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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: Interremnant crosses

In summer 2023, Amy continued the interremnant crosses experiment to understand how the distance between plants in space and their timing of flowering influences the fitness of their offspring. This experiment builds on her study of gene flow and pollen movement in the remnants, asking the question of how pollen movement patterns affect offspring establishment and fitness. If plants that are located close together or flower at the same time are closely related, their offspring might be more closely related and inbred, and have lower fitness than plants that are far apart and/or flower more asynchronously. In other words, if distance in space or time is correlated with relatedness, we’d expect mating between more distant or asynchronous individuals to result in more fit offspring.

To test this hypothesis, Amy performed crosses between plants across a range of spatial isolation (within the same population, in adjacent populations, and in far-apart populations) in 2020. With the team’s help, she also kept track of the individuals’ flowering time to assess whether reproductive synchrony is associated with reduced offspring fitness, suggesting that individuals that flower at the same time are more closely related.

In 2021, Amy repeated the same hand crossing methods to assess the fitness consequences of outcrossing, this year on 44 focal plants.

In spring 2022, she planted the seedlings as plugs into exPt01 and measured the seedlings throughout the summer. Amy measured plants again in summer 2023!

Amy’s two batches of plants (that were alive this year) were assigned cg plaids and are now integrated in the p01 workflow. They are named as integers from 29001 – 29319 and are referred to as “Amy’s Annex”.

A young Echinacea Plant in Amy’s Annex
  • Start year: 2020
  • Location: On27, SGC, GC, NGC, EELR, KJ, NNWLF, NWLF, LF
  • Overlaps with:  phenology in the remnantsgene flow in the remnants
  • Data collected: Style shriveling and seed set and weight from crosses, start and end date of flowering, coordinates of all individuals in the populations listed above. Leaf count and height of seedlings at three points during the summer (two weeks after planting, mid-summer, and late summer). Summer 2023 measure data can be found here: “~/Dropbox/CGData/125_measure/measure2023/measure2023_out”
  • Samples or specimens collected: NA
  • Products: Amy wrote up a related analysis using parentage data from P2 to look at interparent distance and asynchrony in relation to offspring fitness. That manuscript is in prep now.

You can read more about the interremnant crosses experiment here.

2022 Update: Interremnant crosses

In summer 2022, I continued the interremnant crosses experiment to understand how the distance between plants in space and their timing of flowering influences the fitness of their offspring. This experiment builds on my study of gene flow and pollen movement in the remnants, asking the question of how pollen movement patterns affect offspring establishment and fitness. If plants that are located close together or flower at the same time are closely related, their offspring might be more closely related and inbred, and have lower fitness than plants that are far apart and/or flower more asynchronously. In other words, if distance in space or time is correlated with relatedness, we’d expect mating between more distant or asynchronous individuals to result in more fit offspring.

To test this hypothesis, I performed crosses between plants across a range of spatial isolation (within the same population, in adjacent populations, and in far-apart populations) in 2020. With the team’s help, I also kept track of the individuals’ flowering time to assess whether reproductive synchrony is associated with reduced offspring fitness, suggesting that individuals that flower at the same time are more closely related.

In 2021, I repeated the same hand crossing methods to assess the fitness consequences of outcrossing on 44 focal plants. However, instead of planting the offspring from these crosses as seeds, I germinated them in the growth chamber and transferred sprouts to a plug tray.

In spring 2022, with help from the team, I planted the seedlings as plugs into ExPt1. I measured the seedlings throughout the summer.

To learn more about Amy’s project, check out this video created by 2021 RET participant Alex Wicker.

  • Start year: 2020
  • Location: On27, SGC, GC, NGC, EELR, KJ, NNWLF, NWLF, LF
  • Overlaps with: phenology in the remnantsgene flow in the remnants
  • Data collected: Style shriveling and seed set and weight from crosses, start and end date of flowering, coordinates of all individuals in the populations listed above. Leaf count and height of seedlings at three points during the summer (two weeks after planting, mid-summer, and late summer).
  • Products: Stay tuned!

Amy visits CBG!

On Friday, grad student Amy W. paid a visit to the lab at the Chicago Botanic Garden to x-ray Echinacea achenes for several of her projects including the Dust Project, interremnant crosses, and gene flow experiments. We’re thrilled to have a functional x-ray machine once again. Amy noticed lots of variation in her samples, so we’re excited to learn about seed set for these experiments!

2021 Update: Interremnant crosses

In summer 2021, Amy Waananen continued the interremnant crosses experiment to understand how the distance between plants in space and in their timing of flowering influences the fitness of their offspring. This experiment builds on Amy’s study of gene flow and pollen movement in the remnants, asking the question of how pollen movement patterns affect offspring establishment and fitness. If plants that are located close together or flower at the same time are closely related, their offspring might be more closely related and inbred, and have lower fitness than plants that are far apart and/or flower more asynchronously. In other words, if distance in space or time is correlated with relatedness, we’d expect mating between more distant or asynchronous individuals to result in more fit offspring.

To test this hypothesis, Amy performed crosses between plants across a range of spatial isolation (within the same population, in adjacent populations, and in far-apart populations) in 2020. With the team’s help, she also kept track of the individuals’ flowering time to assess whether reproductive synchrony is associated with reduced offspring fitness, suggesting that individuals that flower at the same time are more closely related.

In 2021, Amy repeated the same hand crossing methods to assess the fitness consequences of outcrossing, this year on 44 focal plants.

To learn more about Amy’s project, check out this video created by RET participant Alex Wicker.

