During the summer of 2023, Team Echinacea embarked on an ENRTF funded mission to better understand how prescribed fires influences solitary bee nesting habitat, food resources, and diversity is critical for providing recommendations about how prescribed fire should be used to promote pollinator conservation and healthy prairie.
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 investigate composition of solitary bees in prairies. This was complemented by detailed measures of soil and litter to characterize how prescribed burning influences the nesting habitat (read more here).
We deployed emergence traps at our random points (bb points) in prairie remnants and restorations in mid-June – early September. Our deployment spanned three rotations of bb points and we put out a total of ~1,238 emergence traps.
El, Luke, and Jan, 2023 pollinator crew, deploy an emergence trap at a bb point.
As of September 28, members of Team Echinacea had processed 850 vials, 122 of which contained bees. Our preliminary catch rate is 14%! These specimens were pinned and are currently at Chicago Botanic Garden, awaiting transportation to 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. Bycatch is currently stored in our freezer at Chicago Botanic Garden.
Jan pins a bee that they found while processing vials from emergence trapping!
Ian Roberts, a M.S. student with the Echinacea Project, has taken charge of the Emergence trapping project and is currently coordinating data entry. When emergence trapping resumes in the 2024 field season, we will be well set up, thanks to detailed written and videotaped protocols made by our summer 2023 pollinator team. The prtocol can be found here: “~/Dropbox/enrtf/emergenceTrapping2023/Emergence Trap Protocol.pdf”. Video instructions are located in “~/Dropbox/enrtf/emergenceTrapping2023/exampleVideos”.
Start year: 2023
Location: prairie remnants and restorations in Solem Township, MN.
For the ENRTF-funded research project investigating fire effects on ground-nesting bees, plant-pollinator interactions, and other insects within fragmented prairies, Team Echinacea sampled 45 total prairie sites (30 remnants and 15 restorations).
To obtain robust inferences, it is important to sample randomly so that our sampling effort is not biased by what we perceive to be “good” or “bad” habitat, even subconsciously. To this end, we sampled at random locations within each site. At each site, we established between 30 and 72 sampling locations with unique identifiers (four-digit bbpts, for “burning and bees sampling points”). Early in the summer, before sampling at these points began, we ground truthed the points to ensure we were not choosing in places where we could not sample at all (e.g., think a big rock, a water body, a big patch of poison ivy, a gravel road, etc.).
Jared generated a large number of random points for each site, more points than we actually intended to sample. trap. We visited these points using a high precision gps unit and evaluated whether to “keep” the points and assign them a bbpt or “reject” the point if it could not be sampled safely or effectively.
Jan, 2023 pollinator team member, ground truths bb points at Torgen.
Start year: 2023
Location: prairie remnants and restorations in Solem Township, MN
Overlaps with: ground nesting bees, fire x fragmentation, soils in remnants and restorations, floral resources in remnants and restorations, microhabitats in prairie remnants and restorations
Data collected: spatial locations of accepted bb points are in “~/Dropbox/geospatialDataBackup2023/convertedXML2023/bbptsForEnrtf”. Maps of bb points are located in “~/Dropbox/enrtf/emergenceTrapping2023”
During summer 2023, Team Echinacea Echinacea characterized local environmental conditions to better understand which environmental factors are associated with good habitat for ground-nesting bees. This microhabitat assessment complemented emergence trapping for our ENRTF funded research on fire’s influence on ground nesting bees habitats. We sampled local environmental conditions near randomly placed bbpts in remnants and restorations.
We used a light meter to quantify light availability via a measure of photosynthetically active radiation. We took PAR readings at 1 meter and at ground level ~40 cm NE of the bb point. We also used a soil penetrometer to quantify soil compaction at ~40 cm NE of the bb point.
Team Echinacea conducted microhabitat assessments for three rotations of bb points (rotations 1,2,&3) across 46 sites. Over the summer, we took microhabitat assessment measurements at a total of 1,238 bb points.
