If you love bees, and you have not yet subscribed to PolliNation, you’re missing out! OSU Professor and PolliNation podcast host, Andony Melathopolous, does a wonderful job assembling a diverse array of guests to talk all things pollinator.

Aaron Anderson recently joined Andony on episode 94 of thePolliNation podcast, to talk about his research on native plants, different insect groups, and gardeners.

Aaron talks about the 100+ study plots that he manages (two of which you can see, below), as well as which plants were most attractive to bees (such as the California poppy, on the left) versus those that were more attractive to gardeners (such as the Oregon iris, on the right).

In other news, our lab group has been very busy. All of the 2017 and 2018 bees from our garden pollinator study have been identified to species (unless they are truly recalcitrant to being ID’d to the level of species).  Gabe has been working with Lincoln Best to identify the 2018 bees.  The 2017 were verified by Sara Kornbluth, and provided a great reference collection against which we could compare the 2018 bees. Gabe has been a short-time member of our lab group, but his expertise has been a huge benefit to our program. He leaves us at the end of April to start field work in the College of Forestry. After that, he heads to UC Davis to do his Ph.D.

For the garden bee project, we have >50 verified species of bees collected from Portland-area gardens, with a few more at the morpho-species level. This summer will be our final year of collections.

This summer will also be Aaron’s final year of field work at the North Willamette Research and Extension Center. This final year will help to resolve some of the differences we saw between his 2017 and 2018 data set.

After two years of amazing assistance in the lab and in the field, Isabella has started an independent research project on campus. She has planted some of Aaron’s study plants in gardens on campus, and is looking to see if bee visitation and bee communities markedly change, when you take them out of single-species plantings (like Aaron is studying) and put them into a garden setting.

Mykl is working to write up his urban soils data for publication. We are also hoping to do a side publication, comparing the soil types that we’re finding in home gardens, and seeing how they align with the types of soils that nesting bees prefer.

Lauren is writing up her capstone paper, and is preparing to defend this term. She surveyed gardeners to try to understand how well they can identify bees from other insects, and how well they knew bee-friendly plants from those that offered few or no nectar/pollen resources to bees.

Signe is taking the data that we are collecting, and working our findings into the online Master Gardener course. The best part of our work is being able to see gardeners put some of our research-based recommendations into action. Signe plays a huge role in translating our work for the general public.

Angelee is a relatively new member of the lab. She comes to us from the OSU STEM Leaders program. She’s learning lab protocols and lending a hand on just about every project. She has been a joy to work with.

Lucas has moved on from the lab, but still helps us with remote data-basing work, on occasion. He was a joy to work with, and I feel lucky that he stuck with us for a few years.

This fall, Jen will be joining our group as a new M.S. student. We will also be close to launching the first course in the online Urban Agriculture certificate program, which is being spear-headed by Mykl. We should also be pushing out a few more papers from our garden work, to join our first concept paper on the value of urban garden bees to urban and peri-urban agriculture.

 

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?

 

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)

If you are interested in hearing more about our research, please consider sitting in on one of the upcoming webinars we are presenting, as part of the Advanced Training Series for Master Gardeners, organized by OSU Extension Faculty Member, Brooke Edmunds. Gail will be speaking on August 30th, about garden bees. Aaron will be speaking on October 22 on his native plant research. There is also a presentation in November by Melodie Putnam (not in our lab group ~ but a great speaker) on plant galls.

Webinars qualify for Master Gardener continuing education units in Oregon. The webinars are free, but you must pre-register. After the presentations, all webinar recordings are posted on Brooke’s YouTube channel.

More details, and link to the registration page, can be found, below.

Thursday 8/30 at 11am PT

The latest research on bees in the garden: an update from the OSU Garden Ecology Lab.

Speaker: Dr. Gail Langellotto (OSU)

 https://learn.extension.org/events/3443

Monday 10/22 at 11am PT

‘First Look’: OSU Research on Native Plants in the PNW Garden

Speaker: Aaron Anderson (OSU graduate student)

https://learn.extension.org/events/3494

Monday 11/19 at 11am PT

The Weird and Wonderful World of Plant Galls

Melodie Putnam (OSU Plant Clinic)

https://learn.extension.org/events/3493

Missed a webinar? 

Catch up with the 2018 series here: https://tinyurl.com/yczwxjvr (opens in YouTube)

It has been a busy summer in the Garden Ecology Lab!

