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Spring Prescribed Burns

Team Echinacea has successfully completed some spring prescribed burns! Our mighty team of seven (Stuart, Gretel, Jared, Wyatt, Fannie, Brad, and I) took to Minnesota this past week to conduct a handful of spring prescribed burns. We set off bright and early on Sunday morning at around 9am to make the 9 hour drive from Chicago Botanic Garden to our study sites in Minnesota. Weather in Minnesota on Monday and Tuesday allowed us to get multiple different sites done including the coveted P1 and P8 experimental plots. The sun was shining, the sky was clear, humidity was low, the wind was blowing just enough, and the grass was very dry making it a perfect day. The days were long and the temperatures were high (in the 80’s), but we polished off both days with some great food and great conversations which are essential to any good burn trip to keep up morale.

Experimental plot p1 during the burn (left) and after the burn (right)

Fannie using the drip torch for the first time (left) and Jared lecturing Blue on the importance of fire safety (right)

Not only did we get some good burns in, but we were able to visit Runestone County Park on Tuesday morning. We used this trip to see the current restoration work being done at the park, and it allowed us to find spots for potential signs discussing different topics such as why prescribed fire matters, the history of prairies, and more. We also used our time in MN to get many pictures and videos to be used for dissemination projects discussing why prescribed fire is important for native pollinators.

Of course it wouldn’t be a complete trip to Minnesota without a stop at Staffanson Prairie Preserve.

This is part of our project “How Do Prescribed Fires Affect Native Prairie Bees?”

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).

Ian presents thesis research

Ian Roberts presented his thesis research “Impacts of Prescribed Fire and Land Use History on Ground Nesting Bees” at the Chicago Botanic Garden on April 30th. The presentation was well received by those attendees in the room and those who attended via zoom. After the public presentation, Ian successfully defend his Masters thesis for the program in Plant Biology and Conservation at NU. Congratulations, Ian!

Ian’s research advances our understanding of ground nesting bees, prescribed fires, and nesting habitat for bees in remnant and restored tallgrass prairie. Stay tuned for a publication and recommendations for land managers!

Watch the video recording.

This is part of our project “How Do Prescribed Fires Affect Native Prairie Bees?”

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).

Presentation at Chicago Plant Science Symposium

Jared gave a presentation at the Chicago Plant Science Symposium on April 19th about our big prescribed fire experiment. He focused this talk on fire effects on plant reproduction & demography.

This is part of our project “How Do Prescribed Fires Affect Native Prairie Bees?”

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).

Emma presents poster on honors project

Emma presented results of her honor’s project at the poster symposium on April 15th at the U of MN. Emma assessed concentrations of several types of sugar in nectar collected from tiny florets of Echinacea plants. We are learning how prescribed fire affects sugars in nectar because nectar is an important food for pollinators, like bees. Emma worked in the lab of Dr. Rahul Roi at St Catherine University and was advised by Dr. Ruth Shaw at University of Minnesota. We are so proud of Emma!

Emma presenting her poster with Rahul & Ruth.

This is part of our project “How Do Prescribed Fires Affect Native Prairie Bees?”

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).

2024 Update: Pollen and Nectar Quantity and Quality of Echinacea

We’re interested in investigating what resources are available to Echinacea visitors and learning more about the pollen and nectar Echinacea produces. We hope to learn if the nutritional resources available differ before and after burns. In 2022, Britney House developed methods for collecting nectar from Echinacea using microcapillary tubes. Read more about her methods here.

During the summer of 2024, the team collected pollen and nectar samples from Echinacea angustifolia at 12 sites in and around Solem Township, MN. We searched for and shot the ~10 plants (or, if few were available, as many as we could find) at each site that were closest to a random point. We then bagged up to five of the heads with pollinator exclusion bags for those 10 plants. Throughout the duration of their flowering, we collected pollen from all bagged plants and nectar from five of them per site.

We removed bags from pollen/nectar plants and backup plants when they were done flowering, and we collected until a a limit was set of a cumulative 10mm of nectar from each plant. This year we also collected immature florets from each bagged head at the start of sampling.

