Flowering Phenology in South Dakota and Minnesota

Last week I assessed Echinacea flowering phenology at Grand River National Grassland south of Lemmon, SD, Samuel H. Ordway Prairie west of Leola, SD and Staffanson Prairie near Kensington, MN. Here are a couple of figures I generated to compare phenology at the 3 sites.
First, I made pie charts to show the relative proportions of flowering plants.

Next, to show more quantitative information, I used a stacked bar graph.

These figures illustrate that the flowering phenology is most advanced at Staffanson and least advanced at S. H. Ordway Prairie. Nevertheless, I am encouraged that there are lots of flowering plants at all 3 sites, suggesting that a long-distance cross involving plants from these 3 locations would be possible. I am considering tackling that project next summer, to assess whether there would be lower seedling recruitment from between-population crosses compared to within-population crosses at these 3 sites.

Here’s a picture of some flowering Echinacea at Perch Lake, which is near the S. H. Ordway prairie.

Flowering plants in the common garden

We are very interesting in observing (and participating in) the Echinacea mating season this summer. We are still waiting for the action to begin.

Here is a map of the flowering plants in the main garden. Each dot represents a plant with 1 or more buds (immature capitula). The short purple bar indicates a plant with one bud, a long bar indicates two, and n short bars indicates n buds. In the main garden we found 869 plants with at least one bud and a total of 1572 buds. The most buds on a plant is 11. This is a modified “sunflower plot” that was generated with R.


We are waiting for the action to begin. At this time last year, like most years, Echinacea flowering was in full swing.

We are prepared for the flowering to begin. We flagged all positions evenly divisible by 5. We mowed paths between rows so we can avoid stepping on plants. We have flagged every flowering plant. Note: don’t buy fluorescent colored pin flags. The flags tend to detach from the more frequently than non-fluorescent colors. What’s up, Forestry Suppliers? We weeded thistles and sweet clover, trapped gophers, found plants with Aster yellows, and are waiting for the action to begin.

This flog entry from last year proved valuable. I just looked it up and followed the common garden maintenance protocol.

2019 Update: Reproductive Fitness in Remnants

Monitoring reproductive fitness in the remnant populations is a staple of Team Echinacea’s summer activities. Understanding the reproductive success of plants in remnant populations provides insight to a vital demographic rate contributing to the persistence (or decline) of remnant populations in fragmented environments.

In summer 2019, we harvested 40 seedheads to study patterns of reproductive fitness in 8 remnant Echinacea populations (ALF, EELR, KJ, NWLF, GC, NGC, SGC, NNWLF) (the same populations used where I studied phenology and gene flow). I randomly selected 1/3 of flowering heads at each remnant to harvest. In addition, I collected all seedheads from especially small or isolated remnants (specifically, GC, KJ, and the cluster of plants just north of EELR).

In early January, I dissected the seedheads. I extracted the achenes by row so that I will be able to observe temporal variation in seed set within heads. Ideally, next I will x-ray the achenes and assess seed set by observing the proportion of achenes that contain embryos. However, the x-ray machine at the Chicago Botanic Garden is currently out of service, so instead I may need to weigh or germinate the achenes to see if viable embryos are inside.

Extracting achenes by row, so that I know which achenes resulted from florets that flowered early (i.e., at the bottom of the seedhead) or late (i.e., at the top of the seedhead). Tedious but possible!

Start year: 1996

Location: Roadsides, railroad rights of way, and nature preserves in and around Solem Township, MN

Overlaps with: Phenology in the RemnantsGene Flow in Remnants

Products: We will compile seed set data from 2019 into a dataset with seed set data from previous years, which is located here:

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

2019 Update: Dykstra’s Interpopulation Crosses

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 that we call “Northwest Landfill.” We also performed within-population crosses as a control. Amy Dykstra planted achenes (seeds) that resulted from these crosses in an experimental plot at Hegg Lake WMA.

Plants in the crossing plots were originally found as seedlings like this one

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. This summer we found 48 surviving plants. None of these plants has flowered, but we think some of them are close! The largest plant we measured had 4 leaves, the longest of which was 35 cm.

You can read more about the interpopulation crosses, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.

Start year: 2008

Location: Hegg Lake WMA

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.

Products: Dykstra, A. B. 2013. Seedling recruitment in fragmented populations of Echinacea angustifolia. Ph.D. Dissertation. University of Minnesota. PDF

2019 Update: West Central Area Environmental Learning Center

In the fall of 2018, the Echinacea Project scientists came to West Central Area Schools (WCA) and mapped out twelve plots to transplant E. angustifolia into the following summer. The WCA Environmental Learning Center has 35 acres of restored prairie, making it a perfect place to plant experimental plot 10. During the summer of 2019, Team Echinacea planted over 1400 E. angustifolia seedlings into the 12 subplots. Three plantings were performed: the first was a planting organized by Michael and had offspring from exPt1, the second consisted of plants from Amy W’s gene flow experiment, and the third planting had offspring from the Big Event. All plants originate from Grant or Douglas County, MN. To test how different fire regimes affect fitness in Echinacea, folks from West Central Area will apply a fall burn treatment to four plots, a spring burn treatment to four other plots, and the remaining four plots will not be burned. 

