2022 Field Update: Native plants & native cultivars

This summer we completed our third and final field season surveying pollinator visitation to native plants and native cultivars! We will maintain our experimental garden for one additional season, to finish up some plant measurements and data collection missed in our initial three seasons. This post will serve as a 2022 field update in addition to summarizing some of our preliminary results from our field observations!

Study Plants (2020-2022)

Photo | Scientific Name | Common Name | Plant Type
| Achillea millefolium | Yarrow | Native

Achillea millefolium
‘Calistoga’*

Yarrow

Cultivar

Achillea millefolium
‘Salmon Beauty’

Yarrow

Cultivar

Achillea millefolium
‘Moonshine’**

Yarrow

Cultivar

Aquilegia formosa

Western Red
Columbine

Native

| Aquilegia x ‘XeraTones’ | | Cultivar (hybrid)
| Camassia leichtlinii | Great Camas | Native

Camassia leichtlinii
‘Caerulea Blue Heaven’

Great Camas

Cultivar

Camassia leichtlinii
‘Sacajawea’

Great Camas

Cultivar

Symphyotrichum
subspicatum

Douglas’ Aster

Native

S. subspicatum
‘Sauvie Sky’

Douglas’ Aster

Cultivar

S. subspicatum
‘Sauvie Snow’

Douglas’ Aster

Cultivar

| Clarkia amoena | Farewell-to-spring | Native

Clarkia amoena
‘Aurora’

Farewell-to-spring

Cultivar

Clarkia amoena
‘Dwarf White’

Farewell-to-spring

Cultivar

Clarkia amoena
‘Scarlet’**

Farewell-to-spring

Cultivar

Eschscholzia
californica

California Poppy

Native

E. californica
‘Mikado’

California Poppy

Cultivar

E. californica
‘White’

California Poppy

Cultivar

E. californica
‘Purple Gleam’**

California Poppy

Cultivar

Nemophila menziesii

Baby Blue Eyes

Native
(California)

N. menziesii
‘Penny black’

Baby Black Eyes

Cultivar

N. menziesii
‘Snow White’

Baby Blue Eyes

Cultivar

Sidalcea asprella
ssp. virgata***

Rosy checkermallow

Native

Sidalcea malviflora
‘Purpetta’***

Cultivar

Sidalcea malviflora
‘Party Girl’***

Cultivar

*Discontinued in 2021 due to lack of vigor and availability of replacement plants
**Added in 2021 to replace removed plants
***Discontinued after 2020 due to taxonomic inconsistencies

We conducted 5-minute visual observations on our study plants over three seasons. During these observations, we recorded all insects that interacted with a plant. These interactions included foraging, resting, basking, mating, etc. We recorded insect IDs to morphological group levels, as many bees are hard to identify to species in the field! We were able to identify common bumble bees, honey bees, butterflies, and a few other insects to the species level, but many were identified to groups for ease (e.g. ‘green bees’, ‘black bees’, ‘leafcutter bees’).

Field Season Stats

Year | # Sample Dates | # Collected Pollinators | # Observed Pollinators
2020 | 28 | 2159 | 6238
2021 | 33 | 2471 | 6225
2022 | 29 | ~2000 | ~4700

Number of sampling dates, total number of collected pollinator specimen (via insect vacuum), and cumulative pollinators observed during 5-minute observations for each of our three field seasons.

Is there a difference in native bee visitation to native plants and their cultivars?

Graphs of cumulative and mean foraging native bees from 5-minute observations conducted over three field seasons. Plant Type (y-axis) is abbreviated with a 6 letter code, e.g. “SYMSUB” = Symphyotrichum subspicatum = Douglas’ Aster. Natives have a box around each bar, and cultivars can be identified by an underscore followed by 1-2 letters, e.g., SYMSUB_SN = Symphyotrichum subspicatum ‘Sauvie Snow’ = a native cultivar of Douglas’ Aster with white petals.

Our initial graphs show a subtle preference for native types by native bees. Douglas’ Aster, California Poppy, Farewell to Spring, and Columbine (4/7) have higher visitation by native bees when looking at cumulative and mean counts. The difference is marginal for Douglas’ Aster, but trends for the other three plants are strong. The remaining three species (Yarrow, Baby Blue Eyes, Camas) are difficult to assess, based on these figures alone.

Across these seven species, we do see differences in visitation between natives (wild types) and native cultivars. Whether these differences are statistically significant, and whether there is a trend across all plant groups, remains to be seen!!!

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I want to recognize my amazing Bee Team this year, as this field season would not have been possible without them! I am grateful for all of their hard work and their success in managing this project while I was away numerous times this season. They are thoughtful, inquisitive, and resourceful students, all of whom would make amazing lab or field technicians upon their graduation this spring! Nicole is not pictured below, but also deserves recognition for all her contributions to this project. Thank you all

Svea working on her ultraviolet photography

Mallory ft. some hybrid Clarkia plants that showed up in the garden this year

An incredible capture by Devon, an aspiring nature photographer

Mallory, Svea, and Devon count leafcutter use of farewell-to-spring (Clarkia amoena) flowers.