From the Lab to Your Laptop: Getting Research to the Public

The members of the Garden Ecology lab spend much of their time on research into subjects that affect, what else, the ecology of home gardens. Pollinators and their relations with native and non-native plants, bee variety and abundance in gardens, and soil nutrient levels, are among the topics they are delving into.

One of the challenges for the lab members – and for all scientists – is how to get the results of their research into the hands of people who can use it. Scientific papers are the traditional way, but not many people actually read those, and it can take a long time for research to trickle out from papers to the general public. If you read this blog, you’ve discovered one of the ways current research is disseminated quickly, and you’re learning new ideas that you may be able to implement in your own research or gardening.

Science you can use in your garden

Another way research gets to the public is through teaching. Lab members present new data in lectures, interviews, presentations, workshops and classes, including OSU Extension’s Online Master Gardener training, which I teach. Each year the course reaches around 40 Oregon MG trainees, plus another 60 or so horticulturally-minded people who take the course simply to improve their garden knowledge. In addition, our single-subject Short Courses are accessed by several thousand people per year. So any new research I can include in these courses can potentially reach hundreds or thousands (depending on the subject) of gardeners per year, who in turn may influence other gardeners.

With this in mind, I have cited Mykl Nelson’s research on excessive nutrient levels in managed vegetable garden soils to caution students about the perils of over-fertilizing. In 2020, my new module on Gardening with Pacific Northwest Native Plants will be influenced by Aaron’s data on the native flowers most favored by native pollinators. His research, plus other research taking place elsewhere, is showing that just planting a garden of pollinator-attracting plants may not be the best tactic to help native pollinators. A garden full of bees is often, really, a garden full of honey bees. What about all the native bees that are less visible, but at least as important? Aaron Anderson’s research into which plant species attract which bee species is beginning to show that the plants most attractive to honey bees are generally not the same as those most attractive to native bees.

Native bee on a native rose
Honeybees on non-native sunflower

The takeaway? Gardeners who want to support pollinators can take the extra step of searching out and growing native plants that are especially attractive to native bees, in addition to the many flowers that honey bees frequent. This is what I will be teaching my Master Gardener trainees in Oregon, and the rest of my students all over the country; many of them will in turn teach other people. Bit by bit the new information gets out there, and more native bees may find the flowers they need to thrive.

2019 Native Plant Field Season Update

I’m thrilled to announce that this summer I completed the third field season of my study. This is slightly bittersweet – while I’m excited that we are done with hot fieldwork, I will miss chasing bees around the farm and the view of Mt. Hood. I’m incredibly thankful for this third season of data, as it will help account for some of the temporal variation inherent in ecological studies. In fact, pollinator communities in particular tend to be highly variable both within and across field seasons. Having three seasons of data will hopefully allow us to identify more reliable patterns of pollinator visitation between my study plants.

Lots of lab work remains, as I’m tackling the insect samples that we collected with the bee vacuum. With the help of a dissecting scope, I’m attempting to identify the each specimen to at least the taxonomic level of family to get a sense of the broader insect communities associated with each flower species in my study. It will be several months before I can share this species-richness data, but in the meantime I have bee abundance data to share with you!

Aaron and Lucas in the native plant study site, in 2017. You can see the 1m by 1 m plot in the foreground by Aaron, a second one near Lucas, and a few more in the distance.

As a refresher, we performed timed pollinator observations at each plot. This consisted of observing each blooming plot for five minutes and counting all the insects that landed on open flowers. Bees were sorted to “morpho-type” (honey bee, bumblebee, green bee, and other native bee). Though this doesn’t give us species-level information on the floral visitors, it allows us to understand which plants attracted the most pollinators overall, and allows us to detect any patterns of visitation between honey bees, bumblebees, and solitary native bees. Below is a summary of some of the highlights.

