References of "Lejeune, Philippe"
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See detailI know what you did last summer - High resolution mapping of wild boar damages with drones
Michez, Adrien ULg; Morelle, Kevin ULg; Lehaire, François ULg et al

Poster (2014, September 01)

Wild boar ability to cause important damages to agricultural lands is not anymore to be demonstrated. These damages often raise conflicts between farmers and hunters due to the associated economic losses ... [more ▼]

Wild boar ability to cause important damages to agricultural lands is not anymore to be demonstrated. These damages often raise conflicts between farmers and hunters due to the associated economic losses. Objective and accurate method for real impact assessment of losses suffered by farmers is thus needed. Currently,in Wallonia damage assessment is performed from the ground by experts, asked to evaluate precisely the area impacted. This task is time and man power consuming. Moreover, damaged areas are often large and consequently, sampling is mandatory and can induce accuracy issues. Recent development of unmanned aerial vehicle (UAV / drone) toghether with lower cost and better accessibility for civil society and scientific community, makes now possible the use of this technology for wildlife researches. Through photogrammetric 3D reconstruction of the field crop, UAV can allow to objectively and precisely measure the area impacted by wild boar damages. In a context of increasing issues caused by wild boar to agriculture, and the need for stakeholders for accurate impact assessment, we tested an innovative approach to estimate more effectively the area impacted by wild boar. [less ▲]

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See detailIs wild boar heading towards movement ecology? A review of trends and gaps
Morelle, Kevin ULg; Lehaire, François ULg; Lejeune, Philippe ULg

in Wildlife Biology (2014), 20(4), 196-205

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See detailKeep the nest clean: survival advantages of corpse removal in ants
Diez, Lise; Lejeune, Philippe ULg; Detrain, Claire

in Biology Letters (2014), 10(7),

Sociality increases exposure to pathogens. Therefore, social insects have developed a wide range of behavioural defences, known as ‘social immunity’. However, the benefits of these behaviours in terms of ... [more ▼]

Sociality increases exposure to pathogens. Therefore, social insects have developed a wide range of behavioural defences, known as ‘social immunity’. However, the benefits of these behaviours in terms of colony survival have been scarcely investigated. We tested the survival advantage of prophylaxis, i.e. corpse removal, in ants. Over 50 days, we compared the survival of ants in colonies that were free to remove corpses with those that were restricted in their corpse removal. From Day 8 onwards, the survival of adult workers was significantly higher in colonies that were allowed to remove corpses normally. Overall, larvae survived better than adults, but were slightly affected by the presence of corpses in the nest. When removal was restricted, ants removed as many corpses as they could and moved the remaining corpses away from brood, typically to the nest corners. These results show the importance of nest maintenance and prophylactic behaviour in social insects. [less ▲]

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See detailDétection de l'érosion dans un bassin versant agricole par comparaison d'images multidates acquises par drone
Lisein, Jonathan ULg; Pineux, Nathalie ULg; Pierrot-Deseilligny, Marc et al

Conference (2014, June 26)

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See detailModélisation de la canopée forestière par photogrammétrie depuis des images acquises par drone
Lisein, Jonathan ULg; Bonnet, Stéphanie ULg; Lejeune, Philippe ULg et al

in Revue Française de Photogrammétrie et de Télédétection (2014), 206

Les petits drones civils développés à des fins de cartographie rapide offrent, à une échelle locale, de nombreuses opportunités pour le suivi d’écosystèmes forestiers. Nous utilisons dans cette recherche ... [more ▼]

Les petits drones civils développés à des fins de cartographie rapide offrent, à une échelle locale, de nombreuses opportunités pour le suivi d’écosystèmes forestiers. Nous utilisons dans cette recherche des images acquises avec un avion sans pilote à voilure fixe afin de modéliser la surface de la canopée de peuplements feuillus. Une chaine de traitements photogrammétriques est mise en place au moyen des outils de la suite open source MICMAC. Nous comparons différentes stratégies de corrélation automatique d’images afin de déterminer le paramétrage qui permet au mieux de reconstruire les détails de la canopée. Bien que le modèle de surface photogrammétrique ne permette pas d’appréhender les petites dépressions et élévations des houppiers, nos résultats montrent que l’utilisation conjointe d’images drone et d’un modèle numérique de terrain LiDAR permet d’estimer la hauteur dominante des peuplements feuillus. Ces résultats confirment la faisabilité de modéliser l’évolution de la hauteurs des peuplements forestiers depuis une série temporelle d’images drone. [less ▲]

