Biodiversity Management under Cashew Agro-ecosystems in Central Africa: A case study from Cameroon

The aim of this study was to assess the floristic composition, vegetation structure and species associations of Cashew agro-ecosystems in the North region of Cameroon. The data were collected in 100 m x 20 m transect methods. An analysis of the data collected in the field was carried out around the diversity and richness of the flora, but also the structure of Cashew agrosystems. The vegetation structure is determined by tree density, basal area and biovolume. The inventory included trees with a dbh = 5 cm on an area of 1 ha per plot. The experimental device installed is a complete random Fisher block with five repetitions. A total of 7849 individuals in 17 families, 20 genera and 38 species were recorded. The Species Important Value of vegetation cover indicated that Diospyros mespiliformis, Anogeissus leiocarpus, Annona senegalensis and Terminalia laxiflora are the most represented. Combretaceae are the most ecologically important families. In addition, the grouping of species into four subdivisions showed that the Shannon diversity index varies from 2.18 ± 0.09 - 3.47 ± 0.17 bits, Pielou index varies from 0.98 ± 0.01 - 0.99 ± 0.01, Simpson's index ranges from 0.70 ± 0.18 - 0.93 ± 0.11, density ranges from 102 ± 1.92 - 128 ± 6.36 indiv/ha, basal area ranges from 2.02 ± 0.31 - 12.68 ± 2.01 m²/ha, biovolume ranges from 11.58 ± 1.29 - 68.03 ± 13.21 m3/ha. The Sorensen similarity index is generally very high with floristic affinities greater than or equal to 90 %. The diameters and heights structure shows a predominance of young individuals for the diameter and height classes on all plots. The most represented species associations are legumes (Arachis hypogeae: 40.54 %) and native fruit trees (Vitellaria paradoxa: 15%). These results show the contribution of Cashew agroecosystems in the biodiversity conservation.