The team after planting the original cohort of Echinacea in experimental plot 10. It was a long day!

During science classes with John VanKempen, WCA high school students will assess the effects of differential burning regimes on the fitness of E. angustifolia. For the first time this fall, juniors in VanKempen’s classes used data they collected on plants to answer their own scientific inquiries. Students developed hypotheses, then measured various morphological traits on surviving Echinacea in the 12 plots. The students used the data they collected to create graphs based on their data. VanKempen plans to continually integrate these Echinacea experimental plots into his classroom lessons and hopes other teachers at WCA will utilize the experimental plots for student science projects.

Start year: 2018

Location: West Central Area High School’s Environmental Learning Center, Barrett, MN.

Overlaps with: Pollinators and Echinacea male fitness, Gene flow in remnants

Data collected: Planting and survival data for seedlings planted in summer 2019. GPS points taken for plots. Planting data is available in the Echinacea Project ~Dropbox/CGData/195_plant/. Contact John VanKempen for survival data taken by his students. GPS points are available here: ~Dropbox\geospatialDataBackup2019\planting2019\nailStakeWCA.csv

Products: High School Posters. Contact John VanKempen for info.

Scott at Botany, 2019

Hi everyone!

Long time no see! I am a grad student at the University of Colorado now, but thankfully I have still had plenty of time to work on some Echinacea work. Last week I got to present at Botany in beautiful Tucson, Arizona 🌵.

First I presented a poster about fire and Echinacea demography. This is something we started in Chicago and Stuart, Amy Dykstra and I have been working on since. We used demap, the seedling search dataset, and the seedling recruitment experiment dataset to estimate vital rates (survival, flowering, and recruitment) within several Echinacea populations. We then estimated how these vital rates varied with fire. To see how these changes in vital rates affected actual population dynamics, we then constructed matrix models to estimate the average growth rates of several remnant populations under various fire frequencies. Finally, to see which demographic pathway was primarily responsible for changes in population growth, we decomposed the changes in population growth rates under different fire regimes into contributions from each vital rate’s response to fire. We used Bayesian modeling to estimate the vital rates. Stuart, Amy D. and I are putting the finishing touches on a manuscript for this project, so keep your eyes open!

Click for poster!

I got some good questions from people at the conference. One is: would seed addition help bolster growth rates? Very interesting question – I think it probably would in populations with high juvenile survival, given that under these circumstances higher recruitment has the largest contribution to population growth. Another person asked about climate change and whether I thought the Echinacea range was likely to move north with warmer temperatures. I can’t answer that question but we did use climate data in our models; climate was warmer and wetter in our observation period than they were in the 100 years prior, and these covariates were featured in some of our models. It would be fun to incorporate climate change into estimates of vital rates and population growth.

I also gave a three-minute lightning talk to briefly present an idea I have had since I was in Chicago in 2017. Amy, Jennifer, Gretel, and Stuart have done some prior work looking at synchrony, mating opportunity, and mating success in Echinacea. I have been curious about whether populations exhibit nested structure in their flowering schedules, i.e., whether or not individuals which flower less often flower in the same years as plants which flower most often. There are some interesting potential consequences of deviation from non-nested structure. Hopefully I have time to study this in Colorado.

Also of note: Jennifer gave an awesome talk synthesizing a lot of the pollinator work done in the Echinacea system the last several years. It was great to see so many facets of Echinacea pollination discussed together. One of the most interesting parts of this talk was Mia’s poster, looking at the diversity of male pollen donors on bees, and how they varied by pollinator species. I remember when Laura was collecting this data in 2016. She was so good at wiping! Very cool to see final results for this project!

Otherwise, there were some great talks and posters. A couple of good ones: Joseph Braasch from Katrina Dluglosch’s lab at the University of Arizona talking about community shift with climate change and Jessa Finch (from CBG) talking about how gene flow affects early life stages of milkweeds. Maybe the best talk I saw came from a student in Julie Etterson’s lab at UM Duluth talking about how seed collections for restorations is artificially selecting for traits. Very cool question!

I’m glad I was able to make it out to the conference. Huge thanks to my advisors Brett Melbourne and Kendi Davies for allowing me to work on this project for the last two years. Also thanks to the BioFrontiers Institute at CU Boulder for providing me funding while I worked on this project, the United Government of Grad Students at CU Boulder for funding my trip to the conference, and friends at CU Boulder and Colorado State who allowed me to drive down with them and crash in their hotel rooms in Tucson. Hope to see everybody at ESA in Louisville, KY later this month, where I will have a poster about some of the non-Echinacea work I am doing in Colorado.

Dining in Tucson: Mexican food, no, waffles, yes!
Ipomopsis longiflora I spotted on the drive back outside Taos, NM. The CO crew identified this plant with a key while I tried to find a gas station.

