Land use patterns drive demographic collapse and reveal urgent conservation needs of Balanites aegyptiaca (L.) Delile Stands in resilient dryland forests

<title>Abstract</title> <p> Land-use intensity is a major determinant of structural vulnerability in dryland ecosystems, posing a threat to resilient multipurpose tree species globally. We investigated how specific land-use patterns affect the stand structure and dynamics of <italic>Balanites aegyptiaca</italic> , a keystone species for the Great Green Wall Initiative, across the Lake Chad Basin. Using dendrometric surveys (200 plots) and Factor Analysis of Mixed Data (FAMD), we characterized population attributes across different soil types and land-use systems (rangelands, cultivated fields). The stands exhibited a low average density (4.02 ± 2.7 stems ha⁻¹) and an inverted J-shaped diameter distribution, dominated by young individuals (DBH 10-50 cm). This structure indicates high post-recruitment mortality, resulting in a scarcity of mature trees (≥ 40 cm) and vulnerability to demographic collapse. FAMD results showed that the first factorial axis (16.9% of variance) primarily separates lightly exploited sandy soils from intensely cultivated loamy soils. This confirms that land-use patterns emerge as the key driver of the spatial organization and structural degradation of <italic>B. aegyptiaca</italic> populations. Our findings provide a scientific basis for urgent management strategies, emphasizing the need to mitigate intensive land-use impacts on adult cohorts to ensure the long-term sustainability of this vital resource in the Sahelian context. </p>