93 research outputs found

    Spatial Distribution of Cedrela Odorata Smaller Trees Affects Forest Regeneration in Exotic Tree Plantations in Central Côte d’Ivoire

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    Cedrela odorata L. was introduced as a possible forest restauration species in classified forests at Côte d’Ivoire. Because of its demonstrated invasive behavior in other tropical forests, this study aimed to assess the impact of Cedrela odorata on the regeneration of spontaneous plant species in tree plantations. On the base of Cedrela odorata larger tree densities, two types of forest plantation were considered: Type I (240 stems/ha) and Type II (176 stems/ha). In these plantations, plots with 0.25 ha were chosen to locate each tree with dbh ≥ 2.5 cm, in an orthonormal reference. The tree density, the basal area, the species richness, the Shannon diversity index and the rank-abundance curves were determined considering smaller and larger trees. The horizontal spatial arrangement and Ripley’s K function were performed to understand the spatial relationship between Cedrela odorata smaller trees and those of spontaneous species. The results shown lower spontaneous plant species richness (15-20 species) and diversity (1.15 - 1.43); the dominance of Cedrela odorata smaller trees (43.02 – 62.95 % of all stems). The Cedrela odorata smaller trees and those of other species have dependent spatial distributions; expressed by a spatial repulsion between the two groups up to a distance of 18 m in the most densified forest plantation. This repulsion was related to an aggregated distribution of Cedrela odorata smaller trees in plantation with higher tree density. The study suggests a 170-stems/ha (or lower) of Cedrela odorata planting density for biodiversity establishment improvement outcomes in forest plantations.

    Value-adding post harvest processing of cooking bananas (Musa spp. AAB and ABB genome groups)

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    Cooking bananas (including plantains) are among the major commodities used in Sub Saharan Africa to combat food insecurity. It is estimated that more than 30% of the banana production are lost afterharvest. The losses are mostly due to the rapid ripening of the fruits, poor handling, inadequate storage and transportation means, and poor knowledge of food processing options. Processing the fresh fruits into food products with a longer shelf life can provide a major outlet to use surpluses and to exploit a greater number of marketing options. In this paper, we provide ingredients and recipes for food products made by the International Institute of Tropical Agriculture (IITA) from its improved hybrids of cooking bananas to decrease post harvest losses, diversify the industrial potentials of bananas, and add value to farmers’ products. Some of these processing methods can be used by farmers and ruralentrepreneurs in their communities to ensure food security and raise their incomes, or upgraded by the private sector in a value chain approach to curb production losses in bananas.Keywords: Bananas, food security, post harvest, food processing, value additio

    Evaluation De La Diversité Et Estimation De La Biomasse Aérienne Des Arbres Du Jardin Botanique De Bingerville (District d’Abidjan, Côte d’Ivoire)

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    The Bingerville Botanical Garden is an urban green space which can contribute to the quality of the living environment and to attractivity of tourists in Abidjan city. Its floristic diversity and socio-economic and ecological benefits remain still unknown. The present study was conducted to assess botanical species diversity and the reduction of CO2 emissions in this space. Trees species with dbh ≥ 10 cm were recorded in 41 plots of 500 m² surveyed in four types of biotopes: two arboretums with 20 and 100 years old, one secondary forest with more than 100 years and a fallow of 20 years old. Floristic indices and aboveground biomass (AGB) were determined for each biotope. A total of 742 trees with dbh ≥ 10 were counted: 127 species. Preponderance species are Cassia siamea, Terminalia mantaly, Milicia excelsa and Ceiba pentandra in arboretums, Pentadesma butyracea and Acacia mangium in the secondary forest, Ficus exasperata and Borassus aethiopum in the fallow. Arboretums are richest (96 species), and they have more AGB (566.7 t/ha). The secondary forest has 71 species with an aboveground equal to 381.4 t/ha. The fallow is less rich (13 species) with an AGB of 21 t/ha. This study has shown the importance of Bingerville Botanical Garden in plant and fighting against climate change

    Des modèles biologiques à l'amélioration des plantes

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    Déterminismes De La Dynamique De La Forêt Des Marais Tanoé-Ehy (Sud-Est, Côte d'Ivoire)v

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    Objective: The Tanoé-Ehy Forest (FMTE) has been identified as a top priority site for primate conservation in West Africa. Pending the completion of the measures of its final classification in protected area, anthropic pressures are constantly nibbling the types of habitat that the FMTE contains. The objective of the present study was to analyze the spatial and temporal evolution of this forest from 1986 to 2016. The study consisted in mapping and following through Landsat satellite images from 1986, 2000, and 2016 the dynamics of the land use that constitute the FMTE. To better understand the underpinnings of this evolution, based on anthropogenic threats, surveys were carried out in the five villages closest to the forest. Treatments show a 10% degradation of swamp forest area to degraded forests in 30 years. The habitats temporarily flooded forests remained intact during this 30 years period, reflecting efforts to maintain the integrity of the FMTE. Surveys have shown that the types of pressure and their intensity vary from peripheral villages. Overall, this involves wood harvesting and hunting. In view of the importance of the FMTE in terms of a particular ecosystem and the conservation of biodiversity, it is desirable and urgent that, in addition to awareness-raising campaigns for local populations, the process of its final ranking be accelerated to end its degradation

