EXPOTROPHIQ “Exposome of plant-phytophage-natural enemy food webs to plant protection products in agricultural landscapes: cascading effects on organisms, species communities and on the regulatory service of phytophagous insects”
Funding: ECOPHYTO
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
Summary: 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.
RESI-ADAPT “Residual pesticide contamination in agricultural landscapes: a factor in the adaptation of organisms to phytosanitary products?”
Funding: CNRS EC2CO DYCOVI
Partners/collaborators: UMR 6553 ECOBIO ; UMR 5805 EPOC ; UMR 7360 LIEC ; UMR 1349 IGEPP
Dates/period/years: 2023-2025
Summary: 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.
Project INTERREG CPES (Channel Payment for Ecosystem Services)
This project aims to increase water quality by developing PES (Payment for Ecosystem Services) schemes. PES remunerate the farmer, provided by public or private buyers, in return for the adoption of practices that reduce losses of nutriments (P, N, or generally erosion).
One of the 6 case studies (3 in France, 3 in UK) concerns Lac au Duc in Brittany and its catchment. Like in many water reservoirs, eutrophication results also there in the mass development of cyanobacteria during summer, which can harm the environment and human health by toxic or allergenic metabolites. This leads to the ban of recreational activities and increasing costs for drinking water production. In freshwater ecosystems, excess phosphorus (P) is generally seen as the responsible factor. The Lac au Duc case study addresses the catchment area where diffuse sources of P from agricultural activities and point sources such as waste water treatment plants contribute to the P charge of the river Yvel-Hyvet, emptying into the reservoir Lac au Duc.
The CPES case study Lac au Duc is a collaboration between scientists from OSUR-Geosciences and ECOBIO, INRA- and Agrocampus Ouest, and the SMGBO (Syndicat Mixte du Grand Bassin de l'Oust). Hydrologists, Geologists, Agroecologist tackle the scientific complexity together with the SMGBO, responsible for the contact to the farmers, local politicians and stakeholders. Moreover, we collaborate with a farmers’ association (Alli’Homme) and the CRAB.
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
