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In 2017, we monitored the start and end dates of flowering for the 676 flowering plants (1116 heads) in experimental Plot 2. The first head started shedding pollen on June 26 and the latest bloomer ended flowering on August 19. Peak flowering was on July 13th. Note that these dates are subject to change as this is preliminary data that has not been fully cleaned and analyzed.
To examine the role flowering phenology plays in the reproduction of Echinacea angustifolia, Jennifer Ison planted this plot in 2006 with 3961 individuals selected for extreme (early or late) flowering timing, or phenology. Using the phenological data collected this summer, we will explore how flowering phenology influences reproductive fitness and estimate the heritability of flowering time in Echinacea angustifolia.
 One of the earlier flowering plants at exP2 this summer, a plant with 5 heads at Row 2 Position 1. Start year: 2006
Location: Experimental Plot 2, Hegg Lake WMA
Overlaps with: phenology in experimental plots, phenology in the remnants
Physical specimens: We harvested approximately 1081 heads from exPt 2 (preliminary inventory). Some of these heads had a major loss of achenes, either due to the early flowering time that we were not expecting or windy and rainy weather that dispersed the achenes quickly. We brought the harvested heads back to the lab, where we will count fruits and assess seed set for each head.
Data collected: We visited all plants with flowering heads every two days (three days after weekends) until they are done flowering to record start and end dates of flowering for all heads. We will manage phenology data in R and add it to the full dataset.
Products: Will estimated heritability of flowering time using data from 2015 and presented his findings last summer at ESA (see his poster). He is continuing this work by assessing how heritability estimates differ between years in burn and non-burn years, now including 2016.
You can find more information about the heritability of flowering time and links to previous flog posts at the background page for the experiment.
This summer we collected samples of pollinators from 39 roadside sites using yellow pan traps. We captured over 400 insects across 8 weeks. The specimens are stored frozen until pinning and identification. We will use this information to make comparisons between the pollinator communities collected in 2004. This information could inform potential diversity and abundance changes across the 13 years, and provide valuable insight into potential pollinator decline in this system.
Pollinator diversity and abundance are declining due in part to land use changes such as habitat destruction & fragmentation, pesticide contamination, and numerous other anthropogenic disturbances. The extent to which pollinator diversity and abundance is changing is not well understood, especially within tallgrass prairie ecosystems. Pollinators are important in the prairie: they provide valuable ecosystem services to native plants and to important plants used in agriculture.
The goal of this experiment was to repeat a similar study done in 2004 by Wagenius and Lyon, in which they collected information on pollinator abundance and diversity with the aim of relating landscape characteristics to bee community composition.
 Augochlorella sp. foraging for pollen. Our yellow pan traps are similar in color.
 Flowering Solidago speciosa at Staffanson Prairie Preserve. In the summer or 2017, Lea repeated her observational study quantifying flowering phenology and reproductive success (seedset) for Liatris aspera and Solidago speciosa plants located along a transect at Staffanson Prairie Preserve. Staffanson is divided into east and west units. The west unit of Staffanson was burned Spring 2016. In 2016, Lea looked for differences in phenology and reproduction of east vs. west Liatris and Solidago plants. In 2017, neither unit was burned. Data collected this year combined with data collected in 2016 will enable us to to see if burns influence phenology or reproduction. To assess phenology, Lea visited plants three times a week and recorded if they were flowering. She took GPS data for each plant included in the study. To assess reproduction (seedset), plants were harvested and brought back to the Chicago Botanic Garden so that seeds could be removed from the plant and x-rayed. This study helps us understand how fire, phenology, and reproduction are linked in species that are related to Echinacea angustifolia.
Start year: 2016
Location: Staffanson Prairie Preserve
Overlaps with: Fire and fitness of EA, Flowering phenology in remnants
Physical specimens:
- 70 harvested Liatris aspera specimens from summer 2017, located at the CBG
- 70 harvested Solidago speciosa specimens from summer 2017, located at the CBG
Data collected: Phenology data was taken on the visors every Monday, Wednesday, and Friday through the growing season. Paper harvest data sheets were used and will remain in Minnesota until the final harvest of the season.
GPS points shot: ~140 new GPS points were shot, one for each plant monitored in summer 2017 and ~180 points were staked to revisit plants that flowered last year. For each point staked, the plant status was recorded as either basal, flowering, or not present.
 Successful pollination leads to full achenes and higher fitness later in the season! This summer we counted shriveled and non-shriveled rows of styles three times per week for every Echinacea head in 8 of the 28 remnant populations. We also harvested 121 Echinacea heads to be analyzed for seedset data. This year we selected heads for harvest based on their position within randomly selected plots where Tracie Hayes and Lea Richardson collected vegetation data. In every randomly selected vegetation plot, all species were identified and we recorded their abundance. We marked any Echinacea head within a vegetation plot for harvest. Harvested heads are ready to be processed by citizen scientists at the Chicago Botanic Garden. In the lab, heads will be cleaned so that all achenes can be counted and x-rayed to determine seedset.
