CONTRASTING FLOWERING PHENOLOGY AND SPECIES RICHNESS IN ABIOTICALLY AND BIOTICALLY POLLINATED ANGIOSPERMS

Abstract

Biotic pollination is thought to correlate with increased interspecific competition for pollination among plants and a higher speciation rate. In this study we compared patterns of flowering phenology and species richness between abiotically (wind) and biotically pollinated plants, using phylogenetically independent contrasts. We compiled phenological data from eight local seasonal floras, in which we found geographically overlapping sister clades. Of 65 documented origins of wind pollination, we were able to use up to 17 independent contrasts. In contrast to previous studies we found no difference in global species richness between wind- and biotically pollinated sister clades. Regarding phenology, we found wider phenological spread in biotically pollinated clades, earlier flowering onset in wind-pollinated trees, but no difference in duration of flowering between pollination modes. These results corroborate previous views that niche space is more constrained for wind-pollinated species, and that niche partitioning is less important between wind-pollinated plants compared to plants pollinated by animals.