Effects of land use on the diversity, population structure, and regeneration of Sclerocarya birrea across two phytogeographical sectors in Burkina Faso (West Africa)
摘要
Sclerocarya birrea is a multipurpose savanna tree species of high socio-economic and ecological importance, increasingly threatened by land-use intensification in West Africa. This study aimed to (i) assess the influence of land use on woody species diversity in Sclerocarya birrea stands across phytogeographical sectors, (ii) assess the population structure of Sclerocarya birrea, and (iii) evaluate the effects of land use on demographic, structural, and regeneration patterns. A total of 150 plots were established using a stratified sampling design based on land-use types across the North and South Sudanian sectors of Burkina Faso. Species diversity was assessed using Hill indices, and ANOVA was used to analyze differences among land-use types. A total of 99 woody species were found in Sclerocarya birrea stands, with higher richness in classified forests (89 species) than in fallows (78 species) and farmlands (62 species). Species richness and diversity indices differed significantly among land-use types (p < 0.001). Sclerocarya birrea population density was highest in classified forests (79.64 ± 44.42 individuals ha−1 and 87.00 ± 23.10 individuals ha−1 in the North and South Sudanian sectors, respectively), followed by fallows and farmlands. Regeneration modes (seedlings, suckers, and coppices) varied significantly between land-use types, with seedling density highest in farmlands (up to 415.25 ± 330.20 individuals ha−1). Diameter class distributions showed stable inverted J-shaped in classified forests, whereas farmlands exhibited unstable, bell-shaped structures, with fallows showing intermediate dynamics. Sustainable management should prioritize assisted natural regeneration, protection of juveniles, and improved agroforestry practices to enhance population stability and long-term ecosystem services.