Environmental Contaminants

Funding: ECOPHYTO

Ecobio collaborators: Cécile Sulmon, Cécille Le Lann, Gwenola Gouesbet, Axel Beringue, Nathalie Le Bris, Marion Chorin, Frédérique Pallois, Olivier Jambon, Rémi Bodiguel, Stéphanie Llopis, Thierry Fontaine

Partners/collaborators: UMR 6553 ECOBIO ; UMR 5805 EPOC ; UMR 7360 LIEC ; UMR 1349 IGEPP ; Chambre Régionale d’Agriculture de Bretagne

Dates/period/years: 2023-2025

The use of plant protection products (PPP) in conventional agriculture induces contamination of cultivated plots and adjacent areas via atmospheric drift and runoff processes. However, these adjacent areas are biodiversity refuges and sources of services in agricultural landscapes. They host species of plants, phytophagous, natural enemies and predators organized into food webs, which constitute elements of biodiversity, nutritive resources, and support for the regulation service of crop pests. In these areas, species are exposed to a diversity of PPPs at varying residual concentrations, and whose impacts on organisms, communities, and ecosystem services are unknown. The project wants to characterize the exposure of food webs to PPPs in grassy margin-type areas, and to assess the in situ and laboratory impact of PPPs on the different trophic levels, the functioning of the network and the regulating service provided by auxiliaries. Species exposome takes into account the edaphic, atmospheric and trophic exposure pathways and the study of the impacts integrates the non-target effects, low doses and cascading effects along the network. The project is partly focused on the model trophic chain Plant-Phytophage-Natural Enemy and a model of trophic interaction Flowering Plant -Natural Enemy exploiting the floral resource. This project makes the link between exposure of organisms to PPPs in grassy margins and impacts on the health of organisms, communities and ecosystems.

Keywords: biodiversity, exposome, pesticides and degradetion products, ecosystemic services

Funding: CNRS EC2CO DYCOVI

Ecobio collaborators: Cécile Sulmon, Cécille Le Lann, Gwenola Gouesbet, Axel Beringue, Nathalie Le Bris, Marion Chorin, Frédérique Pallois, Stéphanie Llopis, Thierry Fontaine

Partners/collaborators: UMR 6553 ECOBIO ; UMR 5805 EPOC ; UMR 7360 LIEC ; UMR 1349 IGEPP 

Dates/period/years: 2023-2025

The massive use of pesticides to control weeds and crop pests has led to widespread contamination of cultivated soils, but also of soils in ecosystems adjacent to crops. However, these environments constitute refuge areas for biodiversity, in particular for plant species, phytophagous insects and their natural enemies, which represent, respectively, a threat or a benefit for crops. These species, which organize themselves into trophic systems, are therefore chronically exposed to residual doses of a multitude of pesticides, which pass from one trophic level to another via nutrient flows. Many adaptations to pesticides have been described in response to repeated exposures to high doses of pesticides. Recently, work has shown that low doses of pesticides can also induce adaptations in plants and insects, but these results remain limited to laboratory experiments.

The objective of the RESI-ADAPT project is to determine whether the residual contamination of pesticides present in the soil around crops can induce, within a plant-phytophage-natural enemy system, adaptations to pesticides. RESI-ADAPT therefore seeks to characterize the level of exposure and contamination of these organisms, and to determine whether these recurrent exposures to pesticides result in the establishment of adaptations in the species studied, considering the generic or specific character of these adaptations. The role of endosymbionts in the acquisition of adaptations is also discussed. Finally, adaptations inducing compromises on key biological functions, RESI-ADAPT will characterize the potential consequences of adaptations on trophic interactions and pesticide dynamics within this system, and biological regulation services.

The work is carried out in the field and in the laboratory. The field study is carried out on devices of grassy margins located within the Armorique workshop area and adjacent to crops grown in conventional (AC) and organic (AB) agriculture, to represent contrasting exposures to pesticides. The trophic model includes a poaceae, a phytophagous aphid and its natural enemy (parasitoid). The populations of these organisms are sampled on the AB and AC margins. Their pesticide content is analyzed and their level of adaptation to pesticides is evaluated in the laboratory via dose-response ranges in the presence of different molecules. The comparative analysis of the AC and AB trophic systems will make it possible to identify the consequences of potential adaptations on the functioning of the system. At the same time, an experimental evolution test will make it possible to highlight, in pest aphids, their ability to develop adaptations over generations after chronic exposure to low doses of pesticides.