    Diversity Analysis of Elite Maize Inbred Lines Adapted to West and Central Africa Using SSR Markers

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    Seventeen elite maize inbred lines of West and Central Africa adaptation with tropical and temperate x tropical origin were investigated for diversity at 18 SSR loci in non-coding regions of the maize genome, alongside two temperate inbred lines (B73 and Mo17), perennial teosinte (Zea diploperennis) and gamagrass (Tripsacum dactyloides). A total of 174 alleles were detected with a range of 5 to 15 alleles per maker and an average of 9.7 alleles per locus. Polymorphic information content (PIC) ranged from 0.29 in umc1226 to 0.92 in bnlg2122 with an average of 0.75. Relationships between heterotic groups and groups based on SSR data were quite varied for the lines studied. Primarily, the SSR markers grouped the lines on the basis of their origin, with three instances of a pair of heterotic lines clustering together; one pair of temperate origin and the other two tropical vs temperate x tropical. Four inbred lines (CMR 19, CMR 20, CMR 21, and CMR 26), belonging to three heterotic groups were, however, differentiated by SSR data. The markers showed potential for use in managing inbred lines germplasm adapted to West and Central Africa, particularly for classifying inbred lines for which records of ancestry are not readily available and for exploiting the heterosis known for tropical vs. temperate x tropical crosses

    Diversité Et Variabilité Du Régime Alimentaire Des Éléphants Du Parc National d’Azagny (Sud - Côte d’Ivoire)

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    In CĂ´te d'Ivoire, Azagny National Park has a small forest elephants population, described as isolated, self-contained and whose survival depends on the diversity of local biological resources. A study was undertaken to assess the diversity of the plant species consumed and the feeding preference of this large mammal. Pedestrian surveys were carried out in the different biotopes traveled by the elephants during one year, in search of fresh and old traces of nutrition and droppings. As a result of these inventories, six organs of 282 plant species have been identified has consumed by elephant. In this plant species list, three families are the most represented: the Apocynaceae, the Euphorbiaceae and the Rubiaceae. Among the elephant diet, five species appear to be the most consumed: Aframomum melegueta (1.45%), Aframomum sceptrum (1.45%), Sacoglottis gabonensis (1.27%), Echinochloa pyramidalis (1.2%) and Albizia adianthifolia (1.2%). Considering the number and type of organs harvested from plants, the study reveals that they varied from one species to another well. In general, leaves (256 species 90.8%) and fruits (95 species or 33.7%) have emerged as the most consumed organs of elephants. In view of this diet importance in elephant survival in the park, it would be important to identify the type of species consumed seasonally and to assess their availability in each of the biotopes traveled

    Système agroforestier à cacaoyers en Côte d’Ivoire: Connaissances existantes et besoins de recherche pour une production durable

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    This study has assessed the ecological sustainability of cocoa production systems in Côte d'Ivoire. The litterature has shown that cocoa crop has been introduced in 1988 and this crop has been suitable with various pedoclimatic and vegetation factors in Côte d’Ivoire. This suitability has involved a move of the cocoa boom area and some changing practices from the South-east to the South-west of the country. The study has shown the existence of some divergences between farmers and scientists about the choice of associated tree species in cocoa agrosystems. Also, none adequate scientific research have been achieved in order to suggest to the farmers the most sustainable cocoa agroforest system. Future research should be focused on finding a trade-off about the choice of associated tree species which can be profitable to the farmers and ecological sustainable. These research will approve or deny some empirical perceptions from traditional practices. These research will also demonstrated to the farmers, the political decision-maker and management structures the need of a synergy between cocoa production and the economic value from of the ecosystem services produced in the farms. Key words: Shade trees, Agroforest, cocoa pioneer front, Traditional agricultural practices, Ecosystem servicesLa présente étude a fait un diagnostic écologique de la durabilité des systèmes de production de cacao en Côte d’Ivoire. L’analyse de la bibliographie a montré que cette culture introduite en 1988, a été compatible à divers facteurs pédoclimatiques et de végétation de la Côte d’Ivoire. Cette comptabilité se traduit par l’évolution de la boucle de cacao et des pratiques culturales du Sud-est au Sud-ouest du pays. L’étude a fait le constat de l’existence de divergences entre les paysans et les scientifiques au sujet des espèces d’arbres à associer aux cacaoyers. Elle soulève également le manque de preuves suffisantes et scientifiques pouvant guider le choix d’un système agroforestier à cacao, à la fois profitable aux producteurs et écologiquement soutenable. Des recherches futures devront être orientées vers la recherche de compromis sur le choix des espèces à associer aux cacaoyers ; ce qui nécessitera la confirmation ou l’infirmation scientifique des perceptions empiriques issues de pratiques traditionnelles. Il faudra également éclairer le producteur, le décideur politique et les structures d’encadrement de paysans, sur la nécessité d’une complémentarité entre la production de cacao et la valeur économique des services écosystémiques produits dans les cacaoyères. Mots-clés: Arbres d’ombrage, Agroforêt, Front pionnier du cacao, Pratiques agricoles traditionnelles, Services écosystémique

