References of "Bogaert, Jan"
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See detailEffets de lisière et sex-ratio de rongeurs forestiers dans un écosystème fragmenté en République Démocratique du Congo (Réserve de Masako, Kisangani)
Iyongo Waya Mongo, L; De Cannière, C; Ulyel, J et al

in Tropicultura (2013), 31(1), 3-9

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See detailEffets de la fragmentation des forêts par l'agriculture itinérante sur la dégradation de quelques propriétés physiques d'un ferralso échantillonné à Yangambi, R.D. Congo
Alongo, Sylvain; Visser, Marjolein; Drouet, Thomas et al

in Tropicultura (2013), 31(1), 36-43

The knowledge of changes occurring in the soil cover at the forest edge is needed to better understand the impact of forest fragmentation on soil parameters. The objective of this study is to evaluate the ... [more ▼]

The knowledge of changes occurring in the soil cover at the forest edge is needed to better understand the impact of forest fragmentation on soil parameters. The objective of this study is to evaluate the effects of forest fragmentation caused by shifting agriculture on texture, bulk density, total porosity and soil hydraulic conductivity in the layers at 0-10, 10-20 and 20-30 cm depth by the transect method in a perspective of sustainable land management in the region of Yangambi. The results obtained show that the edge between the fallow grassland and dense forest has a width of 70 m. Degradation of all the physical properties of soils relative to the dense forest is very significant (p<0.01) for the studied layers. Fragmentation of forests by shifting cultivation increases the phenomenon of selective loss of clays of the surface soil layers and consequently increases its bulk density and decreases the permeability and porosity with depth under the fallow grass and edge. The texture data associated with textural classes in the FAO textural triangle indicate a change in texture of the soil under different land uses for the tree layers studied. [less ▲]

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See detailOptimizing scale search in species distribution models
Serckx, Adeline ULg; Huynen, Marie-Claude ULg; Beudels-Jamar, Roseline et al

in Folia Primatologica : International Journal of Primatology = Internationale Zeitschrift für Primatologie = Journal international de Primatologie (2013), 84

The influence of spatial scale on ecological processes and pattern formation, such as species distribution is a major research topic since decades. It has become even more relevant in the context of ... [more ▼]

The influence of spatial scale on ecological processes and pattern formation, such as species distribution is a major research topic since decades. It has become even more relevant in the context of global change. In many studies the influence of a predictor on a response derived over multiple and discrete spatial scales is evaluated. Due to inherent issue of multiple testing, this approach can be problematic. In this study on bonobos distribution, we suggest a 3-steps procedure that overcomes this problem. It takes into account the decay of a predictor by using a weighting function of distance to the observation of interest. We use variables to account for human pressure, food availability, patchy structure of the forest and nesting sites re-use. In a first step, we run a model with a fixed scale for every predictor based on expert opinion. For significant variables, we derive then in a second step the distance weighted influence over a range of scales. This helps to narrow down the search for the final model parameter estimates. Findings indicate that bonobo distribution is driven on the intermediate scale by forest patches structure. Food availability explains their abundance only at smaller scales. Those results demonstrate the sadly well-known influence of habitat fragmentation on animals’ density and distribution but also highlight the importance to understand influences of scale, the animal perceptions of their environment, by using appropriate statistical procedures. Our method can be particularly useful to formulate specific management hypotheses for conservation. Furthermore, its principles can be of use to other types of studies, such as behavior. [less ▲]

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See detailLa soie naturelle des Hauts-Plateaux de Madagascar: les facteur socio-institutionnels entravant une filière dynamique et pérenne
Rabearisoa, Misha; Ramamonjisoa, Bruno; Poncelet, Marc ULg et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

Despite the cultural, social and socio-economic importance for societies situated in the Highlands of Madagascar, the endemic silk moth Borocera cajani and its habitat Uapaca bojeri are endangered by many ... [more ▼]