Blaire, high school participant 2023, takes a light measurement at a bb point. We were particular about position and timeframe to ensure consistent measurements.
Start year: 2023
Location: prairie remnants and restorations in Solem Township, MN
Data collected: light availability (par measurements) and Soil Compaction (psi measurements) are stored in ~Repos/bbnest/data/microhabitatDataCuration/curate2023MicrohabitatData.R
The aphid addition and exclusion experiment was started in 2011 by Katherine Muller. The original experiment included 100 plants selected from exPt01 which were each assigned to have aphids either added or excluded through multiple years. The intention is to assess the impact of the specialist herbivore Aphis echinaceae on Echinacea fitness.
Last summer (2022), team members Emma Reineke and Kennedy Porter were in charge of the experiment and did not find any aphids in exPt01, so they introduced a new population of Aphid echinaeceae into ExPt1. Learn more in the 2022 summer aphid update. During summer 2023, we did not do any fieldwork for this experiment and we didn’t see any aphids while measuring exPt01.
Andy Hoyt’s poster presented at the Fall 2018 Research Symposium at Carleton College
2016 paper by Katherine Muller and Stuart on aphids and foliar herbivory damage on Echinacea
2015 paper by Ruth Shaw and Stuart on fitness and demographic consequences of aphid loads
You can read more about the aphid addition and exclusion experiment, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.
Every year since 1996, Team Echinacea members record flowering phenology, taking measuring data and harvest heads of thousands of Echinacea angustifolia plants in common garden experiments. These experimental plots are prairie restorations and abandoned agriculture fields that are managed as grassland habitat. Some plots have multiple ongoing experiments within. Currently, the Echinacea Project currently has 10 established experimental plots.
This project status report will contain updates on experimental plots 1, 2, 4, 5 and 8, as well as management updates for all plots. Specific reports for the remaining experimental plots can be found on separate posts including Amy Dykstra’s plot (exPt03), the hybrid plots (exPt06, exPt07, exPt09), and the West Central Area common garden (exPt10).
exPt01: Experimental plot 1 was first planted in 1996 (cleverly termed the 1996 cohort), and has been planted with nine other experiments in subsequent years, with the most recent planting being Amy Waananen’s inter-remnant crosses. It is the largest of the experimental plots, with over 10,000 planted positions; experiments in the plot include testing fitness differences between remnants (1996, 1997, 1999), quantifying effects of inbreeding (inb1, inb2), and assessing quantitative genetic variation (qgen1). There are also a number of smaller experiments in it, including fitness of Hesperostipa spartea, aphid addition and exclusion, and pollen addition and exclusion (the last experiment was continued the summer of 2023 and will have separate update posts). In 2023, we visited 3,699 of the 10,992 positions planted and found 3,118 alive. 560 plants were classified as “flowering” in exPt01 this year. This is a little less than half of the plants that flowered in summer 2022 (1,111) – an interesting note considering exPt01 was burned the spring of both 2022 and 2023. In summer 2023, we harvested 796 total Echinacea heads in exPt01. We also added 270 additional staples to the experimental plot this year, signifying positions were a living plant has not been found for over three years.
Some numbers for experiments within exPt01
Inb1: The INB1 experiment investigates the relationship between inbreeding level and fitness in Echinacea angustifolia. Each plant in experiment INB1 originates from one of three cross types, depending on the relatedness of the parents: between maternal half siblings; between plants from the same remnant, but not sharing a maternal or paternal parent; and between individuals from different remnants. All individuals were planted in 2001. We continued to measure fitness and flowering phenology in these plants. In 2023, of the original 557 plants in INB1, 85 were still alive. Of the plants that were alive this year, 24 of them were flowering; this count is down from summer of 2022 where 40 of the plants were flowering.
qgen: The qGen1 (quantitative genetics) experiment in p1 was designed to quantify the heritability of traits in Echinacea angustifolia. We are especially interested in Darwinian fitness. Could fitness be heritable? During the summer of 2002 we crossed plants from the 1996 & 1997 cohorts of exPt01. We harvested heads, dissected achenes, and germinated seeds over the winter. In the spring of 2003 we planted the resulting 4468 seedlings (this great number gave rise to this experiment’s nickname “big batch”). 1,417 plants in qGen1 were alive in 2023. Of those plants, 298 flowered this summer.
