Resource-related variables drive individual variation in flowering phenology and mediate population-level flowering responses to climate in an asynchronously reproducing palmPalabras clave

摘要

Many tropical plant species show wide intra-population variation in reproductive timing, resulting in the protracted presence of flowering and fruiting individuals. Various eco-evolutionary drivers have been proposed as ultimate causes for asynchronous phenology, yet little is known about the proximate factors that control reproductive onset among individuals or that influence the proportion of trees producing new inflorescences within a population. We employed a nine-year phenological record from 178 individuals of the hyperdominant, asynchronously flowering canopy palm,Oenocarpus bataua(Arecaceae), to assess whether resource-related variables influence individual- and population-level flowering phenology. Among individuals, access to sunlight increased rates of inflorescence production, while the presence of resource sinks related to current investment in reproduction-developing infructescences-reduced the probability of producing new inflorescences. At the population level, climate anomalies induced by El Nino Southern Oscillation (ENSO) affected the proportion of the population producing inflorescences through time. Moreover, the effects of ENSO anomalies on flowering patterns depended on the prevalence of developing infructescences in the population, with stronger effects in periods of low developing-infructescence frequency. Taken together, these results suggest that resource-related variables can drive phenological differences among individuals and mediate population-level responses to larger-scale variables, such as climate anomalies. Consequently, a greater focus on the role of resource levels as endogenous cues for reproduction might help explain the frequent aseasonal phenological patterns observed among tropical plants, particularly those showing high intra-population asynchrony. in Spanish is available with online material.