Despite the cultural, social and socio-economic importance for societies situated in the Highlands of Madagascar, the endemic silk moth Borocera cajani and its habitat Uapaca bojeri are endangered by many factors. In order to sustainably manage these resources, the silk production chain has been studied combining economic and socio-anthropologic approaches. Silk chain production analysis situates the underlying rural realities in an economic context; socio-anthropological considerations link those economic factors to their social context. The current study focuses on decentralized natural resource management in Itasy and Amoron’i Mania. It appears that institutional, economic and social factors tend to determine silk moth production chain dynamics. Considering all of these parameters and their interactions is considered crucial for a sustainable management of these endangered resources. [less ▲]

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See detailInfluence des reboisements d'eucalyptus (Eucalyptus robusta) et de pin (Pinus kesiya) sur la régénération naturelle de tapia (Uapaca bojeri) en forêt d'Arivonimamo
Rakotondrasoa, Olivia Lovanirina; Stein, Julien; Ayral, Astrid et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

Confronted with the ongoing degradation of the tapia woodlands (Uapaca bojeri), reforestation by Pinus sp. and Eucalyptus sp.was considered as an alternative in Arivonimamo to substitute tapia for the ... [more ▼]

Confronted with the ongoing degradation of the tapia woodlands (Uapaca bojeri), reforestation by Pinus sp. and Eucalyptus sp.was considered as an alternative in Arivonimamo to substitute tapia for the production of firewood. However, the invasion by these alien species is actually considered as one of the threats to the tapia woodland in Madagascar. In this context, this study aimed to analyze the regeneration of the tapia woodlands in Arivonimamo. Consequently, “contact zones” between stands of exotic species, Pinus kesiya or Eucalyptus robusta, and U. bojeri were identified, in order to study tree regeneration along transects in each cardinal direction starting inside the exotic forests and continuing into the native populations. This study showed that the density of tapia regeneration varied between sites. It also appeared that the capacity of P. kesiya to invade the tapia woodland is much higher than for E. robusta. Moreover, the regeneration of pine inside the pine’s plantations was rather low. In addition, it was observed that the canopy opening rate had no significant influence on the development of the regeneration of the three species involved. Differences in canopy opening are due to various human activities such as the collection of non-timber forest products (tapia), the forestry operation of cleaning (pine) and early cutting (eucalyptus). [less ▲]

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See detailIdentification des indicateurs de dégradation de la forêt de tapia (Uapaca bojeri) par une analyse sylvicole
Rakotondrasoa, Olivia Lovanirina; Malaisse, François ULg; Rajoelison, Gabrielle Lalanirina et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

Deforestation is a serious problem in Madagascar leading to natural resource degradation. In this context, this study aims to identify indicators of forest degradation for the tapia forest of Arivonimamo ... [more ▼]

Deforestation is a serious problem in Madagascar leading to natural resource degradation. In this context, this study aims to identify indicators of forest degradation for the tapia forest of Arivonimamo. A forest map of the area consists of a document in which the forest is stratified into two types: degraded tapia forest and highly degraded tapia forest. The approach consisted of the comparison of these two types of forest, the degraded tapia being the reference. Data collection was based on a forest inventory through discontinuous transects related to the structure of the tapia forest, with a total length of 1,500 m per type. It appears that tree density, average tree height, average tree diameter, basal area and density of regeneration and undergrowth, are indicators for the identification of the state of degradation of the tapia forest. The distribution of U. bojeri is aggregated in both sites; however, the degree of aggregation is significantly higher in the highly degraded forest in response to the lower tree density. Leptolaena pauciflora and Erica sp. are the main undergrowth indicator species of degradation; their abundance is correlated with degradation. Knowledge of these indicators of tapia degradation will provide guidance and technical tools to improve evaluation and monitoring of the degradation of the tapia forest. [less ▲]

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See detailLes bois de Tapia de Madagascar: approches phytogéographique, floristique et écologique
Malaisse, François ULg; Pinel, Romain; Razafimanantsoa, Tsiresy Maminiaina et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

This chapter has three objectives. Firstly, it is emphasized that tapia-dominated areas are spatially distributed into four localities situated on the so-called “Highlands”. Secondly, based on a global ... [more ▼]

