A rainbow-like cloud glows over exPt01 while the team was in MN for fall 2023 burns. A good omen for the field season that followed!
Introduction
Every year since 1996, members of Team Echinacea have recorded flowering phenology, taking measure data and harvested heads from thousands of Echinacea angustifolia plants in plots with “common garden” experimental designs. These experimental plots are located in prairie remnants, restorations, and abandoned agricultural fields that are managed as grassland habitat. Currently, the Echinacea Project has 10 established experimental plots. Some plots have multiple ongoing experiments within.
In the past few years, we have scaled back significantly on taking phenology records in the experimental plots. During 2023 and 2024, our primary goals with phenology were to a) map out the positions of flowering plants/heads within the plots, b) deploy twist ties to all flowering heads to ease measuring and harvesting, and c) to record the day of first flowering for all heads in plots to continue the long-term data collection in a more scaled-back fashion. As a result, we conducted only a few rounds of phenology per plot and did not capture the full range of flowering dates for every head. Phenology info is briefly reported on in each plot’s update along with the location of the data. This applies to the hybrid experimental plots as well.
Crew members Wyatt and Emma search can’t find positions in 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). It also houses a number of smaller experiments, including fitness of Hesperostipa spartea, aphid addition and exclusion, and pollen addition and exclusion (these experiments have separate posts).
In 2024, we conducted phenology in this plot between July 8th and July 18th. During measure, we visited 3123 of the 10,992 positions planted and found 2728 living plants. 83 plants were classified as “flowering” in exPt01 this year, totally 96 heads. This is a significantly fewer plants than flowered in summer 2023 (560). In summer 2024, we harvested 82 total Echinacea heads in exPt01 (including many from the ever-productive 99 south garden).
ExPt01 is also the only plot to have staples marking positions where plants that have died used to be. We added 67 staples to the experimental plot this year, but only in locations that we couldn’t find staples during measure that were already supposed to be there. We didn’t have time to get to every position with a missing staple (see where we covered here: Dropbox/CGData/125_measure/measure2024/staple2024/2024addStaplesExPt01.pdf). We did not have time to re-search locations that we called plants “can’t finds” at three years in a row in 2023 and 2024. Once these locations receive their final search, hopefully in 2025, we can put staples at them as well.
This experiment was started in 2020 by Amy Waananen to understand how the distance between plants in space and in their timing of flowering influences the fitness of their offspring. 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. Plants in this experiment resulted from interremnant hand-crossings from 9 remnants: On27, SGC, GC, NGC, EELR, KJ, NNWLF, NWLF, LF. Crossing took place in 2020 and 2021, and individuals were planted in 2020 (as seed) and 2022 (as plugs). Surviving plants were assigned cgPlaIds in 2023 and incorporated into the p1 workflow. Mortality in this experiment has been high, with 80.3% of positions searched in 2024 resulting in “can’t finds.”. We did not re-search “can’t find” positions in 2024 due to time constraints (with Amy’s approval).
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.
The inb2 experiment investigates the relationship between inbreeding level and fitness in Echinacea angustifolia. Each plant in experiment inb2 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 2006. We continued to measure fitness and flowering phenology in these plants. In October 2024, former team member Riley Thoen recently published a paper in the Journal of Hereditary on the conservation value of small remnants using results from this experiment.
The qGen1 (quantitative genetics, or just qGen) 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”).
data in cgData repo: ~/cgData/summer2024/exPt01Phenology
Measure data (status, size, etc.)
data in SQL database
Harvest data (IDs of harvested heads, missing achenes, etc)
detailed data in dropbox: dropbox/CGData/140_reconcile/reconcile2024/reconcileOut/2024harvestListReconciledExport.csv
data in SQL database
data in echinaceaLab package (hh.2024)
Samples collected:
82 heads harvested
At cbg for processing (counted, ready to randomize)
Products:
Publications
Thoen, R. D., A. Southgate, G. Kiefer, R.G. Shaw, S. Wagenius, The conservation value of small population remnants: Variability in inbreeding depression and heterosis of a perennial herb, the narrow-leaved purple coneflower (Echinacea angustifolia). 2024. Journal of Heredity esae055. https://doi.org/10.1093/jhered/esae055.
