Allometric models for estimating aboveground biomass and carbon in Faidherbia albida and Prosopis africana under agroforestry parklands in drylands of Niger

This study developed allometric models to estimate aboveground biomass and carbon of Prosopis africana and Faidherbia albida. The destructive method was used with a sample of 20 trees per species for the two parkland sites. Linear regression with log transformation was used to model aboveground biomass according to dendrometric parameters. Error analysis, including mean absolute percentage of error (MAPE) and root mean square of error (RMSE), was used to select and validate the models for both species. Model 1 (biomass according to tree diameter) for P. africana and F. albida were considered more representative. The statistical parameters of these models were R-2 = 0.99, MAPE 0.98% and RMSE 1.75% for P. africana, and R-2 = 0.99, MAPE 1.19%, RMSE 2.37% for F. albida. The average rate of carbon sequestered was significantly different for the two species (P <= 0.05). The total amount sequestered per tree averaged 0.17 x 10(-3) Mg for P. africana and 0.25 x 10(-3) Mg for F. albida. These results could be used to develop policies that would lead to the sustainable management of these resources in the dry parklands of Niger.