Low intra-canopy variability of floral traits in temperate woody plants

Floral traits represent a valuable yet underutilized resource for functional ecology. We aimed to examine the variability of six quantitative floral traits (carbon [C] and nitrogen [N] contents, C:N ratio, flower length and width, and dry biomass) among a randomly selected group of 79 temperate woody species at both interspecific and intraspecimen levels. We hypothesized that (1) flower traits are closely related to the evolutionary history of the species, resulting in a strong phylogenetic signal, and (2) flowers collected from the most and the least exposed to sunlight parts of the crown would not differ in trait values. We detected statistically significant phylogenetic signals for all six floral traits under study. We found significant differences between samples from the two light variants only for flower N content and C:N ratio. Given the substantial interspecific and the negligible intra-specimen variability observed, we are convinced that the incorporation of these studied traits, especially those related to flower size (i.e., dry biomass, length, and width), into research on flowering biology and ecology can significantly enrich our comprehension of the plant reproductive processes.