After 5 months of preparation, we officially applied the first experimental treatments for our NSF proposal to study prescribed fire effects on prairie plant reproduction and population dynamics.
Weather conditions Tuesday afternoon were favorable for burning but wind forecasts were at the upper end of our burn prescription. Given our success burning p8 in similar conditions just a week earlier, we decided to proceed cautiously by starting with a prescribed burn on the north side of east riley. Here light and discontinuous fuel (mostly brome), a gravel road for a firebreak on the south side, and agricultural fields downwind mitigated our concerns about gusty winds. Earlier in the day, Mia mowed fire breaks along the east and west end of the burn unit. We ate lunch, loaded up our equipment, and drove down to east riley. Along the way, the crew got a great look at a western kingbird perched along Sandy Hill Road.
Once at the site, we reviewed the burn plan and staged equipment. We ignited a test fire in the southeast corner of the burn unit. Despite a slow start to the test fire and stiff NW winds that kept extinguishing the drip torch, the backing fire burned well through brome and scattered warm season grasses. With scattered poison ivy in the eastern third of east riley, we were cautious to stay upwind of smoke by lighting small strips perpendicular to the wind. Once sufficient black (burned area downwind) had been established, we proceeded to ignite the southern edge of the unit along Mellow Ln and wrap around the western end of the unit to ignite a head fire along the northern edge of the burn unit.
While somewhat patchy, we considered the burn a success. The fire behaved predictably and we felt comfortable that we could continue burning other units with more fuel. After the burn, Stuart shared the observation that the fire did not carry well in areas where fuel was covered by a film of silt/gravel. We packed up and drove a short distance into Grant County for our next set of burn units…
Temperature – 52 F Relative humidity – 34% Wind speed (max gusts) – 13 (22) mph wind direction – NNW Ignition time – 2:22 PM End time – 2:58 PM Burn crew: Jared, Stuart, Gretel, Mia
Before and after comparison looking west along Mellow Ln.
Last week Stuart, Gretel, Jared, and I headed northward from Chicago to Minnesota to perform the first prescribed burn of the season! On our drive up we hit some snow that was almost whiteout conditions very exciting, especially for April. We arrived in Douglas County late Wednesday night and quickly bundled into our sleeping bags.
Stuart examining the test fire of the Island
The next morning, we walked the unit/p8 and saw two bald eagles flying over the plot, we decided that this was a good omen for the burn. There are two areas in the unit that haven’t been burned in the past that we decided to burn this year, this was the island that is northeast of the plot and the “bee trees”. After examining the unit we set off to prep the unit and gather supplies. After a break for lunch, we ran a test of how the wooded area would burn by burning the island area. This burn went well, the fire moved slowly but we did kill a frog :(. Halfway through this burn Ruth and Frank arrived from the Cities, they were greeted with excitement and backpack sprayers.
After the success of burning through the woods in the island, we decided to burn through the bee trees. The bee trees burned very slowly Frank and I spend most of the burn focused on ensuring that no sparks from the bee’s trees got taken in the wind downhill. To the south of the bee trees, the burn brake is only mowed and still has quite a bit of brome that could be fuel. We were all shocked by the civilized behavior that the fire had around this burn break. Once we had a sufficient backfire Stuart light the head fire in the windward portion of the plot and boy it was spectacular. Our civilized fire politely ripped through the brome of p8 and even left many pin flags untouched!
The backfire heading southThe head fire heading through p8
After we were satisfied with the large p8 unit fire being out we gathered, including John VanKempen who arrived during the course of the p8 burn. We then headed down to Jean’s prairie plant garden and Jared, who was the burn boss for the final two burns, light a nice line around the perimeter of the garden, this burn only took 16 minutes. When we were waiting for the garden to burn we noticed a small adjacent patch of dried duff and we decided to burn that too! This burn went even faster than the prairie garden it was also much more powerful.
The burn crew! Left Gretel, Jared, Mia, John, Ruth, Frank (Stuart not pictured)
After the prairie garden and adjacent area were done burning, Stuart, Gretel, Jared and I made sure that everything was put out back at p8. We found a smoldering log and made some s’mores!
The next day, Jared and I inspected the remnant sites that we are planning on burning. Jared, Stuart, and I also broadcast some native prairie seeds (mostly two grasses: side-oats grama and little bluestem) that we collected in the fall in p8.
We performed this burn a week ago now, on Earth Day, performing a prescribed burn that aids in the restoration of the prairie was a wonderful way to celebrate. This was my first prescribed burn, overall it was really fun, impressive, exciting, and also boring. I am very excited to be heading back up to Minnesota to conduct more burns but also to see how the community changes after the burn.
