2022 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 experimental plots 1, 2, 4, 5 and 8. 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).

Jo, Emma, Kennedy and Sophia measuring in the picturesque views of exPt02.

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 latter two experiments were continued the summer of 2022 and will have separate update posts). In 2022, we visited 7,273 of the original 10,673 positions planted and found 2,985 alive. Only 1,111 plants were classified as “flowering” in exPt01 this year. This is a drastic increase from the mere 79 plants that flowered in summer 2021 – coincidentally, the plot was burned in the spring prior to summer 2022 and not prior to summer 2021. In summer 2022, we harvested 1,588 total Echinacea heads in exPt01. No additional staples were added to the experimental plot this year.

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 2022, of the original 557 plants in INB1, 92 were still alive. Of the plants that were alive this year, 40 of them were flowering; this is a drastic difference from summer of 2021 where only one of the plants was 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”). 1,467 plants in qGen1 were alive in 2022. Of those plants, 592 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 2022, we visited 1,856 positions of the 3,961 positions originally planted. We measured 1,438 living plants, of which 651 were flowering, with a total of 1,168 flowering heads. In the fall, we harvested 558 heads from exPt02. We began harvesting on August 10th and completed harvesting on September 12th. 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. This 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 2022 we found 11 living plants, four of which were flowering! There were two heads that should’ve been harvested, but Alex and I forgot to harvest them (oops). 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 363 plants were found alive in 2022. There were 14 flowering plants in 2022, and 15 heads. On a side note, 3 additional flowering plants were found in t-plot, but the heads were eaten before we could harvest any of them. Location: Wagenius property

  • 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 eventually uploaded to SQL database. Currently, SQL database has measuring data up until 2021.
  • Samples or specimens collected: See above for total harvested heads in each plot.
  • Products: Many publications and independent projects.

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