Method for evaluating perceptions about animals and plants among the inhabitants of the northwestern coastal zone of Madagascar

The evaluation of global perceptions about animal and plant species by villagers living in protected area including fragmented dry forests has been conducted in the northwestern coastal zone of Madagascar. The methodology used in field conditions is presented and discussed in relation to possible integration of the results into localized botanical and zoological surveys, which have been conducted during the same perio

A SURVEY OF MARCHANTIALES FROM MADAGASCAR

Based on the authors’ recent collections and on older herbarium specimens (PC, TAN, EGR), the species of Marchantiidae (Marchantiopsida, Marchantiophyta) of Madagascar are reported with their description based on Malagasy specimens. A distribution map for each taxon is provided. Among the fifteen taxa identified, six are newly recorded for the island, including a new synonymy: Asterella coronata (Steph.) H.A.Mill = Asterella bachmannii (Steph.) S.W. Arnell. Most of Marchantiidae live in xeric areas (Riccia species, Exormotheca pustulosa Mitt.) or in exposed, only temporarily wet stations (Plagiochasma, Asterella). This preliminary study shows the evidence of under-prospection of such areas in Madagascar for bryophytes and the need of taxonomic work to clarify some genera (Riccia, Asterella, Plagiochasma) and to confirm the species hitherto reported

Win-win opportunities combining high yields with high multi-taxa biodiversity in tropical agroforestry

Resolving ecological-economic trade-offs between biodiversity and yields is a key challenge when addressing the biodiversity crisis in tropical agricultural landscapes. Here, we focused on the relation between seven different taxa (trees, herbaceous plants, birds, amphibians, reptiles, butterflies, and ants) and yields in vanilla agroforests in Madagascar. Agroforests established in forests supported overall 23% fewer species and 47% fewer endemic species than old-growth forests, and 14% fewer endemic species than forest fragments. In contrast, agroforests established on fallows had overall 12% more species and 38% more endemic species than fallows. While yields increased with vanilla vine density and length, non-yield related variables largely determined biodiversity. Nonetheless, trade-offs existed between yields and butterflies as well as reptiles. Vanilla yields were generally unrelated to richness of trees, herbaceous plants, birds, amphibians, reptiles, and ants, opening up possibilities for conservation outside of protected areas and restoring degraded land to benefit farmers and biodiversity alike

Concepte de Modèle Ecologique pour la Zone Humide Alaotra

The wet zone Alaotra consists of the largest lake of Madagascar with about 20,000 ha of open-water and up to 23,000 ha of marshes. This wet zone is unique by the presence of an endemic fauna, and its marshes consist of a monospecific vegetation. The local communities directly depend on this wet zone with fishing and agriculture being an integral part of the region’s economy. Consequently, various anthropological pressures such as burning of the vegetation, over-fishing, pollution of the lake by the use of weed-killers, and sedimentation of the watersheds due to heavy erosions of the surrounding hills, negatively impact on this ecosystem. The wet zone Alaotra has been classified as an official Ramsar wetland site since 2003 and also as a SAPM protected area in January 2007 because of its ecological importance and its various threats to this ecosystem. The objective of this article is to present and describe the ecological model, which consists of the identification of the various ecological entities as well as their interdependence, in order to justify the wetlands classification as both a Ramsar and a New Protected Area site. The model has been adopted from Ogden (2005), and its ecological entities integrated in the conceptual model are derived from various research works conducted on the wet zone Alaotra. The model will be critically important in convincing the local authorities as well as the local communities to work together with the researchers, in order to implement the best conservation practices and ensure the sustainable management of the wet zone Alaotra. RESUMELa zone humide d’Alaotra comprend le plus grand lac de Madagascar qui a une superficie de 20,000 ha ainsi qu’un marais d’une superficie de 23,000 ha. Elle est unique au monde par l’existence d’une faune endémique dont l’habitat est un marais composé d’une végétation mono-spécifique. La vie de la population dépend de cette zone humide, si on ne prend en compte que la pêche, l’agriculture, et l’économie de la région. Cependant, différentes pressions anthropiques affectent cet écosystème telles que la mise à feu du marais et la surpêche, la pollution du lac par l’utilisation des herbicides et la sédimentation à cause d’une forte érosion des bassins versants. Ces pressions causent des impacts sur la faune et la flore de la zone humide d’Alaotra. Cela entraîne un changement environnemental de l’Alaotra, comme la fragmentation du marais, constatée depuis plus de dix ans, et un danger pour la vie de la population aussi bien dans le présent que dans le futur. L’importance de cette zone humide ainsi que les différentes menaces dont elle est la cible, ont conduit a sa classification en tant que site Ramsar en 2003 et fait partie du Système Aire Protégée en janvier 2007. Cet article a pour objectif de décrire le concept de modèle écologique, qui consiste à identifier les différentes entités écologiques ainsi que leur interdépendance, afin de justifier son classement dans le site Ramsar et en Nouvelle Aire Protégée. Ces entités résultent des différents travaux de recherche effectués sur la zone humide Alaotra. Le modèle adopté est celui d’Ogden (2005). Le modèle écologique présent est une de clé principales de la restauration qui devrait permettre de convaincre les autorités locales ainsi que les villageois à assurer ensemble avec les chercheurs la meilleure conservation et la gestion durable de la zone humide Alaotra.

