Allometric Equations for the Biomass Prediction in Azadirachta indica Plantations in Sub-Saharan Africa: A Case Study from Cameroon

This study took place in the Far North region of Cameroon. It aimed at developing and standardizing a specific allometric equation to neem Agroforets in Sub-Saharan Africa. A sample of twenty (20) individuals of Azadirachta indica was cut over all the diameter classes, located between 5 and 105 cm. The dbh and height were measured. Biomass of the compartments of leaves, branches and trunks were determined after drying and weighing. Different allometric equations between biomass and two tree parameters (diameter and height) were tested. The adjusted coefficients of determination (R2aj), the residual standard error (RSE) and the Akaike information criterion (AIC) were used to choose the best models. The main results show that there is a positive and significant relationship between the height of trees and diameter (R2 = 0.98; n = 20 and p ? 0.05). The best model for the prediction of the total Above Ground Biomass (AGB) in Azadirachta indica plantations is AGB = e(- 0.456 + 1.673 x ln (DBH)) with a coefficient of determination adjusted at 0.72

Vegetation structure, carbon sequestration potential and species conservation in four agroforestry systems in Cameroon (Tropical Africa)

ABSTRACT As the rate of forest degradation continues to rise, agroforestry may serve as a way of conserving species and carbon sinks. The aim of this study was to assess agrobiodiversity and carbon sequestration potential in agrosystems in Cameroon. Three age groups of agrosystems were studied. Data were collected in 100x50 m2 quadrates. Density ranged from 53.17±0.08 to 1463±50.11; basal area from 2.07±0.00 to 988.39±16.13 m2/ha; Shannon diversity from 3.3±0.71 to 3.68±0.72; Carbon storage from 12.1±0.27 to 54.65±1.38 t C/ha for 1-10-year-old agrosystems with lowest values in neem; 34.78±0.87 to 71.34±1.6 t C/ha for 10-20-year-old stands with lowest values in cashew; 28.24±0.04 to 108.51±2.46 t C/ha for +20-year-old stands with highest values in eucalyptus; Carbon sequestration potential from 296.7±1.98 to 859.33±10.01 t CO2eq/ha. The highest carbon stocks were found in eucalyptus stands (p<0.05). Several endogenous species, especially Afzelia bipindensis (EN), Leptoderris ledermannii (EN), Mansonia altissima (EN), Entandrophragma cylindricum (VU), Nesogordonia papaverifera (VU), Quassia sanguinea (VU), Vitellaria paradoxa (VU), Afzelia africana (VU), Erythrina senegalensis (LC), Detarium microcarpum (LC), senna spectabilis (LC), were assessed. Other overexploited species, especially Carissa edulis, Zanthoxylum zanthoxyloides, Adansonia digitata, Securidaca longepedonculata, were assessed as well. The studied systems are significant CO2eq sinks and refuge centre for agrobiodiversity