  • Mykl Nelson successfully defended his thesis on urban garden soils, and graduated with a M.S. in Horticulture this past June.
  • Gail, Aaron, and Mykl all shared their research results with Master Gardeners, at the recent Growing Gardeners conference.
  • Aaron continues his fieldwork, documenting the attractiveness of several Willamette Valley native plants to pollinators. You can find his full list of plants here.
  • Aaron launched the survey part of his research, to document the attractiveness of these same plants to gardeners. If you would like to participate, you can find our recruitment letter, here.
  • Gail and Isabella continue to sample insects on a monthly basis, from 24 Portland area gardens. Our July sample has been pushed to the week of July 30th, because Gail was invited to serve as a panelist on a USDA grant panel. Sampling takes four long days ~ made all the more difficult by Portland’s heat wave. But, sampling during the heat wave will be interesting. Do garden habitats become even more important to bees, when the heat dries up forage in natural and wild habitats? We shall see.
  • Bees from our 2017 sampling effort have been pinned, labelled, and sent to the American Museum of Natural History for expert identification. Thank you to the Oregon Master Gardener Association for a $500 grant to help pay for the expert bee identification.

Today, I’m packing field supplies and clothes for the July 30-August 2nd garden bee sampling effort. It seemed like a good time to provide an update on our garden soils work. I wrote this article for the Hardy Plant Society of Oregon quarterly magazine. I thought that others who are interested in garden ecology might be interested in seeing an update on this work. We are currently working on a manuscript of Mykl’s research, for submission to the journal Urban Ecosystems. In the meantime, some of the highlights can be found below.

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Despite the popularity of urban agriculture, we know virtually nothing about urban agricultural soils, including residential vegetable gardens. We thus studied urban garden soils to get a sense of the characteristics of residential-scale, urban agricultural soils in western Oregon. Last year, we took soil samples from 27 vegetable gardens in Corvallis and Portland, and tested for differences between garden sites based upon bed-type (e.g. raised beds versus in-ground beds). All gardens were managed by certified Extension Master Gardeners.

If you have taken a Master Gardener soils class, perhaps you have heard the soil management mantra ‘just add organic matter!’. This mantra comes from the idea that adding more organic matter (OM) can improve soil tilth and nutrition. However, this mantra was derived from research in large-scale farming systems, where farmers often struggle to raise their soil OM by even 1%, across tens or hundreds of acres of crop production.

We found that nearly every garden that we sampled had an excess of OM (Table 1). Soil management guidelines suggest that farmers should aim for 3-6% soil OM. Across all of our garden study sites, vegetable garden soils were on average 13% OM, by volume. Raised beds were significantly over-enriched in organic matter (15% OM, on average), compared to in-ground beds (10% OM, on average). To put it another way, Master Gardener-tended vegetable gardens were over-enriched in OM by 2-5 times the recommended level!

This excess in organic matter likely contributed to excessive levels of other soil parameters. For example, most garden study sites were above recommended levels for electrical conductivity (a measure of soil ‘salts’). All gardens were above recommended levels for sulfur (S), phosphorus (P), calcium (Ca), and magnesium (Mg) (Table 1). Only nitrogen (N), potassium (K), and boron (B) were generally within recommended levels (Table 1).

Table 1. Percent of garden study sites that were within, above, and below recommended ranges for various soil parameters. OM: organic matter. EC: electrical conductivity. N: nitrogen. S: sulfur. P: phosphorus. K: potassium. Ca: calcium. Mg: magnesium. B: boron.

Soil Parameter Percent of Garden Study Sites
Within Recommended Range Above Recommended range Below Recommended Range
OM 6% 94% 0%
EC 18% 82% 0%
N 70% 30% 0%
S 0% 100% 0%
P 0% 100% 0%
K 73% 24% 3%
Ca 0% 100% 0%
Mg 0% 100% 0%
B 42% 3% 55%

The excessive organic matter in residential-scale garden soils makes sense, when considered in the context of garden size. In small garden plots, gardeners can easily over-apply products which have been recommended for successful, large-scale, agricultural production. It is easy to imagine that the over-abundance of organic matter in soils results from large amounts of compost added to a relatively small area.

Our results point to the importance of conducting periodic soil tests in garden soils. Instead of ‘just adding organic matter’, gardeners need to understand where they are starting from, before adding amendments and fertilizers to their soil. Apply focused applications of specific nutrients (such as boron or nitrogen) to correct nutrient deficiencies, as needed, while avoiding additions of nutrients that are at relatively high levels. For example, nitrogen is extremely mobile in soils, while phosphorus tends to build up over time. Adding focused applications of synthetic (15-0-0) or organic nitrogen (in the form of feather meal) can help meet crop needs without providing excessive amounts of phosphorus, over time. Gardeners who annually apply organic matter to their soils, without the benefit of a soil test, may be unintentionally adding too much phosphorus to their soils. Soils with excessive micronutrients may hinder plant growth. Soils with excessive phosphorus might contribute to water quality issues in their watershed. Excessive phosphorus also harms or kill beneficial mycorrhizal fungi.

