Accurate estimates of above-ground biomass (AGB) and below-ground biomass (BGB) are essential for estimating carbon (C) balances at various geographical scales and formulating effective climate change mitigation programs. This study aimed to formulate specific allometric equations and carbon stock for B. senegalensis in Cameroon. Destructive sampling technique was used for harvesting and weighing the biomass of 40 individual trees. Allometric models were developed using biomass as dependent variable and tree dendrometric parameters as independent variables. The best models selected based with Adjusted coefficients of determination (Adj.R²), residual standard error (RSE) and Akaike's information criterion (AIC) were: ln (leaf biomass) = 0.08 + 0.31*ln (D²×H×ρ); ln (branch biomass) = 0.14 + 0.65*ln (D²×H×ρ); ln (stem biomass) = 2.03 + 1.32*ln (D²×H); ln (AGB) = 4.55 + 2.85*ln(D) and ln (BGB) =3.04 + 1.64*ln(D). The belowground biomass of B. senegalensis represents on average 25 % of the total aboveground biomass. Aboveground carbon ranged between 7.09 ± 0.42- 9.01 ± 0.50 tC/ha; Belowground carbon ranged between 4.37 ± 0.26 - 7.11 ± 0.35 tC/ha; litter carbon ranged between 0.50 ± 0.02 - 0.95 ± 0.04 tC/ha; herbaceous carbon ranged between 1.05 ± 0.28 - 1.86 ± 0.20 tC/ha ; dead wood carbon ranged between 3.03 ± 0.40 - 8.98 ± 0.44 tC/ha; Soil Organic Carbon Stock varies between4.33 ± 0.79 - 6.14 ± 1.05 tC/ha ;Total carbon were 33.24 ± 4.28;27.40 ± 3.35;27.27 ± 3.27and 21.18 ± 3.00 tC/ha in site 3, site 2, site 1 and site 4 respectively.The specific allometric equation developed for B. senegalensis can be used in similar Sudano-Sahelian savannas to implement activities to reduce emissions from deforestation and degradation (REDD+) for the benefit of local carbon trading communities.

In the agroforestry systems of sub-Saharan Africa, the vertical and horizontal distribution of tree root biomass according to the soil profile is still poorly documented. The objective of this study is to verify the root distribution of four species of trees established in living hedges, namely, Commiphora kerstingii,Erythrina sigmoidea,Ficus thonningii and Jatropha curcas according to two types of soil (light soil and heavy soil) and three agroforestry technologies (fallows, wooded parks and plantations). The hedges were mostly monospecific in order to facilitate the identification of the roots. The experimental set-up is an entirely random factorial design with two factors. The evaluation of the distribution of tree roots was carried out using the profile method. To determine the different textural classes, a particle size analysis was undertaken in the laboratory. The results obtained show that the number of roots decreases rapidly after 30 cm of depth. The highest root densities are observed in the first 30 cm. Soil type has a slight effect (p <0.05) on rooting density in the last 30 cm of depth for all root classes, higher densities were obtained in light soil compared to heavy soil. Commiphora kerstingiistands out significantly by obtaining a higher number of roots than the other species for all classes. Among the technologies, the plantations showed the lowest root density at 0-5 cm and the highest at 55-60 cm. The root density was higher in the fallows. The results show that the root system is mainly concentrated near the stump.

This study aimed 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 conducted around the diversity and richness of the flora, but also the structure of Cashew agro-ecosystems. For the analyzes of vegetation structure, tree density, basal area and biovolume were calculated. The inventory included trees with a dbh greater than or equal to 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. 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. Additionally, 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 vary 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 Sörensen similarity index is very high with floristic affinities greater than or equal to 90%. The diameters and heights structure show 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 agro-ecosystems in biodiversity conservation.