Understanding phenology and forest meteorology dynamics in a South American pharmacological tree.

Protium heptaphyllum (Burseraceae) is a native species widely studied for its secondary metabolites, yet with limited records regarding its ecology and conservation. To address this gap, the present study describes the vegetative and reproductive phenology of the species in an Atlantic Forest fragment in Rio Grande do Norte, Brazil, examining the relationship between phenological events and meteorological variables. Twenty adult individuals (twelve females and eight males) were monitored biweekly over two years. The phenophases assessed included leaf senescence, leaf flushing, flower buds, flowers at anthesis, and immature and mature fruits, and were correlated with precipitation, temperature, relative humidity, solar radiation, and wind speed. The species exhibited a seasonal pattern, with heightened reproductive activity from October to February. Flowering was intense and synchronous, suggesting efficient pollination; however, mature fruit production was low. The findings reveal limitations in reproductive success, indicating that extreme climatic events, such as El niño, may influence the species' phenological behavior. Identifying periods of peak phenological activity contributes to guiding seed collection, seedling production, and restoration efforts, providing concrete insights for the conservation of P. heptaphyllum in its natural habitats.