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).
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
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.
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)
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).
Currently, I’m writing this from my new apartment in Chicago! Classes start next week for me, and I’m moving on to the data management portion of my summer project. This summer, I looked at pollen and nectar quantity in Coreopsis palmata (prairie coreopsis) in burned vs. unburned sites. But why does this matter? Pollinators depend on pollen and nectar from flowers to supply the nutrients they need to survive. However, there has yet to be a strong comparison between common Asteraceae plants identifying the quantity and quality of plants that can be shared with land managers to help create more viable resources for pollinators in their prairie restoration efforts. Therefore, I wanted to conduct a study looking at pollen and nectar quantity in common non-Echinacea prairie plants to examine how prescribed fire affects plant resources for pollinators.
The sites I collected data from included Torgeson North and South, Tower and Nice Island, and Yellow Orchid Hill West. Pollen data was collected by selecting three immature florets from three flower heads in a “patch,” defined as five or more stems in one central location. These immature florets will then go through a lab process where they are sliced open and placed into an agar solution, allowing the pollen to float to the top, where it can be counted. Nectar collection was done using microcapillary tubes, where we measured the amount of nectar in each tube in millimeters. The volume of nectar can then be calculated based on the size of the microcapillary tube in relation to the measurement in millimeters obtained from the tube. In total, I had around 75 pollen and nectar measurements. I also collected transect density data for each “patch” that we sampled and mapped them in Avenza for future reference. This allows me to identify and see how dense the populations are within a certain site, and to determine if there is a difference between burned vs. unburned areas.
I was not able to study more than one species this summer, but we shall see what the next summer holds!
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).
Big project update! For my summer project I am looking at nectar and pollen volumes in other Asteraceae plants that are non – Echinacea in burned sites versus unburned sites. This is important because pollinators depend on pollen and nectar to get the nutrients they need. A large decrease in pollinators has been found due to prairie fragmentation, and studying whether fire can help in producing a higher quantity of pollen and nectar can be shared with land managers to help create more viable resources for pollinators in their prairie restoration efforts. My two species of focus for now are Coreopsis palmata (also known as prairie coreopsis) and Helianthus pauciflorus (also known as stiff sunflower). Mid-summer coreopsis blooming is starting to come to close and so are my nectar and pollen measurements! Onto sunflowers here in the next couple weeks!
Time for daily update: Total demo continues! One group of 4 and one group of 3 went out to a total of 4 different sites. These included south of golf course, north of golf course, and yellow orchid hill east and west. A few people also finished up or pollen and nectar collection on Echinacea heads.
This afternoon a group went out and did e-trap collection and retrieval. We have been working on rotation 5 this week after finally polishing off rotation 4 late last week! The rest of us went and did measurements of Echinacea in one of our experimental plots (P9). Measurements included: flowering rosette count, basal rosette count, total basal leaves, height of tallest basal leaf, height of tallest cauline leaf (aka leaf on stem without a petiole), and height of head to name a few. Our plant of the day was finding a diseased Echinacea with over 360 basal leaves. To finish off the day we moved the goats to a new paddock and enjoyed some cold watermelon in the late week heat.
Nothing beats cold watermelon after a hot day of field work!Incentive to get the goats to their new paddock.
Today Team Echinacea continued to wrap up the pollen and nectar collection. Only a few focal plants are still in flower. Another group worked on flagging and recording demographic information for every flowering Echinacea plant in every remnant site. Some of these plants have tags dating back decades! In the experimental plots, Stuart trained team members to find and measure all Echinacea. This data will help us understand performance of E. angustifolia x pallida hybrids. Round 5 of emergence trapping started recently. The team members are now pros at deploying and retrieving the traps.
This week was a busy Monday for team Echinacea. Jennifer from College of Wooster joins us this week along with her research assistants Max and Indigo! This morning started off with round 2 of sweet clover pulling, and was promptly followed by a crash course in pollinator observations. We tried our hand in collecting species in small tubes for ID and then release. A big part of this was learning how to differentiate between flys and bees as some flies can look realllyyy close to a bee. But don’t be fooled! To round out the morning we went out in groups to collect pollen for our pollen and nectar study specifically looking at echinacea angustifolia.
After lunch, half of us went and deployed another round of emergence traps while the other half went out and did nectar collection for the pollen and nectar study.
Maddie with round 2 of our sweet clover pulling bounty.
Jennifer prepping us for our crash course in pollinator observations.
Zach holding a micro-capillary tube with a whopping 7mm of nectar!
This morning the whole team got together to pull as much sweet clover as we could from p01. After the drippy morning faded, we split up to collect pollen from Echinacea angustifolia at sites throughout the area. This is part of an MN ENRTF funded project to help determine the impacts of prescribed burns on pollen and nectar quantity and quality in echinacea. After lunch, some people went to retrieve and deploy emergence traps and the rest of us went to collect nectar from echinacea plants. To collect the nectar, we are using tiny glass microcap tubes carefully inserted into the florets. Overall, we had a productive day, and enjoyed the nice weather after a wet 4th!
The beginning of flowering for Echinacea angustifolia means it’s time for Team Echinacea to get collect Echinacea pollen and nectar! This project is part of our MN ENRTF funded research to understand fire’s impacts on ground nesting bee habitat and food resources. It’s our second year of sampling and we have made some modifications and improvements to our protocol.
This year we are collecting from a total of 62 plants across 12 sites (some burned in 2023, some in 2024, and a few not burned in either year). Where possible, we are collecting from plants that we also collected from last year, which will make for some interesting comparisons. Many plants did not re-flower in 2024, so Wyatt and I bolstered our sample by randomly selecting other focal plants.
On Monday, Wyatt and I visited our first flowering focal plants with Grace and Rebecca from NDSU and tested out methods. We learned how to sample immature florets, a new method we are using to assess pollen quantity this year. We also brushed up on nectar and pollen collection.
Wyatt collects pollen from the anthers of a flowering Echinacea
By Tuesday we were able to train the whole team in on the protocol and start collecting! So far our data sheets have worked pretty well, and we are figuring out ways to improve efficiency in the field. Stay tuned as more of our focal plants begin to flower!
Today we welcomed goats to Hjelm. They are already hard at work eating their way through the foliage. Keep up the good work, goats! Most of the humans worked on finishing searching for Stipa in p01 and started planting a new production garden to generate seed to add to the experimental plots. Ian and Liam valiantly continued staking points for the pollinator emergence study. Wyatt and Abby are getting ready to begin a study investigating the effects of fire on pollen and nectar production in Echinacea angustifolia. This project has many excellent collaborators and is part of the MN ENTRF funded research on prescribed fire and ground nesting bees.