Measuring the reproductive success of an Echinacea angustifolia head gives insight into the fitness of the individual. In remnant populations, we measure reproductive success using two methods: style persistence and seedset. Seedset is the proportion of all seeds that are viable in an Echinacea head, and is measured in the lab after heads have been harvested. Style persistence is a fitness measure that can be taken during the field season. Styles, the showy female reproductive structures that emerge from every floret in an Echinacea head, shrivel within 24 hours if they receive compatible pollen. Keeping track of how many styles shrivel and how many persist can give us a sense of the reproductive success of that head without any lab work.
Year: 1996
Location: Roadsides, railroads and rights of way, and nature preserves in and near Solem Township, Minnesota.
Overlaps with: flowering phenology in remnants, mating compatability in remnants
Physical specimens: 121 harvested heads, currently at the Chicago Botanic Garden
Data collected:
- Style persistence data for each flowering head, collected three times per week, stored in remData
- Dates and identities of harvested heads, stored on paper datasheets entered electronically into richHood
GPS Points Shot: A point for each flowering head, stored under PHEN and SURV records in GeospatialDataBackup
Products:
You can find out more about reproductive fitness in the remnants and read previous flog posts about it on the background page for the experiment.
 Echinacea head with pollinator exclusion bag. Does receiving the maximum amount of pollination vs. no pollen at all affect a plant’s longevity or likelihood of flowering in subsequent years? We are trying to find out in this long-term experiment, but flowering rates have been so low in the past few years we are not learning much.
This summer, only three plants flowered of the 27 plants remaining in the pollen addition and exclusion experiment. We continued experimental treatments on these flowering plants and recorded fitness characteristics of all plants in the experiment. Of the original 38 plants in this experiment, 13 of the exclusion plants and 14 of the pollen addition plants are still alive.
In this experiment we assess the long-term effects of pollen addition and exclusion on plant fitness. In 2012 and 2013 we identified flowering E. angustifolia plants in experimental plot 1 and randomly assigned one of two treatments to each: pollen addition or pollen exclusion. When plants flower in subsequent years they receive the same treatment they were originally assigned. Because flowering rates have been so low in 2016 & 2017, differences in flowering due to treatment are not detectable.
Start year: 2012
Location: Experimental plot 1
Physical specimens: We harvested three flowering heads from this experiment that will be processed with the rest of the experimental plot 1 heads to determine achene count and proportion of full achenes.
Data collected: We recorded data electronically as part of the overall assessment of plant fitness in experimental plot 1. We recorded dates of bagging heads and pollen addition on paper datasheets.
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.
 Aphids on an Echinacea leaf This summer Team Echinacea continued adding and excluding aphids to plants in the experiment that Katherine Muller started. In 2011, Katherine Muller designated a sample of 100 Echinacea plants in experimental plot 1 for aphid addition or removal. The presence or absence of these aphids was maintained by team members once a week in the summer of 2017, for a total of 7 weeks from early July to mid August. We maintained addition on 31 plants and exclusion on 30, for a total of 61 plants. Will Reed set up a data entry system where we could enter data twice from the paper sheets and check for data-entry errors. In early October, Lea Richardson and Tracie Hayes recorded signs of senescence in the leaves of treatment plants. This data can be combined with data from our common garden measuring data to explore the richness of the Echinacea-aphid relationship.
Aphis echinaceae is a specialist aphid that is found only on Echinacea angustifolia. Read more about this experiment.
Start year: 2011
Location: Experimental Plot 1
Overlaps with: Phenology and fitness in P1
Data collected:
- Aphid counts for each treatment plant on each observation day, on paper
- Aphid counts recorded in csvs, on the teamEchinacea2017 dropbox
- Leaf senescence data, recorded on paper
- Initial and final assessment of aphid counts on treatment plants, recorded on paper
- Aphid counts also included in p1 measuring data
Products:
- 2016 paper by Katherine Muller and Stuart on aphids and foliar herbivory damage on Echinacea
- 2015 paper by Ruth Shaw and Stuart on fitness and demographic consequences of aphid loads
- 2015 poster by Daniel Brown and Kyle Silverhus (Lake Forest College) on achene and seed set differences on treatment plants
You can read more about the aphid addition and exclusion experiment, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.
This year we monitored the original 28 C. hillii rosettes at Hegg Lake WMA to check the fitness and persistence of our original individuals/population. Presently, 10/28 rosettes remain, all as non-flowering basal rosettes. For each rosette, we measured the length of the longest axis and the corresponding perpendicular axis. No burns were conducted this year.
This experiment assesses effects of fire on the fitness of Cirsium hillii (Hill’s thistle) plants at Hegg Lake WMA. Like Echinacea, C. hillii inhabits dry prairies, but Hill’s thistle is listed as a Species of Special Concern in Minnesota and little is known about how it responds to fire. Burn and non-burn units were created prior to an experimental fall burn conducted by the Department of Natural Resources (DNR) in 2014. That year, we mapped 28 C. hillii rosettes (basal and flowering).
