Status of the woody vegetation in the koyli-alpha community nature reserve (northern senegal): floristic composition, structure, and regeneration trajectory

The Koyli-Alpha Community Nature Reserve, located in northern Senegal, is a major site for ecological restoration and biodiversity conservation within the Great Green Wall zone. This study establishes a baseline assessment of the reserve’s woody vegetation based on 29 systematic sampling plots covering a cumulative area of 7.25 ha. Floristic composition, diversity, stand structure, and natural regeneration were analyzed. A total of nine species, belonging to three families and five genera, were recorded, including six species in the adult compartment and eight in the regeneration layer. The adult stand exhibited a strong oligodominance of Vachellia tortilis subsp. raddiana and Balanites aegyptiaca, which accounted for 95.4% of individuals, 97.5% of basal area, and 97.0% of canopy cover. Adult stand density reached 106.9 individuals•ha⁻¹, with a basal area of 3.00 m²•ha⁻¹ and canopy cover of 28.6%. Natural regeneration was relatively abundant (229.4 individuals•ha⁻¹) but remained dominated by the same species, which accounted for 90.1% of young individuals. Floristic richness was comparable to that reported by Kébé et al. (2020), despite differences in secondary species composition and stand density. These findings indicate an active but still poorly diversified regeneration dynamic. The conservation of less abundant species, monitoring of seedling survival and recruitment, and assessment of herbivory by reintroduced wildlife are essential for evaluating the reserve’s restoration trajectory. Establishing permanent monitoring plots inside and outside the reserve would further strengthen long-term ecological monitoring.