As part of the Echinacea Project’s long-term efforts to monitor reproductive fitness in the remnant populations, we harvested 124 Echinacea seed heads from 16 remnants during summer 2023. All sites burned in 2023 were included in remnant harvest selection and we also prioritized sites with small population sizes. We randomly selected heads from each population at the sites we visited.
Harvesting seed heads and quantifying seed set can help us to better understand how the spatial location and flowering phenology of Echinacea contribute to reproductive fitness. However, this year, we did not conduct field work for phenology, so we were less interested in relating remnant harvest to phenology and spatial mating opportunities. Our primary focus was to examine fire’s affects on reproduction in different sized populations. We narrowed our remnant harvest efforts to small sites where extra data would be helpful in answering questions about how fire influences mating opportunities and seed set across different populations ranging in size. The heads harvested in 2023 are currently in the CBG lab. We have entered the harvest data, and the heads are awaiting inventory!
Echinacea harvest in action!
In order to ensure that we are not disrupting remnant populations, we return achenes to their maternal plants in a way that mimics natural dispersal after they have been processed in the lab. On a recent trip to Minnesota, we visited many small sites, where this process is essential as well as a few bigger ones.
Start year: 1996
Location: Roadsides, railroad rights of way, and nature preserves in and around Solem Township, MN
Data collected: The verified harvest list and legend is located here: ~/Dropbox/remData/130_harvestSeedSet/harvest2023/2023remHarvestDataEntry/2023remEaHarvestDE/remEaHarvestVerified
Samples collected: ~124 seed heads were collected and are currently at the Chicago Botanic Garden lab awaiting inventory.
Products:
We will compile seed set data from 2023 into a dataset with seed set data from previous years.
Padmini, a student from Carleton College, used some of the remnant data for her externship project in winter 2022.
Jared, Amy, and Stuart’s paper “Habitat fragmentation decouples fire-stimulated flowering from plant reproductive fitness” was published in PNAS. Find links and more information here
You can read more about the reproductive fitness in remnants experiment, as well as links to prior flog entries about this experiment, on the background page for this experiment.
Congratulations, Team Echinacea! We are done processing all of the Echinacea heads that were harvested from prairie remnants in 2020, 2021, and 2022. On Thursday, I completed the final step of the ACE process: freezing. We want to preserve some remnant achenes for future experiments, so we stored them in the seed vault freezer at the Chicago Botanic Garden. They are now documented in the seed bank database. Here’s a summary of the remnant Echinacea stored in the freezer:
2020 and 2021: X-ray sheets (random sample of informative achenes) for all heads harvested in 2020 and 2021. Envelopes (achenes not part of random sample) for paired samples only.
2022: X-ray sheets and envelopes for all heads harvested in 2022.
With efficient packing, I was able to cram all of these achenes into two freezer bags. However, sealing the bags was definitely a two-person job. Echinacea from 2020 and 2021 are in one bag, and 2022 gets a bag all of its own. It feels very satisfying to wrap up these three years of data!
Stashing bags the freezerLook at these shiny bags! Do they contain astronaut food?
One of our main goals over the past two years has been to process all of the Echinacea harvested from remnants in 2020, 2021, and 2022 to investigate the effects of prescribed fire on flowering and fitness. We harvested 1,012 heads over these three years.
year
# of heads
rem2020
299
rem2021
383
rem2022
330
For each head, the end goal is to get an accurate count of the number of achenes and the seed set, a measure of pollination success. To collect these data, we sent the Echinacea through our high-throughput seed processing system, which we call the ACE process. (The true meaning of ACE is controversial: Always Cleaning Echinacea? Accurately Counting Echinacea? Achene Chaos Extraordinaire?) The ACE process has many steps: inventory, clean, recheck, scan, count, randomize, x-ray, classify, store.
In spring 2023, we finished processing all of the remnant Echinacea from 2020, 2021, and 2022! We send a huge thank you to all the students and volunteers who put in many hours on this project over the last few years. We couldn’t have done it without you!
Luk and Sue cleanWanying and Caitlin recheckLake Forest College students recheck and scanKat scansAllen countsPriti randomizesMarty, Char, Padmini, Caroline, and Allen agree: it’s a team effort!
Jared is currently adding the achene count and seed set data to the remnant data repository on the Echinacea Project website. All achenes are currently in the dehumidifier at the Chicago Botanic Garden. After two weeks of drying, they can be stored in the seed bank.
As part of the Echinacea Project’s long-term efforts to monitor reproductive fitness in the remnant populations, we harvested 330 Echinacea seed heads from 23 remnants during summer 2022. We randomly selected 15 heads from each population where we conducted phenology. If a population had fewer than 15 flowering plants, we harvested a randomly selected head from all flowering plants. In the fragmented populations we study, flowering plants often fail to produce viable seed due to limited mating opportunities. By harvesting seed heads and quantifying seed set, we can better understand how the spatial location and flowering phenology of Echinacea contribute to reproductive fitness.
