2020 Update: common garden experiments

Since 1996, members of Team Echinacea have walked, crawled, and ~sometimes~ run next to rows of Echinacea angustifolia planted in common garden experiments. Although protocol varies depending on the experimental plot, every year team members record flowering phenology data, measuring data, and harvest the heads of the thousands of plants we have in common garden experiments.

Note that these experiments are not really gardens. “Common garden” refers to the experimental design. Most of our experimental plots are prairie restorations, a few are abandoned ag fields that are manged as grassland habitat. Some plots have multiple experiments within. The Echinacea Project currently has 10 established experimental plots:

exPts01-10. To avoid repetitiveness of reports on yearly phenology, measuring, and harvesting, this project status report will include updates on all experimental plots 1, 2, 4, 5, and 8. Reports for the others will be elsewhere: 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. In 2020, we visited 4,340 of the original 10,622 planted and found 3,258 alive. Only 484 plants were classified as “flowering” in exPt01 this year. This is a drastic increase from the nearly 70 plants that flowered in summer 2019 – perhaps it is a testament to the benefits of controlled burning (we burned in spring 2020 but not in 2019). In summer 2020, we harvested ~815 total Echinacea heads in exPt01 (I have not finished the reconciliation process). In the fall, we added 484 staples to positions where plants were gone for three straight years, however, we ran out of staples, so 130 of these positions have “flaples” which are bent pin flags.

exPt02: Heritability of flowering time is the name of the game in exPt02. Planted in 2006, exPt02 was planted to assess heritability of flowering start date and duration in Echinacea. In summer 2020, we visited 2,010 positions of the 3,961 positions originally planted. We measured 1,638 living plants, of which 444 were flowering. In the fall, we harvested ~626 heads from exPt02. We do not have an exact number of heads harvested from exPt02 yet, as we have not had time to complete head reconciliation. 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 measure 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 2020 we found 11 living plants, two of which were flowering! There was only one head to collect, since one of the flowering plants exhibited only vertical development (no head). 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 562 plants were found alive in 2020. There were 5 flowering plants in 2020, and 5 heads. Note that there were an additional 2 heads collected from transplant plot.

Plot management: To ensure that the common garden environment is as similar as possible to the prairie environment we must actively manage it. This management includes removing foreign species and supplementing with natives. One of our main management methods is through fire. We were unable to burn plots this fall however we hope to burn p8 and p1 this spring. We also collected seed to spread after burns including Schizachyrium scoparium, Bouteloua curtipendula, along with multiple species of Solidago and quite a few Asters.

Asclepias viridiflora in p1: In 2019, plugs of an uncommon prairie milkweed, Asclepias viridiflora, were planted in Experimental plot 1. The purpose of this experiment is to assess the survival and fitness of A. viridiflora. Assessing vitality will also provide a frame of reference for species conservation across modern prairies. In 2020 a protocol was developed to identify and measure A. viridiflora. These data are waiting to be entered and analyzed.

Hesperostipa demography:  In 2009 and 2010, porcupine grass (Hesperostipa spartea, a.k.a. “stipa”) was planted in experimental plot 1. In total, 4417 seeds were planted, 1 m apart from each other and all 10 cm north of Echinacea plants. Between 2010 and 2013, each position was checked, and the plant status recorded. Since 2014, we have searched for flowering plants. The data from this summer can be found here cgdata/summer2020/stipaSearch, these data have not been processed yet.

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. We continued to measure fitness and flowering phenology in these plants. In 2020, of the original 557 plants in INB1, 111 were still alive. Of the plants that were alive this year, 30 (27%) were flowering. This is up from the 4% that were flowering last year. All individuals were planted in 2001.

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”). In 2020 we assessed survival and fitness measures of the qGen1 plants. 1,642 plants in qGen1 were alive in 2020. Of those, 17% flowered in 2020. All were planted in 2003.

Stuart and John measure Echinacea plants in exPt02 under a gloomy sky

For more information on survival in common garden experiments, see this flog post about survival in common gardens.

Start year: Various, see individual listings above. First ever planting was 1996.

Location: Various, see above

Overlaps with: Pretty much everything we do.

Data/ materials collected: Measure data for all plots. All raw measure data available in cgData repository. Processed data should eventually be available in SQL database; ask GK for status of SQL database. GPS points were shot for the exPt09 flowering plant. Find the GPS jobs containing the exPt09 corners here: Dropbox/geospatialDataBackup2020/convertedASVandCSV2020/EXPT9_20200917_DARW.asv The stake file to find exPt5 plants is here: Dropbox/geospatialDataBackup2020/stakeFiles2020/exPt05stakeFile.csv Products: Many publications and independent projects.

Project status update: Phenology and fitness in experimental plot 1


Experimental plot 1 (P1) encompasses 11 different experiments originally planted with a total of 10673 Echinacea individuals. These experiments include long-term studies designed to compare the fitness of Echinacea from different remnant populations (“EA from remnants in P1”), examine the effects of inbreeding on plant fitness (“INB” and “INB2”), and explore other genetic properties of Echinacea such as trait heritability (“qGen”). In 2014, Team Echinacea measured plant traits for the 5409 Echinacea plants that remain alive and followed the daily phenology of 567 flowering heads. Echinacea began producing florets on July 1 and continued flowering in P1 until August 24. The data collected in 2014 will allow us to estimate the heritability of various traits and assess the lifetime fitness of plants from the numerous experiments.

Experiment Year planted # alive # flowering # planted
1 1996 1996 314 115 650
2 1997 1997 270 57 600
3 1998 1998 32 3 375
4 1999 1999 542 106 888
5 1999S 1999 297 37 418
6 SPP 2001 318 14 797
7 Inbreeding 2001 221 15 557
8 2001 2001 170 11 350
9 Monica 2003 2003 28 3 100
10 qGen 2003 2501 122 4468
11 INB2 2006 716 41 1470

Start year: 1996

Location: experimental plot 1


Overlaps with: aphid addition exclusion, Pamela’s functional traits, pollen longevity, pollen addition exclusion