In July, 2023, a team from Minnesota State University, Mankato visited Team Echinacea to sample prairie soil. They are investigating how fire and management history influences physical, chemical and biological soil properties. Differences in soils may also help explain plant fitness and native bee nesting patterns. After three hot days, 263 samples were collected from 28 sites!
Back in Mankato, four undergraduate students processed the soil samples by sieving and weighing out the field collections. The preliminary results show soil bulk density is lower in remnant prairies compared to restored prairies. This makes sense in that remnant prairies have retained their organic-matter rich topsoil, infiltrated with plant roots and filled with pore spaces that develop over time in natural prairies. The soil bulk density is also lower on flat (no slope) topography, in part due to illuviation (deposition) of nutrients and organic material from nearby sloped areas.
The team hopes to continue its investigations to understand which soil properties are sensitive to different management histories and how the patchwork of fragmented prairies in the region vary in carbon, nitrogen and biological activity. These data should provide foundational information for many additional projects.
The Mankato soil team gathers around a bbPoint to discuss sampling. The team visited bbPoints in remnants and restorations over a 3 day period.
Start year: 2023
Location: : 28 study plots on private, federal and state land with different land use histories: remnant and restored grassland
Data collected: Soil bulk density, maximum water-holding capacity, gravimetric soil moisture content, soil aggregate stability (SLAKES), total organic C, total N, inorganic N (plant available forms: ammonium and nitrate), aerobic respiration rate (proxy for microbial activity and decomposition)
Samples or specimens collected: Topsoil bulk density and additional soil (top 15 cm) for each bee nesting trap
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 summer 2023, Amy continued the interremnant crosses experiment to understand how the distance between plants in space and their timing of flowering influences the fitness of their offspring. This experiment builds on her 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, Amy performed crosses between plants across a range of spatial isolation (within the same population, in adjacent populations, and in far-apart populations) in 2020. With the team’s help, she also kept track of the individuals’ flowering time to assess whether reproductive synchrony is associated with reduced offspring fitness, suggesting that individuals that flower at the same time are more closely related.
In 2021, Amy repeated the same hand crossing methods to assess the fitness consequences of outcrossing, this year on 44 focal plants.
In spring 2022, she planted the seedlings as plugs into exPt01 and measured the seedlings throughout the summer. Amy measured plants again in summer 2023!
Amy’s two batches of plants (that were alive this year) were assigned cg plaids and are now integrated in the p01 workflow. They are named as integers from 29001 – 29319 and are referred to as “Amy’s Annex”.
A young Echinacea Plant in Amy’s Annex
Start year: 2020
Location: On27, SGC, GC, NGC, EELR, KJ, NNWLF, NWLF, LF
Data collected: Style shriveling and seed set and weight from crosses, start and end date of flowering, coordinates of all individuals in the populations listed above. Leaf count and height of seedlings at three points during the summer (two weeks after planting, mid-summer, and late summer). Summer 2023 measure data can be found here: “~/Dropbox/CGData/125_measure/measure2023/measure2023_out”
Samples or specimens collected: NA
Products: Amy wrote up a related analysis using parentage data from P2 to look at interparent distance and asynchrony in relation to offspring fitness. That manuscript is in prep now.
You can read more about the interremnant crosses experiment here.
In summers 2018 and 2019, Amy mapped and collected leaf tissue from all individuals in the study areas and harvested heads from a subset of Echinacea individuals at populations in the NW corner of the Echinacea Project study area (populations: ALF, EELR, KJ, NWLF, GC, SGC, NGC, KJ, NNWLF) to map pollen movement (see Reproductive Fitness in Remnants). Amy analyzed patterns of gene flow, by assessing how individuals’ location and timing of flowering influence their reproductive success and distance of pollen movement. The now four-year-old seedlings are planted in p10.
There was no fieldwork conducted this summer but, in exciting news, Amy used the seed set data from the gene flow in remnants experiment in her dissertation chapter, “Variation in reproductive fitness among individual plants depends on the spatial proximity of prospective mates and the timing of their reproduction”. Amy defended her dissertation in May, and this chapter is currently in preparation for publication!
Amy visited the station a few times this summer! Cupcakes in the field to celebrate a successful dissertation defense!
Start year: 2018
Location: Roadsides, railroad rights of way, and nature preserves in and around Solem Township, MN
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.
This recruitment experiment was established in 2000 to quantify seedling emergence and juvenile survival of Echinacea angustifolia during reintroduction to sites with varying land-use history and burn schedules. Before 2014, we collected detailed data on each plant in the plots. Since 2014, Team Echinacea has censused each plot yearly to collect demographic data for every flowering plant.
