References of "Mahy, Grégory"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailPhenotypic traits variation among native diploid, native tetraploid and invasive tetraploid Senecio inaequidens DC. (Asteraceae)
Monty, Arnaud ULg; Maurice, Sandrine; Mahy, Grégory ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14(4), 627-632

Senecio inaequidens DC. is a rapidly spreading plant invader in Europe. In its native range, it occurs at two co-existing diploid and tetraploid cytotypes. To date, only tetraploids are reported in Europe ... [more ▼]

Senecio inaequidens DC. is a rapidly spreading plant invader in Europe. In its native range, it occurs at two co-existing diploid and tetraploid cytotypes. To date, only tetraploids are reported in Europe, even though invasive diploids were recorded in other parts of the world. We compared native diploid and both native and invasive tetraploid populations in common gardens in Europe for a suite of life history traits. Diploids were able to develop, showed high biomass production and produced more flower heads than tetraploids. In contrast, winter survival was null for diploids. It was low for native tetraploids, but reached 40% in invasive tetraploids. Results suggested that diploid cytotype tends to an annual life form when grown in Western Europe, with earlier and more abundant flowering. In contrast, the tetraploid cytotype was mainly perennial which may enhance its invasiveness. [less ▲]

Detailed reference viewed: 49 (7 ULg)
Full Text
Peer Reviewed
See detailEvolution of dispersal traits along an invasion route in the wind-dispersed Senecio inaequidens (Asteraceae)
Monty, Arnaud ULg; Mahy, Grégory ULg

in Oikos (2010), 119

In introduced organisms, dispersal propensity is expected to increase during range expansion. This prediction is based on the assumption that phenotypic plasticity is low compared to genetic diversity ... [more ▼]

In introduced organisms, dispersal propensity is expected to increase during range expansion. This prediction is based on the assumption that phenotypic plasticity is low compared to genetic diversity, and an increase in dispersal can be counteracted by the Allee effect. Empirical evidence in support of these hypotheses is however lacking. The present study tested for evidence of differentiation in dispersal-related traits and the Allee effect in the wind-dispersed invasive Senecio inaequidens (Asteraceae). We collected capitula from individuals in ten field populations, along an invasion route including the original introduction site in southern France. In addition, we conducted a common garden experiment from field-collected seeds and obtained capitula from individuals representing the same ten field populations. We analysed phenotypic variation in dispersal traits between field and common garden environments as a function of the distance between populations and the introduction site. Our results revealed low levels of phenotypic differentiation among populations. However, significant clinal variation in dispersal traits was demonstrated in common garden plants representing the invasion route. In field populations, similar trends in dispersal-related traits and evidence of an Allee effect were not detected. In part, our results supported expectations of increased dispersal capacity with range expansion, and emphasized the contribution of phenotypic plasticity under natural conditions. [less ▲]

Detailed reference viewed: 92 (18 ULg)
Full Text
Peer Reviewed
See detailRestauration écologique: contexte, contraintes et indicateurs de suivi
Cristofoli, Sara ULg; Mahy, Grégory ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14(1), 203-211

Dans un contexte global de perturbations anthropiques toujours croissantes des écosystèmes naturels et semi-naturels, l’unique conservation de ces écosystèmes ne suffit plus. La restauration écologique ... [more ▼]

Dans un contexte global de perturbations anthropiques toujours croissantes des écosystèmes naturels et semi-naturels, l’unique conservation de ces écosystèmes ne suffit plus. La restauration écologique peut ainsi se révéler un complément essentiel à la conservation s.l. L’article consiste en une synthèse de la littérature scientifique dédiée aux concepts de la restauration écologique. Nous abordons la notion d’objectifs de la restauration notamment au travers de la référence écologique. Outre la définition d’objectifs clairs de restauration, la référence permet ensuite d’évaluer les efforts de restauration, par le biais d’indicateurs de suivi. Les indicateurs peuvent par ailleurs fournir des informations quant aux attributs de l’écosystème restauré et/ou la trajectoire écologique empruntée. Les éventuelles contraintes rencontrées par les espèces au travers de filtres à la restauration pourront être détectées et des mesures de compensation adéquates pourront être proposées. [less ▲]