We are keenly interested in understanding how fire influences reproductive outcomes in fragmented prairies. To this end, we harvested seed heads from 7 populations experimentally burned during spring 2022. We will examine how fire influences mating opportunities and seed set across different populations ranging in size. The heads harvested in 2022 are currently in the CBG lab. Volunteers and students have cleaned, rechecked, and scanned all 330 heads, and they have randomized and x-rayed 249 of the heads so far. We are making great progress!
Priti randomizes a head from 2022Allen counts Echinacea fruits (achenes)
Start year: 1996
Location: Roadsides, railroad rights of way, and nature preserves in and around Solem Township, MN
Data collected: The master data sheet of harvested heads is located here: ~Dropbox\remData\150_clean\clean2022\rem2022MasterDatasheetWithLetNos.csv
Samples collected: 330 seed heads were collected and are currently at the Chicago Botanic Garden lab.
Products:
We will compile seed set data from 2022 into a dataset with seed set data from previous years.
Padmini, a student from Carleton College, used some of the remnant data for her externship project this winter.
You can read more about reproductive fitness in remnants, as well as links to previous flog entries mentioning the experiment, on the background page for this experiment.
This summer, we harvested 330 Echinacea angustifolia heads from 23 prairie remnants. Remnant harvest started on August 16th and ended on September 14th, when we finally collected the last 4 heads, 3 at Steven’s Approach and 1 at Landfill West. We harvested the most heads on August 23rd, a total of 109 heads in one day. The heads are located in 15 gbags labeled RA-RP (there is no gbag RJ).
We only visited sites where we recorded phenology this summer, so we harvested from fewer sites than last year. We did not harvest from Aanenson, East Elk Lake Road, Near Town Hall, On 27, Riley, Railroad, or Town Hall.
Volunteers Luk and Sue clean rem2022 heads in the lab
After Manogya and I completed data entry on the harvest list, I inventoried all of the bags that we brought back to the lab. There were a few mysteries to solve. We had several extra heads, but they mostly turned out to be heads that were supposed to be harvested, but someone forgot to check them off on the harvest datasheet, so it looked like they were missing. However, there was one perplexing puzzle that took some sleuthing to unravel. Two different people claimed to have harvested a head with a black twist tie from plant 18066 at Landfill West. In the lab, I found two heads with black twist ties labeled 18066, but I knew that they couldn’t both be the same plant. I donned my Sherlock hat and examined all the available evidence: survey, demography, and phenology data. From the survey data, I figured out that plant 18066’s neighbor, plant 27711, also had a head with black twist tie, so one of the duplicate heads was likely from the nearby plant. The phenology data revealed that 27711’s head had white gunk on it during the summer, and it had more rows of achenes than 18066’s head. Sure enough, one of the heads was larger than the other and had a speck of white on it. Mystery solved! I removed the imposter from the bag of heads to clean.
The volunteers started cleaning the 2022 remnant heads on October 11th. They are currently working on gbag RE, bag 5 of 15, so they are making great progress.
So far this year, we have sadly not been able to have volunteers in the lab due to the continuing threat of COVID-19. However, over the last few months, we made quite a bit of progress on the remnant Echinacea harvests from 2020 and 2021. In the fall, we had help from volunteers, students from Lake Forest College, and externs from Carleton College. Thanks for your help! In January, Sophia finished cleaning the last head from 2021, which was an exciting accomplishment.
To track our progress in the lab, I created an R script to visualize the various steps of the ACE process for each batch of Echinacea. The figures for rem2020 and rem2021 are included here. Hopefully, this method will work for the cg harvests as well.
Click on the figures to enlarge
The ACE stages are listed along the x-axis, and the number of Echinacea heads are on the y-axis. The light blue shows how much we have completed, and the dark blue shows what remains to be done. The small numbers on each bar indicate the corresponding number of heads, and the width of the bars is roughly proportional to the amount of time each step takes. Along the top, the dates indicate the last day that the totals for each stage were updated.
The script to create these graphs can be found here: echinaceasandbox/oop/trackAceProgressTest.R
As part of the Echinacea Project’s long-term efforts to monitor reproductive fitness in the remnant populations, Team Echinacea harvested 383 seeds heads from 29 remnants during summer 2021. We randomly selected 15 heads from each population to harvest. If a population had less than 15 flowering plants, we harvested a randomly selected head from all flowering plants. In the fragmented populations we study, flowering plants often fail to produce viable seed due to limited mating opportunities. By harvesting seed heads and quantifying seed set, we can better understand how the spatial location and flowering phenology of Echinacea contribute to reproductive fitness. We are keenly interested in understanding how fire influences reproductive outcomes in fragmented prairies. To this end, we harvested seed heads from 8 populations experimentally burned during spring 2021. We will examine how fire influences mating opportunities and seed set across different populations ranging in size.
