54 research outputs found
Deployment of organic farming at a landscape scale : impacts on natural enemy communities and natural pest control
Identifier les leviers permettant de stimuler la rĂ©gulation naturelle des bioagresseurs tout en prĂ©servant la biodiversitĂ© est indispensable pour concevoir des paysages agricoles fonctionnels. A partir dâune mĂ©ta-analyse et dâune Ă©tude empirique reposant sur 42 parcelles viticoles localisĂ©es dans Nouvelle Aquitaine (France), nous avons cherchĂ© Ă Ă©valuer lâimpact du dĂ©ploiement de lâagriculture biologique Ă de large Ă©chelles spatiales sur 1) les communautĂ©s dâennemis naturels, 2) les services de rĂ©gulation naturelle, 3) les taux dâinfestation par les bioagresseurs. Dans ce travail, nous avons montrĂ© que la proportion dâagriculture biologique est un facteur structurant plus les communautĂ©s dâennemis naturels que la proportion dâhabitats semi-naturels dans le paysage. De plus, nous avons montrĂ© que les communautĂ©s de bioagresseurs rencontrĂ©es dans les vignes ne sont pas influencĂ©es par la proportion dâagriculture biologique alors quâelles rĂ©pondent plutĂŽt nĂ©gativement Ă la proportion dâhabitats semi-naturels. Par ailleurs, nous avons montrĂ© que lâagriculture biologique, Ă lâĂ©chelle globale et indĂ©pendamment du type de culture considĂ©rĂ©e est un systĂšme de culture stimulant la rĂ©gulation naturelle des bioagresseurs. En viticulture, elle permet de rĂ©duire lâutilisation des produits phytosanitaires, comparĂ© Ă lâagriculture conventionnelle. Enfin, nos analyses ont rĂ©vĂ©lĂ© quâau-delĂ de la diffĂ©rence de systĂšmes de culture, un certain nombre de facteurs locaux (e.g., Ăąge des parcelles, frĂ©quence de traitements, productivitĂ©) permettent dâexpliquer la structure des communautĂ©s dâennemis naturels et des services de rĂ©gulation naturelle des bioagresseurs. Tout en produisant des connaissances sur les processus permettant dâexpliquer les assemblages des communautĂ©s dâennemis naturels et les niveaux de services de rĂ©gulation rendus, notre travail suggĂšre des pistes pour lâamĂ©nagement des paysages viticoles permettant de concilier prĂ©servation de la biodiversitĂ© et maximisation des rĂ©gulations naturelles.Identifying landscape context and farming systems that enhance natural pest control while maintaining biodiversity is crucial to design functional agricultural landscapes. Using a meta-analysis and an empiric study based on 42 vineyards in Nouvelle Aquitaine (France), we investigated the effect of the deployment of organic farming at a landscape scale on 1) natural enemy communities, 2) natural pest control and 3) pest infestation levels. Here, we showed that the proportion of organic farming structured more natural enemy communities than the proportion of semi-natural habitats. On the opposite, pest and pathogen infestations were never influenced by the proportion of organic farming while they were negatively influenced by the proportion of semi-natural habitats. Furthermore, at a global scale and for every crop types, organic farming, per se, enhances natural pest control. In viticulture, it is less dependent of synthetic agrochemicals than conventional farming. Moreover, local factors such as the treatment frequency index, the field age and the crop productivity had important effects on natural enemy communities and natural pest control. Finally, we yielded knowledge on processes that impact natural enemy assembly and natural pest control in agrosystems. For vineyards-dominated landscapes, our work suggests some tracks for landscape planning that support biodiversity conservation and natural pest control
DĂ©ploiement de lâagriculture biologique Ă lâĂ©chelle du paysage : impacts sur les communautĂ©s dâennemis naturels et les services de rĂ©gulation des bioagresseurs
