References of "Monty, Arnaud"
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See detailPlant ecological niche distribution along heavy metal gradients
Boisson, Sylvain ULg; Monty, Arnaud ULg; Seleck, Maxime ULg et al

Conference (2013, June 26)

Why species do not occur everywhere? The concept of ecological niche is central to understand relationships among biotic/abiotic factors and species distribution. Gradients of environmental stress ... [more ▼]

Why species do not occur everywhere? The concept of ecological niche is central to understand relationships among biotic/abiotic factors and species distribution. Gradients of environmental stress associated to interspecific interactions generate testable patterns of specie’s response curves. Distribution of response curves have been seldom tested along toxicity gradient, in contrast to resource gradients. On Katangan copper hills (south R.D.C.), natural copper and cobalt concentrations span a large range: 2 - 1000 mg kg-1 for cobalt and 30 - 10 000 mg kg-1 for copper. In this study, we evaluate three hypotheses related to niche distributions and shapes along metal toxic gradients: (1) Species optima are uniformly distributed over copper-cobalt gradient. (2) Realized niche width varies in relation to the niche optimum along copper and cobalt gradient. (3) Absolute values of skewness coefficient are higher when plant species optima are in the extremes of cobalt gradient with a niche tails toward mesic conditions. Realized niches of 80 taxa were modeled with general additive models (GAM) using presence/absence data in 172 1m² plots. Niche optima, niche widths and skewness coefficients were estimated from species response curves. The three hypotheses were globally validated. Three groups of species were distinguished according to their optima position along metal gradient with packed optima on intermediate concentrations suggesting higher interspecific competition in low metal concentrations. Niche width increased with metal concentrations. Highest metal tolerant plant species had broader niches. Skewness coefficient was inversely related to niche optima positions. Our study demonstrates that species distribution pattern on toxicity gradient presents similarities with resource gradient. Broad realized amplitude of species adapted to high levels of copper cobalt concentrations suggests that fundamental niche of specialist metallophytes may be larger than expected. This should be further tested in controlled conditions in association to competition tests. [less ▲]

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See detailIntegrated management of wild chamomile populations by tillage
Jaunard, Delphine ULg; Monty, Arnaud ULg; Mahy, Grégory ULg et al

in Agricultural and Apllied Biological Sciences (2013, May 21)

Gembloux, Belgium Chemical weeding in agriculture increasingly raises environmental, health and economic preoccupations. European authorities has set up legislations (directive 91/414, settlement 1107 ... [more ▼]

Gembloux, Belgium Chemical weeding in agriculture increasingly raises environmental, health and economic preoccupations. European authorities has set up legislations (directive 91/414, settlement 1107/2009, directive 2009/128) aiming to reduce risks related to the use of pesticides and encouraging integrated pest management. This situation leads professionals and scientists to take interest in the biology and population dynamics of weeds and to study the impacts of integrated pest management on weeds and crops. Tillage can potentially be an efficient weed control method in winter wheat (Triticum aestivum L.). We studied wild chamomile (Matricaria chamomilla L.) population dynamics and crop yields in an experimental winter wheat crop, in relation to tillage methods. Five modalities (i.e. different combinations of a stubble cultivator and/or a moldboard plow, including a no-tillage control) were applied during three years (2009-2012), with four replications, in Gembloux (Belgium). In each plot, M. chamomilla density was recorded throughout the seasons. In summer 2012, wild chamomile density was significantly lower in plots tilled with a moldboard plow. The use of a stubble cultivator did not significantly affect M. chamomilla density. In addition, we found higher wheat yields in ploughed plots, indicating that the decrease in M. chamomilla density reduced competition for wheat. To confirm these results, experiments are still under investigation in similar conditions. [less ▲]

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See detail3. Contrôle des populations de mauvaises herbes
Jaunard, Delphine ULg; Monty, Arnaud ULg; Mahy, Grégory ULg et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc - Céréales (2013, February 27)

