For our seed addition experiment, we want to know exactly how many seeds we planted in each 1 m transect. Each transect got seeds from one envelope. Before planting, we took xrays of the fruits in the paper envelopes. With minimal processing, the radiographs look good! We have a batch of 251 images to classify. This sounds like a job for Allen Wagner aka “the Count” (of Achene County).
Radiograph of Echinacea fruits in envelope 105.3a /230. Other partial envelopes are visible on the margins.
We used the column blower and other techniques to remove empty fruits. We aimed for about 50 seeds per envelope. How many do you count?
In 2021, Team Echinacea established 76 transects (each 4 m long) across 32 patches of remnant prairie in the study area. We planted seeds in one randomly selected segment per transect in fall 2021 but germination trials in the lab and seedling searches in the remnants during summer 2022 revealed that we had used a bad batch of seed
In fall 2022, we repeated seed addition experiment using seed harvested in summer 2022. Stuart, Lindsey, and Alex sowed seed within randomly selected segments in November 2022. For fall 2022, we added 12 seedling transects (beng, fern, hutch, torge) and eliminated transects at two disturbed sites with the goal of maximizing variation in fire history across the study area. We sowed seed in 84 transects across 36 remnant prairie patches in 2022. In 54 segments, we added 50 seeds and at 30 randomly selected segments, we added 100. This variation in number of seeds sown will allow us to understand the implications of seedling density.
Cut to 2023! In early June, Team Echinacea searched for seedlings once again, this time, with more success. We found 260 seedlings in total across our 84 transects during our seedling searches (we did two rounds).
In August we returned to our transects and assessed survival of the seedlings that had emerged earlier in the season. Stay tuned for more information on seedling mortality.
We also measured light availability (using a light meter) and soil compaction (using a soil penetrometer) at each of the segments along the transects. This information will give us a better sense of the conditions under which seedlings emerge and survive. And importantly, how does fire influence these conditions?
I spy seedlings! During our search for Echinacea Seedlings, we used toothpicks to keep track of individuals.
Team Echinacea didn’t stop there. In November of 2023, we went back to Minnesota and sowed seed in randomly selected segments in our 84 transects. Stay tuned to see what emerges in the spring!
Wyatt sprinkles seeds along a seed addition transect during a trip to Minnesota in November!
Start year: 2021
Location: 36 patches of remnant prairie in and around Solem Township, MN
Data collected: Seedling search data, par data and soil compaction data are all stored in ~repos/seedaddexpt. Additional information is stored in ~/Dropbox/burnRems/seedExp”
Samples or specimens collected: NA
Products: Daytona, summer 2023 high school research participant, used the data to ask, “does time since last burn treatment affect seedling emergence?” Materials for this project are located in ~”/Dropbox/teamEchinacea2023/daytonaHoberg”
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.
In 2021, Team Echinacea established 76 transects (each 4 m long) across 32 patches of remnant prairie in the study area. We planted seeds in one randomly selected segment per transect in fall 2021 but germination trials in the lab and seedling searches in the remnants during summer 2022 revealed that we had used a bad batch of seed 🙁 In fall 2022, we repeated seed addition experiment using seed harvested in summer 2022. Jared harvested Echinacea seed heads from Nice Island and Hutching’s hills. High seed predation from Hutchings left us with 155 heads from Nice Island. Stuart, Lindsey, and Alex sowed seed within randomly selected segments in November 2022. For fall 2022, we added 12 seedling transects (beng, fern, hutch, torge) and eliminated transects at two disturbed sites with the goal of maximizing variation in fire history across the study area. We sowed seed in 84 transects across 36 remnant prairie patches in 2022.
Start year: 2021
Location: 36 patches of remnant prairie in and around Solem Township, MN
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.
Last week, we drove to MN in the middle of the week for our last chance for field work before the snow. Jared and Wyatt stayed behind to take care of the Lake Forest College students who are doing a project in the lab on Wednesdays. Our goal in MN was to plant seeds for the seed addition project, an experiment measuring the effects of prescribed fire on seedling germination and emergence in Echinacea.
For the study, we established 4-meter-long transects at 36 sites across the Echinacea Project study area, for a total of 84 transects. Each transect is divided into 4 segments, and this fall, we planted one of those meter-long segments with either 1 or 2 packets containing 50 seeds each. Since we know how many seeds we planted (we know exactly how many because Wyatt x-rayed them!), we can record how many seedlings emerge in the spring and calculate accurate germination rates.