Identifier les leviers permettant de stimuler la rĂ©gulation naturelle des bioagresseurs tout en prĂ©servant la biodiversitĂ© est indispensable pour concevoir des paysages agricoles fonctionnels. A partir dâune mĂ©ta-analyse et dâune Ă©tude empirique reposant sur 42 parcelles viticoles localisĂ©es dans Nouvelle Aquitaine (France), nous avons cherchĂ© Ă Ă©valuer lâimpact du dĂ©ploiement de lâagriculture biologique Ă de large Ă©chelles spatiales sur 1) les communautĂ©s dâennemis naturels, 2) les services de rĂ©gulation naturelle, 3) les taux dâinfestation par les bioagresseurs. Dans ce travail, nous avons montrĂ© que la proportion dâagriculture biologique est un facteur structurant plus les communautĂ©s dâennemis naturels que la proportion dâhabitats semi-naturels dans le paysage. De plus, nous avons montrĂ© que les communautĂ©s de bioagresseurs rencontrĂ©es dans les vignes ne sont pas influencĂ©es par la proportion dâagriculture biologique alors quâelles rĂ©pondent plutĂŽt nĂ©gativement Ă la proportion dâhabitats semi-naturels. Par ailleurs, nous avons montrĂ© que lâagriculture biologique, Ă lâĂ©chelle globale et indĂ©pendamment du type de culture considĂ©rĂ©e est un systĂšme de culture stimulant la rĂ©gulation naturelle des bioagresseurs. En viticulture, elle permet de rĂ©duire lâutilisation des produits phytosanitaires, comparĂ© Ă lâagriculture conventionnelle. Enfin, nos analyses ont rĂ©vĂ©lĂ© quâau-delĂ de la diffĂ©rence de systĂšmes de culture, un certain nombre de facteurs locaux (e.g., Ăąge des parcelles, frĂ©quence de traitements, productivitĂ©) permettent dâexpliquer la structure des communautĂ©s dâennemis naturels et des services de rĂ©gulation naturelle des bioagresseurs. Tout en produisant des connaissances sur les processus permettant dâexpliquer les assemblages des communautĂ©s dâennemis naturels et les niveaux de services de rĂ©gulation rendus, notre travail suggĂšre des pistes pour lâamĂ©nagement des paysages viticoles permettant de concilier prĂ©servation de la biodiversitĂ© et maximisation des rĂ©gulations naturelles
DĂ©ploiement de lâagriculture biologique Ă lâĂ©chelle du paysage : impacts sur les communautĂ©s dâennemis naturels et les services de rĂ©gulation des bioagresseurs
Identifying landscape context and farming systems that enhance natural pest control while maintaining biodiversity is crucial to design functional agricultural landscapes. Using a meta-analysis and an empiric study based on 42 vineyards in Nouvelle Aquitaine (France), we investigated the effect of the deployment of organic farming at a landscape scale on 1) natural enemy communities, 2) natural pest control and 3) pest infestation levels. Here, we showed that the proportion of organic farming structured more natural enemy communities than the proportion of semi-natural habitats. On the opposite, pest and pathogen infestations were never influenced by the proportion of organic farming while they were negatively influenced by the proportion of semi-natural habitats. Furthermore, at a global scale and for every crop types, organic farming, per se, enhances natural pest control. In viticulture, it is less dependent of synthetic agrochemicals than conventional farming. Moreover, local factors such as the treatment frequency index, the field age and the crop productivity had important effects on natural enemy communities and natural pest control. Finally, we yielded knowledge on processes that impact natural enemy assembly and natural pest control in agrosystems. For vineyards-dominated landscapes, our work suggests some tracks for landscape planning that support biodiversity conservation and natural pest control.Identifier les leviers permettant de stimuler la rĂ©gulation naturelle des bioagresseurs tout en prĂ©servant la biodiversitĂ© est indispensable pour concevoir des paysages agricoles fonctionnels. A partir dâune mĂ©ta-analyse et dâune Ă©tude empirique reposant sur 42 parcelles viticoles localisĂ©es dans Nouvelle Aquitaine (France), nous avons cherchĂ© Ă Ă©valuer lâimpact du dĂ©ploiement de lâagriculture biologique Ă de large Ă©chelles spatiales sur 1) les communautĂ©s dâennemis naturels, 2) les services de rĂ©gulation naturelle, 3) les taux dâinfestation par les bioagresseurs. Dans ce travail, nous avons montrĂ© que la proportion dâagriculture biologique est un facteur structurant plus les communautĂ©s dâennemis naturels que la proportion dâhabitats semi-naturels dans le paysage. De plus, nous avons montrĂ© que les communautĂ©s de bioagresseurs rencontrĂ©es dans les vignes ne sont pas influencĂ©es par la proportion dâagriculture biologique alors quâelles rĂ©pondent plutĂŽt nĂ©gativement Ă la proportion dâhabitats semi-naturels. Par ailleurs, nous avons montrĂ© que lâagriculture biologique, Ă lâĂ©chelle globale et indĂ©pendamment du type de culture considĂ©rĂ©e est un systĂšme de culture stimulant la rĂ©gulation