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See detailFire promotes downy brome (Bromus tectorum L.) seed dispersal
Monty, Arnaud ULg; Brown, Cynthia S.; Johnston, Danielle B.

in Biological Invasions (2013), 15(5), 1113-1123

Particularly well-known among the many impacts of the invasive annual grass downy brome (Bromus tectorum, Poaceae) is its ability to alter fire cycles and increase in abundance after fire. However, little ... [more ▼]

Particularly well-known among the many impacts of the invasive annual grass downy brome (Bromus tectorum, Poaceae) is its ability to alter fire cycles and increase in abundance after fire. However, little is known about how fire influences B. tectorum dispersal. We quantified fire effects on B. tectorum dispersal using three recently burned areas in the western region of the Colorado Rocky Mountains by marking diaspores (seeds) with fluorescent powder, and then recovering them at night using ultraviolet lights. Diaspores were of two types: with and without sterile florets attached. We also characterized vegetation cover and near-surface wind speed in burned and unburned areas. Diaspores travelled much farther in burned areas than in nearby unburned areas (mean ± standard error at the end of the experiment: 209 ± 16 cm and 38 ± 1 cm, respectively; maximal distance at the end of the experiment: 2,274 cm and 150 cm, respectively), indicating an increase in dispersal distance after fire. Diaspores with sterile florets attached dispersed longer distances than those without sterile florets (mean ± standard error at the end of the experiment: 141 ± 14 cm and 88 ± 7 cm, respectively). Vegetation cover was lower and wind speeds were higher in the burned areas. Our results indicate that at least one of the mechanisms by which the spread of B. tectorum is promoted by fire is through increased seed dispersal distance. Preventing movement of seeds from nearby infestations into burned areas may help avoid the rapid population expansion often observed. [less ▲]

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See detailLes écosystèmes de demain: quelle biodiversité dans un monde anthropisé?
Monty, Arnaud ULg

Scientific conference (2013)

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See detailEfficacité des méthodes de lutte contre le développement de cinq espèces de plantes invasives amphibies : Crassula helmsii , Hydrocotyle ranunculoides , Ludwigia grandiflora , Ludwigia peploides et Myriophyllum aquaticum (synthèse bibliographique)
Delbart, Emmanuel; Mahy, Grégory ULg; Monty, Arnaud ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17(1), 88-103

Parmi les espèces invasives connaissant une expansion rapide en Europe, les plantes dites « amphibies » sont particulièrement problématiques. Elles sont capables de former des populations très denses à la ... [more ▼]

Parmi les espèces invasives connaissant une expansion rapide en Europe, les plantes dites « amphibies » sont particulièrement problématiques. Elles sont capables de former des populations très denses à la surface des plans d’eau, se développant à la fois sous l’eau et hors de l’eau. La lutte contre ces espèces, en vue de l’éradication totale ou du ralentissement de l’invasion, représente un défi de taille pour les gestionnaires. Une synthèse bibliographique des méthodes de lutte existantes pour Crassula helmsii, Hydrocotyle ranunculoides, Ludwigia grandiflora, L. peploides et Myriophyllum aquaticum a été réalisée, prenant en considération leur efficacité et leur coût. Des 88 études analysées, il ressort une grande disparité d’effort de recherche (nombre d’études, échelles spatiales des études) entre méthodes de lutte et entre espèces. Néanmoins, l’efficacité des différentes méthodes de lutte est comparable pour les cinq espèces étudiées. Globalement, les cas d’éradication sont rares. Ils sont le résultat de luttes mécaniques ou chimiques, souvent couplées à des interventions complémentaires telles que la finition manuelle. Malgré une forte occurrence dans la littérature, la lutte chimique, moins fastidieuse à mettre en place et moins coûteuse que les autres méthodes, n’a montré des niveaux d’efficacité satisfaisants qu’avec certaines matières actives. De même, la lutte biologique a montré peu de résultats encourageants à ce jour. Il est à noter que certains agents de lutte biologique sont d’ores et déjà considérés comme des espèces invasives en Europe. A contrario, malgré leur faible occurrence dans la littérature, l’arrachage manuel ou mécanique suivi de finitions manuelles a donné des niveaux d’efficacité satisfaisants. Vu les difficultés de lutter contre les espèces invasives amphibies et les dommages collatéraux potentiels sur les écosystèmes, un débat impliquant scientifiques, autorités et gestionnaires de plans d’eau devra avoir lieu afin de poser les bases d’une gestion cohérente à grande échelle. [less ▲]