The charred and snow-sprinkled plot on Saturday morning
Echinacea pallida Flowering phenology:Echinacea pallida is a species of Echinacea that is not native to Minnesota. It was mistakenly introduced to our study area during a restoration of Hegg Lake WMA. Since 2011, Team Echinacea has visited the pallida restoration and taken flowering phenology and collected demography on the non-native. We have decapitated all flowering Echinacea pallida each year to avoid pollination with the local Echinacea angustifolia. Each year we record the number of heads on each plant and the number of rosettes. We also get precise gps coordinates of all plants and then chop the flowering heads off! This year we cut E. pallida heads off on June 30th. We revisited plants and shot gps pointson September 17th 2020. When shooting points, we found two E. pallida plants that had missed the big decapitation event. We harvested the heads before any fruit dispersed.
Overall, we found and shot 99 flowering E. pallida. On average, each plant produced 1.96 flowering heads, with a total of 194 beheadings. The average rosette count was 6.1, the maximum was 31 rosettes — absolutely massive!!
Location: Hegg Lake WMA Start year: 2011
exPt6: Experimental plot 6 was the first E. angustifolia x E. pallida hybrid plot planted by Team Echinacea. A total of 66 Echinacea hybrids were originally planted; all have E. angustifolia dams and E. pallida sires. In 2020, we visited 40 positions and found 22 living plants. No plants have flowered in this plot yet. Location: near exPt8 Year started: Crossing in 2011, planting in 2012
You can find more information about experimental plot 6 and previous flog posts about it on the background page for the experiment.
exPt7: Planted in 2013, experimental plot # 7 was the second E. pallida x E. angustifolia plot. It contains conspecific crosses of each species as well as reciprocal hybrids. There were 294 plants planted, of these plants only 148 plants were still alive. There were 2 flowering plants this year! One was the progeny of a E. pallida x E pallida cross and the other of these flowering plants was a hybrid of E. pallida X E. angustifolia! This is the first hybrid to bloom. Anna M. investigated the compatibility of this hybrid with E. pallida and E. angustifolia by performing a series of hand crosses.
Location: Hegg Lake WMA Start year: Crossing in 2012, planting in 2013
exPt9: Experimental plot 9 is a hybrid plot, but, unlike the other two hybrid plots, we do not have a perfect pedigree of the plants. That is because E. angustifolia and E. pallida maternal plants used to generate seedlings for exPt9 were open-pollinated. We need to do paternity analysis to find the true hybrid nature of these crosses (assuming there are any hybrids). There were originally 745 seedlings planted in exPt9. We found 391 living plants in 2020, three of which were flowering! Two of these plants were technically “flowering” because they produced buds, but they produced zero flowering heads because no flowers ever opened (no pollen or fruits). There were 105 plants that we searched for but could not find. Location: Hegg Lake WMA Start year: 2014
You can find out more information about experimental plot 9 and flog posts mentioning the experiment on the background page for the experiment.
There were a total of three flowering heads between the three plots, we collected flowering phenology data on these heads. Flowering started on June 28th and ended between July 7th and 23rd. There were two additional flowering plants that only produced duds.
Data collected for exp679: For all three plots we collected rosette number, length of all leaves, and herbivory for each plant. We used visors to collect data electronically and it is still being processed to be put into our SQL database.
Data collected for E. pallida demography and phenology: Demography data, head counts, rosette counts, gps points shot for each E. pallida. Find demo and phenology visor records in the aiisummer2020 repository. GPS coordinates can be found in demap.
Look at this three-headed E. pallida monster we found! Shown at the beginning and end of season
We are still monitoring the fate of the patch of Hill’s thistle at Hegg Lake WMA. It is a unique patch in our study area, as far as we know. In summer 2020, we did not have time to visit the rosettes that we mapped out in previous years. Twice Stuart went to search for flowering rosettes. He found one! Here’s a photo of the flowering rosette from Sept 17th. Note it is all dried up. Stuart thinks that the head produced zero viable fruits because it looked like the head was intact and it crumbled when he handled it. But it is possible that that was a fruit that had already dispersed and the rest of the head remained intact.
The single flowering rosette of Cirsium hillii from 2020.
Start year: 2014
Location: Hegg Lake WMA
Data collected: none.
Products:
You can find more information about our experiment on how fire affects the fitness of Cirsium hillii and links to previous flog posts regarding this experiment at the background page for the experiment.
Echinacea pallida is a non-native species to the prairie of western Minnesota and E. pallida has the potential to out compete the native E. angustifolia. To learn more about this in 2020, we cross-pollinated E. angustifolia, E. pallida, and a E. angustifolia X E. pallida hybrid plant to assess interspecies compatibility. This experiment investigates the reproductive potential of E. angustifolia and E. pallida hybrids, of which may threaten native E. angustifolia preservation.
Since this was the first year that a hybrid plant flowered it was a great opportunity to investigate this question. On July 6th, 2020, seventy-six total hand crosses were completed to test mating compatibility. Three E. angustifolia and three E. pallida plants from Hegg Lake WMA were selected to serve as maternal plants in the experiment. Each treatment consisted of three crosses with pollen from the plant’s respective species, three crosses with the hybrid pollen, and three crosses with no pollen as a control. E. angustifolia and E. pallida pollen was collected from no less than three plants to reduce risk of self-pollination. Finally, pollen collected from each maternal plant was administered to the hybrid. The hybrid received nine crosses with three different E. angustifolia plants, nine crosses with three different E. Pallida plants, and three styles received no pollen as a control. The order of pollen administration was randomized across a designated row of styles.
