Enjeux des Activités Humaines dans le Maintien de la Diversité Végétale des Forêts Marécageuses de la Sous-Préfecture de Grand-Lahou sur le Littoral Ivoirien

Human activities are recognized as potential threats to the survival of swamp forests and their resources in the rural environment of the GrandLahou Sub-Prefecture. This study proposes to question the relations between the riverside communities and these environments, in a perspective of valorization, use and sustainable management of these environments, as well as their resources. As part of a socioecological approach and based on a qualitative analysis, the information was collected through documentary research, direct observation and semi-structured group and individual interviews with administrative, customary and rural households. Near the swamp forests of the sub-prefecture of Grand-Lahou for a staff of one hundred and forty-three people (146). With systemic and phenomenological analysis tools, the processing and interpretation of the collected data were subjected to statistical data analysis and qualitative content analysis. Thus, the study made it possible to understand that the swamp forests of the subprefecture of Grand-Lahou are an element of the landscape characteristic of the natural, socio-economic and cultural inheritance of this sub-prefecture. They participate through their natural resources in the livelihoods of neighboring communities. For example, according to the data collected, 58.3% of the respondents use them as agricultural areas(perennial crops, food crops (rice, corn,) and vegetables). And for more than 80% of them, they constitute reserves of organic raw materials (lumber and construction, hunting, fishing, pharmacopoeia, fuel, etc.). However, among the accepted human activities of these environments, some, such assustainable agriculture, capitalist logging, hunting, gold panning and agricultural pollution with pesticides, constitute threats that lead to the disappearance or the degradation of these environments at the local level.Les activités humaines sont admises comme des menaces potentielles pour la survie des forêts marecageuses et de leurs resources dans le milieur rural de la Sous-préfecture de Grand-Lahou. Cette étude se propose d’interroger les relations entre les communautés riveraines et ces milieux, dans une perspective de valorisation, d’utilisation et de gestion durable desdits milieux, ainsi que de leurs ressources. S’inscrivant dans une approche socioécologique et partant d’une analyse qualitative, les informations ont été collectées à travers la recherche documentaire, l’observation directe et des entretiens semi-directifs de groupe et individuels auprès des autorités administratives, coutumières et ménages ruraux vivant à proximité des forêts marécageuses de la sous-préfecture de Grand-Lahou pour un effectif de cent quarante-trois personnes (146). Avec les outils d’analyse systémique et phénoménologique, le traitement et l’interprétation des données recueillies ont été soumis à l’analyse statistique des données et à l’analyse de contenu qualitative. Ainsi, l’étude a permis de comprendre que les forêts marécageuses de la sous-préfecture de Grand-Lahou sont un élément du paysage caractéristique du patrimoine naturel, socioéconomique et culturel de ladite sous-préfecture. Elles participent grâce à leursressources naturelles aux moyens d’existence des communautés riveraines en matière d’alimentation, d’habitation, d’artisanat, pharmacopée, etc. Cependant, au nombre des activités humaines admises de ces milieux, certaines, telles que l’agriculture pérenne, l’exploitation forestière de type capitaliste, la chasse, l’orpaillage et les pollutions agricoles aux pesticides, constituent des menaces qui conduisent à la disparition ou à la dégradation de ces milieux à l’échelle locale

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

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

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

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

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

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

Diversité Et Abondance Des Micromammifères Terrestres: Indicateurs De L’anthropisation De La Forêt Classée De Monogaga, Sud-Ouest De La Côte d’Ivoire

Anthropization of Classified Forests (CF) is a recurrent phenomenon in Côte d'Ivoire. It particularly affects coastal forests including Monogaga classified forest. Currently, flora composition and vegetation structure are the only biological tools available to better appreciate impacts of anthropic pressures on Monogaga classified forest. Yet, fauna and more particularly terrestrial small mammals constitute an essential component of this forest. Thus, this study aims to contribute to the understanding of the effects of anthropization of Monogaga classified forest based on "terrestrial small mammal" model. We used conventional Sherman traps to fairly investigate terrestrial small mammal communities in four plots (A, B, C and D) subjected to different anthropogenic pressures through Monogaga classified forest. Plots A and B were more disturbed than plots C and D. We collected 66 specimens in 1920 trap nights. These specimens are distributed among seven rodent species Dephomys defua, Hybomys trivirgatus, Hylomyscus simus, Lophuromys sikapusi, Malacomys edwardsi, Mastomys erythroleucus and Praomys rostratus and one soricomorph Crocidura olivieri. Abundances of terrestrial small mammals are higher in plots C and D. In the same way, diversity indices decrease from the most conserved to the least conserved plots. However, differences in species richness are weak between plots. Hierarchical classification of the four plots based on small mammal’s assemblages allows a good segregation. This study confirms that "terrestrial small mammal" model can contribute to the assessment of anthropization of forest habitats in lower Côte d'Ivoire

