Postdoc on characterization of insect fluxes from aquatic to terrestrial agricultural environments

The University of Rennes has an open Postdoc position for 18 months on the characterization of aquatic insect fluxes from temporary aquatic to terrestrial agricultural environments in Brittany, France.

Research objectives and hypotheses

This post-doctorate is part of the ANR STRANGE project (2023-2027), focused on aquatic insects’ ecosystem services in terrestrial environments. Permanent aquatic environments are the focus of the STRANGE project. This postdoc aims to quantify aquatic insect biomass emergence from temporary aquatic environments, model their fluxes in agricultural landscapes and estimate the associated ecosystem services.

Temporary aquatic insect emergence sources are hypothesized to be largely underestimated compared to permanent habitats. A second hypothesis suggests that water supply type (flooding or groundwater) significantly impacts biomass production, species colonization, and nutrient-related ecosystem services. These temporary sources must be identified in time and space to determine diversity, contributions to production, and hydrological functioning over time. Seasonal monitoring will enable biomass quantification and associated flow modelling in temporary aquatic areas.

Innovative scientific aspects

  • Temporary aquatic areas will be characterized using UAV monitoring tools. The development of methods for systematic, large-scale mapping of submerged areas and their temporal fluctuations to advance aquatic environment quantification.
  • Quantification of biomass and emerging diversity of temporary aquatic environments, primarily Diptera, will be quantified at a landscape scale for the first time. This is a scientific front at the interface between terrestrial and aquatic ecology.
  • Estimation of ecosystem services associated with aquatic insect fluxes, incorporating temporary aquatic environments for an exhaustive view of the impact of aquatic productivity on terrestrial environments.

Objectives and methodologies

1. Identification of temporary aquatic zones (year 1)

Temporary aquatic zones’ spatial and temporal evolution will be characterized and quantified. Monitoring will occur at Zones Ateliers Armorique and Brest-Iroise, socio-ecological research observatories within an interdisciplinary CNRS-approved network. These long-term Socio-Ecological Research observatories provide a large amount of complementary environmental data. Spatiotemporal characterisation and quantification will use image analysis and photo interpretation from UAV overflights and field surveys.

2. Characterisation of insect biomass and diversity (year 1)

Quantifying biomass production and characterising the diversity of emerging insects in flooded areas in winter and spring through field monitoring. In temporary aquatic environments, emerging aquatic insects mainly belong to Diptera. To collect the insects, emergence traps will be set up in flooded meadows, ditches and wetlands during the flooding period. The insects will be identified and quantified in the laboratory, using the morphology and/or molecular tools.

3. Spatialisation of results (year 2)

The data obtained in objectives 1 and 2 will be integrated into developed and validated flux models (Gerber et al. 2023). Three stages will be necessary to produce these models:

  • Update the flux models developed for Ephemeroptera, Plecoptera and Trichoptera using previously collected Diptera data from permanent streams.
  • Calibrate the model to integrate information relating to temporary aquatic environments (e.g. their surface areas, locations and hydrological functioning).
  • Weight the model by the biomass produced.

Host team

The person recruited will be affiliated with UMR CNRS 6553 ECOBIO. The research unit ECOBIO covers all areas of ecology: evolutionary ecology, behavioural ecology, community ecology, functional ecology and landscape ecology. The person recruited will benefit from the support of the technical platforms PEM (for molecular analyses), Ecolex (for support in field protocols and an optical centre for the identification) and the D2T platform for the analysis of images obtained by drone. The person recruited will also be assisted by an engineer to carry out the technical parts of the project concerning the GIS analyses relating to the spatial modelling of the results.

Profile required

The candidate must have a PhD in terrestrial and/or aquatic ecology. Since aquatic insect assemblages in the temporary aquatic environments are mainly constituted by Diptera, experience in identification and/or ecology of Diptera would be greatly appreciated. Insects will be identified in the laboratory (on the basis of morphological criteria) and/or using molecular tools (barcoding and/or metabarcoding). However, experience in using molecular tools is not necessary, as training courses can be provided in our laboratory. The candidate must have knowledge of data processing and an interest in basic and applied research. An aptitude for fieldwork, laboratory work and data processing is essential, as are good English writing skills.
The funding is intended for a post-doc who has spent at least 18 months outside France between May 1, 2021, and the start of the project.

Financial resources

The salary will be covered by the Bienvenüe program. The BIENVENÜE funding covers are:

  • an 18-month fellowship with a gross salary of 4,510€/month and
  • a full social security coverage according to French standards: family allowance, parental and sick leave, 25 vacation days per year minimum, transport contribution, pension contribution, unemployment benefits.

The functional resources are associated with the STRANGE project (Ecosystem Services provided by sTReams to AdjaceNt aGricultural tErrestrial ecosystems; ANR funding, 2023-2027). This project brings together 10 French research units. It aims to assess the ecosystem services provided by aquatic ecosystems to adjacent agricultural environments via winged insects (crop fertilization, pollination, pest control services).

Supervision and application

The new recruit will be supervised by Christophe Piscart (Director of Research) at the CNRS, Benjamin Bergerot (Associate Professor) and Stéphane Derocles (Assistant Professor) at the University of Rennes. For further information, contact the supervisors (benjamin.bergerot@univ-rennes.fr, christophe.piscart@univ-rennes.fr and stephane.derocles@univ-rennes.fr)

To apply: https://emploi.cnrs.fr/Offres/CDD/UMR6553-CHRPIS-007/Default.aspx?lang=EN