Pollinator exclusion bags were used to limit exposure to pollinators. We later collected the heads from the hybrid, maternal E. angustifolia, and maternal E. pallida plants. In the winter, these heads will be x-rayed to assess seed set.
Stopped by P8 this morning and snowshoed out to P2. If you like these plots in the summer, the winter offers a new, unique perspective of the beauty of a prairie. The last few days, all vegetation has been covered in hoarfrost so the prairie lacks all color and seems like a black and white movie scene.
My dog Clyde (official spelling changed to Collyde). If you could meet him, you would understand.
On the south side of the P2, overlooking the plot.
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 field season the team continued the seedling recruitment experiment begun in 2007. The original goal of the project was to determine rates of establishment and growth of seedlings in remnant populations of Echinacea angustifolia. From 2007 to 2013, plants which had flowered in the preceding year were visited in the spring to find any emerging seedlings. Each fall since then, the team has searched for the seedlings, then juveniles, and measured them.
It is awkward to refer to our group of plants former seedlings (all plants were seedling). It’s too long to say juveniles or seedlings. So, Team Echinacea uses ‘sling’ as shorthand for a plant that was initially found as a seedling (with cotyledons!) in one of our remnant populations. After finding the sling, we censused it annually up to the present, unless it died.
In 2020 Team Echinacea visited 66 focal maternal plants in 12 prairie remnants to determine the survival and growth of their offspring (slings). The team searched for 140 of the original 955 seedlings and found 70 of them and couldn’t find another 69. The searches spanned August 24th – September 18th and took place on seven days. The majority of the slings were searched for on the first day, August 24th, 77 slings to be exact. One of the slings flowered this year, however, no achenes were produced–the head was a dud.
In 2020 Emma Greenlee investigated if siling survival can be predicted by its surrounding microhabitat. It turns out that something else is most likely affecting seedling survival not microhabitat.
Mia and Amy D. search for that last seedling at East Elk Lake Road
Sites with seedling searches East Elk Lake Road, East Riley, East of Town Hall, KJ’s, Loeffler’s Corner, Landfill, Nessman, Northwest of Landfill, Riley, Steven’s Approach, South of Golf Course, Staffanson Prairie
Data/materials collected: The EchinaceaSeedlings repository holds the data for this experiment. Lea Richardson restructured the repo in December 2019 to facilitate collaboration on the new project.
The master datasheet and stakefile can be found here Dropbox/remData/115_trackSeedlings/slingRefinds2020. None of the 2020 data are online yet.
Team members who refound seedlings in 2020: Lea Richardson, Drake Mullett, Emma Greenlee, Mia Stevens, Anna Meehan, John Vankempen, Amy Dykstra, Stuart Wagenius.
Products: Amy Dykstra used seedling survival data from 2010 and 2011 to model population growth rates as a part of her dissertation. Scott Nordstrom has used some of the sling data in a manuscript that is now in review.
You can read more about this seedling establishment project, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.
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 (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. 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.
As an intern with the Echinacea Project in summer 2020, Emma Greenlee conducted fieldwork for an independent project investigating whether microhabitat characteristics differ between 1 m-radius circles where Echinacea angustifolia seedlings have emerged and survived and circles where Echinacea seedlings emerged and died. An existing, long-term Echinacea Project experiment, the seedling establishment project (“Sling” for short) provided the GPS points corresponding to the surviving and dead seedling circles used in this project. Emma collected data on microhabitat characteristics (litter depth, vegetation cover, slope, aspect, distance to roads and fields, and community composition) and the floral neighborhood. Emma visited 69 maternal sling circles containing surviving seedlings and 66 sling circles where all seedlings were dead. In winter 2020, Emma conducted data analysis in R with help from Mia and Stuart, and plans to present findings at an ecology conference in summer 2021. You will have to read the presentation below to learn preliminary results or wait for the poster.
The floral neighborhood at Staffanson Prairie Preserve
Start year: 2020
Location: Remnant prairies in Douglas and Grant County, MN
Sites: East Elk Lake Road, East Riley, East of Town Hall, KJ’s, Landfill, Loeffler’s Corner, Nessman, North of Northwest of Landfill, Northwest of Landfill, Randt, Riley, South of Golf Course, Steven’s Approach, Staffanson Prairie Preserve
Data collected: GPS files for navigating to sling circles are at Dropbox/geospatialDataBackup2020/stakeFiles2020. Microhabitat/floral neighborhood data and R scripts are available at aiisummer2020/emma2020.
Products: Emma Greenlee’s Powerpoint presentation (below); poster to come!
