Reproduction in plants can be limited by access to pollen and resources. We previously found that Echinacea plants in the remnants are pollen limited, meaning that if they had access to more pollen, they would produce more seeds. However, the long-term effects of pollen limitation are unknown. Do plants that are super pollen saturated and have high amounts of pollen have a higher lifetime fitness than plants that are pollen limited? Also, we know that the plants in the remnants are pollen limited, but are the plants in the common garden environment also pollen limited? To answer these questions and more, 13 years ago Gretel randomly selected 39 plants from p1; half of these plants were randomly assigned to the pollen addition group, and the others were assigned to pollen exclusion. Every year, plants in the pollen exclusion have their heads bagged and they are not pollinated, while we hand cross every style in the pollen addition group.
In the summer of 2023, six of the original 39 plants were flowering, three from the addition treatment and three from the exclusion treatment. The exclusion treatment plants were covered with exclusion bags to prevent pollination, and the addition plants were hand-pollinated three times throughout the summer.
Start year: 2012
Location: exPt01
Physical specimens: 6 heads harvested from group receiving treatments, and an additional 18 heads harvested from plants in an open, control treatment. Heads are at the Chicago Botanic Garden awaiting processing
Data collected: Plant survival and measurements were recorded as part of our annual surveys in P1 and eventually will be found in the echinaceaLab R package. Data sheets were scanned and entered and can be found here: “~/Dropbox/CGData/115_pollenLimitation/pollenLimitation2023”
You can find more information about the pollen addition and exclusion experiment and links to previous flog posts regarding this experiment at the background page for the experiment.
In 2023, the team continued the seedling recruitment experiment begun in 2007. The original goal of the project was to determine seedling establishment and growth rates in remnant populations of Echinacea angustifolia. Seedling recruitment rates are rarely studied in the field, and this is one of the few studies tracking recruitment in the tallgrass prairie. From 2007 to 2013 in spring, Team Echinacea visited plants which had flowered in the preceding year, and they searched near these maternal plants to find any emerging seedlings. Each fall since then, the team has searched for the seedlings, then juveniles, and measured them.
This year, we visited 51 focal maternal plants at 10 prairie remnants and searched for 86 sling plants, a subset of the original 955 seedlings. We completed sling in two days: September 15th and September 18th. Like last year, team members used the demo form to collect data on the visors, and we also shot any seedlings we could find that didn’t already have a GPS point. In total, the team found 47 basal plants and 5 flowering plants!
Start year: 2007
Location: Remnants in Douglas County, MN
Sites with seedling searches in 2022: East Elk Lake Road, East Riley, KJ’s, Loeffler’s Corner, Landfill, Nessman, Riley, Steven’s Approach, South of Golf Course, Staffanson Prairie
The data were collected on a visor using the demo form. The team recorded plant status (can’t find, basal, dead this year’s leaves, dead last year’s leaves, flowering), number of rosettes, leaf count, nearest neighbors, and head count, if flowering.
Scanned datasheets are in Dropbox: ~Dropbox\remData\115_trackSeedlings\slingRefinds2023
Physical copies of datasheets and maps can be found in the “Search For Sling 2023” black binder located currently in Hjelm on the back desk.
Samples collected: NA
Team members who searched for slings in 2022: Abby Widell, Ellysa Johnson, Jan Anderson, Lindsey Paulson.
Products:
Amy Dykstra used seedling survival data from 2010 and 2011 to model population growth rates as a part of her dissertation.
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.
For more details on the momentous victory that occurred this morning in P1, please refer to Abby’s previous flog post. However, I thought I would add one final graph to the flog for satisfaction purposes. We finished measuring P1 early relative to the past two years. Last year, the team finished measuring P1 on August 24th, and Wyatt went back into the records from 2021 and determined we finished measuring P1 on August 21st last year. Shoutout to the crew this year that finished measuring 10,992 positions in record time!
