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2023 Update: Common garden experiments

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 (inb1inb2), and assessing quantitative genetic variation (qgen1). There are also a number of smaller experiments in it, including fitness of Hesperostipa sparteaaphid 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 hereLocation: 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)
    • Dropbox/teamEchinacea2023/z.scanned/replantPedicularisDatasheetWithEchStatusScanned2023-06-21.pdf”
    • Dropbox/teamEchinacea2023/z.scanned/replantPedicularisDatasheetWithEchStatus2Scanned2023-06-21.pdf
  • Planted plugs in ditch west of exPt01
  • 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.

2023 Update: Quantity and quality of Echinacea pollen and nectar

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
  • Overlaps with: bbFood, nectar experiment
  • Data collected: 
    • plant IDs (tag), location, flowering status, assessments for selection for study
      • Dropbox/teamEchinacea2023/z.pollenNectarDataEntry/scans/metaScans
    • flowering day, male floret count, pollen from N anthers in tube, pollen tube ID, tt color, nectar tube ID, quantity of nectar (mm) per floret
      • Dropbox/teamEchinacea2023/z.pollenNectarDataEntry/scans/coreScans
      • Dropbox/teamEchinacea2023/z.pollenNectarDataEntry/coreVerified
      • Dropbox/teamEchinacea2023/z.pollenNectarDataEntry/summaryData
  • Specimens collected: 
    • 856 pollen tubes (at St. Kate’s)
    • 580 nectar tubes (at St. Kate’s)
  • Team members involved with this project: Summer team 2023, Rahul Roy (St. Kate’s) , Margaret Medini (St. Kate’s)
  • Products: pending
  • Funding: ENRTF

2023 Update: floral resources in prairie remnants and restorations

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
  • Overlaps with:  Ground nesting bees
  • Data collected: Floral survey datasheets can be found in ~/Dropbox/teamEchinacea2023/z.scanned/floralsurvey2023scans.pdf.zip”
  • Samples or specimens collected: NA
  • Products: Stay tuned!

2023 Update: soils in remnants and restorations

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
  • Overlaps with: Fire x Fragmentation; Ground Nesting Bees
  • 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
  • Products: Stay tuned!

2023 Update: Fire and seedling fitness in remnants

In 2021, Team Echinacea established 76 transects (each 4 m long) across 32 patches of remnant prairie in the study area. We planted seeds in one randomly selected segment per transect in fall 2021 but germination trials in the lab and seedling searches in the remnants during summer 2022 revealed that we had used a bad batch of seed 

In fall 2022, we repeated seed addition experiment using seed harvested in summer 2022. Stuart, Lindsey, and Alex sowed seed within randomly selected segments in November 2022. For fall 2022, we added 12 seedling transects (beng, fern, hutch, torge) and eliminated transects at two disturbed sites with the goal of maximizing variation in fire history across the study area. We sowed seed in 84 transects across 36 remnant prairie patches in 2022. In 54 segments, we added 50 seeds and at 30 randomly selected segments, we added 100. This variation in number of seeds sown will allow us to understand the implications of seedling density.

Cut to 2023! In early June, Team Echinacea searched for seedlings once again, this time, with more success. We found 260 seedlings in total across our 84 transects during our seedling searches (we did two rounds).

In August we returned to our transects and assessed survival of the seedlings that had emerged earlier in the season. Stay tuned for more information on seedling mortality.

We also measured light availability (using a light meter) and soil compaction (using a soil penetrometer) at each of the segments along the transects. This information will give us a better sense of the conditions under which seedlings emerge and survive. And importantly, how does fire influence these conditions?

I spy seedlings! During our search for Echinacea Seedlings, we used toothpicks to keep track of individuals.

Team Echinacea didn’t stop there. In November of 2023, we went back to Minnesota and sowed seed in randomly selected segments in our 84 transects. Stay tuned to see what emerges in the spring!

Wyatt sprinkles seeds along a seed addition transect during a trip to Minnesota in November!
  • Start year: 2021
  • Location: 36 patches of remnant prairie in and around Solem Township, MN
  • Overlaps with: Seed addition transects in remnants
  • Data collected: Seedling search data, par data and soil compaction data are all stored in ~repos/seedaddexpt. Additional information is stored in ~/Dropbox/burnRems/seedExp”
  • Samples or specimens collected: NA
  • Products: Daytona, summer 2023 high school research participant, used the data to ask, “does time since last burn treatment affect seedling emergence?” Materials for this project are located in ~”/Dropbox/teamEchinacea2023/daytonaHoberg”

You can read more about the Fire and seedling fitness in remnants experiment, as well as links to prior flog entries about this experiment, on the background page for this experiment.