Other plots:
exPt02: To examine the role flowering phenology plays in the reproduction of Echinacea angustifolia, Jennifer Ison planted this plot in 2006 with 3,961 individuals selected for extreme (early or late) flowering timing, or phenology. Using this phenological data, we explore how flowering phenology influences reproductive fitness and estimate the heritability of flowering time in E. angustifolia. In the summer of 2023, we visited 1,855 positions of the 3,961 positions originally planted. We measured 1,283 living plants, of which 118 were flowering, with a total of 148 flowering heads. In the fall, we harvested 67 heads from exPt02. The large difference between the number of heads and the number harvested has to do with high levels of seed predation, mainly by ground squirrels. Last year, Will, Jennifer, and other members of Team Echinacea published a paper in the American Journal of Botany using data from exPt02 – check it out here! Location: Hegg Lake WMA
exPt04: Experimental plot 4 was planted to gauge whether Echinacea from small remnant populations could be genetically rescued via an outcross to larger, more genetically diverse populations. Caroline Ridley and other members planted this plot in 2008. We did not visit exPt04 this year. Location: Hegg Lake WMA
exPt05: The only experimental plot planted at Staffanson Prairie Preserve (SPP), exPt05, was planted to compare progeny of maternal plants from burned and unburned sections of SPP. There were 2800 plants planted originally, but high mortality made it impractical to visit the plot row-by-row. Now, we and treat the plot like demography. We use our survey-grade GPS to find plants in exPt05 that have previously flowered and add more plants to the stake file if new plants in the plot flower. In 2023 we found 11 living plants, none of which were flowering! We did locate one new flowering plant within the plot boundaries. Location: Staffanson Prairie Preserve
exPt08: Team Echinacea established quantitative genetics experiments to quantify additive genetic variance of fitness in Echinacea, with the idea that we can estimate evolutionary potential of study populations. The maternal parents of qGen2 and qGen3 are plants in the 1996, 1997, and 1999 cohorts. These plants were crossed with pollen from plants in remnants to produce seed for qGen2 and qGen3, which now inhabit exPt08. Originally, 12,813 seeds were sown in the common garden. Seeds from the same cross (shared maternal and paternal plants) were sown in meter-long segments between nails. A total of 3,253 seedlings were originally found, but only 385 plants were found alive in 2023. There were 15 flowering plants in 2023, and 15 heads. On a side note, one additional flowering plant was found in t-plot, and we harvested three heads from that. Location: Wagenius property
Experimental plot management:
Burned exPt01 (3 May 2023) and exPt08 (17 May 2023)
Replanted pedicularis in exPt01 and exPt10, augmenting Drake’s experimental treatments (replaced ones that died)
Broadcast seed in p8 after the spring burn and in the fall, including Comandra umbellata
Stuart trimmed flowering A. gerardii and S. nutans just north of tplot
Some plots in hegg (not exPt02) got run over by heavy machinery
We did not:
Treat sumac
Weed in exPt01 (except hawkweed)
Treat ash in exPt08, but we noticed that ash south of plot responded favorably to last year’s treatment
Details
Start year: Differs between experiment, see above. First ever experimental plot was in 1996.
Location: Differs between experiment, see above.
Overlaps with: …everything!
Data collected: Raw measuring data can be found in cgData repository. Processed data will be uploaded to SQL database. Currently, SQL database has measuring data up until 2022.
Samples or specimens collected: See above for total harvested heads in each plot.
Products: Many publications and independent projects.
