Contrasting responses of pollinators to urbanization and local management in urban farms of Havana.

Urban expansion reshapes ecological interactions in agroecosystems, yet its effects on plant-pollinator interactions remain poorly documented in tropical cities. We assessed how landscape urbanization and floral availability affect pollinator interactions across 16 urban farms in Havana, Cuba, along a gradient of impervious cover (38-97%). Farm area (0.01-11.2 ha) and plant richness (21-200 species) decreased significantly with urbanization, including a ∼90% decline in plant richness. In contrast, relative floral abundance showed a slight increase, suggesting management intensity may mitigate the effect of urbanization. We recorded 16,119 interactions involving eight pollinator morpho-groups, with interaction abundance varying substantially across sites (285-1735; a sixfold variation). Small wild bees, ants, and hoverflies consistently declined with urbanization across both years (2023 and 2024), whereas flies showed a positive response. Floral availability consistently enhanced visitation by Apis mellifera and other wild pollinator groups like small wild bees. Other morpho-groups exhibited strong interannual variability, including reversals in response direction to urbanization and floral resources. In 2023, urbanization reduced overall interaction number, while in 2024 the pattern was weaker and more heterogeneous, although several groups still showed negative responses to higher urban cover. Overall, floral resources consistently enhanced interactions, whereas urbanization effects were temporally variable. Our findings highlight contrasting temporal and taxon-specific responses of pollinators to urbanization. Despite high urban pressure, local floral management supports functional pollinator diversity and helps sustain pollination services in tropical urban agroecosystems. These results underscore the importance of integrating landscape planning and pollinator-friendly practices to enhance agroecological resilience under continued urban expansion.