Floristic characterisation and population status of Erythrina senegalensis DC. and Erythrina sigmoidea Hua in the Guiriko region (Burkina Faso)

Description of the subject. The dependence of populations on natural formations affects the survival of plant species. Objectives. The objectives are to characterize the flora of plant formations with Erythrina senegalensis and Erythrina sigmoidea in the Guiriko region and to analyze the current state of their populations in order to guide their conservation. Method. Floristic and dendrometric data were collected following a targeted sampling after a survey of Erythrina plant formations. The plant formations selected for the study were the classified forests of Péni, Dindéresso, Kuinima, Kou, and the sacred woods of the sandstone hills of Kôrô. Results. A weakly similar floristic diversity (Cs = 0.45) with 213 and 165 species, respectively, in the E. senegalensis formation and the E. sigmoidea formation was observed with Rubiaceae, Combretaceae, Fabaceae-ceasalpinioideae, Anacardiaceae, Fabaceae-faboideae, and Fabaceae-mimosoideae as dominant families. The most dominant biological types are the Phanerophytes. A regressive population dynamic characterized by a near absence of large-diameter individuals and adult individual densities of 25.48 individuals·ha-1 for E. senegalensis and 13.15 individuals·ha-1 for E. sigmoidea was observed. The low densities of juveniles (< 50 individuals·ha-1) and the low renewal potentials (< 2 individuals·ha-1) observed constitute a major risk to the survival of Erythrina populations. The populations of E. senegalensis are more subject to debarking (13.30% of plants), while that of E. sigmoidea is more subject to bush fires (88% of plants). Conclusions. The renewal of these species is seriously compromised in the Guiriko region. Studies must be carried out on their regeneration modes, and special protection measures must be taken in conjunction with the populations to conserve and sustainably manage them.