We are soliciting Master Gardener feedback on the attractiveness of the native wildflowers that Aaron Anderson is studying for pollinator plantings. More detail on the study can be found at:

http://blogs.oregonstate.edu/gardenecologylab/native-plants-2/

As we mention, not only are we interested in finding plants that support ecosystem services; we also want to find plants that gardeners find attractive, and that they would want.

This is where you come in. If you are willing, please let us know which ones you would like to see in your own garden, based on their looks, alone. Below is the recruitment letter, with further information about participation. Thank you for your consideration!

*******************************************

Study: Screening Willamette Valley Wildflowers for attractiveness to Pollinators and Natural Enemies

Graduate Research Assistant: Aaron Anderson (andeaaro@oregonstate.edu; 503-860-9286)

Principal Investigator: Dr. Gail Langellotto (Gail.Langellotto@oregonstate.edu; 541-737-5175)

Dear Master Gardener,

You are invited to take part in a survey that will generate useful information on the ornamental value of pollinator-friendly native wildflowers.

Previous research has shown that urban greenspaces, notably gardens, can provide excellent habitat for pollinators and other invertebrates. The inclusion of pollinator-friendly plantings in gardens has the potential to improve habitat quality and connectivity in otherwise inhospitable landscapes. However, research on which Willamette Valley wildflowers are best to use for these plantings is lacking. Thus, I am conducting a research project to assess the relative attractiveness of 23 wildflower species native to the Willamette Valley (Oregon) to pollinators and natural enemies. Additionally, I would like to assess the aesthetic value of these plants to identify native flowers that are also attractive for ornamental use in home gardens.

As a Master Gardener, I am asking your help with my study, “Screening Willamette Valley Wildflowers for attractiveness to Pollinators and Natural Enemies”.  If you are aged 18 or older, and are currently a Master Gardener, or have been a Master Gardener in the past, I would appreciate it if you could take 10-15 minutes to respond to this survey:

http://bit.ly/OSUNative

Your survey responses will be recorded as a group. Thus, your response will be anonymous.  If the results of this survey are published, your identity will not be made public. The security and confidentiality of information collected from cannot be guaranteed.  Confidentiality will be kept to the extent permitted by the technology being used.  Information collected online can be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses.

Your participation in this study is voluntary and you may refuse to answer any questions(s) for any reason.  There are a limited number of Master Gardeners in Oregon, so your participation in this study is important. If you do not want to participate and do not wish to be contacted further, do not fill out the online questionnaire. There are no foreseeable risks to you as a participant in this project; nor are there any direct benefits. However, your participation is extremely valued.

If you have any questions about the survey, please contact me at 503-860-9286 or via email at andeaaro@oregonstate.edu.  If you have questions about your rights as a participant in this research project, please contact the Oregon State University Institutional Review Board (IRB) Human Protections Administrator at (541) 737-4933 or by email at IRB@oregonstate.edu.

Thank you for your help. I appreciate your consideration.

Sincerely,

Aaron Anderson

It’s been a busy month in the Garden Ecology Lab.

  • Gail’s manuscript on bees in home and community gardens has been published in Acta Hort. Briefly, the results of this literature review are that: 213 species of bee have been collected from a garden habitat; gardens have fewer spring-flying and fewer ground-nesting bees, compared to non-garden sites; I suspect that over-mulching might be cutting out habitat for ground-nesting bees in gardens.
  • Aaron presented his first Extension talk to the Marion County Master Gardeners. This 90-minute talk was an overview of using native plants in home gardens.
  • The entire lab is getting ready to present their research results at the 2018 Urban Ecology Research Consortium annual conference, to be held in Portland on February 5th. A few highlights of our presentations, can be found below.

Gail’s Poster on Urban Bees: we sampled bees from 24 gardens in the Portland Metro area (co-authored with Isabella and Lucas)

  • Langellotto and Messer UERC 2018 Poster: click to see preliminary results
  • Most of the bees that we collected await identification. We did find a moderate relationship between lot size and bee abundance: larger yards hosted more bees. But, we also found evidence that suggests that intentional design can influence bee abundance: one of our smallest gardens (site 56 = 0.1 acre), located in the Portland urban core (surrounded by lots of urban development) had the second largest number of bees (42), of the 24 gardens sampled. This garden was focused, first and foremost, on gardening for pollinators. The plant list for this garden (photos, below) includes: borage, big-leaf maple, anise hyssop, globe thistle, California poppy, nodding onion, yarrow, fescue, goldenrod, Phacelia, Douglas aster, lupine, mallow, columbine, meadow foam, yellow-eyed grass, blue-eyed grass, coreopsis, snowberry, Oregon grape, trillium, mock orange, pearly-everlasting, serviceberry, coneflower, blue elderberry, currant, milkweed, dogwood, shore pine, crabapple, cinquefoil.

