Contrasting Phylogenetic Signals in Flowering and Fruiting Phenology at Species and Assemblage Scales in a Climbing Plant Community

ABSTRACT Aims Climate has long been recognized as an important factor shaping plant phenology. Seasonal climatic variables can exert a strong influence on flowering and fruiting timing. Further, if phenological responses to environmental gradients are phylogenetically conserved in plant species, evolutionary history might be a strong determinant of phenological periods. In this study, we evaluated whether closely related species are phenologically similar, whether there is an association between the composition of flowering or fruiting species and environmental gradients, and to what extent such associations are mediated by the phylogenetic relationships among species. Location Araucaria forest at São Francisco de Paula, South Brazil. Methods We assessed the phylogenetic conservatism of reproductive phenology in a climbing plant community (78 spp.), an understudied life form that highly contributes to ecosystem dynamics. For this, we calculated the phylogenetic signal of species' flowering and fruiting peaks and conducted a phylobetadiversity analysis and model selection considering temporal autocorrelation. Results We found a weak phylogenetic signal in flowering and no signal for fruit phenology at the species scale. However, we found a strong influence of shared evolutionary history on the association between phenological patterns and environmental gradients at the assemblage scale, with different phylogenetic lineages influenced by distinct variables. The daylength, a variable that exhibits subtle changes and consistent patterns across years, explained most of both flowering and fruiting of larger clades (rosids vs asterids), while for fruiting lower level clades (families) were influenced by the canopy openness of tree species. Conclusions The results highlight the fingerprint of phylogenetic relatedness in the association of plant phenology and environmental gradients, enabling the identification of at which phylogenetic levels these gradients are acting. Our approach and results bring a new perspective, showing that even in the absence of a phylogenetic signal in species phenological peaks, there is a phylogenetic conservatism between plant phenology and environmental gradients.