    Relations entre la diversité et la biomasse aérienne des espèces arborescentes dans les agroforêts traditionnelles à base de cacaoyers: Cas de la localité de Lakota (Côte d’Ivoire)

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    En matière de gestion durable des systèmes agroforestiers à base de cacao, il serait important de trouver un compromis pour à la fois conserver la biodiversité et les stocks de carbone ; ce qui constituerait une alternative écologiquement soutenable à l’agriculture conventionnelle. En Afrique sub-saharienne, peu d’études ont mis la lumière sur les relations éventuelles entre la biomasse végétale et la diversité biologique dans ces systèmes. La présente étude a permis de tester ces relations dans des agroforêts à cacao de Lakota en Côte d’Ivoire. Des cacaoyères et des forêts ont été inventoriées selon la méthode des transects à aire variable. Plusieurs indices floristiques, ont été calculés et la biomasse aérienne a été estimée, pour les espèces arborescentes de dbh > 2,5 cm. Au total, 215 espèces ont été dénombrées dans l’ensemble des biotopes dont 57,2 % en forêts anciennes, 50,2 % en forêts secondaires et 26 à 45 % dans les plantations. La biomasse aérienne des arbres sur pied dans les forêts anciennes est plus élevée (203,7 t ha-1) que dans les plantations où la biomasse baisse jusqu’à 90,2 t ha-1. Il n’existe pas de relations significatives entre la biomasse aérienne et la diversité des espèces dans les forêts. Dans les plantations âgées de plus de 15 ans, une forte diversité spécifique peut être bénéfique à 20 % dans l’augmentation de la biomasse sur pied. Les pratiques paysannes traditionnelle sen cacao culture peuvent donc garantircon comitamment, la diversité floristique et la biomasse qui est le facteur déterminant dans la séquestration du carbone.Mots Clés: Réchauffements climatiques, système agroforestier, Côte d’Ivoire, activité anthropiqueEnglish AbstractFor sustainable management of cocoa based agroforestry systems, it is important to find a tradeoff to conserve both biodiversity and carbon stock; which would be an ecologically sustainable alternative to conventional agriculture. In Sub-Saharan Africa, few studies have tested relationships between plant biomass and biodiversity in these systems. This study analysed these relationships in Cocoa based agroforest in Lakota area in Côte d’Ivoire. Cocoa farms and forest patches were inventoried using the variable-area transect method. We considered all trees species with dbh> 2.5 cm. Pearson correlation was used to test probable links between aboveground biomass and diversity indexes. We recorded a total of 215 tree species in all habitats, of which 57.2% were in old growth forests, 50.2% in secondary forests and 26-45% in cocoa farms. Biomass stock of old growth forests was greater (203.7 t ha-1) than in plantations, where it dropped to 90.2 t ha-1. There was no significant relationship between aboveground biomass and floristic indices in forests. In old plantations of over 15 years old, high species diversity could contribute up to 20% in the aboveground biomass. The conservation of floristic diversity in cacao based agroforestry systems may represent an important factor in mitigating global warming, through the storage of large amounts of carbon.Keywords: Climate change, cocoa based agroforestry system, Côte d’Ivoire, human activitie

    Diversité Des Espèces Herbacées Et Lianescentes De La Forêt Classée Du Haut-Sassandra (Centre-Ouest, Côte d’Ivoire) Après Plusieurs Années D’exploitation Forestière

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    Natural and anthropogenic disturbances affect forest integrity and floristic composition. The resulting secondary habitats is characterised by liana and herb species which modified the forest physiognomy. To elucidate the floristic characteristics of these secondary forests, the present study was carried out after logging operations in the the Haut-Sassandra protected Forest. The inventory has been realised in 18 individual one ha in three level of logging operation. A total of 445 species have been identified. Floristics parameters vary according to the time after logging operation: from 255 in the south sector, 296 species in the center sector, 271 species in the north sector, 15 years after logging. The family diversity is between 56 and 62 with a predominance of Rubiaceae. Phytogeographic-types are characterized by Guinean-Congolese species (71,2 %), and species endemic to SavannahForest transition zone (14,6 %). The presence of herb and liana species which are pioneer and heliophile, could generate a micro climate favorable to the recovery of other forest plant species
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