Continuing our May 6 burning adventures, we departed mapp and drove west to nwlf. Our goal was to burn nwlf when conditions were most extreme to maximize burn coverage at nwlf.
After arriving at the site, staging equipment, and taking weather, I ignited a test fire in the NW corner of the unit. We were pleased with fire behavior and went ahead with securing the north edge of the burn unit. After rounding the tricky northeast corner, I tried extending the black in the ditch with little success. The fire did not carry well in the bottom of the ditch. We decided the best course of action was to ignite along the eastern edge of the unit before igniting in the ditch. I used a lot of fuel in the bottom of the ditch. This generated a lot of smoke but didn’t dramatically improve burn coverage in the bottom of the ditch at the north end of the unit. I ignited one more line along the western edge of the unit for good measure. The smoke soon subsided and we were left with a sufficiently charred ditch to leave us proud of our work. We packed up and departed for our last remnant burn of the afternoon.
Igniting along the north edge (Alex’s photo)
Securing the north break was strenuous work (Alex’s photo)
Lighting in this ditch bottom was an exercise in futility (Alex’s photo)
Jared re-evaluating tactics from the ditch (Alex’s photo)
Fire carried much better along eastern edge of unit (Stuart’s photo)
Jared dismayed by ratio of fire to drip torch fuel in the bottom of the ditch (Alex’s photo)
Who made all this smoke? (Stuart’s photo)
Pretty complete burn on south end of unit
Patchy burn in ditch on north end of burn unit (Stuart’s photo)
Temperature: 69 F Relative Humidity: 31 % Wind Speed: 13 mph Wind Direction: SE Ignition time: 3:30 PM End time: 3:58 PM Burn Crew: Jared, Stuart, Alex C., Trygg
Upon completion of our waa burn on May 6, we ventured north to mapp. After a quick discussion, we decided to enlarge the unit by ~10 m to the west just in case there were any Echinacea plants lurking outside the area where plants have flowered in the past. Stuart ignited a test fire in the NW corner. We installed a wet line along the western edge of the unit and Stuart ignited along the north edge. We secured the eastern edge where fuels were a bit heavier and watched the interior of mapp burn slowly and patchily. The thin film of silt seemed to prevent litter from burning in spots. We tried igniting unburned patches in the interior but soon concluded it was not worth the effort. We were eyeing at least two more burns and wanted to move quickly. While packing up equipment, we noticed a large plume of smoke rising from Staffanson!
A nice sequence of photos from the mapp burn courtesy of Alex C.
Temperature: 68 F Relative Humidity: 31 % Wind Speed: 11 mph Wind Direction: SE Ignition time: 2:45 PM End time: 2:58 PM Burn Crew: Jared, Stuart, Alex C., Trygg
After conducting a successful burn in the pilot Andropogon plot and eating lunch on May 6, we packed up our equipment and ventured over to waa to conduct two prescribed burns. Echinacea within two small patches at waa separated by ~100 meters. We chose to burn two small patches given our time constraints and the prairie restoration with lots of fuel immediately to the north. Plus Douglas County Parks plans to burn the restoration and ditch within the next couple years.
After staging equipment and taking weather, we ignited a test fire in the NW corner of the western unit. Fire behavior looked good so we secured the western edge of the unit before igniting along the northern edge. Stuart did what he could with the drip torch but the burn was patchy and crept slowly. Light and discontinuous fuels made a thorough burn impossible but the Echinacea patches burned well so we moved on to the east unit.
Stuart questioning the wisdom of burning ditches
Stuart concluding the solution is more fire in the ditch
Western burn complete
Our procedure was identical for the eastern burn unit: test fire, secure western edge, ignite along northern edge, go back with drip torch to ignite unburned patches to the best of our ability. Fuels in the eastern unit were more continuous but also greener. The eastern unit of waa was also somewhat patchy but the patches of Echinacea experienced good fire and we had our eyes on additional burns…
Stuart doing his best to burn light fuels
Echinacea tag awaiting the flames
Stuart’s view of the patchy east unit (Stuart’s photo)
Temperature: 69 F Relative Humidity: 31 % Wind Speed: 6-10 mph Wind Direction: SE Ignition time (west): 1:47 PM End time (west): 2:00 PM Ignition time (east): 2:08 PM End time (east): 2:35 PM Burn Crew: Jared, Stuart, Alex C., Trygg
To kick off our 2022 burn season, we conducted a prescribed burn in our eastern pilot Andropogon experimental plot on Friday, May 6. We burned the western plot in spring 2021.
