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

• 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!

**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).