Analyse Des Connaissances Sur Pterocarpus Erinaceus Poir. En Afrique Occidentale Et Centrale

Pterocarpus erinaceus (Fabaceae) est une arbre multiusage des zones sahéliennes et soudaniennes d’Afrique. L’espèce a fait l’objet de nombreuses études scientifiques très peu coordonnées, conduisant à des biais sur les besoins réels de connaissances devant permettre une bonne gestion et valorisation. Pour pallier cette insuffisance, les publications sur cette espèce ont été recherchées à partir de Google scholar, Bielefeld Academic Search Engine et Science direct. Après un filtre des publications trop généralistes, 127 publications réalisées entre 1974 et 2019 ont été retenues et classées suivant neuf thématiques préalablement identifiées. Les résultats, issus de 49 institutions de recherche provenant de 19 pays, montrent que les propriétés pharmacologiques, la caractérisation des peuplements de P. erinaceus et le rôle socio-économique sont les thématiques les plus abordées avec respectivement 41,7 %, 29,1 % et 16,5 % des publications alors que celles relatives aux techniques de multiplication, à la régénération et au rôle alimentaire sont peu abordées avec des fréquences respectives de 6,3 %, 4,7 % et 3,9 %. Les résultats indiquent également que 9 pays de l’Afrique de l’ouest totalisent plus de 84,2 % des publications contre de 3,2 % des publications effectuées par 2 pays de l’Afrique centrale et 12,6 % pour 8 pays européens. L’analyse a montré aussi que des études complémentaires sont nécessaires pour améliorer les connaissances sur les techniques de multiplication de l’espèce pour sa sylviculture et les facteurs qui influencent sa régénération en milieu naturel. Pterocarpus erinaceus (Fabaceae) is a multipurpose tree species of Sahelian and Sudanian zones in Africa. Tough the species has been actively studied, the lack of coordination and orientation in these studies lead to some biases in the knowledge needed for the better management and valorization of this species. To overcome this insufficiency, scientific publications available on the species were collected from Google scholar, Bielefeld Academic Search Engine (BASE) and Science direct portals. After filtering the generalist publications identified, 127 publications produced between 1974 and 2019 were classified according to nine previously identified themes. The results from 49 research institutions from 19 countries show that the pharmacological properties, the characteristics of the stands of P. erinaceus and the socioeconomic role are the most discussed themes with respectively 41.7 %, 29.1 % and 16.5 % of publications, while those relating to the propagation of the species, natural dissemination and the role of food are rarely addressed with respective frequencies of 6.3 %, 4.7 % and 3.9 %. These results also indicate that 9 West Africa countries published more than 84.2 % of the publications when 3.2 % were published by 2 countries from Central Africa and 12.6 % for 8 European countries. The analysis shows that more studies are needed to improve knowledge about techniques of the propagation of the species for silviculture and factors that influence the natural dissemination of the species in its natural habitat. &nbsp

ESSAI DE GERMINATION ET DE CROISSANCE AU STADE JUVÉNILE DES SOUCHES LOCALES DE JATROPHA CURCAS L. EN RÉPUBLIQUE CENTRAFRICAINE

Methods: In order tocharacterize the germination and growth of some local varieties of Jatropha curcas at nursery stage in Nzila, a village of Central African Republic, their seeds of were sown in polyethylene bags and arranged in a randomized plot design on raised beds exposed to the sun. The effects of origins and substrate on the studied growing parameters are appreciated by an analysis of variance (ANOVA), with the software R. Results.-The different substrates have significant impact on germination and growth on both devices while their origins have no significant impact. The seeds from forest areas (Nzila and Bangui) have the best rates of germination and better growth on land. They have shown more robust plants with greatest heights and diameters. In polyethylene bags, seeds from savannah areas (Bouar and Boali) are those which have the greatest heights and the largest diameters. A strong correlation was seen between studied parameters with highers values between the diameter and the number of leaves (94.31%). Conclusion In juvenile stage, plants from all origins fit well with the environmental conditions

Distribution locale et estimation des densités des primates dans la réserve transfrontalière du fleuve Mono, Togo (Afrique de l’Ouest)