Location: Hegg Lake WMA. Start year: 2011. Echinacea pallida is a species of Echinacea that is not native to Minnesota. It was mistakenly introduced to our study area during a restoration of Hegg Lake WMA. Since 2011, Team Echinacea has visited the pallida restoration, taken flowering phenology, and collected demography on the non-native plant. We have decapitated all flowering E. pallida each year to avoid cross-pollination with the local Echinacea angustifolia. Each year, we record the number of heads on each plant and the number of rosettes, collect precise GPS points for each individual, and cut off all the heads before they produce fruits.
This year, we cut E. pallida heads on June 22nd. We installed pollinator exclusion bags on select heads of 10 plants rather than immediately cutting them as a part of our quantity and quality of Echinacea pollen and nectar experiment. Overall, we found and shot 73 flowering E. pallida plants, and 193 heads in total, averaging 2.6 heads per plant. These non-native plants were hearty with an average rosette count of 6 rosettes and an individual with a maximum of 20 rosettes! We only did surv on plants with new tags this year, a total of 4. We did not take phenology data on E. pallida this year.
You can find more information about E. pallida flowering phenology and previous flog posts on the background page for the experiment.
Location: near exPt8. Start year: Crossing in 2011, planting in 2012. Experimental plot 6 was the first E. angustifolia x E. pallida hybrid plot planted by Team Echinacea. A total of 66 Echinacea hybrids were originally planted. All individuals have E. angustifolia dams and E. pallida sires. In 2023, we visited 23 positions and found 17 living plants. This year, 3 plants flowered in this plot; this is the first year any plants have flowered in p6! These were allowed to reach day one or two of flowering in order to assess their pollen color before we decapitated them.
Flowering plant in exPt06! Note the paler pollen color compared to the typical E. Angustifolia
You can find more information about experimental plot 6 and previous flog posts about it on the background page for the experiment.
Location: Hegg Lake WMA. Start year: Crossing in 2012, planting in 2013. Experimental plot 7 is the second E. pallida x E. angustifolia plot. It contains conspecific crosses of each species as well as reciprocal hybrids, totaling 294 individuals. This summer, we visited 150 positions, and of these plants, we found evidence of 121 living plants. We did not use pollinator exclusion bags in exPt07 this year. There were 19 flowering plants this year; from these we harvested 32 heads. We have not yet used the pedigree data to see what number of these plants are hybrids or not.
You can find more information about experimental plot 7 and previous flog posts about it on the background page for the experiment.
Location: Hegg Lake WMA. Start year: 2014. Experimental plot 9 is a hybrid plot, but, unlike the other two hybrid plots, we do not have a perfect pedigree of the plants. That is because the E. angustifolia and E. pallida maternal plants used to generate seedlings for exPt9 were open-pollinated. We need to do paternity analysis to find the true hybrid nature of these crosses (assuming there are any hybrids). We did not use pollinator exclusion bags in exPt09 this year. There were originally 745 seedlings planted in exPt9. We searched at 292 positions and found evidence of 238 living plants in 2023. Of these individuals, 30 were flowering. We harvested 39 heads from this plot!
You can find out more information about experimental plot 9 and flog posts mentioning the experiment on the background page for the experiment.
Data collected for exp679: For all three plots, we collected flowering status, rosette count, leaf length, head count and head height. All measuring data can be found in the cgdata repository (~/cgdata/summer2023/measureGood). Measuring data should be uploaded to SQL database eventually, but it is not currently there for 2023. For experimental plots 7 and 9, we also took phenology data starting on July 7th and ending on July 12th, which we scaled back from previous years. This data can be found in the cgdata repository (~cgdata/summer2023/p79phenology).
Data collected for E. pallida demography: Demography data, head counts, rosette counts, GPS points shot for each E. pallida with a new tag. Find demo and surv records as well as GPS points in demap.
