Linking Fabaceae diversity to rhizobial symbiosis across Mozambique’s environmental gradients

Legumes are key components of tropical ecosystems, enhancing soil fertility, supporting primary productivity, and strengthening ecological resilience through their mutualist associations with nitrogen-fixing bacteria. Yet, the diversity, nodulation status, and biogeographic patterns of Fabaceae in Mozambique remain poorly known. We present the first comprehensive taxonomic and functional assessment of Mozambique’s native Fabaceae, integrating trait data, georeferenced occurrence records, and spatial analyses. A total of 760 taxa, representing 126 genera and five subfamilies, were documented across 50 × 50 km grid cells. Papilionoideae dominated (77%), followed by Caesalpinioideae (18%). Most taxa (88%) are native, including 46 strict endemics and 42 near-endemics, though nearly 70% remain unevaluated by the IUCN. Species richness peaked in the northern and central provinces, particularly within the dry and wet miombo woodlands and coastal forest mosaic, while montane and floodplain habitats were comparatively species-poor. Nodulation was confirmed in 32% of taxa and inferred in 52%, mainly among herbaceous and shrubby forms. Spatial modelling identified broad-scale associations between nodulation probability, Fabaceae richness, and selected soil variables, including a negative relationship with total soil nitrogen, together with pronounced spatial clustering in central and northern Mozambique. Overall, this study provides a baseline for understanding the diversity, distribution, and symbiotic potential of Fabaceae in Mozambique and highlights key knowledge gaps relevant for future ecological, biogeographical, and conservation in southern Africa.