These heads we harvested are currently in the CBG lab being cleaned by volunteers and interns. We have even started scanning and counting achenes! Soon the new x-ray will be up and running, and we will begin to answer the burning questions we have about Echinacea reproduction in fragmented prairie remnants.
Stuart and Mia playing a game “harvest now?” to get independent assessments of whether Echinacea heads are ready to harvest
Start year: 1996
Location: Roadsides, railroad rights of way, and nature preserves in and around Solem Township, MN
Data/Materials collected: 383 seed heads were collected; these are currently at the Chicago Botanic Garden. Data sheets and other materials can be found here: ~Dropbox/remData
Products: We will compile seed set data from 2021 into a dataset with seed set data from previous years.
You can read more about reproductive fitness in remnants, as well as links to previous flog entries mentioning the experiment, on the background page for this experiment.
After wrapping up our first remnant burn of the season at east riley, the crew ventured into the wild western prairies of Grant County. Earlier in the day, Mia mowed burn breaks at yellow orchid hill east. This roadside patch had considerably more fuel than east riley and NW winds remained stiff when we arrived. Once water buckets had been staged and the crew briefed, we ignited a test fire in the southeast corner. This fire backed beautifully against the wind, moving steadily and burning fuel completely. One of my takeaways from burns this spring is that prescribed burns in a little lower relative humidity (RH = 25-30) and a little higher winds (12-18 mph sustained) seem to produce great results in burn units where brome is the primary fuel.
A nice sequence of photos illustrating how the burn at yoh.e progressed. We started with a test fire and observed that small fire before proceeding to burn the entire unit. We decided to ignite the downwind edge of the burn unit and allow that fire to back against the stiff wind. Looking at the fourth and fifth photos, you can see the wind push smoke to the south as the fire backs slowly against the wind moving north.
We decided to let the fire back against the wind across the entire burn unit. Once sufficient black had been established in the southeast corner of the unit, we ignited a backing fire along the entire southern edge of the unit along Wennersborg Rd. After fire lines were secured, Gretel grabbed the push power and finished mowing burn breaks at yellow orchid hill west while Jared, Stuart, and Mia extinguished any remaining hotspots. 30 minutes after ignition, we were left with an almost entirely blackened burn unit. Beautiful, predictable prescribed burn!
Temperature – 53 F Relative humidity – 30% Wind speed (max gusts) – 18 (21) mph wind direction – NNW Ignition time – 3:44 PM End time – 4:14 PM Burn crew: Jared, Stuart, Gretel, Mia
Before and after photos looking east along Wennersborg Rd
Before and after photos looking west along Wennersborg Rd
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.
Monitoring reproductive fitness in the remnant populations is a staple Team Echinacea summer activity. Understanding the reproductive success of plants in remnant populations provides insight to a vital demographic rate contributing to the persistence (or decline) of remnant populations in fragmented environments.
In the summer of 2020, we harvested 304 seeds heads from 29 populations (AAN, AAS, ALF-E, ALF-W, BTG, DOG, EELR, ERI, ETH, GC, LCE, LCW, NESS, NNWLF, NRRX, NWLF, ON27, RIN, RIS, RRX, SAP, SGC, TH, TOWER, WAA, YOH). These are the same populations where we measured flowering phenology. We randomly selected 15 heads from each population, if a population did not have 15 heads, we harvested all of the heads. We harvested heads from the following populations.
These heads are currently in the CBG lab and soon we will start the process of removing the achenes and assessing seed set. We are unsure how exactly we will assess seed set because the x-ray at the Chicago Botanic Garden isn’t working now. We may weigh the seeds.
Mia Stevens heading out to harvest
A harvested head
In the spring, we plan on burning some of these remnants and also collecting heads next fall. Estimates of seed set from these heads will serve as a baseline for comparing seed set before and after a burn. We will learn how fire affects reproductive success in small prairie remnants.
Start year: 1996
Location: Roadsides, railroad rights of way, and nature preserves in and around Solem Township, MN
Data/Materials collected: 304 seed heads were collected, these are currently at The Chicago Botanic Garden along with the paper data sheets. These data sheets need to be scanned, double-entered, and checked.
Products: We will compile seed set data from 2020 into a dataset with seed set data from previous years.
You can read more about reproductive fitness in remnants, as well as links to previous flog entries mentioning the experiment, on the background page for this experiment.