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 2023, the team collected pollen and nectar samples from Echinacea angustifolia at 19 sites in and around Solem Township, MN (plants at Hegg Lake were Echinacea pallida). We searched for and shot the ~20 plants (or, if few were available, as many as we could find) at each site that were closest to a random point. We then selected ten of those plants to bag up to three of their heads with pollinator exclusion bags. Throughout the duration of their flowering, we collected pollen from all bagged plants and nectar from five of them per site.
Stuart collects nectar from an Echinacea head
Midway through the experiment (mid-July), we removed bags from some of the pollen only plants to adjust our sample size to only the five pollen/nectar plants plus two backups per site. We removed bags from pollen/nectar plants and backup plants when they were done flowering, we’d collected a cumulative 50 mm of nectar from them, or we had received less than 15 mm of nectar from the plant in the last three visits (the latter was more of a guideline than a rule, used to save time by eliminating plants that were unlikely to provide us with enough nectar for analysis). At the Hegg pallida restoration, any heads that were not originally bagged were decapitated, and all heads were decapitated upon the final removal of their bags.
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 856 vials of pollen and 580 vials of nectar from 104 plants. These were given to Rahul Roy and Margaret Medini at St. Catherine University in St. Paul, who will be doing data analysis.
Data entry for collection datasheets is complete, and verified csvs for each site can be found at: Dropbox/teamEchinacea2023/z.pollenNectarDataEntry/coreVerified. Scans can be found at: Dropbox/teamEchinacea2023/z.pollenNectarDataEntry/scans.
Start year: 2023
Location: Various prairie remnants and one restoration (Hegg Pallida) around Solem Township, MN
During the summer of 2023, Team Echinacea conducted floral surveys at randomly selected bb points in remnant prairies and restorations. We are interested in quantifying floral resources (i.e., food for bees) and we want to understand how fire influences the diversity and abundance of flowering plants.
At each focal point (bbpt) we identified species rooted within a 2 meter radius and recorded the furthest stage of development. We measured abundance by binning a range of floral units (i.e., 1-5 flowering units got label “5”).
Floral surveys were split into “visit group A” and “visit group B”. We surveyed different random points when revisiting sites. In total, we conducted 415 floral surveys across 45 sites.
Liam Poitra, a 2023 Summer Research Experience for Undergraduates (REU) Participant, contributed to this research project investigating the effects of fire on diversity and abundance of flowering plants. Liam assisted in fieldwork and data organization. Inventory, protocols, and blank datasheets for floral assessments are located in ~/Dropbox/enrtf/floralSurveys2023.
Liam Poitra, REU 2023, navigates to a floral assessment focal point at Staffanson Prairie Preserve. The 2-meter stick he carries will help keep track of what is in the bounds for survey.
Start year: 2023
Location: prairie remnants and restorations in Solem Township
In 2023, Team Echinacea did not conduct any fieldwork for this experiment.
Pollinator populations are declining worldwide, and pollinator habitat in western Minnesota has diminished over the years, but it is unclear whether the native bee community is changing as well. The Pollinators on Roadsides project, also known as the Yellow Pan Trap (YPT) study, is investigating how native bee diversity and abundance have changed from 2004-2022 and learning about whether the amount of agricultural land and grassland correspond to the nearby bee community.
In the lab, rock star pinner and volunteer Mike Humphrey finished pinning all 789 bees from 2022 on 6 April, 2023. Intern Alex Carroll brought the bees to Zach Portman, the bee taxonomist at the University of Minnesota, for identification on 6 June, 2023. Zach recently reported that he’s all done with our 2022 bees, and we will be picking them up from UMN next chance we get!
Mike shows off a finished bee case
Alex worked to put datasets together (view in Dropbox/ypt2004in2017/yptDatasets/) for this experiment to prepare us for when Zach finishes his identifications. Alex also created this to-do list of next steps:
When Zach finishes identifying the 2022 specimens, fill in zachGenus, zachSpecies, and zachSex for 2022 spids.
Remove 2022 spids that are nonbees.