La réserve de biosphère de Mono est située dans le « Dahomey Gap » qui sépare la ceinture des forêts denses humides ouest-africaines en deux blocs forestiers : guinéen (occidental) et congolais (oriental). Cette discontinuité climatique dahoméenne est caractérisée par des mosaïques de forêts denses semi-décidues, des savanes guinéennes, des prairies marécageuses, des marais, des mangroves et des plans d’eau, des mosaïques d’agroforêts, champs et jachères. Dans cette réserve centrée sur la vallée du Mono entre le Togo et le Bénin, d’une surperficie de 2042,18 km2, nous nous évalué le statut des populations des espèces de primates. Au total, 9 espèces ont été recensées : Galago senegalensis, Galagoides demidoff, Perodicticus potto, Papio anubis, Colobus vellerosus, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Erythrocebus patas et Chlorocebus tantalus. Les populations de ces espèces sont distribuées dans quatre unités fondamentales de la réserve : la forêt d’Asrama, le complexe d’aires protégées de Togodo, la forêt sacrée de Godjé-Godjin et la forêt sacrée d’Akissa. Les travaux ont clairement établi un déplacement saisonnier et régulier des populations de ces espèces de primates dans ces différentes unités écologiques. Le complexe d’aires protégées de Togodo constitue le sanctuaire pour les populations de primates dans le Sud du Togo et du Bénin et principalement celle du Hocheur à ventre roux (Cercopithecus erythrogaster erythrogaster) considéré comme espèce en danger critique sur la liste rouge de l’UICN.The reserve of biosphere of Mono river is located in the Dahomey Gap, which is the relatively arid interruption in the West African forest belt that stretches from the Accra Plains in Ghana across the Volta River through Togo to the eastern border of Benin. This West African climate discontinuity is characterized by mosaics of dense semi-deciduous forests, Guinean savannahs, swampy meadows, marshes, mangroves and bodies of water, mosaics of agroforest, farms and fallow land. In this reserve, centered on the Mono valley between Togo and Benin, with 2042.18 km2 area, we assessed the status of populations of primate species. Overall, 9 species were recorded: Galago senegalensis, Galagoides demidoff, Perodicticus potto, Papio anubis, Colobus vellerosus, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Erythrocebus patas and Chlorocebus tantalus. The populations of these species are distributed in four basic units of the reserve: the Asmara forest, the Togodo protected area complex, the Godjé-Godjin sacred forest and the Akissa sacred forest. Our works clearly established a seasonal and regular displacement of primate species populations among different ecological units. The Togodo protected areas complex is the sanctuary for primate populations in southern Togo and Benin, and mainly for the Red-bellied Monkey (Cercopithecus erythrogaster erythrogaster), which is considered a Critically Endangered species on the IUCN Red List

Challenges of Conservation and Sustainable Management of African Rosewood (<em>Pterocarpus</em><em>erinaceus</em>) in West Africa

Pterocarpus erinaceus is an endemic and threatened plant species in arid and semiarid zones of West Africa and is highly exploited for timber, animal feeding, and various medicinal uses. The species is currently native to the Guinean forest-savannah mosaic ecoregion and reported from Senegal to Cameroon. The values of the main characteristics of the P. erinaceus forest stands (density, average diameter, average height and average stem height) vary significantly (P < 10−3) from the Guinean zone to the Sahelian zone. It has high technological performance and can be classified as heavy and very hard wood with a density of the order of 0.80 ± 0.07 g/cm3 and an average hardness of 12 ± 3.7 g/cm3. The species is the subject of large-scale international traffic between West Africa and Asia, which is by far the greatest threat to the species. The various uses induce repeated mutilation and increase pressures on the species resulting in a significant reduction in its natural populations. In response to this situation, measures are proposed, including large-scale plant production strategies, the definition of minimum felling diameters, policy measures, etc., to meet the restoration needs of natural stands of P. erinaceus and the fight against climate change

Ecological challenges for the buffer zone management of protected areas of forest-savannah mosaic in West Africa

In sub-Saharan Africa, the management of buffer zones around protected areas does not often take into serious account the needs of resource exploitation by the local populations or the conservation needs of these areas. We described the ecological characteristics and management issues affecting the buffer zone around the Fazao-Malfakassa National Park; a 192,000-ha protected area in central-western Togo of utmost conservation importance within the Dahomey Gap region. Within the buffer zone (10 km radius, 334,800 ha), we focussed on four high conservation value areas totalling 65,594 ha (20% of the total buffer zone area). Using 2015 sentinel-2 images we analyzed land cover patterns and described existing ecological zones. We complemented these with field surveys and interviews with 300 people living in 22 villages within the buffer zone to describe the conditions affecting the resident human population. Although over 60% of the total buffer zone area is degraded, we identified four areas of high conservation value (total area = 65,594 ha). Interviewees recognized that slash-and-burn was the most common form of land use, followed by agroforestry practices. Agriculture, charcoal, and firewood production were the main drivers affecting habitats, and land conflicts were recurrent due to the rise in human population. The decline in agriculture, reported by interviewees in some sectors, was attributable to ravages of crops by elephants. Three independent diversity indices showed that, in preserved zones, a greater diversity of animals (with similar utilization frequencies) were hunted than in degraded sites (where grasscutters were the dominant hunted species). There were also significant differences between degraded and preserved zones in terms of plants used for charcoal production and for non-timber forest products. We advocate the development of community-controlled hunting areas to enhance the conservation value of the four well-preserved zones. Instead, promoting sustainable agricultural production systems in the degraded areas can help to further stabilize the agricultural front and reduce land pressure on the park

Changes in the West African forest-savanna mosaic, insights from central Togo.

