RÉSUMÉEn 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 anthropique 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. 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.

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.

The Mont Péko national Park (MPNP) located to the West of Côte d'Ivoire underwent severe human pressure related to a succession of political and military crises from 2002 to 2011. Since 2013, the Ivoirians government is engaged in a process of rehabilitation of this park. This study aimed to evaluate the dynamics of human pressures from 1996 to 2018, in order to allow the manager of the park to better focus their awareness and protection activities. To achieve this, the RAPPAM method of WWF international was adopted for the collection of data. The study identified 10 types of pressures of which farm is the most severe followed by pressure on land, logging, bush fires, the establishment of settlements, poaching and pollution. The intensity of pressures on the MPNP doesn’t significantly vary depending on the areas, but this varies according to the socio-political gradient in time. The pressures have evolved gradually from 2002 to 2011 before beginning to decline progressively until 2018. Currently, except for uncontrolled bush fires, all pressures declined significantly, or even disappear for some. The existence of a variety of pressures on the MPNP to disturbing proportions is therefore related in part to the lack of monitoring during the crises. The anthropization of the MPNP found the springs of its acceleration in the existence of an armed gang who have organized, systematic exploitation of the resources.

Cola lorougnonis is an endemic, rare, and treated species. It was recently recorded in Dékpa forest near Agbaou (a village of Divo region, Côte d'Ivoire). In the same forest, 20 other rare and endemic plant species were recorded. Accurate modeling of geographical distributions of these species is crucial to various applications in ecology and biodiversity conservation. The present study analyzed suitable habitat models for the 21 species. The main objective was to test geographical predictions for the focused species: Cola lorougnonis. We used Maxent modelling method for predicting potential suitable habitats combining environmental variables and species records. We evaluated Maxent predictions using the area under the receiver-operating characteristic curve (AUC). For each species, the map of distribution was engineered using DIVA-GIS. We compared the suitable habitat areas among species. Principal Canonical Analysis allowed the ordination of species according to environmental variables. AUC values allowed to get 11 species with excellent distribution models, 8 species with good distribution models, and 2 species with predictive models considered as acceptable. Cola lorougnonis (AUC = 0.99) and Drypetes singroboensis (AUC = 0.96) have the same focused area: moist semi-deciduous forest in Côte d'Ivoire. They are more sensitive to changes in rainfall of both warmest and coldest seasons. The State of Côte d'Ivoire has to undertake monitoring, assessment and reporting of conservation status facilitation for all habitats where these species could be found within the territory. Additional studies focusing on the investigation areas and niche models onto future conditions of climate could be considered.

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.