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!
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.
I’m still here! In Chicago, that is. Hilary, the volunteers, and I have been quietly and methodically catching up on lab work for the last month. An update on our progress:
Earlier this week, Art completed counting the last achenes from 2014! Now we have estimates of seed set for every plant harvested in 2014. He and Aldo will now count achenes from one of the inbreeding experiments, before moving on to P2, which Lois has been working on since March.
Anne has finished scanning qGen_a in 2015. These have been uploaded and are ready to be counted.
Thanks to Char, Susie, Suzanne, Shelley and Laura, we are almost done randomizing qGen_a in 2015. These guys finished randomizing the massive P2 experiment last month. I think they are randomizing so quickly I am going to have to ask some of them to switch to cleaning soon.
Speaking of cleaning, there are only 31 heads left from 2015 to clean. Wow! That is less than 1% of that year’s massive harvest of over 3200 heads. Soon, they will start the much smaller and more manageable harvest of 2016, which had only 1060 heads. Naomi, Allen and Susie have done a lot of the cleaning recently.
Leslie and Kathryn have been rechecking very efficiently and providing good, clean achene packets for scanning. They are currently rechecking qGen_b from 2015.
Art and Anne have picked up in assembling sheets for x-raying in the Fall. All of 2013 and 2014’s sheets have been assembled, so they are assembling sheets from P2 in 2015. Today Anne assembled over 10 sheets! In her words it was, “kinda meditative”.
Echinacea is only starting to flower in Minnesota, but it has been flowering here at the Botanic Garden for a few weeks now. I’ve taken some pictures of some of the pollinators I’ve seen!
Just a reminder that it’s not just bees that feed on pollen! Here is a fly I saw sitting directly on an anther . Interestingly, I didn’t see it move around the head — I wonder how much pollen it was actually transferring.
This bumblebee was going to down on this Echinacea pallida outside the Rice building! This surprised me because Stuart said he has only once ever seen any type of bumblebee pollinating angustifolia.
In other exciting news, today we had a power outage at CBG due to construction! This meant that I worked for part of the day in the dark. Anne and Shelley came in later to keep me company and we moved to a room with big windows to enjoy the ambient light. We were so inspired by this day without electricity that Shelley took me to Stuart and Gretel’s house, where I harvested some of the lettuce from their garden. I was happy for the lettuce, but sad because today was my last day of working with both Shelley and Anne. Hopefully I will see them again some day.
Me living off of that rich Highland Park soil! Thanks Stuart and Gretel!
The team after an initial measurement of p9. Blue flags are positions where Echinacea weren’t found.
This summer, we remeasured plants in experimental plot 9 at Hegg Lake. These plants are hybrids of Echinacea angustifolia (native) and Echinacea pallida (non-native, but planted at a nearby restoration). Unlike the plants in p7, these plants came from open-pollinated parents – that is, there was no artificial crossing done. Stuart and Lydia English planted the seeds in May of 2014. Much like with plot p7, an analysis the survival and fitness of these plants can give insight into whether or not hybrid populations can be viable in our study areas, and whether or not they pose a threat to native E. angustifolia in our remnants. We have returned to the plot each of the last three years to measure number of rosettes and leaf lengths of these plants.
Table 1 shows the number of plants found alive during each search. These plants were measured on August 4th and rechecked on August 23rd. No plants flowered this year, although there were several found that had leaves over 40cm long.
Year / Event
Number Alive
% Original remaining
% Of prev. year
Planting (2014)
746
100
2014
638
85.5
85.5
2015
521
69.8
81.7
2016
493
66.1
94.6
Start year: 2014
Location: Hegg Lake Wildlife Management Area — experimental plot 9
Data collected: Rosette number, length of all leaves, herbivory for each plant collected electronically and exported to CGData. Recheck information for plants not found was also collected electronically and stored in CGData.
You can find out more information about experimental plot 9 and flog posts mentioning the experiment on the background page for the experiment.
In 2009 and 2010, porcupine grass (Hesperostipa spartea, a.k.a. “stipa”) was planted in experimental plot 1. In total, 4417 seeds were planted, 1 m apart, 10 cm north of Echinacea plants. Between 2010 and 2013, each position was checked, and the plant status recorded. Since 2014, we have only searched for flowering plants. This summer, 143 flowering stipa were found, with a median of 24 fruit per plant. We also checked for living plants in positions where stipa was observed in 2011 or 2014. In these additional 492 positions, 89 plants were found alive, with 19 of those plants flowering.
The following table shows how many plants have been found alive in each year.
