This experiment was designed to quantify how well Echinaceaangustifolia populations are adapted to their local environments. In 2008, Amy Dykstra collected achenes from Echinacea populations in western South Dakota, central South Dakota, and Minnesota and then sowed seeds from all three sources into experimental plots near each collection site. Each year, Team Echinacea takes a demographic census at the western South Dakota and Minnesota plots; we abandoned the central South Dakota plot after it was inadvertently sprayed in 2009, killing all the Echinacea.
In 2023, we found a total of 119 basal plants and 8 flowering plants. All of the flowering plants observed in 2023 were in the western South Dakota sowing site. Only 2 plants in the Minnesota site have ever produced flowers. In contrast, 31 plants flowered in the western South Dakota site in 2022 alone. Mortality has been much higher in Minnesota than in western South Dakota; thus, the total number of plants at each sowing site is now about equal.
Surviving plants at GRNG (Grand River National Grassland in western South Dakota) and HL (Hegg Lake in Minnesota) in annual censuses from 2014-2023.
Start year: 2008
Location: Grand River National Grassland (Western South Dakota), Samuel H. Ordway Prairie (Central South Dakota), Staffanson Prairie Preserve (West Central Minnesota), and Hegg Lake WMA (West Central Minnesota).
Data collected: Plant fitness measurements (plant status, number of rosettes, number of leaves, and length of longest leaf)
Samples or specimens collected: Heads from all flowering plants; Amy stores the heads in her office at Bethel University.
Products:Dykstra, A. B. 2013. Seedling recruitment in fragmented populations of Echinacea angustifolia. Ph.D. Dissertation. University of Minnesota. PDF
You can read more about Dykstra’s local adaptation experiment and see a map of the seed source sites on the background page for this experiment.
Small remnant Echinacea populations may suffer from inbreeding depression. To assess whether gene flow (in the form of pollen) from another population could “rescue” these populations from inbreeding depression, we hand-pollinated Echinacea from six different prairie remnants with pollen from a large prairie remnant (Staffanson Prairie) and from a relatively small population (Northwest Landfill) in 2008. We also performed within-population crosses as a control. Amy Dykstra (with help from Caroline Ridley) planted the achenes (seeds) that resulted from these crosses in an experimental plot at Hegg Lake WMA.
We sowed a total of 15,491 achenes in 2008. 449 of these achenes germinated and emerged as seedlings. Each summer, we census the surviving plants and measure them.
In the 2023 census, Amy found 23 surviving basal plants and no flowering plants. She had observed 26 basal plants in 2022. Mortality was high during the first four years, but has been lower as the surviving plants have increased in age.
Number of plants observed in annual censuses 2008-2023
Data collected: Plant fitness measurements (plant status, number of rosettes, number of leaves, and length of longest leaf), and notes about herbivory. Contact Amy Dykstra to access this data.
Samples or specimens collected: NA
Products: Dykstra, A. B. 2013. Seedling recruitment in fragmented populations of Echinacea angustifolia. Ph.D. Dissertation. University of Minnesota. PDF
You can read more about Dykstra’s interpopulation crosses, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.
You might think three weeks is too short a time to conduct research, but our 2023 Carleton College externs can prove you wrong! We just said goodbye to 4 undergraduate students who spent their winter break in our lab at Chicago Botanic Garden. During this time, they processed data, explored statistics, dove into the world of R, and learned more about the research objectives of the Echinacea Project. All of this contributed to their investigations into research questions of their own. The externs were also able to explore Chicago and the gardens, and connect with other scientists.
Rebecca and Vo worked with Jared to investigate effects of fire on reproduction in Andropogon gerardii. They developed methods for quantifying seed set in Andropogon, and put them into practice during the externship! Learn more about them and their research here and here!
Io worked with Abby and Wyatt to investigate vegetative and reproductive patterns in Echinacea Angustifolia. She was specifically interested in understanding how traits like basal leaf count and longest basal leaf length over time may influence reproductive effort. Read more about her project here.
Conlan worked with Abby and Wyatt to investigate structural reproductive traits and their relationship with pollination success. He wondered if taller head heights and larger head numbers led to higher pollination rates. Read more about what he found here!
There was some disagreement as to whether we were saying, “Echinacea” or “Andropogon” in our group picture this year. No matter- the photo still turned out nicely!
It was a pleasure to work with these 4 externs this year! We wish them the best!
During the summer of 2023, Team Echinacea embarked on an ENRTF funded mission to better understand how prescribed fires influences solitary bee nesting habitat, food resources, and diversity is critical for providing recommendations about how prescribed fire should be used to promote pollinator conservation and healthy prairie.
We surveyed solitary bee diversity and nesting habitat before and after prescribed fires in a subset of 30 prairie remnants and 15 prairie restorations to determine how prescribed fire affects solitary bee nesting habitat and abundance. We used emergence traps to investigate composition of solitary bees in prairies. This was complemented by detailed measures of soil and litter to characterize how prescribed burning influences the nesting habitat (read more here).
We deployed emergence traps at our random points (bb points) in prairie remnants and restorations in mid-June – early September. Our deployment spanned three rotations of bb points and we put out a total of ~1,238 emergence traps.
