References of "Mahy, Grégory"
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See detailInvasive plant species management tests in Southern Belgium
Delbart, Emmanuel ULg; Halford, Mathieu ULg; Pieret, Nora et al

Poster (2009)

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See detailClinal differentiation during invasion: Senecio inaequidens (Asteraceae) along altitudinal gradients in Europe.
Monty, Arnaud ULg; Mahy, Grégory ULg

Poster (2009)

Plant population differentiation may play a role in decreasing the ability to predict whether, where, and when an introduced species will invade. However, few studies have addressed the level of genetic ... [more ▼]

Plant population differentiation may play a role in decreasing the ability to predict whether, where, and when an introduced species will invade. However, few studies have addressed the level of genetic change an alien species may undergo during range expansion, e.g. in response to climatic variation with altitude. In the present study, we tested the hypothesis that invasive populations of Senecio inaequidens (Asteraceae) differentiated during migration from two independent introduction sites into divergent altitudinal and climatic zones. We carried out two years of common garden experiments with eight populations from a Belgian altitudinal transect and ten populations from similar French transect. Climatic analysis revealed that the Belgian transect followed a temperature and precipitation gradient. A temperature and summer drought gradient characterized the French study site. We evaluated differentiation and clinal variation in the following characters: days to germination, days to flowering, height at maturity, final plant height and aboveground biomass. Results showed that S. inaequidens populations differentiated in growth traits during invasion. First year of experiment, regressing population growth trait means against source population altitude indicated the presence of clinal variation along both transects. Second year, similar results were found along the French transect, i.e. a reduction in height at maturity, plant height and aboveground biomass with increasing altitude. Including seed mass as a covariate did not change the outcome of the analysis. The possible evolutionary causes for the differentiation observed are discussed. [less ▲]

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See detailEditorial : Les invasions biologiques ... appréhender la démesure
Vanderhoeven, Sonia ULg; Branquart, Etienne; Mahy, Grégory ULg

in Parcs & Réserves (2009), 3

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See detailSources of phenotypic variation of life history traits in an invasive species, Senecio inaequidens DC. (Asteraceae)
Monty, Arnaud ULg; Mahy, Grégory ULg

Conference (2009)

The importance of different sources of phenotypic variation, namely adaptation, phenotypic plasticity, environmental maternal effects, ploidy level and genetic drift, were estimated in several life ... [more ▼]

The importance of different sources of phenotypic variation, namely adaptation, phenotypic plasticity, environmental maternal effects, ploidy level and genetic drift, were estimated in several life history traits among populations of an invasive plant species within its invasion range. Several common garden experiments were set out, two of which in a reciprocal transplants experiment. The populations considered in this study were located in Belgium, in France and in the native range of the model species. Senecio inaequidens DC. (Asteraceae) is native to Africa. It was introduced in Europe via wool trade in the late 19th century. In the native range, the species occurs at two co-existing cytotypes: diploid and tetraploid. Only tetraploid individuals are reported in Europe. The particular and well-documented invasion history of S. inaequidens makes it an excellent plant model for evolutionary studies. Several life history traits were measured, related to germination, growth and sexual reproduction. The sources of phenotypic variation in those traits were analysed with respect to climatic variation along altitudinal gradients in the invaded areas. The influence of the ploidy level and the range (native vs introduced) on those traits was also analysed. Results showed that diploid and tetraploid populations differed, mainly in winter survival capacity. Along altitudinal gradients, clinal phenotypic differentiations with a genetic basis were observed among populations. However, environmental maternal effects were found to significantly influence phenotypic variation in areas with harsh climatic conditions. Monty A., Mahy G. 2009. Clinal differentiation during invasion: Senecio inaequidens (Asteraceae) along altitudinal gradients in Europe. Oecologia 159:305–315. Monty A., Lebeau J., Meerts P., Mahy G. 2009. An explicit test for the contribution of environmental maternal effects to rapid clinal differentiation in an invasive plant. Journal of Evolutionary Biology22: 917-936 [less ▲]

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See detailEvolutionary potential of the Fallopia spp. complex in Europe
Vanderhoeven, Sonia ULg; Krebs, Christine; Schaffner, Urs et al

Conference (2009)

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See detailDette d'extinction dans un hotspot de biodiversité: approches communauté et espèces
Piqueray, Julien ULg; Bisteau, Emmanuelle; Cristofoli, Sara et al

