PhD proposal 2018 in Ecology – Université de Lorraine, Metz, France

Supervisor: Michael DANGER (Assistant professor, HDR)
Co-supervisor: Elise BILLOIR (Assistant professor)
Collaborator : Philippe USSEGLIO-POLATERA (Professor)

LIEC – Laboratoire Interdisciplinaire des Environnements Continentaux
CNRS UMR 7360 – Université de Lorraine-Metz
Campus Bridoux, rue Claude Bernard, 57070 Metz, France
Tel.: +33 (0) ; Web site:
E-mails: [email protected] and [email protected]

Funding: IUF program to MD (2017-2022; 75k€), Lorraine Université d’Excellence (LUE, 100k€)
Beginning of the PhD: September 2018; 3-year funding.

Stoichiometric traits as Predictors of Aquatic Community and Ecosystem responses to global changes.

Keywords: Ecological stoichiometry; Community ecology; Functional ecology; Global change (eutrophication, contaminants, climate change)

General context

Over the past 200 years, human activities have significantly altered the carbon (C), nitrogen (N) and phosphorus (P) biogeochemical cycles, inducing in turn strong changes in the global climate and ecosystem functioning (Falkowski et al. 2000). While the consequences of these global changes on plant, animal and microbial communities and on ecosystem processes have received much attention in the past decades, predicting the interactive effects of these changes still represent a central challenge for ecologists (Cross et al. 2015).

To investigate the relationships between community structures and ecosystem functioning in response to global change, the use of functional traits has often been proposed as a pertinent approach (Diaz & Cabido 1997; Sala et al. 2000; Bonada et al. 2007; Floury et al. 2017; Latli et al. 2017). While often successfully predicting some general ecosystem processes (Colas et al. 2013), such trait-based approaches often lack accuracy for precisely relating communities and biogeochemical cycles.

Ecological stoichiometry (ES), a unifying conceptual framework focusing on how proportions of elements in resources and consumers (mainly C, N, and P) affect organisms and ecosystems (Sterner & Elser 2002), might represent a complementary approach for answering these questions. While commonly applied to single organisms or species, ES has rarely been studied at the community scale (Moe et al. 2005). The integration of stoichiometric traits (sensu Meunier et al. 2017, e.g. organisms’ C:P or N:P ratios) in the general framework of trait-based community ecology might represent a promising way for enlarging ES results from organisms’ physiology and individual based approaches to communities and ecosystem functioning.

Main objectives of the PhD project and succinct methodology

This project mainly aims at 1) developing an original database on stoichiometric traits of macroinvertebrates and fishes in rivers, and then integrate these traits in long term community structure databases for 2) understanding the responses of river communities to different parameters of global changes, and 3) investigating the outcomes of stressor interactions on community structures and predict their consequences for ecosystem functioning and C, N, and P biogeochemical cycles. The main hypotheses are that species occurring in communities are selected by their elemental requirements, and that global changes parameters, by changing nutrient availabilities and consumers’ requirements, can impact community structures in a predictable way. These hypotheses will be tested using large scale and long term data bases on fish and macroinvertebrate assemblages from National bioassessment surveys (databases already available in the LIEC laboratory).

Skills required for the applicants

The applicants should have a good knowledge of fundamental ecology, and be interested and potentially competent in the analysis of databases. In particular, a good knowledge of parametric and non-parametric statistical methods and a good background in R software utilization would be appreciated. Good writing skills (in English) will be required for results valorization. A small part of the PhD project requiring field sampling and organisms’ elemental content analysis, minimal competences in field and lab work could also be useful.

To apply:

Interested candidates should send :
– a detailed letter describing their motivation and competences,
– an updated curriculum vitae,
– an official document with marks and/or rankings obtained in master 1 and, if available, master 2
– a short summary of the master 2 internship
– reference letters (e.g. former or current internship supervisors)
to Michael Danger ([email protected]) and Elise Billoir ([email protected]).
You are welcome to submit your application no later than 30 April 2018. Pre-selected applicants will then be invited to present themselves and their project for a final selection between the 15th of May and the 15th of June (in Metz or possibly by visioconference/skype, the final date will be communicated later).

Bonada, N., Dolédec, S., & Statzner, B. (2007). Taxonomic and biological trait differences of stream macroinvertebrate communities between mediterranean and temperate regions: implications for future climatic scenarios. Global Change Biology, 13(8), 1658-1671.
Colas, F., Baudoin, J.M., Danger, M., Usseglio-Polatera, P., Wagner, P. & Devin, S. (2013). Synergistic impacts of sediment contamination and dam presence on river functioning. Freshwater Biology, 58, 320–336.
Cross, W. F., Hood, J. M., Benstead, J. P., Huryn, A. D., & Nelson, D. (2015). Interactions between temperature and nutrients across levels of ecological organization. Global Change Biology, 21(3), 1025-1040.
Díaz, S., & Cabido, M. (1997). Plant functional types and ecosystem function in relation to global change. Journal of vegetation Science, 463-474.
Falkowski, P., et al. (2000). The global carbon cycle: a test of our knowledge of earth as a system. Science, 290(5490), 291-296.
Floury, M., Usseglio-Polatera, P., Delattre, C. & Souchon, Y. (2017). Assessing long-term effects of multiple, potentially confounded drivers in ecosystems from species traits. Global Change Biology, 23, 2297-2307.
Latli, A., Descy, J.-P., Mondy, C.P., Floury, M, Viroux, L., Otjacques, W., Marescaux, J., Depiereux, E., Ovidio, M., Usseglio-Polatera, P., Kestemont, P. (2017). Long-term trends in trait structure of riverine communities facing predation risk increase and trophic resource decline. Ecological Applications, 27(8), 2458-2474.
Meunier, C.L., Boersma, M., El-Sabaawi, R., Halvorson, H.M., Herstoff, E.M., Van de Waal, D. B., Vogt R.J. & Litchman, E. (2017). From Elements to Function: Toward Unifying Ecological Stoichiometry and Trait-Based Ecology. Frontiers in Environmental Science, 5, 18.
Moe, S.J., Stelzer, R.S., Forman, M.R., Harpole, W.S., Daufresne, T. & Yoshida, T. (2005). Recent advances in ecological stoichiometry: insights for population and community ecology. Oikos, 109, 29-39.
Sala, O.E., Chapin, F.S., et al. 2000. Global biodiversity scenarios for the year 2100. Science, 287(5459), 1770-1774.
Sterner R.W. & Elser J.J. (2002). Ecological stoichiometry: the biology of elements from molecules to the biosphere. Princeton University Press, Princeton, USA

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