After staging equipment and checking the weather with our new bluetooth-enabled Kestrel, we ignited a test fire in the NW corner of the plot. The fire looked great and out mowed break was doing its job so we proceeded with the fire. Stuart kept watch over the northern line while Alex and Trygg tended to the western edge. We allowed the fire to back downhill against the wind. After putting in a few strips to quickly widen the black, we ignited along the eastern and southern lines. The headfire quickly ran uphill. Apart from areas with discontinuous fuels along the northern edge, the burn was pretty thorough. Stuart noted that the wind was consistently southeast except for a southern push when we ignited the headfire. We agreed that lighting the headfire sooner would have been possible given conditions and the fire behavior we observed. All-in-all, a successful first burn of 2022 for the Echinacea Project. We are eager to learn how Andropogon gerardii responds to fire.
Staging equipment for the burn (Stuart’s photo)
Stuart’s view of strip fire from the NE corner (Stuart’s photo)
Jared and Trygg keeping an eye on the western break (Alex C.’s photo)
Alex C. tending to the southern break as the headfire runs uphill.
Temperature: 65 F Relative Humidity: 37 % Wind Speed: 13 mph Wind Direction: SE Ignition time: 12:03 PM End time: 12:24 PM Burn Crew: Jared, Stuart, Alex C., Trygg
A cold, wet spring put an early damper on our 2022 burn season but we got a great start this week with an efficient two-day trip to Minnesota. The weather looked sufficiently warm and dry to justify the trip from CBG. Our goal was to prep burn units in anticipation of better burn weather. Stuart and I thought there was an outside chance we might be able to burn P1 or the Andropogon pilot plot on Friday but conditions were far better than anticipated. Fuels were dry and steady south winds brought drier air. We focused our efforts Thursday on preparing burn units. Alex and I mowed/raked breaks at waa and mapp in the morning. Stuart joined us after lunch to scout lcw, mark the burn unit boundary at lfw, and remove a handful of pine and cedar trees within the unit. Alex and I finished the day by mowing breaks at nwlf and cutting breaks at sgc.
Pasqueflowers, prairie skies, and fresh ash at Staffanson Prairie.
The weather conditions that materialized Friday were ideal for prescribed burns: steady southeast wind, high temperatures in the mid 60s, relative humidity dipping to 30-35 percent, and good smoke dispersal. We were able to burn six experimental units and one bonus prairie garden between 11 AM and 6 PM. The Echinacea Project was not alone. TNC burned the western half of Staffanson on Friday and USFWS burned several WPAs. It was a very successful and efficient trip. Stay tuned to the flog for more detailed information about each experimental burn.
Burning Jean’s prairie garden at the end of the day. Thanks to Alex C. for the photos.
For the remnants, I finished data reconciliation for all the plants at Staffanson Prairie Preserve (spp) through 2021 in demap, our repository for data from the remnants. Each summer, we use the GPS to record the positions of every flowering Echinaceaangustifolia plant within the transect at Staffanson, and we also revisit plants that flowered previously to check whether they are still alive, a process called total demo. This winter, I connected records between years so we can track the life of individual plants across the years.
Last week, I completed demo.out for Staffanson in 2017, 2018, 2019, 2020, and 2021. Demo.out makes one record for each plant that we visited each year and records whether it was living or dead, whether it flowered, and how many heads it had. This is the dataset that we can use to do longitudinal data analysis and study the demography of Echinacea plants over time. In 2020, both sides of Staffanson burned, and it had the highest flowering rate in the past 5 years – 275 plants! Of those plants, 33 flowered for the first time. In 2021, there was just one new flowering plant.