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

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)

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

In Côte 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

Caracterisation Des Pratiques Agroforestieres A Base De Cacaoyers En Zone De Foret Dense Semi- Decidue : Cas De La Localite De Lakota (Centre- Ouest, Cote d’Ivoire)

In the area of Lakota (Midwest, Côte d'Ivoire), where the vegetation is a semi-deciduous forest, cacao growing is practiced by people from different origins. Cacao cropping techniques seem to be influenced by some social and cultural habits, according to the people and the agroecological areas. The present study aimed to understand(1) the cacao cropping systems and to identify(2) the reasons underlying the choice of vegetal species combined to cacao trees in these rural communities. To achieve this goal, interviews were realised with cacao farmers of four villages of the area. These interviews concern farmers’ profiles, the former agriculture practices, the variety of the cultivated cacao and the plants combined to cacao trees. The results show that among the 223 interviewed farmers, 72 (32.3% of the farmers) are natives, 42 (18.8% of the farmers) are immigrants and 109 (48.9% of the farmers) are non-native Ivorians. In total, 77 species regularly combined to cacao trees were named by the farmers and they can be divided into local species and exotic species. Plots ordination shows three agroforestry systems according to ethnic group of the locality. Cacao farms with the large proportion of local species are owned by Lakota native people "Dida". The exotic species are dominant in cacao farms that belong to immigrants (Malian, Burkina Faso and Guinean people) and "Malinké" people (a non-native ivorian ethnic group). The Akan people (a non-native ivorian ethnic group) combine in a same proportions exotic and local species in their cacao farms

Pratiques paysannes et dynamique de la biodiversité dans la forêt classée de Monogaga (Côte d'Ivoire)

Dans la forêt classée de Monogaga, patrimoine naturel national de Côte d'Ivoire,les pratiques paysannes exercent une pression incessante sur le couvert forestier.Le gestionnaire forestier officiel, la Sofedor, après moult tâtonnements et conflits avec les populations locales (Wanne et Bakwe) qui ont été maintenues au sein de cette forêt lors de son classement, a décider d'en céder une partie en créant des enclaves agricoles. Pour répondre aux interrogations concernant l'avenir du couvert dans ces enclaves et l'ensemble de la forêt, nous avons adopté une démarche originale associant deux approches. l'une , anthropologique, porte sur l'organisation spatiale des activités et les représentations des deux acteurs principaux. L'autre phytoécologique, est basée sur des inventaires botaniques, relevés et observations de la couverture et de la physionomie végétale. Toutes deux ont permis de décrire l'état actuel du couvert de cette forêt classée encore bien mal connue sur le plan phytosociologique et de comparer les impacts respectifs des pratiques paysannes et des actions de conservation et de restauration de la Sofedor sur la diversité floristique...In the classified forest of Monogaga, a national natural patrimony of Côte d'Ivoire, the farming practices exert a ceaseless pressure on forest cover. After a period of groping and conflict with the local people (Wanne and Bakwe) who were maintened in the forest after its classification, the official manager, Sodefor, decided to yield a part of the protected area to local human activities by creating agricultural enclaves.To answer the interrogations concerning the transformation of forest cover in these enclaves and in other parts of the Forest, this study had two complementary objectives :1)to describe the current state of the forest cover in the classified forets, which is poorly known on a phytosociological point of view and 2)to compare the respective impacts of the villager's practices and action of Sodefor on the vegetation community composition diversity and endemism level. Our methodology associated an anthropological approach, which investigated the patial organisation of the activities and the representations of the two principal forest actors and a botanical approach based on inventories from plots of 500 m2, observations of the vegetation cover and physiogonomy...PARIS-Museum-Bib. Botanique (751052309) / SudocPARIS-Museum Hist.Naturelle (751052304) / SudocSudocFranceF