Global climate change scenarios predict increase in the variability of episodic or extreme events (such as floods and violent storms), which will cause changes in lake subsidies and expose aquatic ecosystems to nutrient pulses and transfer imbalance within aquatic food web. Turbid storms can induce changes in water clarity and affect the lacustrine metabolism (from autotrophy to heterotrophy) and functional processes (production, transfer and recycling). Due to environmental forcing, living organisms undergo physiological stress and altered trophic pathways, which may finally result in functional processes different from the initial conditions. Despite the important consequences involved, the impact of extreme climate events on aquatic organisms and the feedback on trophic interactions and metabolic processes remains largely unknown.
This PhD project aims to strengthen knowledge on how climate forcing (extreme events, altered precipitation regime and lake subsidies) affects the plankton community diversity and lake functional processes. The UMR CARRTEL initiated a mesocosm research in Lake Geneva during summer 2019 (Mésolac project) to study the effect of predicted climate scenarios on the plankton community functioning. in 2021, a permanent experimental ground facility was installed, and a second experiment (DOMLAC project) was run focusing on the effect of the altered lake subsidies on the trophic network. This thesis work will set up : 1) a synergistic approach including analyses of datasets acquired during these previous mesocosms experiments, and 2) a new experiment planned in September 2022 (PARLAC project) with the specific aim to understand the effect of altered light climate on the plankton community functioning.
We will pay special attention to the organisation of the trophic networks (diversity and structure of interactions) and functional processes (production and trophic transfer), to disentangle the regulation factors governing the quantity and quality of nutritional transfer within the aquatic food web. The final objective will be to elucidate how lake ecosystems will face environmental disturbances in terms of ecosystem functioning, stability and recovery rates.
Keywords: plankton diversity; trophic biomarkers; climate stressors; experimental approach
Candidate profile: We seek a highly motivated and creative student with good background in aquatic ecology and excellent university scores. Previous experience with experimental planktology would be an advantage. The candidate will participate to the discussion and will be encouraged to develop an independent line of research targeting the project goals, taking advantage of the facilities and expertise of the supervisors.
Candidature submission: Interested applicants can send an email with a CV, motivation letter, a supporting letter and statements of previous grades and full university scores and rankings to the contacts below.
Deadline for submission: 20.05.2021. A first round of interviews will take place with the supervisors. Selected candidate will be invited for the final audition at the University Savoie Mont Blanc (14 and 15 June), upon which depends the decision on the grant awarding.
Dr. Serena Rasconi (CRCN), INRAE, Savoie Mont-Blanc University, CARRTEL
Prof. Jean-Christophe Clément, Savoie Mont-Blanc University, INRAE, CARRTEL
Serena Rasconi – email@example.com
Lab: INRAE UMR CARRTEL
Alpine Centre for Research on Lake Ecosystems and Food Webs
75 bis avenue de Corzent
74203 Thonon les Bains, FRANCE