2019 overall bee abundance by plant species:

  • Origanum vulgare, Lavendula intermedia, and Eschscolzia californica were top five bee plants in 2019, just as they were in 2018.
  • In 2019, Phacelia heterophylla and Solidago canadensis jump into the top five, while Nepeta cataria and Gilia capitata fall out of the top five. It should be noted that Nepeta was the sixth most attractive plant, with about the same visitation level as Solidago.
  • Again, similar to 2018, it appears that honey bee visitation was driving the high visitation rates of the popular exotic garden species (marked with a red asterisk), while native wildflowers were being visited more frequently by native bees.
  • I’ve included the 2017 and 2018 overall abundance graphs as well, for comparison. You can see that the overall abundance was higher in 2019 for the two most popular plants, at about ~25 bees per observation period!

2017 overall bee abundance by plant species:

2018 overall bee abundance by plant species:

Since honey bee visitation drove the high abundance of many of the top pollinator plants, I took honey bee visits out of the data set and made a new graph, to compare which plants were most attractive to native bees.

2019 native bee abundance by plant species:

As you can see above, honey bees are excluded from the analysis, the top five most popular plant species completely reshuffles.

I’ve included that 2017 and 2018 native bee abundance data below for comparison.

2017 native bee abundance by plant species:

2018 native bee abundance by plant species:

Please stay tuned for more updates on the bee species richness we collected in 2019, as well as data on the other insects (pests and natural enemies) that we collected!

Native Plants and Pollinator Survey

Aaron Anderson is repeating his original survey on native plants and pollinators. This time, he is trying to understand how knowledge of a plant’s ecological function may alter impressions of native plants.

The survey takes about 25-30 minutes to complete. Folks who have taken the survey thus far have commented on how much they learned from taking the time to answer the questions.

If your time and interest allows, we would be extremely grateful if you could take the time to respond to this survey. The direct link to the survey is:

http://oregonstate.qualtrics.com/jfe/form/SV_9Alhv961rZX8Vs9

If you have friends or acquaintances who also might be interested in taking the survey, please feel free to share it with them.

A syrphid fly pays a visit to a California poppy at the North Willamette Research and Extension Center.

A bee visiting one of the Canada goldenrod plots in our Native Plant study.

Gilia capitata

Lotus unifoliolatus

Native plants and pollinators – 2018 field update

It’s been a while since I’ve posted a field update about my native plant – pollinator study, so this post will be a recap of the entire 2018 field season! Sampling this year was successful, though it was a much shorter bloom season for almost all the flowers species, perhaps due to a combination of the heat, low rainfall, and lack of supplemental irrigation. I performed some summary statistics on the data, and there are some intriguing results from this year.

Below is a summary of some of the highlights:

Visitation Data

  • Only two (Gilia capitata and Nepeta cataria) flowers made it into the top-five most attractive in 2017 and 2018. The full results can be visualized in the two histograms below.
  • Three of the non-native garden species were found in the top five in 2018 (though I noted this visitation seemed strongly driven by honey bees).

2017 overall bee abundance by plant species:

2018 overall bee abundance by plant species:

Because of this, I removed honey bees from the dataset and recreated the graphs.

  • The 2017 visitation data is largely unchanged (though Nepeta cataria is less attractive, and Eschscholzia californica jumps into the top-five).
  • When only native bees are considered, the top-five most visited 2018 plants are almost completely different. Eschscholzia californicaAster subspicatus, and Phacelia heterophylla are the three most attractive flowers.
  • It seems like the native wildflowers are being visited more frequently by native bees.

 

2017 native bee abundance by plant species:

2018 native bee abundance by plant species:

Sampling Data
I also take vacuum samples from each plot so that we can identify pollinators (and other insects) to species. I’m excited that my 2017 and 2018 bees have been identified by taxonomist Lincoln Best!

​Across those two years, we collected 36 bee species (from 540 samples, which doesn’t include all the honey bee individuals). You might ask – is  this many bees, or only a few? Simply put – we don’t know! Without knowing how many bee species are found at our site at NWREC, its hard to tell what this number means. However, I was excited to find that we collected two bumblebees that are on the IUCN Red List, Bombus fervidus and Bombus calignosus.

