Allometric Models for Predicting Biomass and Carbon Pools of Boscia Senegalensis(Pers.) Lam. Ex Poir. (Capparaceae) Populations in Central Africa: A Case Study from Cameroon

Abstract

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.R 2 ), residual standard error (RSE) and Akaike's information criterion (AIC) were: ln (leaf biomass) = 0.08 + 0.31*ln (D 2 ×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.

Site-Species Allometry Equation for Theobroma cacao L. Biomass Estimation in Agroforestry Systems of Cameroon

“…Biomass estimation models vary according to the diferent compartments of Teobroma cacao. Te results of this study are similar to those obtained by [36] who showed a variation in allometric equations depending on the parts of the tree. Among the variables explaining the biomass of Teobroma cacao, the diameter appears to be a good predictor with an R 2 greater than 94%.…”

“…With this in mind, this study made it possible to develop single-specifc equations for the estimation of the aboveground, belowground, and total biomass of Teobroma cacao in a diameter range between 5 and 27 cm. Tis result is similar to those of Victor Awé et al [36] (5.76 and 24.80 cm) for the allometric equation of Boscia senegalensis developed in Cameroon. Te allometric models developed vary from one compartment to another.…”

“…Aboveground, belowground, and total biomass of Teobroma cacao were adjusted using the linear form of the power model. Tis mathematical model has been widely used in the literature to predict the standing biomass of African woody species [36]. Indeed, power models generally remain extrapolable with good reliability because they are based on an allometric model invariant at all scales, which explains their wide use in biomass-forecasting equations in favor of logarithmic or polynomial models [38].…”

“…Indeed, the size of the sample in the development of allometric equations varies in the literature and takes into account the fnancial and material resources and the time allocated to the study [39]. Some allometric biomass equations were constructed from a limited number of individuals, i.e., 17 trees [39], 20 trees [33], 38 trees [40], 15 and 43 trees [41], 40 trees ( [36]), and 40 and 50 trees [42]. Biomass estimation models vary according to the diferent compartments of Teobroma cacao.…”