Use patterns and population dynamics of Boscia salicifolia Oliv. in Boussouma, Burkina Faso: implications for sustainable conservation

Abstract

Leafy vegetables play a vital role in food and nutritional security across sub-Saharan Africa, but increasing human pressures threaten their sustainability. This study investigated the ethnobotanical uses, population dynamics, and conservation needs of Boscia salicifolia Oliv. in Boussouma, Burkina Faso. Ethnobotanical data were collected from 140 informants, stratified by gender, age, and education, using semi-structured questionnaires to document plant uses, perceived threats, and conservation strategies. Vegetation surveys were conducted in 31 plots across protected areas (17 plots, 900 m²) and agroforestry systems (14 plots, 2,500 m²), with all individuals measured for basal diameter, diameter at breast height, total height, and pruning intensity. Generalized linear mixed models (GLMMs) and generalized linear models (GLMs) were used to test the effects of sociodemographic factors on plant use and perceived benefits, while Fisher’s exact tests were used to examine associations with perceived population trends. Population structure was analyzed through diameter-class distributions, supplemented by slope, permutation index, and consecutive class quotients. Leaves were the most exploited organ (Index Value of Organs = 72.3%), primarily for food. Most informants (75%) reported a population decline due to drought, low regeneration, and intensive exploitation. Vegetation data revealed higher tree densities in protected areas, but consistently low juvenile abundance and high pruning intensity across land-use types (69.9 ± 27.6%–71.9 ± 32.2%). Diameter-class distributions showed unimodal structures dominated by medium-sized individuals, indicating limited recruitment. These findings highlight the dietary and medicinal importance of this species while underscoring threats from intensive pruning and poor regeneration. Conservation measures such as assisted natural regeneration, reforestation, and community awareness programs are recommended to promote species recovery and sustainable use.