This project could ultimately encourage consideration of the effects of low doses of pesticides on trophic systems and agricultural support services in a risk assessment process.

Keywords: plant-phytophage-natural enemy system, grassy margins, pesticide dynamics, regulation services, trophic system

The Interreg France (Channel) England Programme is a European Cross-Border cooperation programm funding high quality cooperation projects in the Channel border region between France and England. The Interreg France (Channel) England Programme is funded through the European Regional Development Fund (ERDF).

Ecobio collaborators: Claudia Wiegand (Pr), Luc Brient, Morgane Le Moal (PostDoc), Gorenka Bojadzija (PostDoc), Emilian Mineaud (M2), Marion Chorin. Many thanks to Alexandrine Pannard and Guillaume Bouger for their help and contribution §

Partners: OSUR-Geosciences and ECOBIO, INRA- and Agrocampus Ouest collaborated with the SMGBO (Syndicat Mixte du Grand Bassin de l'Oust), a farmers’ association (Alli’Homme) and the CRAB

Dates: Dec 2017-Avril 2022. 

This project aimed to increase water quality by developing PES (Payment for Ecosystem Services) schemes between public or private buyers and farmers. PES remunerate the farmer for the adoption of practices reducing loss of phosphate, nitrate, or general erosion. One of the 6 case studies (3 in France, 3 in UK) concerned Lac au Duc in Brittany and its catchment. Like in many water reservoirs, eutrophication results in the mass development of cyanobacteria during summer, harming the environment and human health by toxic or allergenic metabolites. This leads to the ban of recreational activities and increases costs for drinking water production. In freshwater ecosystems, excess phosphate is generally the responsible factor. Thus, diffuse sources of phosphate were assessed in the catchment from agricultural activities and point sources (sewage treatment), and methods to reduce it developed in collaboration with the farmers. Long term data of cyanobacteria and their toxins correlated to the changing climate conditions. Treatment with hydrogen peroxide proved not to be an acute solution for this lake.

further information: https://www.cpes-interreg.eu
and
https://ecobio.univ-rennes1.fr/news/projet-interreg-cpes-ameliorer-la-qualite-de-leau-en-encourageant-les-paiements-pour-services.html

Funding: MAÏMONIDE Hubert Curien Program

Partners/collaborators: Équipe NBG (UMR 6118 - Géosciences Rennes) et French Associates for Agriculture and Biotechnologies (Ben-Gurion University of the Negev, Israel).

Dates/period/years: January 2022 to December 2023

Iron (Fe) is an essential micronutrient for microorganisms and plants. While Fe is abundant in soils, its bioavailability is very low since Fe is commonly found as insoluble Fe3+ oxides and hydroxides in soils. To improve Fe bioavailability, the use of Fe-chelating synthetic organic molecules (such as EDTA) is widespread, yet, toxic to plants and the soil ecosystem. The current project aims at improving the growth of plants and the soil chemical properties (such as cation exchange capacity and nutrient cycling) by developing eco-friendly Fe colloidal phases to amend soils. The project is also intended to unravel the effects induced by the addition of those Fe colloidal phases on soil trace gases emissions and nitrogen (N) cycle.

Keywords: soil, nutrition, iron, nitrogen cycle

Funding: Project PAUSE Emergency Support Programme for Scientists in Exile (University of Rennes 1) for Prof. Nataliia Ryzhenko (Ukraine).

Partners/collaborators: Équipe NBG (UMR 6118 - Géosciences Rennes).

Dates/period/years: 01/01/2023 – 31/12/2023

Plastic pollution is one of the major challenges of the Anthropocene. Plastic production has drastically increased over the last century, resulting in a dramatic generation of plastic wastes in the world. However, most studies assessing plastics focused on microplastics (MPT) in marine environments, while the occurrence of nanoplastics (NPT) has been overlooked in terrestrial water and soil systems. The identification of the interactions and the mechanisms involved in nanoplastic / plant-microbiome interactions are a major prerequisite to understand and predict their dissemination in the environment. The main questions addressed in this project will be: The identification of the parameters controlling the absorption and translocation of nanoplastics and associated pollutants; (ii) Ecotoxicological effects; (iii) Feedback effects from the rhizosphere on the mobility and bioavailability of nanoplastics and associated metals.

Keywords: Nanoplastics-metal-organic pollutants Bio-accumulation – Translocation, Ecotoxicity-rhizo-microbiota.