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See detailSIMMEM comme outil d'aide à la gestion : exemple d'application à une forêt communale en Ardenne belge
Dedry, Laurent ULg; Perin, Jérôme ULg; De Thier, Olivier ULg et al

Scientific conference (2014, April 08)

SIMMEM est un module informatique intégré à CAPSIS permettant de simuler l'évolution des forêts sur des périodes allant jusqu'à plusieurs dizaines d'années

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See detailG-Cube version 2.3.2 - Logiciel de cubage et de lotissement d'arbres
Lejeune, Philippe ULg; Quevauvillers, Samuel ULg; Handerek, Daphné ULg

Software (2014)

This software is dedicated to the volume estimation of tree list using as set of volume equations adapted to belgian forest species. A specific module takes in charge the creation and the price ... [more ▼]

This software is dedicated to the volume estimation of tree list using as set of volume equations adapted to belgian forest species. A specific module takes in charge the creation and the price calculation of trees assortments [less ▲]

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See detailNouvelles courbes de productivité harmonisées pour le douglas, l'épicéa et les mélèzes en wallonie
Perin, Jérôme ULg; De Thier, Olivier ULg; Claessens, Hugues ULg et al

in Forêt Wallonne (2014), 129(mars/avril),

Les courbes de productivité sont des outils de diagnostic précieux en gestion forestière. Elles permettent d'estimer le potentiel de production d'un peuplement de structure équienne d’âge connu à partir d ... [more ▼]

Les courbes de productivité sont des outils de diagnostic précieux en gestion forestière. Elles permettent d'estimer le potentiel de production d'un peuplement de structure équienne d’âge connu à partir d'une mesure ponctuelle de la hauteur dominante. Une nouvelle génération de modèles de productivité plus fiables ont été développés pour l'épicéa, le douglas et les mélèzes en Wallonie et ont été intégrés au sein d'un outil informatique de diagnostic simple et rapide d'utilisation. [less ▲]

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See detailVers une synthèse de la conception et une définition des zones dans le gradient urbain-rural
Andre, Marie ULg; Mahy, Grégory ULg; Lejeune, Philippe ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2014), 18(1), 61-74

The increasing footprint of urbanization on landscapes justifies the study of cities and the zones surrounding them. Paradoxically, the concepts relating to these zones remain unclear. Scientists from ... [more ▼]

The increasing footprint of urbanization on landscapes justifies the study of cities and the zones surrounding them. Paradoxically, the concepts relating to these zones remain unclear. Scientists from different disciplines diverge when defining these zones or their limits; they even often mention the zones without any definition. This practice excludes comparison between studies. By means of bibliographic research, the variety of terms used to describe the different zones composing the urban-rural gradient has been evidenced, as well as the characteristics of the zones themselves. They have been evaluated according to their relative importance and according to a series of criteria. Finally, new definitions for the different zones have been proposed in order to enable their identification in the field. [less ▲]

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See detailThe end of roaming in the forest causes a loss of timber resources: the paradox of slash-and-burn agriculture
Morin-Rivat, Julie ULg; Fayolle, Adeline ULg; Favier, Charly et al

Conference (2014, February 27)

Tropical forests are not believed as pristine anymore. Their structure and specific composition are induced by past climatic and human disturbances over years. In the African moist forests, the emergent ... [more ▼]

Tropical forests are not believed as pristine anymore. Their structure and specific composition are induced by past climatic and human disturbances over years. In the African moist forests, the emergent trees are mainly light-demanding. These trees are considered to derive from the recent disturbances of the last centuries. Most of them are exploited for their timber. However, several of these tree species are currently suffering from a lack of regeneration that threatens the specific diversity of the forests and the sustainability of timber exploitation. Through dendrometric and radiocarbon analyses we found that the majority of the trees of the Congo Basin are not older than 160 years. This corresponds to about the year 1850 when the Europeans colonized the inner regions of Central Africa. By reassembling people along the road axes, the colonial administration reduced the forest roaming. Former activities such as slash and burn agriculture created large openings in the canopy that allowed light-demanding tree species to establish. Currently we observed that timber logging does not provide openings large enough for the recruitment of these species. We thus anticipate that adjustments in forest management strategies shall be made to preserve the forest resources, for instance by recreating the conditions of slash and burn agriculture. [less ▲]

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See detailSpeciation slowing down in widespread and long-living tree taxa : insights from the tropical timber tree genus Milicia (Moraceae)
Daïnou, Kasso ULg; Mahy, Grégory ULg; Duminil, Jérôme et al

in Heredity (2014)