Start year: 2020

Location: On27, SGC, GC, NGC, EELR, KJ, NNWLF, NWLF, LF

Overlaps with: phenology in the remnants, gene flow in the remnants

Data/Materials collected: Style shriveling and seed set and weight from crosses, start and end date of flowering, coordinates of all individuals in the populations listed above

Products: Stay tuned!

2020 Update: Interremnant Crosses

This summer I started a new experiment to understand how the distance between plants in space and in their timing of flowering influences the fitness of their offspring. This experiment builds on my study of gene flow and pollen movement in the remnants, asking the question of how pollen movement patterns affect offspring establishment and fitness. If plants that are located close together or flower at the same time are closely related, their offspring might be more closely related and inbred, and have lower fitness than plants that are far apart and/or flower more asynchronously. In other words, if distance in space or time is correlated with relatedness, we’d expect mating between more distant or asynchronous individuals to result in more fit offspring.

To test this hypothesis, I performed crosses between plants across a range of spatial isolation (within the same population, in adjacent populations, and in far-apart populations). With the team’s help, I also kept track of the individuals flowering time so that I can assess whether reproductive synchrony is associated with reduced offspring fitness, suggesting that individuals that flower at the same time are more closely related.

I ended up using 42 focal plants (two of which were mowed before I could harvest them) and a total of 167 sires. I planted 359 offspring from these crosses in November. Next spring and summer, I will measure the seedlings to collect data on emergence and growth. Seed set was lower than I wanted it to be (only ~20%, when I would have expected 60-70% based on compatibility rates in the remnants), so I will also likely perform more crosses in summer 2021 to shore up my sample size.

Crossing at scenic On 27

Start year: 2020

Location: On27, SGC, GC, NGC, EELR, KJ, NNWLF, NWLF, LF

Overlaps with: phenology in the remnants, gene flow in the remnants

Data/Materials collected: 40 seedheads, style shriveling and seed set and weight from crosses, start and end date of flowering, coordinates of all individuals in the populations listed above

Products: I planted the seeds from the crosses in a plot adjacent to P1 in November, as detailed in this flog post.

Planting a new experiment in P1*

* well, adjacent to P1.

This past Friday I planted the seeds from the inter-remnant crossing experiment I completed over the summer. The goal of this experiment is to understand how the distance between plants that live in little fragmented remnants and the difference in their timing of flowering influences the fitness of their offspring. The expectation is that if plants that are close together and/or flowering at the same time are closely related, their offspring might be more closely related (i.e., inbred) and have lower fitness than plants that are far apart and/or flowering more asynchronously. If this is true, then it would suggest that individuals in small, fragmented habitats would benefit from reaching more distant or dissimilar mates, such as by introducing seeds from faraway populations to remnants, creating corridors that promote pollinator movement, or managing habitat to increase heterogeneity in flowering time.

Plot location & layout:

The plot is located directly to the east of P1, spanning 12 m east to west and 30 m north to south, between positions 860 and 890. See Mia’s flog post from September for more information about how we prepared the plot by clipping the grass and treating the sumac with Garlon. Mia also used Darwin to shoot points within and along the edges of P1 so that I could generate coordinates for each position in my planting that aligned with P1’s crooked grid. This was a good exercise in geometry. I figured it out, but not before googling how to find the intersection of two lines. Oh well!

When I laid down the meter tapes based on the end points of the rows in this grid, it matched pretty well (the rows were supposed to be exactly 30 m long), but they were off a bit due to topography and the vegetation keeping the tape from laying perfectly flat. It was right on for row 58 and off by ~5cm in rows 62 and 65. We lined up meter sticks with the flags placed ever two meters and positioned achenes relative to according to the flag positions, rather than the tape. We placed 4 achenes per meter in positions 860-889.75.

Randomization:

Based on the number of seeds I had, and the expectation that I might want to plant more for this experiment in the future, I randomly chose three rows (58, 62, and 65) to plant out of the twelve total rows that fit in the area that we prepared. I randomly assigned positions to all of the full achenes, based on their weight. Prior to planting, I placed each of these achenes into a 1.5mL microcentrifuge vial and labeled it with its planting position (1-360). I sorted the vials in order of planting position and placed them in vial trays that we brought into the field.

Planting:

It was a dry and unseasonably warm day. This is lucky because there was 10 inches of snow where the plot is located a week and a half earlier. I was able to convince Matthew and Gooseberry to come along to help. Matthew was extremely helpful, but Goose mostly ate deer poop all day and threw up on the way home. Very yucky! To set up for planting, I staked to the end points for the rows we were planting, set up a meter tape, and then staked to and placed pin flags at positions every two meters along the rows. I started by placing pin flags every meter, but this was time consuming and a pin flag every two meters gave us a sufficient reference point for each meter.

We liked breaking the actual planting into two steps, and working in a pair, because it meant that we had fewer items to fumble around with and it was easy to catch and fix each other’s mistakes, such as accidentally skipping positions. I do not believe we made any actual goofs, which is a first for me with planting! For the first step, one person cleared the duff, and the other placed the corresponding vial. For the second, one person placed the achene and collected the vial, while the other placed the toothpick and carried the clipboard, making any notes, e.g., if the achene was planted a few cm off the row to avoid placing it on a rock or in bunchgrass. The first step took about 10-12 minutes per 50 positions. The second took about 8-10 minutes per 50 positions. We set the achenes on top of the soil so that they had good contact with the soil, but weren’t buried. We finished around 4 PM and were grateful that we did not have to plant in the dark.

I hope the seeds have a good winter and I look forward to seeing them in the spring!