Microbial effects on floral nectar sugar variation

Variation in composition of floral nectar reflects the action of extrinsic factors as well as intrinsic plant characteristics. Canto and Herrera study the occurrence and density of yeasts across 22 animal-pollinated species in a neotropical plant community and, after controlling for differences between plant species and individuals, find that yeasts account for a significant fraction of community-wide variance in nectar sugar parameters. As nectar features influence pollinator attraction and plant reproduction, they propose that future nectar studies should control for yeast presence and examine the extent to which such a ‘microbial imprint’ affects pollination services in plant communities.