Allometric Equations to Estimate Foliar of <i>Pterocarpus erinaceus</i> and Pod Biomass of <i>Cassia sieberiana</i> and Contribution of Woody Foliage to Soil Litter in Natural Grazing Systems in West Africa

Abstract

In Sahel, livestock productivity is mainly dependent on the production of natural rangelands. Monitoring woody forage biomass can guide for better management of natural rangelands. In this study, we used the branch sampling methods to predict foliar and pods production for two key fodder species in the natural rangelands. Then, the contribution of woody leaves to soil litter was assessed by integral collection of the biomass of fallen dead leaves on sixteen 900 m2 plots distributed between three types of vegetation (gallery forest, tree savanna and grassy savanna) at the Farako-Bâ research station, Burkina Faso. Results showed that the leaf biomass of P. erinaceus varied between 2.68 ± 1.91 and 16.41 t DM. ha−1 per plant. The best simple regression for predicting this biomass is the model BF = −1.29 + 1.69DBH. Pod production of C. sieberiana varied between 0.12 and 6.16 kg DM ft−1. This is significantly correlated with the average crown diameter, with the production prediction equation model being PG = 1.83 Dmh-1.43. We recommend that before practical application, the models should be refined by including data on branch characteristics for Cassia sieberiana and trunk characteristics for Pterocarpus erinaceus. However, the contribution of woody foliage to soil litter was 16.41 ± 1.97; 11.58 ± 5.14; 2.68 ± 1.91 t MS/ha/year, for gallery forest, tree savanna and grassy savanna respectively. Tree foliage potentially contribute to the constitution of soil carbon stocks in rangelands, thus improving their physicochemical properties.