Update 2017 collectDate. In 2017, traps were put out one day and then collected the next day. Some of the 2017 dates are the day the trap was put out and some are the collection day. These should be standardized. MAS figured out most of the timeline here: ypt2004in2017/yptDataAnalysis2022/collectionDatesAndMowedTraps/2017listOfCollectionDatesAndMowedTraps-11-May-2022.csv These dates are based on the 2017 summer datasheets: ypt2004in2017\YPT2017\YPTsummer2017\ypt2017FieldDatasheets.pdf
Locate missing trap numbers for 35 bees, all collected on 07/26/2004. There is a memo for half of the traps collected on 07/26/2004, but half (the outerloop) are missing. See ypt2004in2017/YPT2004/yptMemos2004/ypt04-js.doc
Determine what to do about missing specimens. Some specimens were identified by Sam Drogee in the past, but we couldn’t find the bee. SW remembers that Sam took some specimens, so he may still have them. A few specimens have gone missing. See the notes column.
Summary
Start year: 2004, rebooted in 2017
Location: Roadsides and ditches around Solem Township, Minnesota. GPS coordinates for each trap are located here: ~Dropbox\teamEchinacea2022\YPTsummer2022\yptTrapLocations2022.csv
Zach Portman identified all specimens from 2004-2019, and the specimens are stored in eight cases at the CBG lab.
Mike finished pinning specimens from 2022 on April 6th, 2023. Alex delivered 2 cases of specimen to Zach on June 6th 2023. A little over a month ago, Zach said he had a backlog and wouldn’t get to them for a month. So, hopefully he’ll be working on them soon!
Team members involved with this project: Geena Zebrasky (2022), Mia Stevens (2020-2023), Alex Carroll (2021-2023), Erin Eichenberger (2019-2020), Anna Stehlik (2020), Shea Issendorf (2019), Mike Humphrey (2018-2021), John Van Kampen (2018-2019), Kristen Manion (2017-2018), Evan Jackson (2018), Alex Hajek (2017), and Steph Pimm Lyon (2004)
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). The Trust Fund is a permanent fund constitutionally established by the citizens of Minnesota to assist in the protection, conservation, preservation, and enhancement of the state’s air, water, land, fish, wildlife, and other natural resources. Currently 40% of net Minnesota State Lottery proceeds are dedicated to growing the Trust Fund and ensuring future benefits for Minnesota’s environment and natural resources.
You can read more information about the pollinators on roadsides project here.
In July, 2023, a team from Minnesota State University, Mankato visited Team Echinacea to sample prairie soil. They are investigating how fire and management history influences physical, chemical and biological soil properties. Differences in soils may also help explain plant fitness and native bee nesting patterns. After three hot days, 263 samples were collected from 28 sites!
Back in Mankato, four undergraduate students processed the soil samples by sieving and weighing out the field collections. The preliminary results show soil bulk density is lower in remnant prairies compared to restored prairies. This makes sense in that remnant prairies have retained their organic-matter rich topsoil, infiltrated with plant roots and filled with pore spaces that develop over time in natural prairies. The soil bulk density is also lower on flat (no slope) topography, in part due to illuviation (deposition) of nutrients and organic material from nearby sloped areas.
The team hopes to continue its investigations to understand which soil properties are sensitive to different management histories and how the patchwork of fragmented prairies in the region vary in carbon, nitrogen and biological activity. These data should provide foundational information for many additional projects.
The Mankato soil team gathers around a bbPoint to discuss sampling. The team visited bbPoints in remnants and restorations over a 3 day period.
Start year: 2023
Location: : 28 study plots on private, federal and state land with different land use histories: remnant and restored grassland
Data collected: Soil bulk density, maximum water-holding capacity, gravimetric soil moisture content, soil aggregate stability (SLAKES), total organic C, total N, inorganic N (plant available forms: ammonium and nitrate), aerobic respiration rate (proxy for microbial activity and decomposition)
Samples or specimens collected: Topsoil bulk density and additional soil (top 15 cm) for each bee nesting trap
