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burning btg 2022

After completing the nwlf burn on May 6, we packed up and drove south taking the scenic route to btg. Our goal was to get a look at TNC’s Staffanson west burn. Just north of the intersection of Hwy 27 we spotted a Swainson’s Hawk. Stuart noted this is the first time he has seen a Swainson’s Hawk in Douglas County. The Staffanson burn was ongoing, though the north and west lines were solid black. We circled around to btg in time to see a large column of smoke rising from Staffanson west. Presumably this was the head fire hitting the kettle pond.

Unlike the prior burn units, we had just received permission to burn btg and were not able to mow breaks. We decided the best course of action would be igniting along a wet line on the western and southern edges of the burn unit. We took weather, walked the unit, divided up responsibilities, and ignited a test fire. Stuart and Trygg wet lined down the western edge while I ignited. Upon turning the corner along the southern line, the more southern wind picked up and pushed a head fire across btg. The result was pretty good coverage and an efficient burned. Once the smoke dissipated, we packed up and returned to the farmhouse. Our plan was to burn Jean’s prairie garden quickly and then divide up. Alex and Trygg would take the GPS unit to shoot the boundaries of burn units while Stuart and Jared put away equipment.

Six experimental burn units in one afternoon… not too shabby.

Temperature: 69 F
Relative Humidity: 30 %
Wind Speed: 13 mph
Wind Direction: SSE
Ignition time: 4:35 PM
End time: 4:50 PM
Burn Crew: Jared, Stuart, Alex C., Trygg

burning nwlf 2022

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.

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

burning mapp 2022

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!

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

burning waa 2022

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.

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…

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

burning androPilot (east) 2022

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.

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

April showers bring May fires

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.

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.

Growing Green Milkweed

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.

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.

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!

2021 Update: Andropogon fire and flowering in exPt08

In summer 2020, Team Echinacea established two plots south of experimental plot 8 for a pilot experiment examining fire effects on Big bluestem (Andropogon gerardii) reproduction. Neither plot was burned during 2020. During spring 2021, we randomly selected the western plot to be burned.

Within each rectangular plot, we selected 30 random points. We then counted the number of flowering Andropogon culms within circular 1m2 subplot centered on each random point (within 56.4 cm). After excluding random points that overlapped with the plot boundary or other random points, we were left with 24 usable random points in the eastern plot and 23 usable random points in the western plot.

  • Start year: 2020
  • Location: South of exPt08
  • Overlaps with: Andropogon fire and flowering in remnants
  • Data collected:
    • Stakefile for random plot locations: ~Dropbox/geospatialDataBackup2021/stakeFiles2021/stakeAndroPilot2021.csv
    • Scanned data sheets: ~Dropbox/burnRems/pilotAndro/androPilot2021
  • Samples or specimens collected: Seed heads collected from 2020 and 2021 are currently stored in Jared’s office. These have been dried and will be cleaned / x-rayed to quantify seed set.
  • Products: Stay tuned!

You can read more about the Andropogon fire and flowering in exPt08 experiment, as well as links to prior flog entries about this experiment, on the background page for this experiment.

2021 Update: Seed addition transects in remnants

In 2021, Team Echinacea established 76 transects (each 4 m long) across 32 patches of remnant prairie in the study area. Transect locations were determined by generating an ordered list of random points (random integers corresponding with MN state plane coordinate system) within each remnant and selecting the first 2-4 random points that were located within ~5m of an adult Echinacea but avoided dense patches of flowering plants where we may have difficulty distinguishing experimental seedlings from natural recruits. Each transect originating at a random point is 4-m long and contains four 1-m segments. Most transects extend North from the random point but some extend East (in sites where North-South transects may span an entire ditch). One segment per transect was chosen at random to be planted in fall 2021 and one transect chosen at random to be planted during fall 2022.

  • Start year: 2021
  • Location: 32 patches of remnant prairie in and around Solem Township, MN
  • Overlaps with: Fire and seedling fitness in remnants
  • Data collected: locations for seed addition transects: ~echinaceagis/remSeedAdditionExpt/remSeedExptTransectLocations.csv
  • Samples or specimens collected: NA
  • Products: Stay tuned!

You can read more about the seed addition transects in remnants, as well as links to prior flog entries about this experiment, on the background page for this experiment.

2021 Update: Fire and seedling fitness in remnants

As part of the 2020 NSF grant to study fire effects on plant reproduction and population dynamics, we are implementing a seed addition experiment in numerous remnants. From previous studies, we know that fire can improve recruitment, which is important for population growth. However, our previous observations of recruitment in remnants conflate the amount of seed entering the seed bank and the seedlings emerging from the seed bank. The goal of this seed addition experiment is to help us directly quantify the effects of fire on seedling emergence and early seedling fitness. We will use these data to parameterize demographic models for Echinacea.

For the seed addition experiment, we established 76 transects distributed across 32 prairie remnants with Echinacea. One segment per transect was chosen at random to be planted in fall 2021 and one transect chosen at random to be planted during fall 2022. The study includes 9 sites burned during spring 2021 as well as 7 sites slated to burn during spring 2022. Seeds were sowed in groups of 50 (either one or two packets of 50 per segment planted). All seeds were derived from the 2016 heads harvested in p2.

  • Start year: 2021
  • Location: 32 patches of remnant prairie in and around Solem Township, MN
  • Overlaps with: Seed addition transects in remnants
  • Data collected: All data related to planting can be found here: ~Dropbox/burnRems/seedExp
  • Samples or specimens collected: Seed packets to be planted in fall 2022 are stored in see-through glass cabinets in the population biology lab at CBG.
  • Products: Stay tuned!

You can read more about the fire and seedling fitness in remnants experiment, as well as links to prior flog entries about this experiment, on the background page for this experiment.