Structure, diversity, and regeneration status of fodder tree stands in Sahelian rangelands of Ferlo in Senegal and Mankarga in Burkina Faso, West Africa

This study examined fodder tree species diversity, stand structure, and regeneration patterns in the natural rangelands of Ferlo (Senegal) and Mankarga (Burkina Faso). Vegetation data were collected using a systematic sampling approach. In each site, a total of 106 plots in Ferlo and 119 plots in Mankarga were established. Plot size varied according to vegetation type, with 1000 m² plots (50 × 20 m) used in savanna areas and 500 m² plots (50 × 10 m) in gallery forests. Within each quadrat, measurements included diameter at breast height (DBH), tree height, regeneration classes, and fodder tree species density. DBH was recorded for all individuals with DBH ≥ 5 cm. Species diversity was assessed using the Shannon–Wiener and equitability indices, while structural attributes were analyzed through frequency, density, DBH, height, and basal area. The Importance Value Index (IVI) was also calculated. Regeneration status was determined from the abundance of seedlings. In total, 89 fodder tree species representing 64 genera and 25 families were identified in Ferlo, while 80 species from 57 genera and 23 families were recorded in Mankarga. Fabaceae and Combretaceae were the most represented families across both rangelands. Population structure varied widely among dominant fodder tree species. Overall, the results indicate that small-sized individuals are prevalent, suggesting that these rangelands are in a secondary developmental stage. Several species show weak or absent regeneration, indicating a need for targeted conservation interventions. Strengthening rangeland management and establishing coordinated conservation actions at local and regional scales are therefore essential.