2023 Update: Interremnant crosses

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
  • Overlaps with:  phenology in the remnantsgene flow in the remnants
  • 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.

2023 Update: Gene flow in remnants

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
  • Overlaps with:  Reproductive Fitness in RemnantsPhenology in the Remnants
  • Data collected: exPt10 measure data is in the cgdata repo (no new 2023 data.)
  • Samples or specimens collected: NA for 2023!
  • Products: Amy’s dissertation, which she defended in may!

You can read more about the gene flow in the remnants experiment, as well as links to prior flog entries about this experiment, on this page

2023 Update: Reproductive fitness in remnants experiment

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
  • Overlaps with: Phenology in the Remnants
  • 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.

2023 Update: Fire in recruitment 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
  • Overlaps with: Demographic census in remnants
  • Data collected: 
    • Plant status (basal, flowering, not present), rosette count, flowering head count, GPS point for each flowering plant in each recruitment plot
    • Recruitment plot demography and survey data are stored in demap
  • Samples or specimens collected: NA
  • Products: A paper (Wagenius et al. 2012) published in Restoration Ecology

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.

2023 Update: Demographic census in remnants

Since 1995, the Echinacea Project has been mapping and collecting demographic information on Echinacea angustifolia to generate long-term records detailing individual fitness in prairie remnants. In summer 2023, Team Echinacea visited 42 prairie remnants to search at 2443 locations where adult Echinacea plants had been previously mapped. We call this “total demo.” At small sites, the team took records for all adult plants found at a site (no change in total demo protocol from previous years). At larger sites, we scaled down and visited a subset of adult plants. Burning led to high flowering rates and lots of newly flowering plants entering the census, which stressed our system for total demo. This year we did not visit plants that were “not present” for the past 3+ years and we also capped total demo points at 100 per site. For example, at Landfill, we searched at 100 locations at Landfill East and 100 Locations at Landfill West.

We used stake files on our high-precision GPS units to stake to each Echinacea plant in our total demo visit list, where we recorded flowering status, number of flowering heads, number of rosettes, and near neighbors of the plant on handheld data collectors (visors).

In addition to total demo, we searched and took records for all flowering plants in our remnant sites. For flowering demo, we visited 50 sites. In summer 2023, we took 5,601 demographic records in prairie remnants (demo) and 1929 GPS records (surv). We saw a much lower flowering year following 2022, with ~1586 flowering plants total. At Landfill, there were ~262 flowering plants and at Loeffler’s corner, there were 285.

Alexa and Jak step carefully through Kjs as they search for flowering Echinacea plants. 63 plants flowered at Kjs in 2023!

We also took demo and surv data as part of our Pollen and Nectar project where we will compare characteristics of pollen and nectar in burned vs. unburned prairies. We collected demographic data at a subset of plants at several sites where we have never done demo or surv. We put out our first tags at hulze, hulzw, torges, torgen, hutche, hutchw, and koons.

This year, we put out 528 new tags which started at 28001. Two 29000 tags were accidentally created and placed in Landfill East, but those were quickly removed during our demo rechecks following completion of flowering demo and total demo.

Lindsey visits an 18 headed Echinacea plant at Steven’s Approach. This plant produced the most heads of any this year.

After revisiting a final round of recheck plants during a trip to Minnesota in mid-November, we are just getting ready to move data from aiisummer2023 into demap.

  • Start year: 1995
  • Location: Remnant prairie populations of the purple coneflower, Echinacea angustifolia, in Douglas County, MN. Sites are located between roadsides and fields, in railroad margins, on private land, and in protected natural areas.
    • Total demo: Bill Thom’s Gate, Common Garden, Dog, East of Town Hall, Golf Course, Martinson’s Approach, Near Pallida, Nessman, North of Golf Course, South of Golf Course, Sign, Town Hall, Tower, Transplant Plot, West of Aanenson, Woody’s, Yellow Orchid Hill, plus the recruitment plots REL, RHE, RHP, RHS, RHX, RKE, RKW
    • Annual sample: Aanenson, Around Landfill, East Elk Lake Road, East Riley, KJ’s, Krusemarks, Loeffler’s Corner, Landfill, North of Railroad Crossing, Northwest of Landfill and North of Northwest of Landfill (lumped), On 27, Riley, Railroad Crossing, Steven’s Approach, Staffanson Prairie
  • Overlaps with: Flowering phenology in remnantsreproductive fitness in remnantsEA fire and fitnessfire and flowering at SPP,
  • Data collected:
    • Plant status (can’t find, basal, dead this year’s leaves, dead last year’s leaves, flowering), number of rosettes, nearest neighbors, and head count, if flowering
    • All GPS files are found here: Dropbox/geospatialDataBackup2023
    • All demo and surv records are stored in the aiisummer2023 repo
    • The most recent copies of allDemoDemo.RData and allSurv.RData can be accessed at Dropbox/demapSupplements/demapInputFiles
  • Samples or specimens collected: NA
  • Products:
    • Amy Dykstra’s dissertation included matrix projection modeling using demographic data
    • The “demap” project is a long-term dataset that combines phenological, spatial and demographic data for remnant plants
  • You can read more about the demographic census in the remnants, as well as links to prior flog entries about this experiment, on the background page for this experiment.