This chapter has three objectives. Firstly, it is emphasized that tapia-dominated areas are spatially distributed into four localities situated on the so-called “Highlands”. Secondly, based on a global survey of available literature on tapia vegetation as well as on floristic surveys carried out in two entities (Arivonimamo et Ambatofinandrahana), an actualized list of their floristic diversity is composed. This list is partially illustrated with photographs and plates on a CD-ROM; vernacular names of the considered taxa are quoted. Finally a preliminary ecological interpretation is given based on the vegetation units and (or) ecological niches which are schematically represented. [less ▲]

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See detailLa forêt de tapia, écosystème endémique de Madagascar : écologie, fonctions, causes de dégradation et de transformation (synthèse bibliographique)
Rakotondrasoa, Olivia Lovanirina; Malaisse, François ULg; Rajoelison, Gabrielle Lalanirina et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

This article presents an overview of the tapia forest (Uapaca bojeri Baill.) in Madagascar in order to emphasize its importance for the development of the local population through improving household ... [more ▼]

This article presents an overview of the tapia forest (Uapaca bojeri Baill.) in Madagascar in order to emphasize its importance for the development of the local population through improving household incomes. The tapia forest is a “socio-natural” formation, quasi-monospecific with regard to the tree stratum and endemic to Madagascar. It is only located in the Highlands of Madagascar. Alongside its ecosystem functions, the tapia forest hosts various resources, including non-timber forest products as well as timber itself, all of which play an important role in the informal local economy. However, the tapia ecosystem is threatened by human destruction through bush fires, production of firewood and charcoal, agriculture expansion, and by invasion of exotic species introduced for the purposes of reforestation. Subsequently, the sustainable management and protection of the tapia forest is essential in order to enable local populations to reap its benefits across several generations. [less ▲]

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See detailInfluence de la plante hôte sur le développement larvaire de Borocera cajani (Lepidoptera: Lasiocampidae)
Razafimanantsoa, Tsiresy; Malaisse, François ULg; Raminosoa, Noromalala et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

Borocera cajani Vinson (Lepidoptera: Lasiocampidae) is a silk moth endemic to Madagascar that is currently used to produce silk textiles. This silk moth is polyphagous and colonizes forests situated in ... [more ▼]

Borocera cajani Vinson (Lepidoptera: Lasiocampidae) is a silk moth endemic to Madagascar that is currently used to produce silk textiles. This silk moth is polyphagous and colonizes forests situated in the central Highlands, mainly constituted by tapia trees (Uapaca bojeri). Two host plants are commonly used by the caterpillar of this moth species: tapia and voafotsy (Aphloia theiformis). In this work we have evaluated parameters of different stages (survival rate, development duration, weight and size, fecundity, etc.) of B. cajani on both host plants. We have observed a 30% higher survival rate on U. bojeri. Larval and pupae duration were shorter on U. bojeri (64,8 ± 1,5 days) than on A. theiformis (87,4 ± 2,0 days). Cocoons were bigger when obtained from larvae fed on U. bojeri. This plant is therefore better for the development of B. cajani and should be used in intensive rearing of this silk moth. [less ▲]

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See detailSilk moths inventory in their natural tapia forest habitat (Madagascar): diversity, population dynamic and host plants
Razafimanantsoa, Tsiresy; Raminosoa, Noromalala; Rakotodrasoa, Olivia et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

Endemic silk moths (Lepidoptera: Lasiocampidae) in Madagascar have been collected and exploited for centuries by local populations either for food or as a source of silk cocoons from which textiles are ... [more ▼]

Endemic silk moths (Lepidoptera: Lasiocampidae) in Madagascar have been collected and exploited for centuries by local populations either for food or as a source of silk cocoons from which textiles are made. Moth natural forest habitat has also been degraded, leading to a drastic decrease in silk moth populations. However, very few scientific reports highlighted these observations well known by the local people. We have inventoried silk moths species in tapia (Uapaca bojeri Baill.) forests located in the central Highlands of Madagascar. Inventories have been conducted during one year from August 2009 to July 2010 by sampling transects in Imamo forests. Three species of Lasiocampidae belonging to two genera were found: Borocera cajani Vinson, Borocera marginepunctata Guérin-Méneville and Europtera punctillata Guenée. These three silk moth species are endemic to Madagascar but only one (B. cajani) is commercially exploited in the silk industry. The habitat, host plants, abundance, life cycle and feeding behaviour of these species in their natural habitat are described. [less ▲]