 

 

 

 

 

 

 

 

Mykl’s Poster on Urban Soils: we sampled soils from 33 vegetable beds across Corvallis and in Portland (co-authored with Gail)

  • All gardens were tended by OSU Extension Master Gardeners.
  • Gardens were over-enriched in several soil nutrients. For example, the recommended range for Phosphorus (ppm in soil) is 20-100 ppm. Garden soils averaged 227 ppm. The recommended range for Calcium is 1,000-2,000 ppm, but the mean value for sampled beds was 4,344 ppm.
  • Recommended ranges gleaned from OSU Extension Publication EC1478.
  • There was a tendency for soils in raised beds to be over-enriched, compared to vegetables grown on in-ground beds.
  • Data suggests that gardeners are annually adding additional soil amendments or compost, and that there has a build up of certain elements in the soil.

Aaron’s Talk on Native Plants: measured bee visitation to 23 species of native and 4 species of non-native garden plants (co-authored with Lucas)

  • Field plots established at the North Willamette Research and Extension Center
  • In the first year of establishment, of the 27 flowering plants that were the focus of this study, seven natives (lotus, milkweed, camas, strawberry, iris, sedum, blue-eyed grass) one non-native (Lavender) did not bloom, or else did not establish
  • Several natives attracted more bees than even the most attractive non-native (Nepeta cataria, or catmint). These include:
    • Gilia capitata: Globe Gilia
    • Madia elegans: Common Madia
    • Aster subspicatus: Douglas’ Aster
    • Solidago candensis: Goldenrod

Getting ready to install plants at our field site.

The post below comes from Aaron Anderson, a M.S. student in the OSU Department of Horticulture, and a member of the Garden Ecology Lab.

*************************************

This past summer, we conducted the first field season of a study screening native plants for their attractiveness to pollinators and natural enemies. We selected 23 native Willamette Valley wildflower species based on drought tolerance, as well as four exotic garden species known to be attractive to bees: Nepeta cataria ‘Catnip’; Salvia elegans ‘Pineapple Sage’; Origanum vulgare ‘Italian’; Lavandula intermedia ‘Grosso’.

Table 1.  Native plants selected for this study.

Plant Species Common Name Life History Bloom Color
Clarkia amoena Farewell-to-spring Annual Pink
Collinsia grandiflora Giant blue eyed Mary Annual Blue
Gilia capitata Globe gilia Annual Blue
Lupinus polycarpus Miniature lupine Annual Purple/Blue
Madia elegans Common madia Annual Yellow
Nemophila menziesii Baby blue eyes Annual Blue/White
Eschscholzia californica California Poppy Annual Orange
Helianthus annuus Common sunflower Annual Yellow
Phacelia heterophylla Varied-leaf phacelia Annual White
Acmispon (Lotus) parviflorus Annual White/Pink
Achillea millefolium Yarrow Perennial White
Anaphalis margaritacea Pearly everlasting Perennial White
Asclepias speciosa Showy milkweed Perennial Pink/White
Aquilegia formosa Western red columbine Perennial Red
Aster subspicatus Douglas’ aster Perennial Purple
Camassia leichtlinii Common camas Perennial Purple/White
Eriophyllum lanatum Oregon sunshine Perennial Yellow
Fragaria vesca Wild strawberry Perennial White
Iris tenax Oregon iris Perennial Purple
Sedum oregonense Cream Stonecrop Perennial Yellow
Sidalcea virgata Rose Checkermallow Perennial Pink
Sisyrinchium idahoense Blue-eyed grass Perennial Blue/Purple
Solidago canadensis Goldenrod Perennial Yellow

We planted them in meter squared plots at OSU’s North Willamette Research Center. Between April and October, we monitored floral visitation, sampled visiting insects using an “insect vacuum”, and tracked floral bloom.

With one season in the books, we have some purely anecdotal impressions of which wildflower species are the most attractive to bees. Goldenrod (Solidago canadensis) and Douglas aster (Symphyotrichum subspicatum) were both highly attractive to a wide diversity of native bees, as well as to a variety of beetles, bugs, and syrphid flies. As an added bonus, both these species had long bloom durations, providing habitat and colorful displays for significant portions of the summer. Annual flowers Clarkia amoena and Gilia capitata attracted a range of native bees; Clarkia was also visited by leafcutter bees for a different purpose – cutting circular petal slices to build nest cells with.

Bumblebee on Clarkia.
Syrphid fly on Goldenrod.

Results from this year need to be analyzed, and further research is needed to account for seasonal variability and to gather more data on floral visitors.

Additionally, w e will ask the public to rate the attractiveness of each of our study flower species in an effort to determine the best candidates for garden use. After a few more field seasons (and sorting lots of frozen insect samples!), the result of this study will be a pollinator planting list for home gardeners, as well as a pollinator and natural enemy friendly plant list for agricultural areas. These will help inform deliberate plantings that increase the habitat value of planted areas.