The West African forest-savanna mosaic, an important habitat for biodiversity and humans, is severely degraded, fragmented and modified by human activities. However, few studies have quantified the land cover changes observed over time and/or analysed the drivers of change. This study focused on Fazao-Malfakassa National Park, the largest in Togo, uses a combination of remote sensing, ground surveys and questionnaires to: (i) quantify vegetation changes, (ii) determine the drivers of change, (iii) compare results with findings elsewhere in the region and (iv) suggest management interventions. The images used were Landsat 5 TM, Landsat 7 ETM and Sentinel-2. Different vegetation indices were computed including: number of fragments, index of dominance, mean area of a vegetation type and mean annual expansion rate. In total, 300 people (including park staff and local populations) were interviewed using a semi-structured questionnaire. Results indicate that between 1987 and 2015 closed-canopy forest and tree-savanna became severely degraded and fragmented, following trends in other parts of the West African forest-savanna mosaic. The main drivers of change were agricultural expansion, bush fires and timber extraction. Observed changes and drivers altered with time: e.g. agricultural expansion was greatest during 1987-2001 (linked with political instability) while illegal timber extraction augmented during 2001-2015 (following increased timber value). Park staff and local populations' perceptions on drivers of change did not differ. Our study highlights that action is urgently needed if we are to preserve this important habitat, the biodiversity it hosts and the services it provides to humans. We suggest several management interventions, learning from successful interventions elsewhere in the region

The Pteridaceae family diversity in Togo

Abstract. BACKGROUND: The Pteridaceae family is the largest fern family in Togo by its specific and generic diversity. Like all other families of ferns in the country, Pteridaceae are poorly studied and has no identification key. The objective of this study is to perform a taxonomic revision and list establishment of this family of leptosporangiate ferns in the light of current available knowledge about the family. Pteridaceae was also assessed in terms of its diversity and conservation status, this was conducted through the recent field data and the existing herbaria specimens. The current study permits to confirm the presence of Pteris similis Kuhn. which brought the number of Pteridaceae to 17 in Togo. NEW INFORMATION: This study provides first local scientific information about the fern flora of Togo. It confirmed the presence of Pteris similis Kuhn. in Togo and brought the Pteridaceae family diversity to 17 species. A species identification key is provided for the easy identification of the Pteridaceae of Togo

Climate vulnerability of coffee-cocoa agrosystems in the sub-humid mountain ecosystems in south-west Togo (West Africa)

Abstract Changes in climate patterns are the main challenges being faced by the coffee and cocoa production systems, one of the key sources of livelihood for farmers in Togo’s humid dense forests zone, also known as “Togo ecological zone IV”. The objective of this study was to analyze the climatic vulnerability of coffee-cocoa agroforestry systems (CCAFS) in Togo ecological zone IV both ongoing (last 40 years 1980–2019) and the incoming decades (by 2050) considering climate forecast under AR6 socioeconomic pathways. The Standardized Precipitation Index (SPI) approach with the Mann–Kendall & Sen’s tests and the MaxEnt tool were used to assess the drought condition and the potential impacts on CCAFS suitability in the study area. The results show instability in rainfall series with a non-significant progressive trend in the area during the past four decades, while a significant increase in temperature was observed. Beyond 2050, suitable areas for coffee and cocoa species will drift to the pic mountainous part. Thus, respectively 51.91 and 54.50% of currently suitable areas for the two species, will be lost under the future climate scenario SSP3-7.0 and SSP5-8.5. These losses are mainly due to the reduction of precipitation of the driest month (Bio14), precipitation of the driest quarter (Bio17), and precipitation of the coldest quarter (Bio19) of the year. Drought is therefore revealed as the main limiting climatic factor for coffee and cocoa in Togo. The increasing drought intensity in the future is a source of high vulnerability of CCAFS as well as the local farmers’ livelihoods

Three new records of fern species (Polypodiopsida) in Senegal, from Dindefelo Falls, Kedougou region

International audienceBlotiella currorii (Hook.) R.M.Tryon. (Dennstaedtiaceae), Dicranopteris linearis (Burm.F.) Underw. (Gleicheniaceae), and Aleuritopteris farinosa (Forssk.) Fée (Pteridaceae) are reported for the first time in the flora of Senegal. They represent not only three more species but also two new families, Dennstaedtiaceae and Gleicheniaceae, for Senegal. Data on species, morphology, taxonomy, ecology, and geographic distribution are included. These three species were found in the interstices of the cliff of the 100-m Dindefelo Falls, which is in Kedougou region