Species traits, particularly those that impact fitness, can shape the evolutionary relationships among coexisting species. Trait distribution (underdispersion, overdispersion) within communities can provide evidence of key ecological interactions (e.g., competition, facilitation) that can contribute to assembly. The distribution of floral colors in a community may reflect pollinator-mediated interactions, and the phylogenetic distribution of color can also affect inferences of ecological mechanisms at play. Additionally, the scale of local habitat may influence the type or strength of ecological interactions among co-occurring species. I examined how floral color is distributed within replicated co-flowering assemblages with the use of pollinator color vision models. Incorporating these biologically relevant models into the study of floral color assembly processes is relatively new and untested for an entire co-flowering community with generalist pollinators. I modeled floral spectra of 55 co-flowering species through honeybee and syrphid fly color vision to assess color trait structure across 14 serpentine seep communities in California. I then compared our findings to null model predictions. We asked: is there evidence for nonrandom distribution of floral color in the community? Is there phylogenetic signal for floral color? If so, is there phylogenetic underdispersion or overdispersion across local communities? Is there an effect of habitat scale on these outcomes? I found that the observed color assemblage is not due to any phylogenetic history, and there is no phylogenetic signal for the selected floral color metric. I found a significant negative relationship between habitat scale and trait dispersion. Competitive exclusion could be a dominant interaction outcome at small scales, but it is less detectable/unimportant at larger scales
