Search results for "temi"
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Can a historical analysis of the spread of Ambrosia artemisiifolia explain its actual success in France ?
2008
International audience
What are the keys of the success of Ambrosia artemisiifolia in France ?
2008
International audience
L'ambroisie se développerait au nord de l'Europe
2014
EA EcolDur
Common ragweed growth under different level of competition
2013
Common ragweed (Ambrosia artemisiifolia L.) is colonizing various habitats. From mid-May to September 2012, the growth and development of different plants was monitored in four different habitats. Main development stages were observed and a final aerial biomass was measured. The number of ragweed plants surviving competition and management practices was lower in the plots with alfalfa than in the other plots. The number of ragweed plants reaching the male-flowering stage was significantly higher in the spontaneous vegetation and the “sown wildflowers”. Nevertheless, it was never observed a strong enough competition in any of the plots to avoid the flowering stage. We can extrapolate that in…
Ambrosia artemisiifolia Linnaeus, common ragweed (Asteraceae, Magnoliophyta)
2009
Chapter 13: Species Accounts of 100 of the Most Invasive Alien Species in Europe ; International audience
Do the high phenotypic plasticity of A. artemisiifolia L. explain its invasive success in France?
2008
International audience; Ambrosia artemisiifolia (Asteraceae) is an invasive annual plant introduced from North America to Europe over 100 years ago. This plant species is now widespread in numerous countries all over the world, causing damages to agricultural crops and human health. Ambrosia artemisiifolia is spreading as a weed in many field crops but is also able to invade a wide range of areas such as various human disturbed habitats or riverbanks (Figure 1). A considerable variability of the life history traits of A. artemisiifolia was previously observed among and within different populations (Fumanal et al., 2007). Since the success of colonization of some invasive plant species may r…
Analyse multi-échelles de compromis entre services écosystémiques fournis par la flore adventice
2018
National audience; Les adventices, étant à la base des réseaux trophiques, jouent un rôle important dans les processus biologiques mis en avant en agroécologie. Cependant, elles sont également en compétition avec les cultures, il est donc important de s’intéresser aux compromis entre les services et diservices qu’elles fournissent. Pour cela, nous allons nous intéresser au suivi d’une plateforme paysagère, regroupant près de 150 parcelles contiguës de grandes cultures. Un suivi des pratiques agricoles ainsi que des relevés de flore à l’interface et à l’intérieur de la parcelle y sont réalisés depuis 2008. Les services/diservices fournis par les commuanutés observées peuvent ensuite être dét…
Growth and reproduction responses of French invasive and North American native populations of common ragweed, Ambrosia artemisiifolia L. to defoliati…
2012
Enemy release and Evolution of Increased Competitive Ability hypotheses have been put forward to explain invasion success of introduced plant species. These hypotheses assume that the loss of natural enemies could induce an evolutionary change in plant defence and in resource allocation allowing the introduced plant populations to increase in vigour and fitness. To detect changes in functional traits following defoliation, we compared native and introduced populations of common ragweed, grown in a common garden environment. We compared six populations of Ambrosia artemisiifolia L., three from the North American native range and three from the French introduction range. We explored the effec…
Importance of seeds in the process of common ragweed invasion
2012
International audience; Ambrosia artemisiifolia L. (common ragweed) was introduced into Europe at the end of the 1900s and is now present in several European countries. This annual invasive plant produces seeds that are highly polymorphic. Common ragweed can produce only a few thousand highly viable seeds. Many studies have focused on the seed stage. Greater seedling emergence for the seeds placed near the soil surface could explain the success of this species in open habitats, where the probability of deeper burial is low. Emergence percentage was found to decrease as burial depth increased from 2 to 8 cm, and no germination nor seedling emergence was observed for the seeds buried from 10-…
Conséquences de l’utilisation de variétés de tournesol tolérantes aux herbicides sur la flore des agrosystèmes
2022
The farming practices associated with the use of sunflower herbicide-tolerant varieties (HTVs) have raised concerns among public authorities, who have recommended monitoring the potential effects of HTVs on biodiversity. In this context, at the scale of three French departments, the vegetation of 239 sunflower fields and their margins was studied between 2017 and 2019. This lower weed diversity can be attributed to shorter crop rotations and higher herbicide use. Admittedly, the higher densities of A. artemisiifolia observed in plots with HTVs are the cause of the use of these varieties rather than the consequence of these practices. However, these practices do not seem to solve the problem…