Year
Found
Flowering
Full Fruit
2010*
702
2011
483
2013
442
4
2014**
32
32
199
2015***
26
1
9
2016****
208
143
4391
(*) only one cohort (2009) included, (**) only searched for flowering plants, (***) only searched prior year’s flowering plants, (****) only searched flowering plants + subset of positions
Start year: 2009
Location: Experimental plot 1
Physical specimens: Fruits from 127 flowering plants, currently stored at the lab in Chicago. These may be used in a future study on traits of stipa‘s awns.
Data collected:
Culm count and number of fruits recorded on visors (backed up to CGData)
Fruit harvest information recorded on paper (stored at Hjelm house)
Status of 2011 basal plants recorded on visors (backed up to as “2016stipaRecheck2011positions” in CGData)
Products:
Josh Drizin’s MS thesis included a section on the hygroscopicity (reaction to humidity) of stipa awns. View his presentation or watch his short video.
Joseph Campagna and Jamie Sauer (Lake Forest College) did a report on variation in stipa’s physical traits within and among families in 2009
You can find out more about stipa in the common garden and links to previous flog posts about this project on the background page for this experiment.
Aphis echinaceae is a specialist aphid that is found only on Echinacea angustifolia. It feeds on sap in Echinacea leaves, and can also be found on flowering heads. This aphid also attracts “ant bodyguards”, which protect the aphids from predation, and in the process may also fend off other potential herbivores. Prior studies by Team Echinacea members have demonstrated that aphid presence does not lead to significant changes in plant fitness in observational studies, although in controlled experiments aphid presence does affect herbivore damage. Furthermore, inbred plants are more susceptible to aphid presence than outbred plants.
In 2011, Katherine Muller designated a sample of 100 plants in experimental plot 1 for aphid addition or removal. The presence or absence of these aphids is maintained by team members two to three times per week. In summer 2016, aphid levels were assessed and maintained 14 times on 70 of these plants (addition on 33, exclusion on 37) from early July until early August. In September, Amy Waananen recorded signs of senescence in the leaves of treatment plants. This data can be combined with data from our common garden measuring data to explore the richness of the Echinacea-aphid relationship.
Aphid counts for each treatment plant on each observation day, on paper
Leaf senescence data, recorded on paper
Initial and final assessment of aphid counts on treatment plants, recorded on paper
Paper records stored in ‘Aphids 2016’ binder, currently at Chicago Botanic Garden
Aphid counts also included in p1 measuring data
Products:
2016 paper by Katherine Muller and Stuart on aphids and foliar herbivory damage on Echinacea
2015 paper by Ruth Shaw and Stuart on fitness and demographic consequences of aphid loads
2015 poster by Daniel Brown and Kyle Silverhus (Lake Forest College) on achene and seed set differences on treatment plants
You can read more about the aphid addition and exclusion experiment, as well as links to prior flog entries mentioning the experiment, on the background page for this experiment.
Although originally used as part of Josh Drizin’s experiment with exotic grasses, this plot also has hybrids of Echinacea angustifolia and Echinacea pallida. Gretel and Nicholas Goldsmith performed reciprocal crosses between 5 non-native pallida plants found at Hegg Lake and 31 angustifolia plants in P1 and planted 66 seedlings between grasses in 2012. These plants have been revisited each summer since then. This year, on August 3rd, Laura Leventhal and I found 36 of the original 66 plants – a sharp decline from the 55 found last year. This means that 55% of the original cohort is still alive, with the survival rate this winter of 65%. Of the surviving plants, only three had more than one rosette.
This summer, we remeasured plants in experimental plot 7 at Hegg Lake. These plants are hybrids of Echinacea angustifolia (native) and Echinacea pallida (non-native, but planted at a nearby restoration). Shona Sanford-Long performed these crosses in 2012, Jill Pastick germinated the seeds that winter, and Stuart planted the seedlings the following spring. It is not yet known how the introduction of this non-native species will affect local Echinacea angustifolia populations. The survival rates and reproductive fitness of these plants can tell us how well the hybrids can compete with the native species. We have returned to the plot each of the last three years and measured the plants found there.
198 of the original 294 planted seedlings (67.3%) were found this year. The table below shows the fate of each cross-type in 2016 — the first name in the cross type is the maternal species, and the second name is the paternal species (e.g., ‘ang_pal’ is angustifolia mother and pallida father). These plants were measured on August 3rd and rechecked on September 2nd. No plants flowered this year, meaning that we must wait longer to assess seed set and reproductive fitness.