Évaluation de la prolifération de la Jacinthe d’eau du lac Ravelobe Ankarafantsika et plan de restauration

La jacinthe d’eau ou Eichhornia crassipes envahit les eaux lentiques de Madagascar. C’est le cas du lac Ravelobe du Parc National Ankarafantsika à l’ouest, qui, outre sa richesse en poissons, amphibiens, tortue, et oiseaux endémiques, est le château d’eau de la plaine du second grenier à riz de l’île. Malgré les mesures prises par les responsables du parc, la jacinthe prend une ampleur non négligeable, en occupant presque la moitié du lac alors qu’elle était absente il y a treize ans. Des quadrats et des transects, en plus des méthodes de régulation des espèces invasives ont été appliquées aux espèces végétales du lac, dans le but d’évaluer leur écologie et la prolifération la jacinthe. Toutes les espèces aquatiques du lac sont associées à la jacinthe. La biomasse ainsi que la densité de la jacinthe y sont importantes. La fragmentation de l’écosystème Ravelobe est sévèrement ressentie. L’homme comme les oiseaux ont des difficultés pour pêcher à cause de la prolifération de la jacinthe. Cependant, une quantité importante de biogaz pourrait être obtenue à partir des jacinthes d’eau du lac Ravelobe. Des recommandations sont avancées pour la réguler et maintenir la biodiversité de l’écosystème.The floating water hyacinth or Eichhornia crassipes invades Madagascar waters lotics and lentics. It’s the case of the lake Ravelobe, inside the national park of Ankarafantsika Mahajanga Madagascar, which, besides crocodiles, is very renowned by its wealth endemic in fishes, amphibians, aquatic turtle, and birds. In spite of the measures taken by the persons in charge of the park in 2007, by manual eradicated of the hyacinth by the villagers, the hyacinth proliferates in important scale. Regulation’s methods of the invasive species, besides quadrat and transects are applied to the plant, with the aim of estimating their ecology and the proliferation. Stable, the hyacinth invades almost half of the lake in wet season : it’s monospecific in many aquatics zones, or retained by the stalks of helophytes ; forms a nursery in the river which feds the lake. Entailed by the wind, it invades in a scattered way the entire free surface’s water. Ten plant groups were listed, all associated with Eichhornia crassipes. Three ecological factors are responsible in their distribution. Both maps of vegetations in wet and dry season represent the distribution of hyacinth with their species associate. The biomass as well as the density of hyacinth are important. The lake is filled because of the degraded basin hillsides’s erosion. The lake takes a convex aspect. The river which feds the lake searches an outcome deviant to feed the lake. The fragmentation of the ecosystem Ravelobe is felt. Human and birds have difficulties to fish within the water hyacinth proliferated. Recommendations are advanced to regulate water hyacinth and maintain the biodiversity

Évaluation de la prolifération de la Jacinthe d’eau du lac Ravelobe Ankarafantsika et plan de restauration

The floating water hyacinth or Eichhornia crassipes invades Madagascar waters lotics and lentics. It’s the case of the lake Ravelobe, inside the national park of Ankarafantsika Mahajanga Madagascar, which, besides crocodiles, is very renowned by its wealth endemic in fishes, amphibians, aquatic turtle, and birds. In spite of the measures taken by the persons in charge of the park in 2007, by manual eradicated of the hyacinth by the villagers, the hyacinth proliferates in important scale. Regulation’s methods of the invasive species, besides quadrat and transects are applied to the plant, with the aim of estimating their ecology and the proliferation. Stable, the hyacinth invades almost half of the lake in wet season : it’s monospecific in many aquatics zones, or retained by the stalks of helophytes ; forms a nursery in the river which feds the lake. Entailed by the wind, it invades in a scattered way the entire free surface’s water. Ten plant groups were listed, all associated with Eichhornia crassipes. Three ecological factors are responsible in their distribution. Both maps of vegetations in wet and dry season represent the distribution of hyacinth with their species associate. The biomass as well as the density of hyacinth are important. The lake is filled because of the degraded basin hillsides’s erosion. The lake takes a convex aspect. The river which feds the lake searches an outcome deviant to feed the lake. The fragmentation of the ecosystem Ravelobe is felt. Human and birds have difficulties to fish within the water hyacinth proliferated. Recommendations are advanced to regulate water hyacinth and maintain the biodiversity

Évaluation de la prolifération de la Jacinthe d’eau du lac Ravelobe Ankarafantsika et plan de restauration

The floating water hyacinth or Eichhornia crassipes invades Madagascar waters lotics and lentics. It’s the case of the lake Ravelobe, inside the national park of Ankarafantsika Mahajanga Madagascar, which, besides crocodiles, is very renowned by its wealth endemic in fishes, amphibians, aquatic turtle, and birds. In spite of the measures taken by the persons in charge of the park in 2007, by manual eradicated of the hyacinth by the villagers, the hyacinth proliferates in important scale. Regulation’s methods of the invasive species, besides quadrat and transects are applied to the plant, with the aim of estimating their ecology and the proliferation. Stable, the hyacinth invades almost half of the lake in wet season : it’s monospecific in many aquatics zones, or retained by the stalks of helophytes ; forms a nursery in the river which feds the lake. Entailed by the wind, it invades in a scattered way the entire free surface’s water. Ten plant groups were listed, all associated with Eichhornia crassipes. Three ecological factors are responsible in their distribution. Both maps of vegetations in wet and dry season represent the distribution of hyacinth with their species associate. The biomass as well as the density of hyacinth are important. The lake is filled because of the degraded basin hillsides’s erosion. The lake takes a convex aspect. The river which feds the lake searches an outcome deviant to feed the lake. The fragmentation of the ecosystem Ravelobe is felt. Human and birds have difficulties to fish within the water hyacinth proliferated. Recommendations are advanced to regulate water hyacinth and maintain the biodiversity