Detailed reference viewed: 506 (51 ULg)
Full Text
Peer Reviewed
See detailMucilage and polysaccharides in the halophyte plant species Kosteletzkya virginica : Localozation and composition in relation to salt stress
Ghanem, Michel Edmond; Han, Rui-Ming; Classen, Birgit et al

in Journal of Plant Physiology (2010), 167

Detailed reference viewed: 53 (2 ULg)
Full Text
Peer Reviewed
See detailSpider communities as evaluation tools for wet heathland restoration
Cristofoli, Sara ULg; Mahy, Grégory ULg; Kekenbosh, Robert et al

in Ecological Indicators (2010), 10

Detailed reference viewed: 42 (13 ULg)
Full Text
Peer Reviewed
See detailColonisation credit in recent wet heathland butterfly communities
Cristofoli, Sara ULg; Mahy, Grégory ULg

in Insect Conservation and Diversity (2010), 3

Detailed reference viewed: 36 (10 ULg)
See detailAgriculture et Biodiversité
Hance, Thierry; Demeter, Sébastien; Le Roi, Alain et al

Book published by Direction Générale de Opérationnelle des l'Agriculture, des Ressources Naturelles et de l'Environnement (2010)

Detailed reference viewed: 72 (27 ULg)
Full Text
Peer Reviewed
See detailRevue bibliographique sur la restauration des pelouses calcicoles en Europe : contraintes rencontrées et solutions proposées
Piqueray, Julien ULg; Mahy, Grégory ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14(3), 471-484

Calcareous grasslands, that are considered as biodiversity hotspots in Europe, have suffered an important decline during the last century. In this context, restoration of suitable habitats has been ... [more ▼]

Calcareous grasslands, that are considered as biodiversity hotspots in Europe, have suffered an important decline during the last century. In this context, restoration of suitable habitats has been promoted as a conservation strategy. Restoration consists in the recreation of favourable abiotic and biotic conditions that permit the recolonization by typical species. Depending on the degradations, several constraints can be encountered during restoration, such as soil enrichment, the presence of competitive species, or harsh conditions for plant growth. In order to overcome these constraints, scientists have proposed techniques that were demonstrated to be more or less efficient. In this article, the different constraints that can occur while restoring calcareous grasslands are described as well as the techniques proposed in the scientific literature. We also describe restoration objectives specific to calcareous grasslands, taking the history of these habitats into account and considering global change issue. Different parameters can be considered to value restoration success. Here again, an analysis of the scientific literature is needed in order to best assess restoration monitoring. [less ▲]

Detailed reference viewed: 167 (39 ULg)
See detailExtinction debt and colonization credit: When both phenomena are integrated
Piqueray, Julien ULg; Cristofoli, Sara; Bisteau, Emmanuelle et al

Conference (2010)

Calcareous grasslands are among the most species-rich ecosystems in temperate countries. These ecosystems suffered a high fragmentation process during the last century. Fragmentation can lead to the ... [more ▼]

Calcareous grasslands are among the most species-rich ecosystems in temperate countries. These ecosystems suffered a high fragmentation process during the last century. Fragmentation can lead to the creation of an extinction debt in remaining habitat patches. In our study site, it was shown in a previous study that Fragmented habitat patches (area loss since 1965 >80%) exhibited an extinction debt in comparison to Stable habitat patches (area loss since 1965 <80%). However, human activities also created new habitat patches in the landscape and provided therefore opportunities for calcareous grassland plant species to colonize new sites. They also provide opportunities for studying species colonization abilities in the context of habitat restoration. We analyzed species richness in these new patches in comparison to old patches in order to detect colonization credit. When taking as reference Fragmented patches (that exhibit an extinction debt) or all old patches (Fragmented and Stable), we concluded to the occurrence of a colonization credit in New patches. However, when the reference is Stable patches (the less likely to exhibit an extinction debt) alone, no colonization credit could be detected. Moreover, correspondence analysis revealed that New patches were similar to old patches in term of species composition. These results are encouraging for restoration programs. They also showed that the presence of an extinction debt in reference habitats can lead to mistaken conclusion in restoration monitoring. Extinction debt occurrence should be taken into account in the choice of reference habitats for evaluation of restoration success. [less ▲]

