One Ph.D. position focusing on the ecological consequences of global warming on aquatic ecosystems is available at the RECOVER laboratory in the freshwater ecology (FRESHCO) team at the INRAE of Aix-En-Provence (France). The student will work under the supervision of Arnaud SENTIS (INRAE), in collaboration with other researchers, post-doc, PhD students and technicians. This position is part of a large European project (ERC project Climate CountDown) investigating the thermal vulnerability of freshwater communities (https://www.inrae.fr/en/news/erc-grant-evaluate-thermal-limits-lake-communities). The successful applicant will have the opportunity to work and collaborate with other people involved in this project.
Topic:
Ectothermic animals are particularly sensitive to global warming as their body temperature closely matches the surrounding environmental temperature. Most predictive models of ectotherm responses to extreme warm temperature use the upper critical thermal maximum (CTmax) as an indicator of their heat tolerance (Pinsky et al. 2019). CTmax is typically measured in laboratory trials by exposing a single individual to a gradual temperature increase until it loses its locomotor functions. The CTmax is critical in defining the fundamental niche of ectothermic animals, their biogeographical distribution (Sunday et al. 2012, Desforges et al. 2023) and the lethal effects of heat waves (Genin et al. 2020). Climate change is increasing thermal vulnerability by increasing exposure to heat waves so that extinction risk is becoming critical (Jørgensen et al. 2022).
Temperature as well as predatory and competitive interactions can modulate the composition of communities by influencing their relative abundance. However, it remains unexplored how these processes influence the vulnerability of communities to heat waves. The aim of this phd will be to investigate how temperature, food web structure and species interactions can influence the vulnerability of communities to heat waves using information on the CTmax of each species. For instance, predator-induced trophic cascades can result in a higher relative proportion of smaller organisms from lower trophic levels. This can decrease the vulnerability of the community as smaller organisms have higher CTmax (Peralta-Maraver and Rezende 2021). To investigate the thermal vulnerability of communities, the successful applicants will use mesocosms experiments seeded with pelagic communities of macroinvertebrates, zooplankton and phytoplankton. We will manipulate food web structure and temperature and then sample the mesocosms to monitor changes in community composition (species richness and abundances). We will measure the CTmax of each species at the end of the experiments and assess the vulnerability of the entire community to heat waves.
Candidate competences:
We are seeking highly motivated students with good organizational skills and strong interests in both quantitative and experimental ecology, as well as global change ecology. Master students in biology, ecology or a related field are welcome. Students interested in both experimental and theoretical work are particularly encouraged to apply. Candidates should be sufficiently fluent in English to be able to read and write scientific articles, and engage in discussions. Previous experience with food-web ecology, thermal ecology, freshwater fauna, laboratory/mesocosm experiments, and statistical analyses (R software) will be strongly appreciated. We are looking for persons with open mind attitude, proactive and capable to carry out research with a certain degree of autonomy.
Practical information:
Starting date: 01/09/2025.
Duration: 3 years
Location: INRAE, UMR RECOVER, 3275 route Cézanne, 13182 Aix-en-Provence, France
Dead-line for application: 09/06/2025.
To apply: please send your CV, a motivation letter, Master diploma/results, as well as a maximum of 2 recommendation letters to Arnaud Sentis (arnaud.sentis@inrae.fr).
Informal enquiries are welcome – please contact us by email in french or english.
References:
Desforges, J. E., K. Birnie‐Gauvin, F. Jutfelt, K. M. Gilmour, E. J. Eliason, T. L. Dressler, D. J. McKenzie, A. E. Bates, M. J. Lawrence, and N. Fangue. 2023. The ecological relevance of critical thermal maxima methodology for fishes. Journal of Fish Biology 102:1000-1016.
Genin, A., L. Levy, G. Sharon, D. E. Raitsos, and A. Diamant. 2020. Rapid onsets of warming events trigger mass mortality of coral reef fish. Proceedings of the National Academy of Sciences 117:25378-25385.
Jørgensen, L. B., M. Ørsted, H. Malte, T. Wang, and J. Overgaard. 2022. Extreme escalation of heat failure rates in ectotherms with global warming. Nature 611:93-98.
Peralta-Maraver, I., and E. L. Rezende. 2021. Heat tolerance in ectotherms scales predictably with body size. Nature Climate Change 11:58-63.
Pinsky, M. L., A. M. Eikeset, D. J. McCauley, J. L. Payne, and J. M. Sunday. 2019. Greater vulnerability to warming of marine versus terrestrial ectotherms. Nature 569:108-111.
Sunday, J. M., A. E. Bates, and N. K. Dulvy. 2012. Thermal tolerance and the global redistribution of animals. Nature Climate Change 2:686-690.
Commentaires récents