Decoupling of flowering phenology and pollinator niches despite phylogenetic conservatism in a Neotropical herbaceous Restinga community

Background and aims – Flowering phenology is a key niche axis structuring plant communities by influencing reproductive success, plant-pollinator interactions, and species coexistence. However, how flowering timing interacts with pollinator niches and evolutionary constraints remains poorly understood in stressful Neotropical ecosystems such as Restingas. We investigated whether flowering phenology and pollinator niches are evolutionarily coupled or decoupled in a coastal herbaceous community. Material and methods – We monitored flowering phenology weekly for one year in a Restinga herbaceous community in Sergipe, northeastern Brazil, comprising 15 species from 10 families. We quantified temporal flowering patterns, tested climatic drivers of flowering richness, characterized plant-pollinator interaction networks, and evaluated phylogenetic signal in flowering phenology and pollinator niches using comparative methods. Key results – Flowering occurred continuously throughout the year but showed non-random temporal synchrony at the community level, with a flowering peak during the dry season. Flowering richness was best explained by lagged temperature four months prior and photoperiod, indicating delayed climatic control. Species with yellow flowers exhibited significantly aggregated flowering times. The plant-pollinator network was highly specialized and nested, dominated by a few generalist pollinators, including Xylocopa cearensis , Synoeca cyanea , and Eurema elathea . Flowering phenology exhibited strong phylogenetic signal, with closely related species flowering at similar times, whereas pollinator niches showed no phylogenetic structure and were not predicted by temporal flowering overlap. Importantly, neither floral traits nor temporal overlap in flowering explained variation in pollinator assemblage composition, indicating a decoupling between flowering phenology and realized pollinator niches. Conclusion – Our results reveal a decoupling between evolutionarily conserved flowering phenology and ecologically flexible pollinator interactions. This decoupling promotes species coexistence in Neotropical Restinga herbaceous communities by ensuring temporal continuity of floral resources while allowing niche partitioning through variable biotic interactions.