2023 Update: Demographic census in remnants

Since 1995, the Echinacea Project has been mapping and collecting demographic information on Echinacea angustifolia to generate long-term records detailing individual fitness in prairie remnants. In summer 2023, Team Echinacea visited 42 prairie remnants to search at 2443 locations where adult Echinacea plants had been previously mapped. We call this “total demo.” At small sites, the team took records for all adult plants found at a site (no change in total demo protocol from previous years). At larger sites, we scaled down and visited a subset of adult plants. Burning led to high flowering rates and lots of newly flowering plants entering the census, which stressed our system for total demo. This year we did not visit plants that were “not present” for the past 3+ years and we also capped total demo points at 100 per site. For example, at Landfill, we searched at 100 locations at Landfill East and 100 Locations at Landfill West.

We used stake files on our high-precision GPS units to stake to each Echinacea plant in our total demo visit list, where we recorded flowering status, number of flowering heads, number of rosettes, and near neighbors of the plant on handheld data collectors (visors).

In addition to total demo, we searched and took records for all flowering plants in our remnant sites. For flowering demo, we visited 50 sites. In summer 2023, we took 5,601 demographic records in prairie remnants (demo) and 1929 GPS records (surv). We saw a much lower flowering year following 2022, with ~1586 flowering plants total. At Landfill, there were ~262 flowering plants and at Loeffler’s corner, there were 285.

Alexa and Jak step carefully through Kjs as they search for flowering Echinacea plants. 63 plants flowered at Kjs in 2023!

We also took demo and surv data as part of our Pollen and Nectar project where we will compare characteristics of pollen and nectar in burned vs. unburned prairies. We collected demographic data at a subset of plants at several sites where we have never done demo or surv. We put out our first tags at hulze, hulzw, torges, torgen, hutche, hutchw, and koons.

This year, we put out 528 new tags which started at 28001. Two 29000 tags were accidentally created and placed in Landfill East, but those were quickly removed during our demo rechecks following completion of flowering demo and total demo.

Lindsey visits an 18 headed Echinacea plant at Steven’s Approach. This plant produced the most heads of any this year.

After revisiting a final round of recheck plants during a trip to Minnesota in mid-November, we are just getting ready to move data from aiisummer2023 into demap.

  • Start year: 1995
  • Location: Remnant prairie populations of the purple coneflower, Echinacea angustifolia, in Douglas County, MN. Sites are located between roadsides and fields, in railroad margins, on private land, and in protected natural areas.
    • Total demo: Bill Thom’s Gate, Common Garden, Dog, East of Town Hall, Golf Course, Martinson’s Approach, Near Pallida, Nessman, North of Golf Course, South of Golf Course, Sign, Town Hall, Tower, Transplant Plot, West of Aanenson, Woody’s, Yellow Orchid Hill, plus the recruitment plots REL, RHE, RHP, RHS, RHX, RKE, RKW
    • Annual sample: Aanenson, Around Landfill, East Elk Lake Road, East Riley, KJ’s, Krusemarks, Loeffler’s Corner, Landfill, North of Railroad Crossing, Northwest of Landfill and North of Northwest of Landfill (lumped), On 27, Riley, Railroad Crossing, Steven’s Approach, Staffanson Prairie
  • Overlaps with: Flowering phenology in remnantsreproductive fitness in remnantsEA fire and fitnessfire and flowering at SPP,
  • Data collected:
    • Plant status (can’t find, basal, dead this year’s leaves, dead last year’s leaves, flowering), number of rosettes, nearest neighbors, and head count, if flowering
    • All GPS files are found here: Dropbox/geospatialDataBackup2023
    • All demo and surv records are stored in the aiisummer2023 repo
    • The most recent copies of allDemoDemo.RData and allSurv.RData can be accessed at Dropbox/demapSupplements/demapInputFiles
  • Samples or specimens collected: NA
  • Products:
    • Amy Dykstra’s dissertation included matrix projection modeling using demographic data
    • The “demap” project is a long-term dataset that combines phenological, spatial and demographic data for remnant plants
  • You can read more about the demographic census in the remnants, as well as links to prior flog entries about this experiment, on the background page for this experiment.