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See detailSilk moths in Madagascar: a review of the biology, uses, and challenges related to Borocera cajani (Vinson, 1863) (Lepidoptera: Lasiocampidae)
Razafimanantsoa, Tsiresy; Rajoelison, Gabrielle; Ramamonjisoa, Bruno et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

Borocera cajani ou landibe (nom vernaculaire) est l’un des papillons séricigènes sauvages dont la soie est la plus utilisée dans le domaine textile de Madagascar. Cette espèce endémique s’observe dans ... [more ▼]

Borocera cajani ou landibe (nom vernaculaire) est l’un des papillons séricigènes sauvages dont la soie est la plus utilisée dans le domaine textile de Madagascar. Cette espèce endémique s’observe dans toute l’île, mais colonise particulièrement la forêt de Uapaca bojeri ou forêt de « tapia » des Hautes Terres centrales. La forêt fournit les aliments à B. cajani tels que les feuilles de U. bojeri. L’espèce secrète la soie quand elle entre en nymphose et construit son cocon. Borocera cajani et son habitat naturel sont menacés par les destructions de l’Homme telles que les feux de brousse, la collecte de bois de chauffage, la production de charbon de bois et la surexploitation de leurs cocons. La production de soie sauvage est en constante diminution, alors que la filière soie implique beaucoup de gens dans l’île comme les collecteurs des cocons, les fileurs, les teinturiers, les tisseurs et les artistes qui transforment la soie en habits, en accessoires et objets. Revitaliser la filière soie est un moyen de favoriser la conservation de cette ressource naturelle et de son habitat forestier. [less ▲]

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See detailApport de la surface terrière dans la dénomination des formations végétales dominées par le tapia (Uapaca bojeri) à Madagascar
Malaisse, François ULg; Rakotondrasoa, Olivia; Rakotoniaina, R.T. et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches. Enjeux écologiques et socio-économiques. (2013)

Après avoir rappelé l’intérêt transcendant d’Uapaca bojeri, essence endémique malgache, pour les populations locales et avoir défini l’importance des apports écosystémiques des formations végétales où ... [more ▼]

Après avoir rappelé l’intérêt transcendant d’Uapaca bojeri, essence endémique malgache, pour les populations locales et avoir défini l’importance des apports écosystémiques des formations végétales où cette essence domine, la diversité des dénominations concernant ces dernières est mise en évidence et les causes sous-jacentes en sont analysées. Une situation analogue a été observée antérieurement pour les forêts claires de type miombo en Afrique continentale ; le concept de surface terrière a constitué pour ces dernières un apport pertinent et a autorisé une typologie valorisante des dénominations. Dès lors, l’application du concept de surface terrière aux formations végétales à dominance de tapia est examinée et son apport éventuel discuté. Un système original est proposé. [less ▲]

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See detailActivité journalière et comportement d’alimentation de Borocera cajani Vinson 1863 (Lepidoptera: Lasiocampidae) sur deux de ses plantes hôtes : Uapaca bojeri Baillon 1874 et Aphloia theiformis (Vahl) Bennett 1840
Razafimanantsoa, Tsiresy; Raminosoa, Noromalala; Rakotondrasoa, Olivia et al

in Entomologie Faunistique = Faunistic Entomology (2013), 66

Borocera cajani Vinson 1863 (Lasiocampidae) or "Landibe" is a wild silk-moth, which silk is the most widely used in the textile industry in Madagascar. This endemic species is found throughout the island ... [more ▼]