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See detailRapid Plant Invasion in Distinct Climates Involves Different Sources of Phenotypic Variation
Monty, Arnaud ULg; Bizoux, Jean-Philippe ULg; Escarré, José et al

in PLoS ONE (2013), 8(1), 55627

When exotic species spread over novel environments, their phenotype will depend on a combination of different processes, including phenotypic plasticity (PP), local adaptation (LA), environmental maternal ... [more ▼]

When exotic species spread over novel environments, their phenotype will depend on a combination of different processes, including phenotypic plasticity (PP), local adaptation (LA), environmental maternal effects (EME) and genetic drift (GD). Few attempts have been made to simultaneously address the importance of those processes in plant invasion. The present study uses the well-documented invasion history of Senecio inaequidens (Asteraceae) in southern France, where it was introduced at a single wool-processing site. It gradually invaded the Mediterranean coast and the Pyrenean Mountains, which have noticeably different climates. We used seeds from Pyrenean and Mediterranean populations, as well as populations from the first introduction area, to explore the phenotypic variation related to climatic variation. A reciprocal sowing experiment was performed with gardens under Mediterranean and Pyrenean climates. We analyzed climatic phenotypic variation in germination, growth, reproduction, leaf physiology and survival. Genetic structure in the studied invasion area was characterized using AFLP. We found consistent genetic differentiation in growth traits but no home-site advantage, so weak support for LA to climate. In contrast, genetic differentiation showed a relationship with colonization history. PP in response to climate was observed for most traits, and it played an important role in leaf trait variation. EME mediated by seed mass influenced all but leaf traits in a Pyrenean climate. Heavier, earlier-germinating seeds produced larger individuals that produced more flower heads throughout the growing season. However, in the Mediterranean garden, seed mass only influenced the germination rate. The results show that phenotypic variation in response to climate depends on various ecological and evolutionary processes associated with geographical zone and life history traits. Seeing the relative importance of EME and GD, we argue that a “local adaptation vs. phenotypic plasticity” approach is therefore not sufficient to fully understand what shapes phenotypic variation and genetic architecture of invasive populations. [less ▲]

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See detailEvolutionary mechanisms in colonizing plant populations
Monty, Arnaud ULg

Conference (2012, November)

In a rapidly changing world, human activities offer opportunities for many plant species to colonize new areas. Increasingly, it is recognized that colonization can be accompanied by different ecological ... [more ▼]

