodiversity and (multi-) ecosystem functionality. My project assumes that plant diversity favors symbiotic associations' diversity (mycorrhizae, rhizobia), all of which positively impacting the multifunctionality of ecosystems. It also postulates that the effects of biodiversity on ecosystem functions could be explained by the diversity of different trait pools, each directly related to the targeted function. Finally, it aims at highlighting the effect of environmental variations on diversity-multifunctionality relationships and on the processes generating that variation.

This project involves experiments manipulating the biodiversity of herbaceous plants and their symbiotic associations under controlled conditions. It involves the measurement of a set of functional plant traits, community properties of soil microorganisms (symbiotic and non-symbiotic) and multiple ecosystem functions.

To initiate this project, I will carry out a series of pilot experiments together with LabEx partners to help me refining my research hypotheses and to feed an interdisciplinary reflexion on these questions. In the medium term, this work will feed the writing of ANR International or ERC applications.

Modification date : 07 June 2023 | Publication date : 26 April 2019 | Redactor : Guillaume Cassiède-Berjon & Grégoire Freschet