Following some experimentation, we conducted nectar collection only in the afternoons, while pollen collection could be done any time of day. In total, we collected vials of pollen, nectar, and vials containing immature florets from 60 plants. Pollen and nectar tubes were given to Rahul Roy at St. Catherine University in St. Paul, who will be doing pollen and nectar analysis. Tubes containing immature florets were sent with Grace Hirzel at North Dakota State University in Fargo, ND for pollen grain count and size analysis.

Data entry for collection datasheets is ongoing. Pollen data entry is started and nectar data is a little over half done with the help of Emma Reineke. Emma will also be using part of this dataset for her senior thesis project at the University of Minnesota.

Scans can be found at: Dropbox/teamEchinacea2024/z.pollenNectarDataEntry/scans.

  • Start year: 2024
  • Location: Various prairie remnants around Solem Township, MN
  • Overlaps with: bbFood, nectar experiment
  • Data collected: 
    • plant IDs (tag), location, flowering status, assessments for selection for study
      • Dropbox/enrtf/designField2024/focalPlants2024.csv
      • Dropbox/enrtf/designField2024/findAndBagPlants2024.xlsx
    • flowering day, immature floret tube ID, pollen from N anthers in tube, pollen tube ID, tt color, nectar tube ID, quantity of nectar (mm) per floret
      • Dropbox/enrtf/pollenNectar2024/scannedFieldDatasheets
  • Specimens collected: 
    • TBD immature florets (at North Dakota State)
    • 60 pollen tubes (at St. Kate’s)
    • TBD nectar tubes (at St. Kate’s)
  • Team members involved with this project: Summer team 2024, Rahul Roy (St. Kate’s), Emma Reineke (University of Minnesota), Jarrad Pasifrika and Grace Hirzel (North Dakota State University)
  • Products: pending
  • Funding: ENRTF


Grace Hirzel taking off a pollen excluder bag on an Echinacea angustifolia plant.

2024 Update: Ground-nesting bees in prairie remnants and restorations

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.

2024 Update: Microhabitat in prairie remnants and restorations

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
  • Overlaps with: ground nesting bees
  • Data collected: Surface soil temperature (°C), soil compaction (psi), and litter depth (cm)
  • Samples or specimens collected: NA
  • Products: Poster presented at Entomology 2024 in early November: link to post containing poster

ACE progress update: polOb 2024

Another batch we’re prioritizing in the lab is the pollinator observation (or polOb) experiment. The goal of this experiment is to learn more about the effects of fire on native bees and their behaviors. We spent time this summer observing Echinacea at 10 paired sites, half of which burned before the 2024 growing season. We then harvested heads from our observation plots for processing in the lab. Because we’re specifically interested in learning about pollination, heads in this group will be streamlined all the way through to the classifying steps to learn about seed set, and we are less concerned about counting. Here’s our progress so far:

We are roughly a third of the way through rechecking. We’ll be pausing work briefly on this batch to get the exPt01 2024 experiment rechecked and uploaded for counting ASAP

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).

Live from EntSoc!

Hey all!

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.

Pollen and Nectar Update!

Exciting things are happening with Coreopsis pollen and nectar! Data entry for nectar has been accomplished and a figure has been made! The primary goal of this project is to see if prescribed burns have an affect on pollen and nectar quantity in C. palmata. However first and foremost, I want to go into more detail of how I collected data this summer, and then I’ll talk about my new nectar figure and what our findings are currently looking like.

Field Methods Step by Step:
Pre-Collection:

  • In order to collect pollen and nectar samples we first need to identify the plants we are sampling from.
  • Random bb-points are pre-selected to designate areas of study interest within each site. Identify the closest “patch”, which is a central location with 5 or more stems of coreopsis, relevant to the bb-point. Record the location of each patch using Avenza. (2024 Avenza layer can be found in “Dropbox / teamEchinacea2024 / maddieSadler / coreopsisPalmata”)
  • Place a flag in the relative center of the patch and label it with it’s patch ID number.
  • Select 5 plants that are still completely immature and place a pollen excluder bag over the head of the plant.
  • Monitor plants for a few days until they reach day two or three of anthesis where anthers are protruding and there are still immature florets in the center of the head. This is important later for pollen collection.