Lindsey plants a seed addition transectWe sprinkle seeds between 5 and 95 cm
Our goal on Wednesday was to plant all 84 transects before sunset at 4:50 pm. November 9th, 2022 dawned cold and rainy. Stuart, Lindsey, and I started the day at Tower and Nice Island to do a practice run together. We soon learned that the drizzle would make planting seeds difficult. The achenes stuck to everything: the envelope, the grass, the meterstick, and our fingers when we tried to remove the achenes from the meterstick. Nevertheless, we persisted. After sprinkling seeds along each transect, we carefully checked meterstick to make sure there were no renegade achenes. We finished 59 transects in the morning and regrouped to put on dry clothes and feast on Jean’s delicious hummus for lunch. I greatly regretted that I had no rain pants.
After lunch, the sky was still overcast, but the rain stopped, which made it much easier to sprinkle seeds. This year, we added several new locations, and we needed the GPS to map them out: Torgeson (east and west), Hutchings (east and west), Fern, and Bengston. Unfortunately, Taylor the GPS hadn’t been used since the end of September, so I waited for three excruciatingly slow Windows updates while Lindsey and Stuart headed out to plant more transects. Finally, at 2 pm, Taylor finally finished updating, and we met at Hutchings to install the new transects. At Hutchings East, both of the initial transect locations were in dips between hills, so we moved them both 20 m east. Next, at Hutchings West, one transect started on a rock, so we moved the transect slightly north. This was not an auspicious start to the GPS portion of the afternoon, and we had only 2 hours of light left.
Lindsey and I raced off to Torgeson, the most distant site. I used the GPS to flag the transects. Lindsey followed with nails and planted the seeds. The transects at Torgeson were on two hills separated by a pond. To reach the second hill, I tried to cut across a patch of mud. It looked stable, but when I took my second step, I felt my boot sink deep into the slurping mud. When I tried to pull my foot out, it wouldn’t budge. I nearly toppled over, but I managed to escape with both boots and the GPS unharmed.
Fortunately, the other transects were uneventful. Lindsey and I left Bengston, our second-to-last site, at 4:50 pm, right as the sun was setting. The clouds had trapped a bit of light, so Stuart jumped in the truck, and we headed to our final site: Krusmarks. We needed a flashlight for last two transects, but we finished planting them all! Exhausted, we returned to Hjelm and discovered that Jean had prepared a fabulous dinner: bean soup, homemade bread, pumpkin custard, roasted cinnamon apples, and piping hot gingerbread. It was the best meal I’ve ever eaten.
While the volunteers and I cleaned heads for the seed addition experiment, we encountered something we don’t see every day: seed predators in Echinacea
Busted! This seed predator was still alive and chowing down on Echinacea when I found it. Noticed the holes it gouged in the achenes.The seed predators seemed to produce a thin, sticky filament that would cause achenes and chaff to attach to each other.
The heads we were cleaning were from two sites we don’t typically harvest from, Hutchings and Nice Island. We had 155 heads from each site, stored all together in three gBags, 1 for hutchings and 2 for nice island. The heads were not in individual hBags. This storage method may have made it easier for the predators to move from head to head, but it’s unclear if they were able to cross from one gBag to another.
Hutchings was the most impacted; I would estimate nearly 50% of achenes from the site had been predated. Seed predation was less common, but still present, among the achenes from nice island, with roughly 1/10 achenes being affected. I removed at least 20, most alive, a few dead, from the hutchings heads during the cleaning and enrichment processes, and maybe 5 from the nice island batched
The grubs ranged from roughly 2-5mm long, and were a peachy orange color with a dark and hard head. They resembled the seed predators we’ve observed in Liatris aspera. I removed all the seed predators I encountered from the Echinacea and isolated them in a paper bag (the Grub Hub) to prevent further damage to the achenes.
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.
Map of 76 transects
Start year: 2021
Location: 32 patches of remnant prairie in and around Solem Township, MN
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.
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.
Foggy transect at the hulz hills
Start year: 2021
Location: 32 patches of remnant prairie in and around Solem Township, MN
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.