El, Luke, and Jan, 2023 pollinator crew, deploy an emergence trap at a bb point.
As of September 28, members of Team Echinacea had processed 850 vials, 122 of which contained bees. Our preliminary catch rate is 14%! These specimens were pinned and are currently at Chicago Botanic Garden, awaiting transportation to University of Minnesota where Zach Portman, a bee taxonomist, will identify them. Team Echinacea also collected lots of non-bee bycatch while processing specimens collected in the traps. Bycatch is currently stored in our freezer at Chicago Botanic Garden.
Jan pins a bee that they found while processing vials from emergence trapping!
Ian Roberts, a M.S. student with the Echinacea Project, has taken charge of the Emergence trapping project and is currently coordinating data entry. When emergence trapping resumes in the 2024 field season, we will be well set up, thanks to detailed written and videotaped protocols made by our summer 2023 pollinator team. The prtocol can be found here: “~/Dropbox/enrtf/emergenceTrapping2023/Emergence Trap Protocol.pdf”. Video instructions are located in “~/Dropbox/enrtf/emergenceTrapping2023/exampleVideos”.
Start year: 2023
Location: prairie remnants and restorations in Solem Township, MN.
For the ENRTF-funded research project investigating fire effects on ground-nesting bees, plant-pollinator interactions, and other insects within fragmented prairies, Team Echinacea sampled 45 total prairie sites (30 remnants and 15 restorations).
To obtain robust inferences, it is important to sample randomly so that our sampling effort is not biased by what we perceive to be “good” or “bad” habitat, even subconsciously. To this end, we sampled at random locations within each site. At each site, we established between 30 and 72 sampling locations with unique identifiers (four-digit bbpts, for “burning and bees sampling points”). Early in the summer, before sampling at these points began, we ground truthed the points to ensure we were not choosing in places where we could not sample at all (e.g., think a big rock, a water body, a big patch of poison ivy, a gravel road, etc.).
Jared generated a large number of random points for each site, more points than we actually intended to sample. trap. We visited these points using a high precision gps unit and evaluated whether to “keep” the points and assign them a bbpt or “reject” the point if it could not be sampled safely or effectively.
Jan, 2023 pollinator team member, ground truths bb points at Torgen.
Start year: 2023
Location: prairie remnants and restorations in Solem Township, MN
Overlaps with: ground nesting bees, fire x fragmentation, soils in remnants and restorations, floral resources in remnants and restorations, microhabitats in prairie remnants and restorations
Data collected: spatial locations of accepted bb points are in “~/Dropbox/geospatialDataBackup2023/convertedXML2023/bbptsForEnrtf”. Maps of bb points are located in “~/Dropbox/enrtf/emergenceTrapping2023”
During summer 2023, Team Echinacea Echinacea characterized local environmental conditions to better understand which environmental factors are associated with good habitat for ground-nesting bees. This microhabitat assessment complemented emergence trapping for our ENRTF funded research on fire’s influence on ground nesting bees habitats. We sampled local environmental conditions near randomly placed bbpts in remnants and restorations.
We used a light meter to quantify light availability via a measure of photosynthetically active radiation. We took PAR readings at 1 meter and at ground level ~40 cm NE of the bb point. We also used a soil penetrometer to quantify soil compaction at ~40 cm NE of the bb point.
Team Echinacea conducted microhabitat assessments for three rotations of bb points (rotations 1,2,&3) across 46 sites. Over the summer, we took microhabitat assessment measurements at a total of 1,238 bb points.
Blaire, high school participant 2023, takes a light measurement at a bb point. We were particular about position and timeframe to ensure consistent measurements.
Start year: 2023
Location: prairie remnants and restorations in Solem Township, MN
Data collected: light availability (par measurements) and Soil Compaction (psi measurements) are stored in ~Repos/bbnest/data/microhabitatDataCuration/curate2023MicrohabitatData.R
During the summer of 2023, Team Echinacea conducted floral surveys at randomly selected bb points in remnant prairies and restorations. We are interested in quantifying floral resources (i.e., food for bees) and we want to understand how fire influences the diversity and abundance of flowering plants.
At each focal point (bbpt) we identified species rooted within a 2 meter radius and recorded the furthest stage of development. We measured abundance by binning a range of floral units (i.e., 1-5 flowering units got label “5”).
Floral surveys were split into “visit group A” and “visit group B”. We surveyed different random points when revisiting sites. In total, we conducted 415 floral surveys across 45 sites.
Liam Poitra, a 2023 Summer Research Experience for Undergraduates (REU) Participant, contributed to this research project investigating the effects of fire on diversity and abundance of flowering plants. Liam assisted in fieldwork and data organization. Inventory, protocols, and blank datasheets for floral assessments are located in ~/Dropbox/enrtf/floralSurveys2023.
Liam Poitra, REU 2023, navigates to a floral assessment focal point at Staffanson Prairie Preserve. The 2-meter stick he carries will help keep track of what is in the bounds for survey.
Start year: 2023
Location: prairie remnants and restorations in Solem Township
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.