Conference (2009)

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See detailFiche synthétique de gestion: Les Jussies
Delbart, Emmanuel ULg; Mahy, Grégory ULg

Learning material (2009)

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See detailMéthodes de gestion des principales plantes invasives en zones humides - 1 ère partie
Pieret, Nora; Delbart, Emmanuel ULg; Vanderhoeven, SONIA ULg et al

in Silva Belgica (2008)

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See detailResponse of spider communities to habitat restoration in a wet heathland complex
Cristofoli, Sara ULg; Kekenbosch, Robert; Mahy, Grégory ULg

Poster (2008, September)

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See detailVariability of edaphic conditions in metal-contaminated sites at multiple scales. Two case studies in temperate and tropical environments
Colinet, Gilles ULg; Leclercq, Julie; Faucon, Michel-Pierre et al

Conference (2008, August)

In numerous places, mining and ore treatment activities have generated environmental contaminations which endanger ecosystem viability and/or human health. In some places, the ecological pressure induced ... [more ▼]

In numerous places, mining and ore treatment activities have generated environmental contaminations which endanger ecosystem viability and/or human health. In some places, the ecological pressure induced by the metal contaminations allowed the development a specific flora, fromwhich candidates for phytoremediation may be selected. A survey of edaphic conditions prevailing for plant growing in contaminated areas around metal smelters has been conducted in belgian calaminary sites (Zn, Pb, Cd contaminations) and in the Katanga province of RDC (Cu contaminations). As the processes generated by the modifications of the soil environment may affect the form of a trace element, that is its distribution through various pools, we investigated physical and chemical fractionation of some metallic trace elements (Cu, Zn, Pb, and Cd) in soils and compared temperate and tropical cases. The results stress the need for a typology of the contaminations that takes into account the classical pedological parameters, even if contaminated sites are far from classical soil environment. The variability of edaphic properties that can occur within small distances is also an important point to consider when planning rehabilitation operations. [less ▲]

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See detailDry heathlands and sandy open grasslands in a suburban environment in the south of Brussels (Belgium) : Assessment of the conservation status
Taymans, Julien ULg; Mahy, Grégory ULg

Poster (2008, August)

The Brabant sablo-limoneux region is located in the south and near Brussels, in the phytogeographic district of Brabant (Atlantic domain). This region is characterized by a high diversity of local ... [more ▼]

The Brabant sablo-limoneux region is located in the south and near Brussels, in the phytogeographic district of Brabant (Atlantic domain). This region is characterized by a high diversity of local ecological conditions due to the alternance of important tertiary sand outcrops and quaternary silty layers. The agro-sylvo-pastoral activities, which were practiced on these sandy and sand-silty soils for centuries, caused the evolution of the climactic forest into semi-natural habitats such as dry heathland, sandy grassland and grassheath. The evolution of the heathland distribution from 1770 to the present has been studied on the scale of the Dyle hydrographic subbasin (43.000 ha). It is characterized by an important regression of this habitat in the study area (from 1460 ha in 1770 to 72 ha in 2006), mainly due to Pinus sylvestris orchards, and more recently, to urbanisation caused by the proximity of Brussels. A generalized ageing and an environmental closing characterize the evolution of heathland physiognomy since the middle of the 20th century. The phytosociology of heathlands, sandy grasslands and grassheaths has been characterized and 19 groups of vegetation have been differentiated. Among the 393 listed higher plant species, more than 30 are of great conservation interest in the regional context. A hierarchisation of restoration priorities has been established on the scale of the studied hydrographic subbasin and management measures have been proposed. [less ▲]

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See detailLes landes et pelouses sur sable du Brabant sablo-limoneux (Deuxième partie)
Taymans, Julien ULg; Mahy, Grégory ULg

in Parcs & Réserves (2008), 62(4), 4-12

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See detailQuinoa in Bolivia : an ancestral corp changed to a cash crop with organic fair trade labelling
Del Castillo, C.; Mahy, Grégory ULg; Winkel, T.

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2008), 12

Detailed reference viewed: 93 (1 ULg)
See detailCuivre et biodiversité au Katanga : stratégies de conservation et de valorisation d’un patrimoine exceptionnel.
Meerts, P; Shimba, N; Shutcha, M N et al

in Colloque « La quête des ressources naturelles en Afrique centrale. Le cas du secteur minier en RDC. (2008)

Detailed reference viewed: 27 (6 ULg)