naturelle des bioagresseurs. En viticulture, elle permet de rĂ©duire lâutilisation des produits phytosanitaires, comparĂ© Ă lâagriculture conventionnelle. Enfin, nos analyses ont rĂ©vĂ©lĂ© quâau-delĂ de la diffĂ©rence de systĂšmes de culture, un certain nombre de facteurs locaux (e.g., Ăąge des parcelles, frĂ©quence de traitements, productivitĂ©) permettent dâexpliquer la structure des communautĂ©s dâennemis naturels et des services de rĂ©gulation naturelle des bioagresseurs. Tout en produisant des connaissances sur les processus permettant dâexpliquer les assemblages des communautĂ©s dâennemis naturels et les niveaux de services de rĂ©gulation rendus, notre travail suggĂšre des pistes pour lâamĂ©nagement des paysages viticoles permettant de concilier prĂ©servation de la biodiversitĂ© et maximisation des rĂ©gulations naturelles
Community Ecology, Food Webs and Natural Pest Control
International audienceNatural pest control results from ecological functions like predation or parasitism. Such functions are supplied by an array of natural enemies embedded in a large community of interacting species. In this chapter, we discuss the extent to which natural enemy composition affects pest demography and we highlight the importance of considering how species interact with each other to understand the processes behind pest control. More specifically, we emphasize the importance of identifying the emergence of positive or detrimental interactions in trophic networks by combining both horizontal and vertical approaches. In addition, we show that knowledge of community assembly rules across agricultural landscape scales is in its infancy and that the relative contributions of stochastic and deterministic processes on natural enemy assemblages remain poorly understood. For these reasons, we argue that community ecology and network ecology should help us enhance natural pest control services within agricultural landscapes
Ecologie des communautés, réseaux trophiques et régulation naturelle
International audienceTypes dâinteraction au sein des communautĂ©s et rĂ©gulation naturelle.Relations entre diversitĂ© horizontale des communautĂ©s dâennemis naturels et rĂ©gulation naturelle.Effet de la diversitĂ© verticale des communautĂ©s sur les niveaux de rĂ©gulation naturelle.MĂ©tacommunautĂ©s et Ă©cologie du paysage
Organic farming at local and landscape scales fosters biological pest control in vineyards
While organic farming practices, which are often promoted as models of ecological intensification, generally enhance biodiversity, their effects on the delivery of ecosystem services, such as biological pest control, are still unknown. Here, using a multi-scale hierarchical design in southwestern France, we examined the effects of organic farming and seminatural habitats at the local and landscape scales on biological control services of three pests, including weeds and insects, in 42 vineyards. Organic farming at the local and landscape scales was beneficial to the mean and temporal stability of biological control services, while the proportion of seminatural habitats in the landscape reduced the level of biological pest control potential. The effects of organic farming and seminatural habitats across spatial scales varied with the type of prey considered and with time. Egg moth removal rates were higher in fields under organic management compared to conventional management while weed seed removal rates increased with the proportion of organic farming in the landscape. Larval removal rates as well as seed removal rates were always more stable within time in organic fields than in conventional fields. Moreover, independently of farming system type, local variables describing the agricultural management intensity, such as pesticide use or crop productivity, were also found to be important variables explaining levels of biological control services. Pesticide use tended to reduce biological control potential, while crop productivity was associated with contrasting biological control responses depending on the pest type. Our study demonstrates the need to target multiple spatial scales and to consider farming practices, as well as the proportion of seminatural habitats, to design functional landscapes that optimize biological pest control services
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