Page, M. L., Ison, J. L., Bewley, A. L., Holsinger, K. M., Kaul, A. D., Koch, K. E., Kolis, K. M., and Wagenius, S. 2019. Pollinator effectiveness in a composite: A specialist bee pollinates more florets but does not move pollen farther than other visitors. American Journal of Botany 106: 1487–1498. PDF
Waananen, A., G. Kiefer, J. L. Ison, and S. Wagenius. 2018. Mating opportunity increases with synchrony of flowering among years more than synchrony within years in a nonmasting perennial. The American Naturalist 192: 379-388. PDF | Appendix | online version
Muller, K. and S. Wagenius. 2016. Echinacea angustifolia and its specialist ant-tended aphid: a multi-year study of manipulated and naturally-occurring aphid infestation. Ecological Entomology 41: 51-60. PDF | online version
Shaw, R. G., S. Wagenius and C. J. Geyer. 2015. The susceptibility of Echinacea angustifolia to a specialist aphid: eco-evolutionary perspective on genotypic variation and demographic consequences. Journal of Ecology 103: 809-818. PDF
Kittelson, P., S. Wagenius, R. Nielsen, S. Qazi, M. Howe, G. Kiefer, and R. G. Shaw. 2015. Leaf functional traits, herbivory, and genetic diversity in Echinacea: Implications for fragmented populations. Ecology 96: 1877–1886. PDF
Ison, J.L., and S. Wagenius. 2014. Both flowering time and spatial isolation affect reproduction in Echinacea angustifolia. Journal of Ecology 102: 920–929. PDF | Supplemental Material | Archived Data
Ison, J.L., S. Wagenius, D. Reitz., M.V. Ashley. 2014. Mating between Echinacea angustifolia (Asteraceae) individuals increases with their flowering synchrony and spatial proximity. American Journal of Botany 101: 180-189. PDF
Ridley CE, Hangelbroek HH, Wagenius S, Stanton-Geddes J, Shaw RG, 2011. The effect of plant inbreeding and stoichiometry on interactions with herbivores in nature: Echinacea angustifolia and its specialist aphid. PLoS ONE 6(9): e24762. http://dx.plos.org/10.1371/journal.pone.0024762
Wagenius, S., H. H. Hangelbroek, C. E. Ridley, and R. G. Shaw. 2010. Biparental inbreeding and interremnant mating in a perennial prairie plant: fitness consequences for progeny in their first eight years. Evolution 64: 761-771. Abstract | PDF
Ruth G. Shaw, Charles J. Geyer, Stuart Wagenius, Helen H. Hangelbroek, and Julie R. Etterson. 2008. Unifying life-history analyses for inference of fitness and population growth. American Naturalist 172: E35 – E47. Abstract | PDF | Supplemental Material
Geyer, C.J., S. Wagenius, and R.G. Shaw. 2007. Aster models for life history analysis. Biometrika 94: 415-426. PDF | Supplemental Material
Grad student work
Drake Mullett’s PhD dissertation (2025)
Wyatt Mosiman’s MS thesis (2024)
Amy Waananen’s paper “The fitness effects of outcrossing distance depend on parental flowering phenology in fragmented populations of a tallgrass prairie forb” (with co-authors Ison, Wagenius, and Shaw) was just accepted by New Phytologist–it includes data from parents in exPt01 and progeny in exPt02.
AKA the heritability of flowering time experiment, exPt02 was designed 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, known as 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 2024, we conducted phenology between July 10th and July 19th. During measure, we visited 1,725 positions of the 3,961 positions originally planted. We measured 1,190 living plants, of which 302 were flowering with a total of 402 flowering heads (count excludes vertical developments). In the fall, we harvested 375 heads from exPt02. We observed much lower levels of seed predation by ground squirrels this year than the past few years.
data in cgData repo: ~/cgData/summer2024/exPt02Phenology
Measure data (status, size, etc.)