Below are a two pollinator interaction matrices to visualize these data, but I should note that these are very preliminary – they are not scaled by number of sampling events but are still a neat way to visualize interactions and richness data.  (Darker squares represent higher abundance; a white square means no bees were collected off that flower).

 

Bumblebee Richness and Abundance:

Other Native Bee Diversity and Abundance:

 

Its obvious from looking at these data that the answer to the question “which plants attract the most pollinators?” isn’t simple! Are we interested in certain suites of bee species – honey bees, or bumblebees? Are we interested in high overall abundance, or high species richness? Some species attract many individuals but few species, while other plants attract a higher species richness but fewer overall individual bees. Additionally, there are also seasonal changes in bee populations to consider, as well as seasonal changes in flower phenology and floral display.

Luckily we’re going to have a 2019 field season, which will help account for this temporal variation and allow us to acquire data for species that didn’t flower in one or both of the previous years.

Plant of the Week: Douglas Aster (Revisited)

Image from: http://www.nwplants.com/

This entry is from Lucas Costner, an undergraduate horticulture major at Oregon State University.  It highlights one of the plants that Aaron Anderson is using in his research.

Original “Plant of the Week: Douglas Aster” post available here: http://blogs.oregonstate.edu/gardenecologylab/2017/11/07/plant-week-doulgas-aster/ 

 

Last November I took a look at a Pacific Northwest favorite, the Douglas aster (Symphyotrichum subspicatum (1)). What I didn’t know then was just how popular this species would be with the bees we had been sampling in the field. It turns out that while surveyed gardeners ranked Douglas aster 14 out of 27 in terms of attractiveness, based on the 2017 data it boasted the third highest number of bees (2). This means that it is the most attractive native perennial species for bees that we sampled, and the 2018 data shows this as well (3). Based on the gardeners’ ranking, however, which placed it in the bottom 50% of all the species we sampled, it also looks as though the Douglas aster is in need of some public relations help. 

It is my personal belief that it isn’t just the showiness of the blooms or the potential benefits to X, Y and Z that brings plants into our gardens, but rather the stories we tell about them. Familiarity after all is more than just recognition; it is also marked by appreciation and understanding. One of the stories we can tell through our work in the Garden Ecology Lab about Douglas aster is of its relationship with our native bees. As gardeners we are uniquely positioned to both benefit from and to be of service to these insects. 

Here are some of their “faces”: 

Long-horned Bees

Melissodes sp. 

The most common genus of bees collected from Douglas aster in the field, Melissodes are true summer and fall flyers, easily recognizable by their long antennae. These bees are solitary ground nesters, although they have been observed forming nesting aggregations in the soil (4). While we collected potentially five species of Melissodes in total, one species in particular, Melissodes microsticta, was especially common. Many Melissodes species are generalists, but can usually be found visiting members of the Asteraceae family (such as sunflowers and our Doulgas aster) because of their late season blooms.

 

Image from: https://odabeeguide.weebly.com/melissodes.html

Yellow-faced Bumblebee

Bombus vosnesenskii

The second most commonly collected visitor of Douglas aster, the yellow-faced bumblebee is really a remarkable native pollinator. While many native bees are considered solitary, bumble bees are social insects, with a queen and workers (4). Like non-native honeybees, they have been investigated for their potential as commercial pollinators, being used in greenhouse production (5). Isabella Messer wrote a post for the “Pollinator of the Week” series highlighting these ubiquitous bees that can be found here: http://blogs.oregonstate.edu/gardenecologylab/2017/08/29/pollinator-week-yellow-faced-bumble-bee/ 

 

Image from: https://odabeeguide.weebly.com/bombus-sp.html

Ligated Furrow Bee

Halictus ligatus

The third most commonly collected visitor of Douglas aster is the ligated furrow bee. Found throughout North America, Halictus ligatus is special amongst native pollinators (like the yellow-faced bumblebee) for its social nature (4). Sociality is rare amongst native bees, as it is in nature in general, but amongst the Halictus the situation is even more unique. This is because, unlike other social species, Halictus have been seen to switch back and forth between solitary and social behaviors over time as environmental conditions differ (4). Isabella wrote a post about these bees a while back for the “Pollinator of the Week” series that can be read here: http://blogs.oregonstate.edu/gardenecologylab/2018/04/30/pollinator-week-mining-bee/ 

