Articles scientifiques

Approche expérimentale de la plateforme CA-SYS

• Petit, S., Deytieux, V., Cordeau, S., 2021. Landscape-scale approaches for enhancing biological pest control in agricultural systems. Environmental monitoring and assessment 193. https://link.springer.com/article/10.1007/s10661-020-08812-2 

Abstract - Over the last decades, land management options have been investigated that aim at enhancing services to agriculture delivered by biodiversity and its associated biotic interactions. Such services can be promoted through land management strategies ranging from in-field single agricultural practices, long-term strategies compiling these agricultural practices at the crop rotation scale, to management strategies at the landscape scale. In this paper, we provide an overview of the land management options that can be implemented at multiple scales, with a specific focus on the provision of one service that is key in agriculture, i.e. pest control. We present existing knowledge and highlight current gaps and limitations in our understanding of pest control response to land management. Based on this analysis, we propose two promising and complementary research approaches that could help filling existing knowledge gaps and provide guidelines for designing landscapes for agroecological services: (1) landscape monitoring networks (LMN), based on long-term monitoring of ecological and managerial processes within sets of landscapes located in contrasted production contexts; (2) agroecological system experiments (ASE), which design and assess combinations of land management options at multiple embedded spatial scales.

• Vanbergen, A.J., Aizen, M.A., Cordeau, S., Garibaldi, L.A., Garratt, M.P.D., Kovács-Hostyánszki, A., Lecuyer, L., Ngo, H.T., Potts, S.G., Settele, J., Skrimizea, E., Young, J.C., 2020. Transformation of agricultural landscapes in the Anthropocene: Nature’s contributions to people, agriculture and food security. Adv. Ecol. Res. 63, 193-253. link

Abstract - Multiple anthropogenic challenges threaten nature’s contributions to human well-being. Agricultural expansion and conventional intensification are degrading biodiversity and ecosystem functions, thereby undermining the natural foundations on which agriculture is itself built. Averting the worst effects of global environmental change and assuring ecosystem benefits, requires a transformation of agriculture. Alternative agricultural systems to conventional intensification exist, ranging from adjustments to efficiency (e.g. sustainable intensification) to a redesign (e.g. ecological intensification, climate-smart agriculture) of the farm management system. These alternatives vary in their reliance on nature or technology, the level of systemic change required to operate, and impacts on biodiversity, landscapes and agricultural production. Different socio-economic, ecological and political settings mean there is no universal solution, instead there are a suite of interoperable practices that can be adapted to different contexts to maximise efficiency, sustainability and resilience. Social, economic, technological and demographic issues will influence the form of sustainable agriculture and effects on landscapes and biodiversity. These include: (1) the socio-technical-ecological architecture of agricultural and food systems and trends such as urbanisation in affecting the mode of production, diets, lifestyles and attitudes; (2) emerging technologies, such as gene editing, synthetic biology and 3D bioprinting of meat; and (3) the scale or state of the existing farm system, especially pertinent for smallholder agriculture. Agricultural transformation will require multifunctional landscape planning with cross-sectoral and participatory management to avoid unintended consequences and ultimately depends on people’s capacity to accept new ways of operating in response to the current environmental crisis.

Articles scientifiques de travaux menées sur la plateforme CA-SYS :

Microbiologie des sols

• Romdhane, S., Spor, A., Busset, H., Falchetto, L., Martin, J., Bizouard, F., Bru, D., Breuil, M.-C., Philippot, L., Cordeau, S., 2019. Cover crop management practices rather than the composition of cover crop mixtures affect microbial communities in no-till agroecosystems. Frontiers in Microbiology 10. https://www.frontiersin.org/article/10.3389/fmicb.2019.01618

Abstract - Cover cropping plays a key role in the maintenance of arable soil health and the enhancement of agroecosystems services. However, our understanding of how cover crop management impacts soil microbial communities and how these interactions might affect soil nutrient cycling is still limited. Here, we studied the impact of four cover crop mixtures varying in species richness and functional diversity, three cover crop termination strategies (i.e. frost, rolling and glyphosate) and two levels of irrigation at the cover crop sowing on soil nitrogen and carbon dynamics, soil microbial diversity and structure as well as the abundance of total bacteria, archaea and N-cycling microbial guilds. We found that total nitrogen and soil organic carbon were higher when cover crops were killed by frost compared to rolling and glyphosate termination treatments, while cover crop biomass was positively correlated to soil carbon and C:N ratio. Modifications of soil properties due to cover crop management rather than the composition of cover crop mixtures were related to changes in the abundance of ammonia oxidizers and denitrifiers, while there was no effect on the total bacterial abundance. Unravelling the underlyifng processes by which cover crop management shape soil physico-chemical properties and bacterial communities is of importance to help selecting optimized agricultural practices for sustainable farming systems.

Malherbologie, gestion agroécologique des adventices

• Rouge, A., Adeux, G., Busset, H., Hugard, R., Martin, J., Matejicek, A., Moreau, D., Guillemin, J.P., Cordeau, S., 2022. Weed suppression in cover crop mixtures under contrasted levels of resource availability. European Journal of Agronomy 136, 126499.

• Rouge, A., Adeux, G., Busset, H., Hugard, R., Martin, J., Matejicek, A., Moreau, D., Guillemin, J.-P., Cordeau, S., 2023. Carry-over effects of cover crops on weeds and crop productivity in no-till systems. Field Crops Research 295, 108899.

Biodiversité fonctionnelle (pollinisation, régulation biologique, etc..

