16 research outputs found
Species Accounts of 100 of the Most Invasive Alien Species in Europe: <em>Ambrosia artemisiifolia Linnaeus</em>, common ragweed (Asteraceae, Magnoliophyta)
International audienc
Conservation agriculture affects multitrophic interactions driving the efficacy of weed biological control
International audience1. Biological control is a key ecosystem service in arable lands, but its effectiveness varies according to environmental and biotic contexts. Cascading interactions between several trophic levels can affect natural enemies and their efficacy.2. Here, we analysed how multitrophic interactions drive weed seed control under contrasting farming systems and landscapes. In particular, we analyse how the presence of higher-order predators and alternative prey affects the weed seed consumption by seed predators. We monitored 30 cereal fields organised into 15 pairs, each comprising one conventional and one conservation agriculture field, sampled along a gradient of proportion of conservation agriculture in the landscape.3. We found that local and landscape management under conservation agriculture favours the presence of seed predators like carabids and rodents, higher-order predators like shrews and alternative animal prey. Weed seed predation is promoted by conservation agriculture through an increase in the number of seed predators. However, alternative animal prey reduces the efficacy of carabids to consume seeds, probably due to a prey-switching behaviour. Similarly, shrews negatively affect the activity-density of carabids, resulting in an indirect negative effect on seed predation.4. Synthesis and applications: Our study highlights that the implementation of conservation agriculture can improve the provision of biological control but the resulting effect may be partially limited by the increased complexity of trophic interactions. The different trophic levels respond to local management and/or the surrounding landscape with cascading effects on the delivery of weed control. Our study highlights the importance of considering not only the direct effects of seed predators, but also the indirect effects of higher-order predators and alternative prey when predicting the level of weed biological control
A process-based approach to predicting the effect of climate change on the distribution of an invasive allergenic plant in Europe
Ambrosia artemisiifolia is an invasive weed in Europe with highly allergenic pollen. Populations are currently well established and cause significant health problems in the French RhĂŽne valley, Austria, Hungary and Croatia but transient or casual introduced populations are also found in more Northern and Eastern European countries. A process-based model of weed growth, competition and population dynamics was used to predict the future potential for range expansion of A.artemisiifolia under climate change scenarios. The model predicted a northward shift in the available climatic niche for populations to establish and persist, creating a risk of increased health problems in countries including the UK and Denmark. This was accompanied by an increase in relative pollen production at the northern edge of its range. The southern European limit for A.artemisiifolia was not expected to change; populations continued to be limited by drought stress in Spain and Southern Italy. The process-based approach to modelling the impact of climate change on plant populations has the advantage over correlative species distribution models of being able to capture interactions of climate, land use and plant competition at the local scale. However, for this potential to be fully realised, additional empirical data are required on competitive dynamics of A.artemisiifolia in different crops and ruderal plant communities and its capacity to adapt to local conditions
Avis en rĂ©ponse Ă la saisine du 7 novembre 2013, de Madame Marie-Christine Blandin, relative Ă lâarticle de Snell et al. (Food and Chemical Toxicology, 2012)
Le Haut Conseil des biotechnologies (HCB) a Ă©tĂ© saisi le 7 novembre 2013 par Madame la SĂ©natrice Marie-Christine Blandin, en vertu de lâarticle L531-3 du code de lâenvironnement, dâune demande dâavis relative Ă lâarticle de Snell et al., intitulĂ© «Assessment of the health impact of GM plant diets in long-term and multigenerational animal feeding trials: A literature review», publiĂ© dans la revue Food and Chemical Toxicology (Snellet al.,2012). Pour rĂ©pondre aux questions de la saisine, le ComitĂ© Scientifique (CS) du HCB a constituĂ© un groupe de travail ad hoc. A la suite du compte-rendu de ce dernier, le CS du HCB a procĂ©dĂ© Ă lâexamen du projet de rĂ©ponse le 25 fĂ©vrier 2014 sous la prĂ©sidence de Jean-Christophe PagĂšs
Avis en réponse à la saisine HCB - dossier C/NL/06/01_001. Paris, le 17 octobre 2018
Le Haut Conseil des biotechnologies (HCB) a Ă©tĂ© saisi le 14 aoĂ»t 2018 par les autoritĂ©s compĂ©tentes françaises (le ministĂšre de lâAgriculture et de lâAlimentation) dâune demande dâavis relative au dossier C/NL/06/01_001 de demande de renouvellement dâautorisation de mise sur le marchĂ© de la lignĂ©e dâoeillets gĂ©nĂ©tiquement modifiĂ©s 123.8.12 (identificateur unique FLO- 40689-6) Ă des fins dâimportation et de commercialisation de fleurs coupĂ©es. Ce dossier a Ă©tĂ© dĂ©posĂ© par la sociĂ©tĂ© Suntory Flowers Limited auprĂšs des autoritĂ©s compĂ©tentes nĂ©erlandaises sur le fondement de la directive 2001/18/CE. ConformĂ©ment Ă cette directive, la Commission europĂ©enne a adressĂ© le rapport dâĂ©valuation des Pays-Bas ainsi que le dossier du pĂ©titionnaire Ă lâensemble des Etats membres, qui disposent de 60 jours pour faire des commentaires, demander des informations complĂ©mentaires ou Ă©mettre des objections Ă la mise sur le marchĂ©. Par cette saisine, les autoritĂ©s compĂ©tentes françaises consultent le HCB dans cette perspective, en amont du vote des Etats membres Ă la Commission europĂ©enne. Le ComitĂ© scientifique (CS)2 du HCB a examinĂ© le dossier en sĂ©ance du 17 octobre 2018 sous la prĂ©sidence de Jean-Christophe PagĂšs. Le prĂ©sent avis a Ă©tĂ© adoptĂ© en sĂ©ance et publiĂ© le 23 octobre 2018
Services culturels et récréatifs
Les Ă©cosystĂšmes agricoles sont lâun des six volets de lâEvaluation française des Ă©cosystĂšmes et des services Ă©cosystĂ©miques (EFESE), programme lancĂ© en 2012 par le MinistĂšre en charge de lâEnvironnement pour apporter des connaissances sur lâĂ©tat actuel et lâutilisation durable des Ă©cosystĂšmes (voir encadrĂ© 2). En 2014, le MinistĂšre de lâEnvironnement a sollicitĂ© lâInra pour prendre en charge le volet relatif aux Ă©cosystĂšmes agricoles. Le programme fĂ©dĂ©rateur de recherche EcoSerV (Services rendus par les Ă©cosystĂšmes), lancĂ© par lâInra en 2013, a Ă©galement soutenu cette Ă©tude quâil va ensuite complĂ©ter et Ă©tendre. LâĂ©cosystĂšme agricole, vu comme lâensemble des parcelles dĂ©diĂ©es Ă la production de biomasse agricole, est configurĂ© et gĂ©rĂ© par lâagriculteur qui combine, dans ses pratiques de production, processus Ă©cologiques et apports dâintrants exogĂšnes. Lâun des enjeux forts associĂ©s Ă lâanalyse des services Ă©cosystĂ©miques est la conception de systĂšmes de production reposant sur la valorisation de ces services, donc peu consommateurs en intrants exogĂšnes et rĂ©pondant aux enjeux de sociĂ©tĂ© tels que la conservation de la biodiversitĂ© ou la limitation des impacts environnementaux