data in SQL database
Harvest data (IDs of harvested heads, missing achenes, etc)
detailed data in dropbox: dropbox/CGData/140_reconcile/reconcile2024/reconcileOut/2024harvestListReconciledExport.csv
data in SQL database
data in echinaceaLab package (hh.2024)
Samples collected:
375 heads harvested
at CBG for processing
Products:
Papers
Pearson, A.E., Z. Zelman, L.A. Hill, M.A. Stevens, E.X. Jackson, M.M.N. Incarnato, R.M. Johnson, S. Wagenius, and J.L. Ison. 2023. Pollinators differ in their contribution to the male fitness of a self-incompatible composite. American Journal of Botany 110(6): e16190. https://doi.org/10.1002/ajb2.16190
Reed, W. J., J. L. Ison, A. Waananen, F. H. Shaw, S. Wagenius, R. G. Shaw. 2022. Genetic variation in reproductive timing in a long-lived herbaceous perennial. American Journal of Botany 109(11) 1861–1874: https://doi.org/10.1002/ajb2.16072
Page, M. L., Ison, J. L., Bewley, A. L., Holsinger, K. M., Kaul, A. D., Koch, K. E., Kolis, K. M., and Wagenius, S. 2019. Pollinator effectiveness in a composite: A specialist bee pollinates more florets but does not move pollen farther than other visitors. American Journal of Botany 106: 1487–1498. PDF
Grad student work
Wyatt Mosiman’s MS thesis (2024)
Amy Waananen’s paper “The fitness effects of outcrossing distance depend on parental flowering phenology in fragmented populations of a tallgrass prairie forb” (with co-authors Ison, Wagenius, and Shaw) was just accepted by New Phytologist–it includes data from parents in exPt01 and progeny in exPt02.
We may have missed some other products.
exPt05:
The only experimental plot at Staffanson Prairie Preserve (SPP), exPt05 was planted to compare progeny of maternal plants from burned and unburned sections of SPP. There were originally 2800 individuals planted, but high mortality made it impractical to visit the plot row-by-row. Now, we 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 2024, we found 17 living plants in exPt05 during flowering/total demo, 8 of which were flowering! We also observed (but did not take data on) additional basal plants within the plot boundaries that appeared to be growing on a 1×1 meter grid. ExPt05 persists!
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 plants in 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. In the summer of 2024, we conducted phenology between July 10th and July 19th. A total of 3,253 seedlings were originally found, but due to gradual mortality we only searched 448 positions in 2024 for plants, and we found evidence of 314 living individuals. We identified 24 flowering plants in with a total of 29 heads, of which we harvested 23.
data in cgData repo: ~/cgData/summer2024/exPt08Phenology
Measure data (status, size, etc.)
data in SQL database
Harvest data (IDs of harvested heads, missing achenes, etc)
detailed data in dropbox: dropbox/CGData/140_reconcile/reconcile2024/reconcileOut/2024harvestListReconciledExport.csv
data in SQL database
data in echinaceaLab package (hh.2024)
Samples collected:
23 heads harvested
at CBG for processing
Products:
None… yet!
tplot
tplot is located within the bounds of exPt08. Plants of many species here were rescued from the landfill site. They we transferred as chunks of prairie sod, and individual transplants. This year during flowering and total demo, we encountered 14 living Echinacea plants from which we harvest 12 heads.
Demography data: head counts, rosette counts, etc.
demap input files have been updated with 2024
Spatial location for all flowering and some basal (total demo) plants
demap input files have been updated with 2024
Harvest data (IDs of harvested heads, missing achenes, etc)
detailed data in dropbox: dropbox/CGData/140_reconcile/reconcile2024/reconcileOut/2024harvestListReconciledExport.csv
data in echinaceaLab package (hh.2024)
Samples collected:
12 heads harvested
at CBG for processing
Products:
None… yet!
Experimental plot management:
Just like other areas of the prairie, our experimental plots need management! Here’s a list of the stewardship activities that we conducted in or for our plots during 2024:
NU MS student Maddie Sadler shows off our sweet clover haul
None of our experimental plots burned in the fall or spring prior to the 2024 growing season
Collected seed to plant in p1, p2, & p8, including:
1) Elise collected Carex brevior, Carex bicknellii, and Carex gravida from several sites and from plants that we established a few years ago near exPt01
2) Liam established Viola pedatifida production tub,
3) We collected a few additional species (including Galium boreale, Solidago missouriensis, Astragalus adsurgens, Dichanthelium leibergii, and Bromus kalmii) we plan to establish via plug in spring 2025
Psst – next year person writing this report; I ran my numbers using the script Dropbox/echProjAdmin/projectStatusReports/psr2024/wmGatherDataForReports2024.R. Maybe this can help you out.
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.
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
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.
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.
Lindsey digs a hole for an Echinacea plugA baby Echinacea!Amy plants Echinacea in ExPt1 after the burn
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
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).
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!
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.
Amy collects pollen from Echinacea anthers
Start year: 2020
Location: On27, SGC, GC, NGC, EELR, KJ, NNWLF, NWLF, LF
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
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
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.
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!