 

Image from: https://odabeeguide.weebly.com/halictus.html

Virescent Green Metallic Bee

Agapostemon virescens

The fourth most commonly collected visitor of the Douglas aster is none other than my personal favorite, the virescent green metallic bee. These stunning bees are communal soil nesters and are members of the Halictidae family, cousins of the ligated furrow bee introduced above (4). I wrote a post about them for the “Pollinator of the Week” series last November that can be found here: http://blogs.oregonstate.edu/gardenecologylab/2017/11/13/pollinator-week-virescent-green-metallic-bee/ 

 

Image from: https://odabeeguide.weebly.com/agapostemon.html

In addition to these bees, we also collected striped-sweat bees (Agapostemon texanus/angelicus), brown-winged furrow bees (Halictus farinosus), metallic sweat bees (Lasioglossum sp.), and common little leaf-cutter bees (Megachile brevis). We also collected with a number of long-horned bees (Melissodes) that have yet to be identified to species. 

Walking the streets of Portland and seeing Douglas aster’s purple flowers still in bloom this late in October brings a smile to my face because it tells me that people are indeed planting this species. If only for its benefit to wildlife and pollinators in particular, that is still good news. As you may be able to tell from the information given above, we are still learning about these bee species while we are simultaneously working to save them — not just for future generations but for ourselves as well. Hopefully, by putting a “face” to the bees that visit and depend on these plants and our gardens, the bond that links us to them can be strengthened and our preference for them in our landscape enhanced. 

 

Sources: 

  1. Geraldine A. Allen 2012, Symphyotrichum subspicatum, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=88843, accessed on October 30, 2018.
  2. Langellotto, G. (2018, September 12). Do Gardeners Like the Same Flowers as Bees? [Blog post]. Retrieved from http://blogs.oregonstate.edu/gardenecologylab/2018/09/12/do-gardeners-like-the-same-flowers-as-bees/ 
  3. Anderson, A. (n.d.). First Look: Research Into Native Plants in the PNW Garden. Webinar. Retrieved from http://blogs.oregonstate.edu/gardenecologylab/2018/10/23/webinar-on-willamette-valley-native-plants-and-pollinators/ 
  4. Wilson, J. S., & Messinger Carril, O. (2016). The Bees In Your Backyard. Princeton, NJ: Princeton University Press.
  5. Dogterom, M. H., Matteoni, J. A., & Plowright, R. C. (1998). Pollination of Greenhouse Tomatoes by the North American Bombus vosnesenskii. Journal of Economic Entomology, 91(1), 71-75. doi:https://doi.org/10.1093/jee/91.1.71
  6. Oregon Department of Agriculture: Bee Pollinators of Oregon. (2016). Retrieved October 30, 2018, from https://odabeeguide.weebly.com 

Webinar on Willamette Valley Native Plants and Pollinators

Aaron’s webinar on his Ph.D. research has been posted on YouTube.

He highlights some really interesting results from his 2017 and 2018 field seasons, including recommendations for what to plant, if you are interested in attracting native bees to your garden. I’ve asked him to write a blog post, summarizing the results to readers.

Plant of the Week: Sunflower

This entry is from Lucas Costner, an undergraduate horticulture major at Oregon State University.  It highlights one of the plants that Aaron Anderson is using in his research.

As summer in the Pacific Northwest comes to a close, the sunflower (Helianthus annuus) stands out as a classic garden favorite deserving consideration. These commonly large, tall yellow flowers are a boon to wildlife, provide late summer height and interest in the garden, and have shared an interesting relationship with people wherever we have encountered them. 