On 18 February 2022, Amy, Jared, Mia, and Alex presented at the online Prairie Enthusiasts (TPE) conference. Posters were available online during the conference (February 15-19, 2022), and conference attendees could ask questions via the chat on the 18th. Check out the posters below!
This summer we harvested seed pods from 25 Green Milkweed (Asclepias viridiflora) plants in the study area. Green Milkweed is uncommon and seems to be declining in our study area. This species prefers similar habitat to Echinacea. Plants tend to be sporadically distributed across dry prairies on steep hillsides, sandy soils, and well-drained gravelly areas. Our experience has been that flowering plants often fail to produce seed. We rarely find more than a handful of plants that produce pods in a given year.
Flowering Green Milkweed with bumblebee visitor at Staffanson.
Green Milkweed with three pods at Landfill East.
After harvesting and drying seeds, Jared cleaned seed by removing their fluffy coma. Jared then counted all the seeds and randomly selected a minimum of 30 seeds for x-raying. X-rays revealed variation. Some ovules lacked an embryo , others had whole, intact embryos. Many ovlues fell somewhere in between. They contained embryos that were undersized, shriveled, or fragmented. There was no external evidence of seed predation. The proportion of full ovules ranged from 0 to 100 percent. We are not sure whether “partials” reflect resource limitation and seed abortion, a form of late-acting self-incompatibility, or something else entirely. We are doing some research to help us interpret the biology underlying these patterns.
X-ray image of Green Milkweed seeds. Note the variation in embryo size, shape, and integrity in the x-ray image.
Scanned image of the same Green Milkweed seeds.
After cleaning, counting, and classifying, Jared prepared a subset of Green Milkweed seed for germination. CBG’s production greenhouse will germinate and grow 392 milkweed seedlings representing 15 maternal lines. We will plant these seedlings in an area south of P8. Although these plants grow slowly, our hope is that they will be an excellent resource for investigating milkweed pollination in a couple years. We also hope to harvest seed from these plants and include Green Milkweed in our seed mixes for restoration!
In 2021, Lea Richardson conceived and initiated a 2-year study designed to test how fire affects community flowering phenology in remnant prairies in MN. We randomly sampled points in burned and unburned remnants for a total of 294 points. In a 1m radius around each random point, the number of flowering stems were counted for every plant species present in the circle twice a week from July 1-August 31. For some species, the radius extended past 1m. Random points used in this study were the same points used in the stipa project as well as other projects associated with Jared Beck’s postdoc studying fire in remnants. Lea also obtained estimates of total number of flowering plants of certain species for the whole site if the species in question was not in any of the random circles placed on the site (these additional observations should allow for more accurate flowering abundance curves to be obtained). Sites were divided into two driving routes with roughly half of the points visited on Monday and Thursday, and the other half visited Tuesday and Friday. This sampling protocol for the same sites will be repeated in 2022 to be able to compare points with and without fire across two years and among sites. Over 100 flowering species were identified within the circles. Data analysis will proceed on this first year of data in Spring 2022 and will be included as Chapter 4 of Lea’s dissertation.
Lea searches for flowering plants at a random point
Data collected: community phenology data, using visor form ptPhen (all data in aiiSummer2021 repo in ptPhen folder)
Samples or specimens collected: none
Products: [eventually] chapter 4 of Lea Richardson’s dissertation and hopefully a manuscript after 2022 data collection
You can read more about the community flowering phenology in remnants experiment, as well as links to prior flog entries about this experiment, on the background page for this experiment.
Alondra, Connor, Maeve, and Marina finished their mini-internships with us. It was a great experience for them and us. We appreciate their contributions to science and conservation and they gained valuable experience. As part of their plant biology class, Alondra, Connor, Maeve, and Marina, who are juniors and seniors at Lake Forest College, worked on two projects to assess effects of prescribed fires on reproduction in Echinacea. In the lab, they gained hands-on experience in seed biology over three Wednesday afternoons, including cleaning, scanning, counting, developing hypotheses, and data management. To test their hypotheses, they developed a dataset and summarized their results. In class they presented posters and they are attached here. It was a wonderful mini-internship–thanks to Alondra, Connor, Maeve, and Marina, as well as Prof. Westley!
