During the summer of 2024, Team Echinacea completed the second year of its ENRTF funded project to better understand how prescribed fire influences ground nesting bee habitat, food resources, and diversity. Understanding the associations between land management methods and ground nesting bees is essential for providing reccomendations to policymakers and practitioners interested in native bee conservation.
We surveyed solitary bee diversity and nesting habitat before and after prescribed fires in a subset of 30 prairie remnants and 15 prairie restorations to determine how prescribed fire affects solitary bee nesting habitat and abundance. We used emergence traps to sample the community of solitary ground nesting bees. This was complemented by detailed measures of soil and litter to characterize how prescribed burning influences the nesting habitat (read more here).
2024 REU student Zach Zarling deploys an emergence trap at a site near Hoffman, Minnesota
We deployed emergence traps at our random “burn and bee points”(BBPTs) in prairie remnants and restorations from early June to mid September. Our deployments spanned three rotations (4-6) of BBPTs and we put out a total of ~1,159 emergence traps. On reccomendation from Dr. Alex Harmon-Threatt, we also performed 10 minute “pollard walks” on deployment to estimate the number of foraging bees at each site. These foraging numbers will be compared to nesting incidence as part of Ian Roberts’ thesis project.
As of December 21st, specimens caught in this year’s deployments have been pinned, labeled, and transported from Chicago Botanic Garden to the University of Minnesota, where Zach Portman, a bee taxonomist, will identify them. Team Echinacea also collected lots of non-bee bycatch while processing specimens collected in the traps: including millipedes, flies, and even a prairie skink! To avoid wasting these specimens, we plan to categorize this bycatch into broad taxonomic groups (like Dipterans, Orthopterans, etc) and examine potential associations between our experimental treatments and general arthropod diversity across our study sites.
Pinned specimen from 2024’s emergence trapping, likely an Agapostemon virescens.
While working on pinning and processing specimens, Ian Roberts produced a poster containing analyses from the 2023 emergence trapping data to present at Entomology 2024. The poster can be viewed here. Future data analyses will feature data from both sampling years, as well as microhabitat measurments and and diversity indices.
Start year: 2023
Location: prairie remnants and restorations in Solem Township, MN.
Data collected: insect samples, counts of foraging bees
Samples or specimens collected: Pinned bees are currently being identified at University of Minnesota. Bycatch is in the freezer at Chicago Botanic Garden.
Products: poster presented at Entomology 2024 (see above for link)
During summer 2024, Team Echinacea continued to collect data on local environmental conditions in order to understand which environmental factors are associated with good habitat for ground-nesting bees. These data complement emergence trapping for our ENRTF funded research on fire’s influence on ground nesting bees habitats. We sampled local environmental conditions near randomly placed “burn and bee points” (BBPTs) in prairie remnants and restorations.
A deployed emergence trap next to a set of marking flags. Microhabitat data was sampled within a meter of these marking flags.
Unlike the 2023 season, we did not collect data on light levels at BBPTs this year. Instead, we measured soil temperature just under the surface using a digital thermometer, along with soil compaction via a penetrometer and litter depth via a meter stick.
Team Echinacea conducted microhabitat assessments for remnant prairies at rotation 4 BBPTs. Over the summer, we took microhabitat assessment measurements at a total of 241 measurments.
Start year: 2024
Location: prairie remnants and restorations in Solem Township, MN
It has been a packed few days here in Phoenix, and I’d like to describe some of the presentations I saw at yesterday’s ground nesting bee symposium. There was a broad range of topics, including the microbe communities found on pollen balls, brood parasite and host interactions, rare desert bees, and more! Nick Dorian had great results to share from his mark-recapture work in New Jersey, which was great to see after he demonstrated that method to Team Echinacea over the summer. Lily Fulton’s presentation really stood out to me: She is also studying prescribed fire, at a long term experimental fire site in Florida longleaf pine flatwoods. they found higher bee and wasp abundances during burn years, as well as higher proportions of bare ground. This is strikingly similar to our research findings! It was great to chat with her about it over my own poster.
Title slide of Lily Fulton’s presentation. My poster! It is showing the first year of data from the ENRTF project, since we haven’t sent our 2024 bees to Zach yet.
It’s been incredible getting to meet so many researchers who care about native bees. Many stopped by to have a look at the poster! I’ve cited many of them in my previous work, so running into them in person is almost like meeting a celebrity. One consistent interest I’ve gotten from attendees is to look a the community composition of bees in the different treatment groups. Perhaps the increased abundance in the year of a burn we’re seeing is because of a cohort of burn-loving ground nesters, who don’t stick around in following years. It’ll be exciting to look into!
Shot of the poster sessions. There were a ton of applications, so space was pretty limited.