While there are many individual species and varieties available on the market today, wild populations can be found across North America, and most boast popularity with insect pollinators and other wildlife, including birds (1, 3). In the field, Aaron is using the wild-type and, while you certainly don’t have to do the same, varieties marked as “pollenless” or double-petaled should be avoided when planting for wildlife (3). Sunflowers seeds are well-known for their attractiveness to birds, but the flowers also provide forage to a diverse suite of insects, including bees, wasps, butterflies, and even beetles (2, 3). Four genera of native bee species (Diadasia, Eucera, Melissodes, and Svastra) host members that are sunflower specialists, and the giant leafcutter bee (Megachile pugnata) has even been studied as a managed pollinator for agricultural production of the crop (3). 

The giant leafcutter bee (Megachile pugnata).  Photo Credit: Thomas Shahan. Oregon Department of Agriculture.

Originally domesticated in eastern North America, the sunflower is the only native seed oil plant (1). Its use among North America’s indigenous peoples is well-documented and varied, having been used for everything from food to dye to medicine (2). The sunflower was introduced to Europe in the 16th century, where it first found its place in gardens, but it wasn’t until the 1800s in Russia that our modern ideas of giant, towering sunflowers came to be (1). This is because early American colonists did not cultivate sunflowers, and the seeds were reintroduced from Russia to the United States in 1893 (2). The Russians bred sunflowers that could produce up to 1000 seeds each for oil production, since the Russian Orthodox Church had forbidden the use of other cooking oils during the Lenten season (1). Therefore, in comparison with many common varieties available, and despite 3,000 years of domestication by indigenous peoples in North America, the wild-type appears quite diminutive (2). 

No matter the variety, gardeners should be aware that sunflowers are annual flowers that will need replanting every spring (although allowing squirrels to do the planting could be a fun experiment). They prefer well-draining soil and can reach rather impressive heights depending on the exact species and type. Additionally, the stems can become woody and may require some work removing at the end of the season. 

Sources cited: 

  1. Simpson, B. B., & Connor, M. (2014). Plants in Our World: Economic Botany (4th ed.). New York, NY: McGraw-Hill Education.
  2. Stevens, M. (2006, June 7). Plant Guide: Annual Sunflower [PDF]. Davis: USDA NRCS National Plant Data Center.
  3. The Xerxes Society. (2011). Attracting Native Pollinators. North Adams, MA: Storey Publishing.

Do Gardeners Like the Same Flowers as Bees?

In 2017 and 2018, Aaron and Lucas took weekly counts of bees on their native plant plots. Aaron has summarized the data for 2017 (below) according to bee morpho-type. The morphotype categories are the same general categories that have been used by other researchers: bumblebee, honey bee, green bee, small bee, and big bee. These major bee categories are fairly easy to distinguish from one another in the field. Although, Aaron and I talked quite a bit about whether or not we should combine big bees and small bees into a new category: other bees. When does a small bee become a big bee? We had a general sense that a large Megachile rotundata would be a big bee, and a small Ceratina sp. would be a small bee. But, what about a smaller Megachile species? Is that big bee or a small bee? There is no clear answer.

Aaron and Lucas kept records of big bees vs small bees, as best as they could, but in the end, we might collapse all of that data into an ‘other bee’ category.Aaron recently surveyed gardeners, to ask their opinion on the aesthetics of his study plants. A quick look at the results suggests that gardeners and bees might be attracted to different flowering plants. While Gilia capitata was the most visited plant in Aaron’s study plots, it was ranked 6th most attractive (out of 27 plants) by gardeners. The story gets worse for Madia elegans (2nd with bees, 20th with gardeners), Aster subspicatus (3rd with bees, 14th with gardeners), and Solidago candensis (4th with bees, 23rd with gardeners).

Could it be that bees and gardeners are truly attracted to different types of flowering plants? Or could it be that if gardeners knew about the benefits of these Willamette Valley natives, that they might see a new kind of beauty in these plants?

 

First Bee List from Native Plant Study

We are so lucky that Lincoln Best has been in Oregon, supporting the work of the Oregon Bee Atlas. Linc was kind enough to take a look at Aaron’s bees, before going back to Canada. Aaron is currently taking a bit of time off, following his wedding this past weekend (Congratulations Aaron and Maura!). In everyone’s absence, I’m chomping at the bit to see what bees were identified from Aaron’s study of Willamette Valley native plants. So ~ for your reading pleasure, here is a preliminary list of bees collected from Aaron’s plant plots.