In 2023, Team Echinacea visited 7 recruitment plots and searched for 163 Echinacea angustifolia plants that had flowered previously. Across the 7 plots, we found 118 basal plants and 46 flowering plants, and we were unable to find 16 plants. Of the flowering plants, 11 plants flowered for the first time in 2023. For each flowering plant, the team collected demographic data (number of rosettes and flowering heads) and shot a GPS point at the exact location of the plant. There was at least one flowering Echinacea plant at 6 of the 7 recruitment plots where plants had flowered previously, but we did not find any flowering plants at one site, rhp.
There were also two sites, rhr and rhw, that we have no 2023 demographic information for. We did not visit these sites for total demo censusing, and it’s possible that we never visited them over the summer. Alternatively, we may have visited them and found no flowering plants. Rhw was present on “demopup” (a list of demo sites for mopping-up any flowering plants that may have been missed), so there were likely no flowering plants there this year. Rhr was not on the demopup list. Bizarre! Stay tuned for any updates we may uncover.
Abby, Alexa, and Blaire search for plants at rkw, a recruitment plot located at Kensington WMA. We found 4 flowering plants and 4 basal plants at rkw this year.
This year, we used “demopup” to track progress as we revisted sites where we searched for and demo’ed flowering plants. Rhw made it on the list, but no such luck for rhr.
Start year: Plantings in 2000-2002
Location: Seven study plots on state land with different land use histories: old-field and restored grassland
You can read more about the fire in recruitment experiment, as well as links to prior flog entries about this experiment, on the background page for this experiment.
We established an experiment in 2021 to investigate the effects of fire on Big Bluestem (Andropogon gerardii). reproduction. For the third year, we visited 378 randomly placed plots across 27 remnant patches and counted the number of flowering Andropogon culms rooted within 1 m of the random point. We also harvested seed heads to directly examine reproductive outcomes. In 2023, we counted a total of 1814 culms. The highest density we observed was 165 culms in one plot at KJs, but it wasn’t enough to beat the standing records from 2022 of 197 culms…
With the help of Elif and Carleton externs, we are making progress on a protocol that will enable us to efficiently quantify seed production. Stay tuned!
Should we tell Lindsey that isn’t an Andropogon plot? Nah, what’s the worst that can happen…
Start year: 2021
Location: 27 patches of talgrass prairie near Solem Township, MN
Data collected: All reproductive effort data have been curated and are housed in remag repo.
Samples or specimens collected: Seed heads collected during summer 2023 are in Jared’s office. These samples will be cleaned, processed, and x-rayed to quantify seed set. All 2021 samples have been cleaned and weighed. Most 2022 samples have been cleaned and weighed. All samples will be x-rayed this winter.
Products: Stay tuned!
You can read more about the Andropogon fire and flowering in remnants experiment, as well as links to prior flog entries about this experiment, on the background page for this experiment.
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. In spring 2022, we burned the western plot. Team Echinacea did not collect any new data from the Andropogon pilot experiment during summer 2023. In the lab, Elif and Stuart made progress on developing a protocol for x-raying Andropogon seed heads and processing the X-ray images. During December 2023, Carleton externs Vo and Rebecca are developing a protocol for quantifying seed set. Exciting times ahead!
Data collected: All reproductive effort data are housed within the remag repo. We are currently generating data on reproductive outcomes in the lab.
Samples or specimens collected: All harvested seed heads have been cleaned and x-rayed.
Products: Stay tuned for an updated in the next couple weeks!
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.
You guessed it! Jared AGAIN mapped a bunch of lilies in summer 2023… What a goof. We mapped 277 flowering plants within seven 60 x 40 m plots. Pods were harvested from ~20 plants.
Wait, what were you saying about Echinacea? I got distracted…
Start year: 2021
Location: Remnant patches of prairie in and around Solem Township, MN
Overlaps with: The setting sun and a full night of sleep
Data collected: Spatial and demographic data are housed in the remlp repo.
Samples or specimens collected: Harvested pods are in Jared’s office. They have been cleaned. All unprocessed seeds from prior years were returned to western Minnesota.
Products: Stay tuned!
You can read more about the Lilium fire and flowering experiment, as well as links to prior flog entries about this experiment, on the background page for this experiment.
We did not collect any additional data on Echinacea angustifolia flowering phenology in remnants during summer 2023. During spring 2022, we curated remnant phenology data.
Rays up, rays spreading, first day flowering, and second day flowering all in one plant. If only there was someone studying how this variation influenced reproduct… oh wait, nevermind.
Start year: 1996
Location: Roadsides, railroad rights of way, and nature preserves in and around Solem Township, MN
Data collected: All data have been curated and added to the Echinacea Project’s ‘remPhenology’ data set. Jared also curated all remnant style persistence data.
Products: Check out our recent PNAS paper investigating fire effects on plant reproductive which utilizes our extensive phenology data set!
You can read more about the Flowering phenology in remnants project, as well as links to prior flog entries about this experiment, on the background page for this experiment.