Pollen Collection:

  • Select the plant to sample from bagged plants located in each patch. We chose 3 of the 5 bagged plants based on day of anthesis and general look of the head.
  • Record the bb-point of the coreopsis patch, site name, and location on the data sheet.
  • Remove the pollinator exclusion bag from the selected head.
  • For pollen collection we will be collecting 3 immature florets from the head of the flower.
  • Label your microfuge tube with the plant ID number located on the data sheet.
  • Take the tweezers and carefully extract three immature florets, one by one, from the flower head and place them into the microfuge tube. Make sure to be careful that you do not rip the floret in half or puncture it with the tweezers.
  • Once all three florets are placed inside the tube, close it. Place the tube into the cooler with ice packs for further sorting upon your return from the field.
  • Repeat steps 1-8 for next plant.
  • Upon returning to the Hjelm House, place the collected pollen tubes in the collected samples box, which then is stored in the freezer.

Nectar Collection: This was adapted from the 2022 nectar protocol for Echinacea which can be found here.

  • After pollen collection you will begin the process of nectar collection.
  • On the same heads used from pollen collection, select the anthers that are the most recently presented to sample from.
  • Insert the microcap tube into the anther floret. Insert the microcap down into the floret until there is light resistance when you reach the base of the floret. 
  • Twist or rotate the microcap five times. 
  • Carefully remove the microcap.
  • Repeat steps 3-4 on all presented anther florets on the selected flower head.
  • Record the amount of nectar collected in the microcap in millimeters (mm). It is helpful to hold the microcap up to the sun to see the refraction of light from the nectar to see the amount collected. You can use a magnifying glass if needed to read the amount of nectar in mm on the ruler.
  • Place the entire microcap with the collected nectar sample into a microfuge tube to be disposed of properly outside of the field. 
  • Once this task is completed, it will not need to be done for the same plant in the future.
  • Repeat steps 2-8 for the next plant in the patch.
  • After all plants in patch are sampled from remove any extra pollinator bags and remove the flag from the center of the patch. Collection will not be repeated on the patch.

Field Supply Checklist:

Pollen Supplies:

  • Microfuge tubes (tall enough to put the immature floret inside and close the cap)
  • Permanent marker
  • Pen
  • Extra pollinator exclusion bags
  • Flag bag with flags of the designated color 
  • Magnifying glass glasses with 3.5 – 5 X magnification
  • Tweezers
  • Water and sunscreen 
  • Clipboard with the data sheet
  • Field collection box to hold small supplies 
  • Small cooler with ice packs

Nectar Supplies:

  • Microfuge tubes (tall enough to put the microcap inside and close the cap)
  • Microcaps: Drummond Scientific Microcap 1-000-0005 Microliter Pipets, 0.5 µl Capacity, 0.0056 inch diameter

These guys right here!

  • Extra pollinator exclusion bags
  • Flag bag with flags of the designated color 
  • Permanent marker
  • Pen
  • Magnifying glass glasses with 3.5 – 5 X magnification
  • Ruler with mm markings 
  • Water and sunscreen 
  • Clipboard with the data sheet
  • Field collection box to hold small supplies 

Now for the fun stuff!

Over this past week I’ve worked on creating this graph seen down below. This graph looks at the total amount of nectar in millimeters in each tube from each plant in our burned and unburned site combinations. These site combinations were created based on proximity to each other and burn history. For example, TorgN was burned, but TorgS, directly across from it, was not; Tower was burned, but Nice, directly across from it, was not. For YOHW and YOHE, we ran into an issue in that YOHE, the unburned side, had no flowering C. palmata in it; thus, we only have data from YOHW.

As we can see there is large amount of variation in totals across all the sites. When looking at the mean values (the red and blue squares on the graph) we are finding the slightest bit of evidence that burned sites are showing higher levels of nectar. Meaning my original hypothesis, that we’d see strong evidence that there is difference in quantity in burned sites rather than unburned sites is out the window! However, we can’t fully accept the null hypothesis, that there is strong evidence of no difference in nectar quantity, since there is not enough supporting evidence. Having this knowledge now, it will be interesting to see if there is a similar pattern in our pollen counts. Data and analysis on that to come!

Fig: Total (mm) of nectar in tubes for each plant at each site. Red squares (burned) and Blue squares (unburned) show average total with standard error.

**The code for this graph can be found in: “Dropbox / teamEchinacea2024 / maddieSadler / coreopsisPalmata”.**

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).