 The distribution of Cirsium hillii, a rare endemic to the Great Lakes region. Last year was also a non-burn year, although of rosettes found, there were three flowering rosettes. It’s challenging to determine cases of mortality with this species, since C. hillii is clonal, and it’s possible that each rosette is not a unique individual.
In 2015, Abbey White found that there was only one or two individuals in our C. hillii “population!” We don’t know of any other C. hillii populations in Douglas County. We are possibly monitoring the last individual in the area.
You can find out more about Cirsium hillii fire & fitness and read previous flog posts about it on the experiment background page.
 We observed that 95% surviving members of the 1996 cohort were basal in 2016 Does receiving the maximum amount of pollination vs. no pollen at all affect a plant’s longevity or likelihood of flowering in subsequent years? In this experiment we assess the long-term effects of pollen addition and exclusion on plant fitness. In 2012 and 2013 we identified flowering E. angustifolia plants in experimental plot 1 and randomly assigned one of two treatments to each: pollen addition or pollen exclusion. When plants flower in subsequent years they receive the same treatment they were originally assigned.
Across all experiments, 2016 was a low flowering year. Only four plants flowered of the 29 plants remaining in the pollen addition and exclusion experiment. We continued experimental treatments on these plants and recorded fitness characteristics.
Start year: 2012
Location: Experimental plot 1
Physical specimens: We harvested four flowering heads from this experiment that will be processed with the rest of the experimental plot 1 heads to determine achene count and proportion of full achenes. The labels for these heads, beginning with the letter “p,” identify them as part of the pollen addition and exclusion experiment.
Data collected: We recorded data electronically as part of the overall assessment of plant fitness in experimental plot 1. We recorded dates of bagging heads and pollen addition on paper datasheets.
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.
 E. pallida heads are easily distinguished from E. angustifolia by their white pollen and longer ray florets. Echinacea pallida, an Echinacea species compatible with E. angustifolia, but not native to our study area, was planted at a restoration at Hegg Lake WMA. One trait of E. pallida may limit its potential to hybridize with E. angustifolia individuals is the synchrony of their flowering timing, or phenology. To study this, we have kept track of the start and end dates of flowering for Echinacea pallida individuals in the Hegg restoration plot since 2011. In 2016, we identified 66 flowering plants with 113 heads. Flowering began on June 18th. Then, around July 7th, we chopped off all the Echinacea pallida heads.
Start year: 2011
Location: Hegg Lake WMA restoration
Overlaps with: Echinacea hybrids (exPt6, exPt7, exPt9), flowering phenology in remnants
Physical specimens: 113 heads were cut from E. pallida plants circa 7 July 2016 (the last day of recorded phenology). These specimens were likely composted.
Data collected: We collected phenology data using handheld computers.
GPS points shot: We shot points for the 66 flowering E. pallida plants.
Products: In Fall 2013, Aaron and Grace, externs from Carleton College, investigated hybridization potential by analyzing the phenology and seed set of Echinacea pallida and neighboring Echinacea angustifolia that Dayvis collected in summer 2013. They wrote a report of their study.
Previous team members who have worked on this project include: Nicholas Goldsmith (2011), Shona Sanford-Long (2012), Dayvis Blasini (2013), and Cam Shorb(2014)
You can find more information about Echinacea pallida flowering phenology and links to previous flog posts regarding this experiment at the background page for the experiment.
 The team after an initial measurement of p9. Blue flags are positions where Echinacea weren’t found. This summer, we remeasured plants in experimental plot 9 at Hegg Lake. These plants are hybrids of Echinacea angustifolia (native) and Echinacea pallida (non-native, but planted at a nearby restoration). Unlike the plants in p7, these plants came from open-pollinated parents – that is, there was no artificial crossing done. Stuart and Lydia English planted the seeds in May of 2014. Much like with plot p7, an analysis the survival and fitness of these plants can give insight into whether or not hybrid populations can be viable in our study areas, and whether or not they pose a threat to native E. angustifolia in our remnants. We have returned to the plot each of the last three years to measure number of rosettes and leaf lengths of these plants.
Table 1 shows the number of plants found alive during each search. These plants were measured on August 4th and rechecked on August 23rd. No plants flowered this year, although there were several found that had leaves over 40cm long.
| Year / Event |
Number Alive |
% Original remaining |
% Of prev. year |
| Planting (2014) |
746 |
100 |
|
| 2014 |
638 |
85.5 |
85.5 |
| 2015 |
521 |
69.8 |
81.7 |
| 2016 |
493 |
66.1 |
94.6 |
Start year: 2014
Location: Hegg Lake Wildlife Management Area — experimental plot 9
Overlapping experiments: Echinacea hybrids — experimental plot 6, Echinacea hybrids — experimental plot 7
Data collected: Rosette number, length of all leaves, herbivory for each plant collected electronically and exported to CGData. Recheck information for plants not found was also collected electronically and stored in CGData.
You can find out more information about experimental plot 9 and flog posts mentioning the experiment on the background page for the experiment.
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