Structure, plant diversity and future management of Pentadesma butyracea stands, an endangered oil tree species in Burkina Faso, West Africa

Abstract

Abstract This paper aims to assess the population structure of Pentadesma butyracea Sabine, a local oil tree species and to analyze the occurrence of woody plants in P. butyracea natural stands. Data were collected in 41 plots of 50 × 20 m across natural stands of P. butyracea in two regions of the south-Sudanian phytogeographic zone of Burkina Faso. Stem diameter, total height and tree health were recorded and the woody plant diversity was assessed. Stand data were calculated and the diameter structure was analyzed at the regional level using the Weibull distribution. Significant differences (P < 0.05) were found in density and basal area between regions. In both regions, 32 per cent of trees show signs of poor health. The diameter distributions of individuals showed a structure close to a reverse J-shape (c < 1). Natural stands of P. butyracea exhibit good natural regeneration, but the large trees in the sampled populations commonly had poor health. The data may indicate early signs of stands of P. butyracea changing into savanna in the Banfora region as a consequence of human activities and climate deterioration. P. butyracea is a dominant species in riparian forest, its conservation has a potential to restore the riparian forest; appropriate management guidance and support that involves local communities is required to ensure sustainable management.