• Monticelli, L.S., Labonte, A., Turpin, M., Biju-Duval, L., Felten, E., Laurent, E., Matejicek, A., Vieren, E., Deytieux, V., Cordeau, S., Vanbergen, A.J., 2022. Agroecological farming, flowering phenology and the pollinator-herbivore-parasitoid nexus regulate non-crop plant reproduction. Journal of Applied Ecology 59, 2046-2058. https://doi.org/10.1111/1365-2664.14205

Agroecological farming uses crop and non-crop plant biodiversity to promote beneficial insects supplying pollination and biocontrol services to crops. Non-crop plants (sown or weeds) are integral to supporting these beneficial insect species interactions. How the uplift of biotic complexity by agroecological management (crop diversification, ecological infrastructure) influences mutualistic and antagonistic insect interactions regulating the reproduction of non-crop plants remains less understood. Using a pesticide-free farm-scale (125 ha) agroecological experiment, we tested how the individual reproduction of pollinator-dependent, non-crop plant species with different flowering phenology (Cyanus segetum, Centaurea jacea) and their mutualistic (pollinator) and antagonistic (seed herbivore-parasitoid) insect interactions were affected by agroecological practices. Seed set and species interactions of replicate C. segetum and C. jacea randomly introduced to field margins were correlated with floral resource heterogeneity at focal plant (e.g. flower display size), local community (floral richness/abundance driven by sown wildflower or grass margins) and local landscape (crop diversification, area of semi-natural habitat or mass flowering crops) scales. At the seasonal peak of non-crop floral diversity and abundance, antagonistic interactions weakly regulated C. segetum seed set with gains from pollinator activity predominating. Conversely, C. jacea, which flowered past the peak of non-crop floral diversity/abundance, benefited from the promotion of seed herbivore parasitism and pollinator activity by the local landscape cover of semi-natural habitat and mass flowering crops. Synthesis and applications. Agroecological management produced spatial and temporal gradients in crop and non-crop floral resources that interacted to modify pollinator or seed herbivore-parasitoid interactions and Cyanus segetum and Centaurea jacea seed set. The degree of phenological overlap between C. segetum and C. jacea flowering and floral resources in the local community or landscape dictated the type and level of exposure to insect interactions influencing reproduction. Design of agroecological practices to deliver pollination and biocontrol services must consider how effects will vary with species traits and the mutualistic (pollination) and antagonistic (herbivory, parasitism) interactions governing non-crop plant reproduction. Agroecological management supporting beneficial insect interactions may feedback to help restore functional non-crop plant populations and associated biodiversity, potentially reducing the frequency of management interventions (e.g. re-sowing wildflower strips).

• Labonté, A., Monticelli, L., Turpin, M., Felten, E., Laurent, E., Matejicek, A., Biju-Duval, L., Ducourtieux, C., Vieren, E., Deytieux, V., Cordeau, S., Bohan, D.A., Vanbergen, A.J., 2023. Individual flowering phenology shapes plant-pollinator interactions across ecological scales affecting plant reproduction. Ecology and Evolution 13, e9707. https://doi.org/10.1002/ece3.9707

Abstract - The balance of pollination competition and facilitation among co-flowering plants and abiotic resource availability can modify plant species and individual reproduction. Floral resource succession and spatial heterogeneity modulate plant–pollinator interactions across ecological scales (individual plant, local assemblage, and interaction network of agroecological infrastructure across the farm). Intraspecific variation in flowering phenology can modulate the precise level of spatio-temporal heterogeneity in floral resources, pollen donor density, and pollinator interactions that a plant individual is exposed to, thereby affecting reproduction. We tested how abiotic resources and multi-scale plant–pollinator interactions affected individual plant seed set modulated by intraspecific variation in flowering phenology and spatio-temporal floral heterogeneity arising from agroecological infrastructure. We transplanted two focal insect-pollinated plant species (Cyanus segetum and Centaurea jacea, n = 288) into agroecological infrastructure (10 sown wildflower and six legume–grass strips) across a farm-scale experiment (125 ha). We applied an individual-based phenologically explicit approach to match precisely the flowering period of plant individuals to the concomitant level of spatio-temporal heterogeneity in plant–pollinator interactions, potential pollen donors, floral resources, and abiotic conditions (temperature, water, and nitrogen). Individual plant attractiveness, assemblage floral density, and conspecific pollen donor density (C. jacea) improved seed set. Network linkage density increased focal species seed set and modified the effect of local assemblage richness and abundance on C. segetum. Mutual dependence on pollinators in networks increased C. segetum seed set, while C. jacea seed set was greatest where both specialization on pollinators and mutual dependence was high. Abiotic conditions were of little or no importance to seed set. Intra- and interspecific plant–pollinator interactions respond to spatio-temporal heterogeneity arising from agroecological management affecting wild plant species reproduction. The interplay of pollinator interactions within and between ecological scales affecting seed set implies a co-occurrence of pollinator-mediated facilitative and competitive interactions among plant species and individuals.

• Labonté, A., Le Corre, V., Matejicek, A., Felten, E., Turpin, M., Laurent, E., Michel, S., Ducourtieux, C., Vieren, E., Proesmans, W., Deytieux, V., Cordeau, S., Vanbergen, A.J., 2024. Pollinator functional group abundance and floral heterogeneity in an agroecological context affect mating patterns in a self-incompatible wild plant. American Journal of Botany 11, e16440.

• Bannwart, P., Gardarin, A., Deytieux, V., Cordeau, S., Petit, S., 2026. Pesticide-free fields under minimum tillage and flower strips enhance generalist arthropod predators through increased overwintering and spill over processes. Agric Ecosyst Environ 400, 110250.

• Toukem, N.K., Felten, E., Laurent, E., Bottini, D., Pouget, S., Cordeau, S., Petit, S., Vanbergen, A., 2026. Phylogenetic relatedness of a focal plant to weed species and field crop species affects its seed production through insect-mediated trophic interactions. Agric Ecosyst Environ, 110347.