I've been leaving this post summarizing my 2017 field season simmering on the side burner for much too long. Some of the perennials in my plots are beginning to emerge, which has provided a needed kick start to publish this before the 2018 sampling begins in a few months!
As a quick summary, my study aims to determine the relative attractiveness of 23 native wildflowers to pollinators (and natural enemies). “Saving the bees” is getting lots of attention, both in popular and social media. Declines have been observed in many pollinator populations, due to habitat loss and fragmentation caused by urbanization and agricultural expansion. Planting flowers to provide nectar and pollen is one easy way to improve habitat quality in these degraded landscapes, and because of this there are a plethora of pollinator-friendly planting lists available.
Unfortunately, most of these lists are based on the authors’ observations, not on empirical research, a widespread issue coined "Listmania" by Garbuzov and Ratnieks (2014). Researchers at Michigan State University (Tuell et al. 2007) performed a study comparing the relative attractiveness of various upper Midwest wildflowers (which inspired my study), but otherwise scant research exists on this topic. Observational data are still very important…but they have limitations. What if an author observed yellow-faced bumblebees on a certain flower because it was the only species blooming, not because it is the most attractive? Thus, I want to screen Willamette Valley natives to see which flowers prove the most attractive to pollinators, and produce ranked planting lists that can be used home gardeners (and anyone interested in pollinator habitat).
Over the past year, my coworker Lucas and I have spent a substantial amount of time at OSU’s North Willamette Research and Extension Center. Most of that time was spent maintaining my research plots by planting, replanting, and constantly weeding. Plus, early in the season the irrigation system was not yet installed, and we watered perennial starts by driving a trashcan full of water in the bed of a John Deere Gator. (We did have a moment of vindication while doing this when a farm employee leaned out of his pickup and said, “goodness, you two work hard”).
In between planting columbines and pulling thistles, we sampled insects. My initial plan was to sample and monitor pollinator visitation every week, and we were largely able to stick to that schedule – save for a week of rain in the spring (bees aren’t keen on flying in a downpour), and a summer week when the wildfire smoke in the valley made working in the field unhealthy. The result of this April through October work is a freezer full of samples to slowly sort through and pin. It’s exciting though; the contents of each ethanol-filled bag tells a small story that will contribute to a larger (hopefully compelling!) narrative.
Additionally, I’m lucky to have observed the seasonal changes of this distinct set of flowers and their associated insect communities. We saw the overwhelming buzzing of activity on goldenrod in full bloom, the precision of leaf cutter bees snipping discs from Clarkia petals, the longevity of Douglas aster blooms, and the fleeting beauty of open Madia elegans flowers flecked with morning dew.
It would be impossible to capture the entire field season in one post, so I’ll instead post photo-highlights in a subsequent post. And after that, hopefully some photos of pinned bees in the lab! Thanks to Gail, Lucas, and Izzy for all their help this past year.
Garbuzov, M., & Ratnieks, F. L. (2014). Listmania: the strengths and weaknesses of lists of garden plants to help pollinators. BioScience, 64(11), 1019-1026.
Tuell, J. K., Fiedler, A. K., Landis, D., & Isaacs, R. (2008). Visitation by wild and managed bees (Hymenoptera: Apoidea) to eastern US native plants for use in conservation programs. Environmental Entomology, 37(3), 707-718.