Aaron and Lucas in the native plant study site. You can see the 1m by 1 m plot in the foreground by Aaron, a second one near Lucas, and a few more in the distance.

A few things to note about this list:

  1. I give no mention of abundance of each bee species. Some specimens were caught many, many times off of a flowering plant species. Others were rare, and only caught once.
  2. This list is not all-inclusive. It’s Labor Day. I’m working. I got excited about the bees, and wanted to share. But, I am not carefully going through every small label.
  3. Some bees were only found on one or two flowering plant species ~ even though Aaron’s plots are all in the same 3 acre field (1X1m plots, with each plot separated from every other plot by 6 m).
  4. Yellow-faced bumblebees were collected off of most plants ~ so I am not listing them, below. I also did not look at the honey-bee plant associations.
  5. Linc dissected male genitalia (yes ~ that is how you need to ID some bees to species), and found FOUR Bombus calignosus (all associated with lavender)~ a vulnerable species on the IUCN Red List.
  6. We also have Bombus fervidus, another species on the IUCN Red List (Vulnerable) on lavender, Salvia, and Gilia.

I’ll leave it to Aaron to make a rigorous accounting of bee-flower associations. But for now . . . on this holiday weekend, I was too excited to not take a peek and share initial findings with all o fyou.

Nepeta (non-native comparitor)

Oregano (non-native comparitor)

Salvia (non-native comparitor)

Lavender (non-native comparitor)

Phacelia (native)

Clarkia (native)

Goldenrod (native)

California Poppy (native)

Doug Aster (native)

Oregon Iris (native)

Gilia capitata (native)

Oregon Sunshine

Madia (native)

Sidalcia (native)

Yarrow (native)

Pearly Everlasting (native)

Plant of the Week: Common Yarrow

This entry is from Lucas Costner, an undergraduate horticulture major at Oregon State University.  It highlights one of the plants that Aaron Anderson is using in his research.

Common Yarrow (Achillea millefolium) isn’t just common — it’s nearly ubiquitous throughout the Pacific Northwest. Found in lawns, along roadsides, in fields and gardens, it’s easy to allow yarrow’s abundance to overshadow its potential in the landscape, its benefit to wildlife, and its historical value as a medicinal plant. 

A perennial native across the temperate Northern Hemisphere, yarrow has a long history of human association (1, 2). Its scientific name, Achillea, comes from the ancient Greek hero Achilles, who used the plant to help dress battle wounds (2). Similarly, in the Northwest, indigenous peoples made poultices and teas from the plant (2). 

In the landscape, it may be helpful for gardeners to consider mimicking natural distribution patterns by massing yarrow into larger groups of plants (3). Yarrow grows densely — emerging up to three feet in height and spreading from a fibrous horizontal root system (1). White, sometimes pink, ray flowers appear at the end of stems in nearly flat inflorescences (2). These plants are very drought tolerant and appear naturally in disturbed areas, meaning they will thrive in the average garden (1). 

As a member of the Asteraceae family along with goldenrod and Douglas aster, yarrow’s bountiful floral display offers excellent forage for generalist pollinator species throughout the summer months and is a common choice for butterfly gardens (1). In addition to its floral resources, the foliage is noted as a source of food and habitat to many species of butterfly and moth caterpillars (4). 

References: 

1. Hurteau, M. D. (2013, November 13). Common Yarrow [PDF]. USDA NRCS National Plant Data Center.

2. Mathews, D. (2016). Natural History of the Pacific Northwest Mountains. Portland, OR: Timber Press.

3. Rainer, T., & West, C. (2015). Planting in a Post Wild World. Portland, OR: Timber Press.

4. Robinson, G. S., P. R. Ackery, I. J. Kitching, G. W. Beccaloni & L. M. Hernández, 2010. HOSTS – A Database of the World’s Lepidopteran Hostplants. Natural History Museum, London. http://www.nhm.ac.uk/hosts. (Accessed: 29 Aug. 2018).