Detailed reference viewed: 88 (10 ULg)
Full Text
Peer Reviewed
See detailCopper endemism in the Congolese flora: a database of copper affinity and conservational value of cuprophytes.
Faucon, M. P.; Meerseman, A.; Shuta, A. et al

in Plant Ecology and Evolution (2010), 143

Detailed reference viewed: 82 (12 ULg)
Full Text
Peer Reviewed
See detailHistorical landscape structure affects plant species richness in wet heathlands with complex landscape dynamics
Cristofoli, Sara; Monty, Arnaud ULg; Mahy, Grégory ULg

in Landscape & Urban Planning (2010), 98

The spatio-temporal dynamics of wet heathlands from two landscapes in high Ardenne (Belgium), as well as the consequences of such dynamics on plant communities were investigated. Past and present ... [more ▼]

The spatio-temporal dynamics of wet heathlands from two landscapes in high Ardenne (Belgium), as well as the consequences of such dynamics on plant communities were investigated. Past and present destruction and origin of habitat patches have resulted in a complex network of different aged habitat patches. Current specialist and generalist species richness were assessed in 59 patches and analyzed with respect to present and past patch spatial metrics (controlled for habitat quality). Current patch area affected specialist species richness and current patch connectivity influenced both specialist and generalist species richness. Thirteen of the 59 patches were historical patches, i.e. patches that have remained since the 1770s. In these historical patches, including past landscape structure in the analysis explained more of the variability in current species richness than the current landscape structure alone, suggesting the existence of an extinction debt. [less ▲]

Detailed reference viewed: 69 (7 ULg)
Full Text
See detailMapping of soil-sediment systems contaminations around a metal-ore smelter. The example of Cu in Lubumbashi (R.D. Congo)
Mpundu, Michel; Kaya Muyumba, Donato ULg; N'gongo, Michel et al

Conference (2009, December 02)

Detailed reference viewed: 50 (15 ULg)
Full Text
See detailLes invasions biologiques ... quand Darwin s'en mêle
Vanderhoeven, Sonia ULg; Mahy, Grégory ULg; Vanparys, Valérie et al

in Parcs & Réserves (2009), 64(4), 7-9

Detailed reference viewed: 90 (23 ULg)
Peer Reviewed
See detailBiodiversity Conservation and Mining : a Study Case of Ecosystem Reconstruction in Katanga (DRC)
Lebrun, Julie ULg; Seleck, Maxime ULg; Semereab, Ezana et al

Conference (2009, September 03)

The South of the Democratic Republic of Congo (Katanga) and adjoining regions in the North of Zambia comprise some of the largest ore bodies of cobalt and copper in the world. Katangan copper hills harbor ... [more ▼]

The South of the Democratic Republic of Congo (Katanga) and adjoining regions in the North of Zambia comprise some of the largest ore bodies of cobalt and copper in the world. Katangan copper hills harbor about 40 endemics as well as particular steppic plant communities. This Biological Diversity Action Plan (BDAP) is an activity program for the conservation of copper-cobalt flora and vegetation and mitigation of potential species extinction risk, during the early construction phase of the Tenke Fungurume Mining Corp. (TFM) project. Six potential taxa of concern (IUCN criteria) have been identified in the TFM concession. In situ conservation is fulfilled through the setting of a single large reserve. In parallel, important efforts have been devoted to ex-situ conservation strategy to re-establish vegetation and species after mining activities cessation. This includes: - Translocation of 3500 individuals of plants of concern to the nature reserve. - Ecosystem engineering with the reconstruction of an artificial copper/cobalt ecosystem. - Ex-situ seed bank with 300 seed samples (at least 50 seeds) collected belonging to 40 species and used for short and long term conservation, germination tests and micro-propagation tests. All these efforts represent an important step towards the conservation of copper-cobalt flora. [less ▲]

Detailed reference viewed: 183 (32 ULg)