Résumé
Highlights: • Provides the first dendroecological assessment of Neltuma juliflora in Cabo Verde. • Reveals strong variability in radial growth across four bioclimatic zones. • Shows negative effects of off-season rainfall and a modulatory role of temperature. • Highlights the ecological plasticity of N. juliflora under semi-arid conditions.Offers baseline knowledge to guide reforestation and climate adaptation in dry islands.Abstract: Neltuma juliflora (syn. Prosopis juliflora) is the dominant woody species in Cabo Verde, introduced through extensive reforestation efforts to combat land degradation. Despite its ecological and socio-economic relevance, little is known about its growth dynamics and climatic sensitivity in this region. This study investigates growth ring formation and climate-growth relationships of N. juliflora on Santiago Island. We sampled 165 trees across 11 blocks, grouped into four bioclimatic zones. Tree-ring widths were measured using standard dendrochronological techniques. Generalised Linear Models (GLMs) were applied to assess the influence of climatic variables, with multicollinearity controlled using the Variance Inflation Factor (VIF). Although false rings were present, distinct growth boundaries were observed. Mean radial growth varied from 1.53 to 2.11 mm/year across bioclimatic zones. The best GLMs suggest that higher precipitation outside of the usual rainy season could negatively affect growth, while mean annual temperature could have a marginally positive effect. Significant differences in tree-ring growth rate were observed between trees sampled at the four bioclimatic areas, likely reflecting the influence of climate and elevation, and of other factors such as soil and tree density. These results highlight the ecological plasticity of N. juliflora and support its potential use in dendroclimatic research in semiarid tropical regions. These findings have significant implications for ecosystem-based adaptation strategies and sustainable land management practices in Cabo Verde, particularly in the context of climate change and land degradation mitigation. The study underscores the need for longer chronologies and expanded geographic sampling across the archipelago in future work.