In a rapidly changing world, human activities offer opportunities for many plant species to colonize new areas. Increasingly, it is recognized that colonization can be accompanied by different ecological and evolutionary processes, acting over relatively short periods of time. When populations colonize novel environments, individuals’ phenotypes will depend on a combination of different, non-exclusive processes, including phenotypic plasticity (PP), local adaptation (LA), environmental maternal effects (EME) and genetic drift (GD)(Monty and Mahy 2009b). Despite these processes have long been studied independently, few attempts have been made to simultaneously address the importance of those processes in plant colonization. Here, we present a set of related studies aiming at disentangling the role of PP, LA, EME and GD in Senecio inaequidens (Asteraceae) in southern France, where it was introduced at a single wool-processing site in the late 19th century. We used seeds from populations growing in contrasted climates to explore the phenotypic variation related to climate. We performed several common garden experiments (Monty et al. 2009, Monty and Mahy 2009a, 2010), as well as a reciprocal sowing experiment with gardens under Mediterranean and Pyrenean climates (Monty et al. in revision). We analyzed climatic phenotypic variation in germination, growth, reproduction, leaf physiology and survival. We characterized genetic structure in the studied populations using AFLP. We found consistent genetic differentiation in growth traits but no home-site advantage, thus weak support for LA to climatic conditions. In contrast, genetic differentiation showed a relationship to colonization history. PP in response to climate was observed for most traits, and it played a particularly important role in leaf trait variation. EME mediated by seed mass influenced all but leaf traits under harsh climate. Heavier, earlier-germinating seeds produced larger individuals that eventually produced more flower heads throughout the growing season. However in a milder climate, EME were negligible. Our different studies suggest that phenotypic variation in response to climate depends on various ecological and evolutionary processes associated with geographical zone and life history traits. Therefore, we argue that a “local adaptation vs. phenotypic plasticity” approach, as often considered in the literature, is not sufficient to fully understand what shapes phenotypic variation and genetic architecture of colonizing populations. References Monty, A., J.-P. Bizoux, J. Escarré, and G. Mahy. in revision. Rapid plant invasion in distinct climates involves different sources of phenotypic variation. PLoS ONE. submitted Monty, A., J. Lebeau, P. Meerts, and G. Mahy. 2009. An explicit test for the contribution of environmental maternal effects to rapid clinal differentiation in an invasive plant. Journal of Evolutionary Biology 22:917-926. Monty, A. and G. Mahy. 2009a. Clinal differentiation during invasion: Senecio inaequidens along altitudinal gradients in Europe. Oecologia 159:305-315. Monty, A. and G. Mahy. 2009b. Évolution des traits d’histoire de vie lors des invasions végétales. Biotechnologie, Agronomie, Société et Environnement 13:449-458. Monty, A. and G. Mahy. 2010. Evolution of dispersal traits along an invasion route in the wind-dispersed Senecio inaequidens (Asteraceae). Oikos 119:1563-1570. [less ▲]

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See detailEffect of mechanical weeding on wild Chamomile populations in winter wheat crop
Jaunard, Delphine ULg; Monty, Arnaud ULg; Henriet, François et al

in Communications in Agricultural and Applied Biological Sciences (2012, May 22)

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See detail10. Perspectives - Dynamique des populations de trois adventices des céréales en vue de la mise au point de méthodes intégrées de leur contrôle
Jaunard, Delphine ULg; Henriet, François; Monty, Arnaud ULg et al

in Livre Blanc - Céréales - Gembloux (2012, February 29)

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See detailModelling realized niche of metallophyte species along copper and cobalt gradients on Katanga copper hills
Boisson, Sylvain ULg; Seleck, Maxime ULg; Guillaume, Arielle et al

Poster (2012, February 10)

In South Central Africa were identified more than 650 plant species tolerant to heavy metals, several of which endemic to Katanga and critically endangered by mining activities. These metallophyte are ... [more ▼]

In South Central Africa were identified more than 650 plant species tolerant to heavy metals, several of which endemic to Katanga and critically endangered by mining activities. These metallophyte are distributed over a hundred hills containing high copper and cobalt concentrations (20 to 10000 mg/kg for copper and 2 to 1000 mg/kg for cobalt). To understand the response of metallophyte to heavy metals, the ecological niches of 80 cupro-cobaltophytes were modeled with general additive models (GAM). Results show that (1) three groups of species were identified according to their optimum along a metal concentrations gradient and (2) a positive relationship exists between niche amplitude and optimum copper concentration. [less ▲]

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See detailCan Land Managers Control Japanese Knotweed? Lessons from Control Tests in Belgium
Delbart, Emmanuel; Mahy, Grégory ULg; Weickmans, Bernard et al

in Environmental Management (2012), 50

Japanese knotweed Fallopia japonica is an extremely abundant invasive plant in Belgium and surrounding countries. To date, no eradication method is available for land managers facing the invasion of this ... [more ▼]