Cross Type
Found16 ang_ang ang_pal pal_ang pal_pal
no 34 10 20 32
yes 37 21 65 75
Start year: Crossing in 2012, Planting in 2013
Location: Hegg Lake Wildlife Management Area – Experimental Plot 7
Overlaps with: Echinacea hybrids: ex Pt 6; Echinacea hybrids: ex Pt 9
Data collected: Rosette number, length of all leaves, herbivory for each plant collected electronically and exported to CGData. Recheck information for plants not found was also collected electronically and stored in CGData.
Products: Taylor Harris’s 2015 poster demonstrating fitness benefits of pallida parenthood.
You can find more information and links to previous flog entries involving experimental plot 7 on the background page for the experiment.
One of many visits to each flowering plant in prairie remnants.
Assessing fitness is a key part of understanding change in any population. The Echinacea Project has focused on two quantifiable components of reproductive fitness of Echinacea angustifolia: style persistence and seed set. Styles shrivel when they receive compatible pollen, and thus persistence of styles reflects pollen limitation. A floret sets a seeds only when it has been successfully pollinated. Together, these two indicators can be used to predict how effectively individual plants produce viable offspring, giving insights into the persistence of remnant populations.
This year, we counted shriveled and non-shriveled rows of styles on each flowering head of every plant in 28 remnants three times per week. Well after the flowering season, we harvested 104 heads at a subset of these sites. The harvested heads will have their achenes removed, counted, and x-rayed by citizen science volunteers to estimate how many seeds they produced. There were several concurrent projects this summer and in the lab that use these measures, including Amy Waananen’s compatibility study and James Eckhardt’s study of edge effects.
Year: 1996
Location: Roadsides, railroads and rights of way, and nature preserves in and near Solem Township, Minnesota.
Between the summers of 2007 and 2013, team Echinacea observed the recruitment of Echinacea angustifolia seedlings around focal plants at 13 different prairie remnants. The locations of these seedlings were mapped relative to each focal plant and the seedlings (now former seedlings) are revisited each year. For each of these former seedlings, we make a record each year updating its status (e.g., basal, not found), rosette count, and leaf lengths. We also try to update the maps, which are kept on paper and passed down through the years, and add toothpicks to note useful landmarks when searching. This summer, we checked 119 focal plants at 12 remnants for 239 former seedlings. We found 148 of these former seedlings (out of the original 955). Although challenging to obtain, this data on the early stages of E. angustifolia in remnants is valuable and rare for us, as nearly all of our data from the remnants comes from plants that have already flowered (several years after first establishing). This data can tell us, for example, how long it takes plants to flower, and the mortality rate among seedlings in remnants.
Year started: 2007
Location: East Elk Lake Road, East Riley, East of Town Hall, KJ’s, Loeffler’s Corner, Landfill, Nessman, Riley, Steven’s Aproach, South of Golf Course remnants and Staffanson Prairie Preserve.
Electronic records of status, leaf measurements, rosette count, and 12-cm neighbors for each seedling. Currently in Pendragon database
Updated paper maps with status of searched-for plants and helpful landmarks
Products: Amy Dykstra used seedling survival data from 2010 and 2011 to model population growth rates as a part of her dissertation.
You can read more about the seedling establishment experiment and links to previous flog entries about the experiment on the background page for this experiment.
We revisited locations in remnants where flowering plants were observed in previous years.
We tag each Echinacea plant we see flowering in our prairie remnants, and record its location using the GPS. This is useful because it allows us to revisit the same plant in future years, checking to see if it is still alive, and if so how large it is and whether or not it is flowering. This has provided us with a very rich longitudinal dataset of life histories, dating back two decades and including thousands of plants. This year, we did total demo, visiting each plant in our database, at several sites including Staffanson, Loeffler’s Corner East, Northwest of Landfill, and East Elk Lake Road. In the interest of time, we only did flowering demo (only visiting plants that flowered this year) at several sites, including Landfill, Around Landfill, and Railroad Crossing. For each plant visited, we recorded its status (e.g., basal, flowering), its number of rosettes, and any neighboring Echinacea within a 12 cm radius. This data can be used to study inter-annual variation in flowering, population dynamics, and response to fire.
Year: 1996
Location: Roadsides, railroad rights of way, and nature preserves in and near Solem Township, Minnesota.
Data collected: Flowering status, number of rosettes, number of heads, neighbors within a 12 cm radius of plants found, stored in demo2016
GPS points shot: Points for each flowering plant this year shot mostly in PHEN records, stored in surv.csv. Some points of flowering plants stored in SURV records, also in surv.csv. Each location should be either associated with a loc from prior years or a point shot this year.
Products:
Amy Dykstra’s dissertation included matrix projection modeling using demographic data
Project “demap” merges phenological, spatial and demographic data for remnant plants
You can find out more about the demographic census in the remnants and links to previous posts regarding it on the background page for this experiment.