Amy Waananen

Echinacea Project 2019

PhD Student, Ecology, Evolution, and Behavior, University of Minnesota

Research Interests

I’m interested conservation biology, especially as it relates to pollination, phenology, movement ecology, and population genetics. For my dissertation, I’m studying pollinator-mediated gene flow and trying to figure out under what conditions pollinators maintain connectivity between plant populations in fragmented environments. I think a lot about how the processes that drive how species respond to habitat fragmentation vary among spatial and temporal scales.


I grew up in a suburb of the Twin Cities and currently live in the silver city of St. Paul. I started working with the Echinacea Project as an intern in 2015. In my free time, I like to spend time outside, read, garden, and go on walks with my dog Gooseberry!

Here’s me on a snowy day!


2018 Update: Reproductive Fitness in Remnants

In summer 2018, I harvested 80 seedheads from 12 remnant Echinacea populations (ALF, EELR, KJ, NWLF, GC, NGC, SGC, NNWLF, LC, RRX, NRRX, YOH) to study patterns of reproductive fitness. I sampled heads in two ways – (1) I randomly selected 20% of the individuals at each site (43 individuals) and (2) I randomly sampled up to 5 individuals from full factorial combinations of high, medium, and low spatial isolation and early, peak, and late flowering time (i.e., high spatial isolation/early flowering, high spatial isolation/peak flowering, etc.) across all sites (37 individuals).

In January 2019, I dissected seedheads that I collected from the NW sites (ALF, EELR, KJ, NWLF, GC, SGC, NGC, KJ, NNWLF). I extracted the achenes by row to observe temporal variation in seed set within heads. I x-rayed the achenes and assessed seed set in January.

Xray images that show whether achenes contain embryos or not

Start year: 1996

Location: Remnant prairies in central Minnesota

Overlaps with: Phenology in the Remnants, Gene Flow in Remnants

Products: Check back with the flog for preliminary results and annual reports.

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

2016 update: Amy D’s interpopulation crosses

Inbreeding has negative effects on Echinacea, leading to reduced survival and fitness. In isolated populations, populations could benefit from genetic diversity introduced by mating with individuals from other populations (“outcrossing”). However, gene flow from other populations may compromise a population’s adaptation to its local environment. Amy Dykstra designed an experiment to test how mating with individuals from other populations affects Echinacea fitness. In the summer of 2008, Amy and Team Echinacea performed 259 crosses between individuals randomly selected from 6 of the largest remnant populations. That fall, Amy planted the offspring of these crosses (15,491 achenes) into an experimental plot at Hegg Lake WMA.

Every summer, including 2016, we measure plant status, number of rosettes, number of leaves, and length of the longest leaf of the individuals in the plot. We also note damage (herbivory) to the leaves.


Hegg Lake WMA (Amy’s plot is visible on the horizon to the right of the lake)

Start year: 2008

Location: Hegg Lake WMA

Overlaps with: Dykstra’s local adaptation

Data collected: We collected plant fitness measurements (plant status, number of rosettes, number of leaves, and length of longest leaf) electronically.

GPS points shot: We shot points at all surviving plants (and a few that we couldn’t find this year, but will check next year) in the experimental plot, which will make finding and monitoring these plants much more efficient in the future. The points are stored in ‘AMYSCROSSIG_20160712_SULU.tsj’ and some rechecks to those points are in “AMYSCROSSING_20160830_SULU.tsj’.

Products: Read about Amy’s analysis of the interpopulation crossing experiment in her flog post from last summer.

You can find more information about Amy’s experiment and links to previous flog posts regarding this experiment at the background page for the experiment.

Dykstra’s interpopulation crosses


Seedlings are marked with toothpicks to make them easier to find the following year

In 2008, Amy Dykstra began an experiment designed to assess the effects of inbreeding and outbreeding on small isolated populations of Echinacea. Inbreeding can result in the fixation of maladaptive alleles in populations and experiments by Team Echinacea have shown that the offspring of related Echinacea individuals have reduced fitness (Wagenius et al. 2010). In some cases, a population may benefit from new genetic material introduced by cross-breeding with another population. Alternatively, outcrossing may result in “genetic swamping,” where the adaptation of individuals to their local environment is compromised by gene flow from other populations.

In the summer of 2008, Amy and Team Echinacea performed 259 crosses between individuals randomly selected from 6 of the largest remnant populations. That fall, Amy planted the offspring of these crosses (15,491 achenes) into an experimental plot at Hegg Lake WMA. She weighed the achenes to estimate the success rate of the crosses and found that 40% of the achenes contained embryos. The experimental plot is divided into three blocks and achenes from each cross were divided into three groups. Amy sowed one group per cross in each block, randomly assigning location within the block.

Every summer, we measure plant status, number of rosettes, number of leaves, and length of the longest leaf of the individuals in the plot. We also note damage (herbivory) to the leaves.

Start year: 2008

Location: Hegg Lake WMA


Dykstra, A. B. 2013. Seedling recruitment in fragmented populations of Echinacea angustifolia. Ph.D. Dissertation. University of Minnesota. PDF

Overlaps with: Dykstra’s local adaptation, inbreeding experiments– inb1 and inb2

Link to flog posts: Read updates and annual reports about this common garden experiment on our flog (field blog) as written by members of Team Echinacea.