Borocera cajani Vinson 1863 (Lasiocampidae) or "Landibe" is a wild silk-moth, which silk is the most widely used in the textile industry in Madagascar. This endemic species is found throughout the island, but colonizes especially the "Tapia" forest in the central highlands. The species has an important economic, culinary and cultural role in the Island. It is polyphagous and frequents several host plants. The daily activity of the larvae of B. cajani has been studied in their natural habitat on two native host plants of the "Tapia" forest: Uapaca bojeri Baillon 1874 (Phyllanthaceae) and Aphloia theiformis Bennett 1840 (Flacourtiaceae). Continuous observations during 24 hours on 54 individuals of the last instar of B. cajani have been conducted. Daily period of activity were found to vary according to the host plant species. Larvae feeding on U. bojeri allocate 6.9% of their time to feed, while the larvae feeding on A. theiformis spend 3.3% of their time. Only 1.0% (15 minutes) and 0.7% (10 minutes) of the observed period was allocated to movement, in the larvae feeding on U. bojeri and A. theiformis, respectively. Larvae observed on A. theiformis took an average of 3.1 ± 0.2 meals a day, which lasted 15.4 ± 1.3 min. Larvae observed on U. bojeri took an average of 1.9 ± 0.1 meals a day, which lasted 54.8 ± 5.2 min. [less ▲]

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See detailInfluence de la plante hôte sur les stades de développement de Borocera cajani (Lepidoptera: Lasiocampidae)
Razafimanantsoa, Tsiresy; Malaisse, François ULg; Raminosoa, Noromalala et al

in Entomologie Faunistique = Faunistic Entomology (2013), 66

Borocera cajani Vinson (Lepidoptera: Lasiocampidae) is a silk moth endemic to Madagascar that is currently used to produce silk textiles. This silk moth is polyphagous and colonizes forests situated in ... [more ▼]

Borocera cajani Vinson (Lepidoptera: Lasiocampidae) is a silk moth endemic to Madagascar that is currently used to produce silk textiles. This silk moth is polyphagous and colonizes forests situated in the central highlands, mainly constituted by Tapia trees (Uapaca bojeri). Two host plants are commonly used by the caterpillar of this moth species: Tapia and Voafotsy (Aphloia theiformis). In this work we have evaluated parameters of different stage (survival rate, development duration, weight and size, fecundity…) of B. cajani on both host plants. We have observed a 30% higher survival rate on U. bojeri. Larval and pupae duration were shorter on U. bojeri (64,8 ± 1,5 days) than on A. theiformis (87,4 ± 2,0 days). Cocoons were bigger when obtained from larvae fed on U. bojeri. This plant is therefore better for the development of B. cajani and should be used in intensive rearing of this silk moth. [less ▲]

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See detailSilkworm moths inventory in their natural tapia forest habitat (Madagascar): diversity, population dynamics and host plants
Razafimanantsoa, Tsiresy; Raminosoa, Noromalala; Rakotondrasoa, Olivia et al

in African Entomology (2013), 21(1), 137-150

Endemic silk moths (Lepidoptera: Lasiocampidae) in Madagascar have been collected and exploited for centuries by local populations either for food or as a source of silk cocoons from which textiles are ... [more ▼]

Endemic silk moths (Lepidoptera: Lasiocampidae) in Madagascar have been collected and exploited for centuries by local populations either for food or as a source of silk cocoons from which textiles are made. Moth natural forest habitat has also been degraded, leading to a drastic decrease in silk moth populations. However, very few scientific reports highlighted these observations well known by the local people.We have inventoried silk moths species in tapia (Uapaca bojeri Baill.) forests located in the central highlands of Madagascar. Inventories have been conducted during one year from August 2009 to July 2010 by sampling transects in Imamo forests. Three species of Lasiocampidae belonging to two genera were found: Borocera cajani Vinson, Borocera marginepunctata Guérin-Méneville and Europtera punctillata Guenée. These three silk moth species are endemic to Madagascar but only one (B. cajani) is commercially exploited in the silk industry. The habitat, host plants, abundance, life cycle and feeding behaviour of these species in their natural habitat are described. [less ▲]

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See detailL'anthropisation du paysage et ses impacts sur les écosystèmes forestiers
Bogaert, Jan ULg; Andre, Marie ULg; Lejeune, Philippe ULg et al

Conference (2012, October 24)

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See detailEtude de la fragmentation d'un paysage cas de la forêt de Uapaca Bojeri, Madagascar
de Haulleville, Thalès ULg; Bogaert, Jan ULg

Scientific conference (2012, October 16)

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See detailStockage du Carbone dans les forêts de Yangambi (RDC)
de Haulleville, Thalès ULg; Kearsley, Elizabeth; Bogaert, Jan ULg et al

Scientific conference (2012, October 12)

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