In diverse communities, insect pollinators – like native bee species – visit flowers of plant species, forming complex webs of interactions. These interaction webs can have special structural characteristics. For example, some plant species are visited by many bee species (generalists), whereas others are only visited by a few (specialists). Also, bee-plant interaction webs often contain subgroups of species that form many connections amongst themselves (“modules”), but rarely mingle outside this group. Another property is “nestedness” in which specialist pollinator species visit plant species that are subsets of those visited by generalist pollinators. Nestedness increases overlap across modules and can stabilize interaction webs. Floral scent – complex mixtures of airborne chemical compounds – is one cue used by bees to locate preferred flowers and avoid others. Pollination biology has largely focused on the role of visual cues for pollinator attraction, like floral color, size and shape, and these traits are known to contribute to patterns in plant-pollinator webs, but if or how floral scent structures plant-pollinator webs is unknown. Understanding seasonal patterns in floral scent and bee visitation could guide selection of plants for use in pollinator restoration and have important implications for plant-pollinator interactions as shifts occur in suites of co‐flowering species due to climate change.
We sampled the floral scent, phenologies and bee visitors of 47 naturally growing plant species in a montane meadow in Montana in order to acquire a base understanding of how floral scent may structure plant-pollinator interactions across the growing season.
Matrix of flower-bee interactions as filled boxes (PDF) Credit to Laura Burkle and Justin Runyon