Overall, this has been a fantastic experience and opportunity to expand my network. I got to reconnect with some old friends, and make plenty of new ones. I can’t wait to get back to work on my thesis, now that I know who might be viewing it once it’s published! Expect more on that in the next few months.
A close up of an Agapostemon specimen with its tongue sticking out. The current collection of bees. Many more to come!
As of a few weeks ago, Emergence trapping for the ENRTF project is finished! It was a massive endeavor to complete, and I’m thankful for everyone on the team who pitched in. Now that our vials of bugs have been moved from Minnesota to Illinois, it’s time to start going through them to look for bees. It’s smelly work, but also a great opportunity to brush up on taxonomy and identification skills. We’re planning to hire a work-study student to help with pinning and data entry in the next few days. Until then, more for me!
NOTE: Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).
It’s heating up in western Minnesota! Temperatures and humidity were high today. In the morning, much of Team Echinacea performed the pollinator observations we learned about yesterday with Dr. Ison. These involved recording the pollinator with a camcorder, describing its activities, and attempting to ID to morphospecies level.
Lots of echinacea in bloom at Torgeson north.
In the afternoon, emergence trapping crews had a great session of deployments and retrievals, while others worked on phenology in the common garden plots, and others gathered nectar. It’s exciting to see new species starting to bloom: two major species of prairie clover are just getting started, as is the wild bergamont and wild licorice.
Daleapurpurea, or purple prairie clover, in bloom at Hulzbos CRP north.
Once everyone was back from the field, we enjoyed some ice cold watermelon and headed home. Another great day in the field!
A smooth start to the first emergence trapping deployment! Today we placed 23 traps at three sites, making good use of our new color-coded flagging system. So cool to see our work from the last few weeks starting to pay off!
Some emergence trapping sites are a lot smaller than others! It will be interesting to see whether size is associated with catch rate. Do bees prefer to nest in big sites? REU student Zach deploys a trap at our first site of the day. This site was burned earlier in the spring, can you see how short the vegetation is?
These traps will be out for four days, then emptied and sent back out to new sites on Monday. Fingers crossed we’ll see some bees!
NOTE: Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).
I Graduated University of Minnesota Class in 2022 with a B.S. in Ecology, Evolution, and Behavior, and a B.A. in Classics (aka. Latin). Currently I am a graduate student at Northwestern University/Chicago Botanic Garden, pursuing a M.S. in Plant Biology and Conservation.
Pronouns: He/Him/His
Research Interests
I am interested in restoration ecology, in particular for grassland ecosystems like prairies. Bees have always had a special place in my heart, especially the ground-nesters! Much of my the data for my master’s thesis will be coming from Echinacea Project’s ENTRF study on bees and fire in prairies.
Statement
I grew up in Saint Paul, Minnesota, and remained in the area until I moved to Chicago to start my M.S. When not in the field, I like to run, climb, get on the water in any capacity, make my own kombucha, read, and hang out with my pet python!
As part of my recent independent study with Stuart and Northwestern undergrad Lena Parnassa this spring, I took an initial pass at analyzing the data from our 2023 emergence traps. These data are an important contribution to the broader ENRTF project, which is geared at understanding how ground-nesting bees respond to prescribed fire in prairies. This independent study enabled me to learn a great deal about database organization, coding, and collaboration between data scientists. Before we could run any of our analyses, we had to wade through quite a bit of data cleaning to ensure all our joins were functioning properly. This meant that we had to prioritize the bee analysis rather than the bycatch in our traps (millipedes, grasshoppers, and so forth), so stay tuned for more in that department! We were also working with abundance data rather than species data, as identifications of all the bees we caught in 2023 are still forthcoming. This means that some of the data points in our analysis are most likely incidental, but nevertheless, here’s a visual of what we found!
Figure 1: Mean bee catch rate by site type. Catch rate refers to the proportion of traps which had bees.
Figure 2: Bee catch rate by site. Catch rate refers to the proportion of traps which had bees.
Mean bee catch rate by burn history. Only three sites were 3 years post-burn in 2023, other burn treatments had 7-8 sites.
It looks like remnant prairies had more bees than restorations, but there’s a ton of variation across sites of the same land use type. It’ll be interesting to see what other factors may be associated with this variation, if any. Once we get those species ID’s and confer with our taxonomist, we’d like to tweak our protocol slightly going into this summer to maximize our chances of catching the bees at a given site. We’re considering stocking our traps with propylene glycol to better preserve specimens, trimming the vegetation around traps to make sure bees can find the entrance, and deploying later in the day to give foraging bees time to find their way back to their nests. Looking forward to kicking of the 2024 trapping season!
NOTE: Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).