The long generation time and large effective size of widespread forest tree species can result in slow evolutionary rate and incomplete lineage sorting, complicating species delimitation. We addressed ... [more ▼]

The long generation time and large effective size of widespread forest tree species can result in slow evolutionary rate and incomplete lineage sorting, complicating species delimitation. We addressed this issue with the African timber tree genus Milicia that comprises two morphologically similar and often confounded species: M. excelsa, widespread from West to East Africa, and M. regia, endemic to West Africa. We combined information from nuclear microsatellites (nSSRs), nuclear and plastid DNA sequences, and morphological systematics to identify significant evolutionary units and infer their evolutionary and biogeographical history. We detected five geographically coherent genetic clusters using nSSRs and three levels of genetic differentiation. First, one West African cluster matched perfectly with the morphospecies M. regia that formed a monophyletic clade at both DNA sequences. Second, a West African M. excelsa cluster formed a monophyletic group at plastid DNA and was more related to M. regia than to Central African M. excelsa, but shared many haplotypes with the latter at nuclear DNA. Third, three Central African clusters appeared little differentiated and shared most of their haplotypes. Although gene tree paraphyly could suggest a single species in Milicia following the phylogenetic species concept, the existence of mutual haplotypic exclusivity and nonadmixed genetic clusters in the contact area of the two taxa indicate strong reproductive isolation and, thus, two species following the biological species concept. Molecular dating of the first divergence events showed that speciation in Milicia is ancient (Tertiary), indicating that long-living tree taxa exhibiting genetic speciation may remain similar morphologically. [less ▲]

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See detailPrerequisites for a Black locust genomic selection program
Verdu, Cindy ULg; Mengal, Coralie ULg; Henrotay, Frédéric ULg et al

Poster (2014, February 07)

The use of renewable resources as an alternative to fossil fuels has become a priority. Efficient use of forest as a resource for energy and green chemistry purposes require the development of suitable ... [more ▼]

The use of renewable resources as an alternative to fossil fuels has become a priority. Efficient use of forest as a resource for energy and green chemistry purposes require the development of suitable selected genotypes that are competitive and ready to meet the challenges of global change. In this context, the black locust, Robinia pseudoacacia L., is a very promising species which has many advantages in the context of current global change: high phenotypic plasticity, drought resistance, high biomass production and fixation of atmospheric nitrogen. The genetic improvement of woody species using traditional methods can take between 20 to 30 years. These times can be greatly reduced with the development of new selection methods such as genomic selection. Before starting a genomic selection program, it is necessary to 1) develop new molecular markers to achieve a very dense genetic map for genomic selection, 2) study the genetic diversity of the species present in Belgium and compare it with that of the native area, 3) study the structure and the relatedness of different populations, 4) establish a core collection gathering the most genetically diverse individuals, and 5) as black locust is an exotic species, verify its invasiveness in Belgium. These 5 steps will be detailed and the first results obtained will be discussed. [less ▲]

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See detailA diachronic analysis of the dynamic of two cities: Kisangani and Lubumbashi (Democratic Republic of Congo): How do the extension and/or of the densification of these cities impact the urban internal and peripheral ecosystems?
Andre, Marie ULg; Mahy, Grégory ULg; Lejeune, Philippe ULg et al

Poster (2014, February 07)

The dynamics of two cities between two years (2002 and 2010 for Kisangani; 2002 and 2008 for Lubumbashi, both part of the Democratic Republic of Congo) have been examined in order to estimate how their ... [more ▼]

The dynamics of two cities between two years (2002 and 2010 for Kisangani; 2002 and 2008 for Lubumbashi, both part of the Democratic Republic of Congo) have been examined in order to estimate how their extension and/or of the densification have impacted the urban internal and peripheral ecosystems. This study singularizes itself from the subjective ones by its quantified and objective approach based on landscape ecology. This discipline assumes that the landscape pattern description is important because, according to its central hypothesis called “pattern-process paradigm”, the ecological processes influence landscape structure and vice versa. Composition metrics, which are commonly used in landscape ecology, describe the pattern among other things in quantifying the presence and the number of patches from the various classes within the landscape. For each city two SPOT 5 images were classified with a oriented-object supervised approach; then built area proportion index, a composition landscape metric, has been evaluated in order to 1) identify the extent of each area (urban, suburban, rural) within the urban-rural gradient, 2) quantify the dynamic of the different areas in the urban-rural gradient during the last decade and 3) quantify the effect of a decade of urban and suburban growth on ecosystems. The similarities and differences between these cities, relevance and gaps in the method have then been identified and discussed. [less ▲]

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