Japanese knotweed Fallopia japonica is an extremely abundant invasive plant in Belgium and surrounding countries. To date, no eradication method is available for land managers facing the invasion of this rhizomatous plant. We tested different chemical herbicides with two application methods (spraying and stem injection), as well as mechanical treatments, on knotweed clones throughout southern Belgium. The tested control methods were selected to be potentially usable by managers, e.g., using legally accepted rates for herbicides. Stem volume, height and density reduction were assessed after one or two years, depending on the control method. Labor estimations were made for each control method. No tested control method completely eradicated the clones. Stem injection with glyphosate-based herbicide (3.6 kg ha-1 of acid equivalent glyphosate) caused the most damage, i.e., no sprouting shoots were observed the year following the injection. The following year, though, stunted shoots appeared. Among the mechanical control methods, repeated cuts combined with native tree transplanting most appreciably reduced knotweed development. The most efficient methods we tested could curb knotweed invasion, but are not likely to be effective in eradicating the species. As such, they should be included in a more integrated restoration strategy, together with prevention and public awareness campaigns. [less ▲]

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See detailEarly detection of alien plants in xeric Natura 2000 sites in Southern Belgium
Monty, Arnaud ULg; Frisson, Gwenn; Mahy, Grégory ULg

Poster (2012)

The Natura 2000 network consists of sites designated by the member States of the European Union, under the Habitats and Birds Directives. Setting up that network is one of the biggest challenge in nature ... [more ▼]

The Natura 2000 network consists of sites designated by the member States of the European Union, under the Habitats and Birds Directives. Setting up that network is one of the biggest challenge in nature conservation in Europe, since habitats and species for which Natura 2000 sites are designated must be maintained in a “favorable conservation status”. Little is known so far, however, about how Natura 2000 sites are invaded by exotics species. Xeric habitats of high biological value included in the Natura 2000 network are among the most species-rich in Southern Belgium. They include calcareous grasslands, sandy meadows, dry heathlands, boxwood stands, siliceous rocks and calcareous rocks. We randomly sampled 15% of sites in each of these six categories (with a minimum of five sites per category) , with a total of 86 sites out of 470 existing sites. In each site, we recorded the presence/absence of 63 alien plants know to develop in xeric habitats (species list based on Verloove (2006) and expert’s personnal observations.), and estimated species cover. 25 naturalized alien plant species were observed in xeric habitats of the Natura 2000 network in Southern Belgium. Generally, alien species populations were still limited. [less ▲]

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See detailFire promotes downy brome (Bromus tectorum L.) seed dispersal
Monty, Arnaud ULg; Brown, Cynthia; Johnston, Danielle

Poster (2012)

Particularly well-known among the many impacts of the invasive annual grass downy brome (Bromus tectorum, Poaceae) is its ability to alter fire cycles and increase in abundance after fire. However, little ... [more ▼]

Particularly well-known among the many impacts of the invasive annual grass downy brome (Bromus tectorum, Poaceae) is its ability to alter fire cycles and increase in abundance after fire. However, little is known about how fire influences B. tectorum dispersal. We quantified fire effects on B. tectorum dispersal using three recently burned areas in the western region of the Colorado Rocky Mountains by marking diaspores (seeds) with fluorescent powder, and then recovering them at night using ultraviolet lights. Diaspores were of two types: with and without sterile florets attached. We also characterized vegetation cover and near-surface wind speed in burned and unburned areas. Diaspores travelled much farther in burned areas than in nearby unburned areas (means ± standard error at the end of the experiment: 209 ± 16 cm and 38 ± 1 cm, respectively; maximal distance at the end of the experiment: 2274 cm and 150 cm, respectively), indicating an increase in dispersal distance after fire. Diaspores with sterile florets attached dispersed longer distances than those without sterile florets (means ± standard error at the end of the experiment: 141 ± 14 cm and 88 ± 7 cm, respectively). Vegetation cover was lower and wind speeds were higher in the burned areas. Our results indicate that at least one of the mechanisms by which the spread of B. tectorum is promoted by fire is through increased seed dispersal distance. Preventing movement of seeds from nearby infestations into burned areas may help avoid the rapid population expansion often observed. [less ▲]

Detailed reference viewed: 96 (4 ULg)