Structural characterization and pod yields of populations of the fodder legumes trees <i>Piliostigma thonningii.</i> and <i>Prosopis africana</i> along the toposequence in western Burkina Faso

Abstract

Plant communities including fodder trees play an important role in livestock production in semi-arid zones of West Africa. This study was carried out at two sites of the western region of Burkina Faso and aimed to provide information on the current status of the natural savanna-woodland pastures and predict the pod production of Piliostigma thonningii and Prosopis africana, two key fodder species of these ecosystems. All woody species were systematically identified and their dbh and height were measured in plots along a toposequence. Pods were collected from 60 trees of P. thonningii and P. africana and the stem circumference at breast height and the crown diameter were also measured. To predict pod production, regression analysis was used to develop predictive allometric equations by selecting tree size variables for fitting to models. Results showed a total of 24 species belonging to 11 families and 22 genera were inventoried with clear tendency to shrub invasion of the toposequence locations. P. thonningii trees had a good regeneration status while P. Africana individuals were old. The two species had good potential for natural regeneration of the stands from seedlings. The pod production prediction equations for both species were significantly correlated to dendrometric traits (P˂0.0001). They were species-specific, and the equations developed for each species were different. It is not advised to apply the same formula to predict pod production of fodder trees species at different savanna-woodland locations throughout West Africa.

Keywords: Browse species, dendrometric traits, class distribution, Fodder equation, Natural savannawoodland pastures, Toposequence, West Africa.