Categories

Authors

Carleton Externs – Sarah’s Final Update

Hello flog, one last time!

Today marks the end of my three weeks here on Team Echinacea, and I’m certainly sad to say goodbye! Nevertheless, it was exciting and rewarding to culminate this externship with a week of data analysis, poster creation, and presentation of findings to the team. While Tris chose to analyze data from Michael’s Echinacea pollen limitation experiment, Julie and I decided to delve into the worlds of Liatris aspera and Solidago speciosa, two other Asteraceae common to prairie ecosystems. Lea has been working with these species for her PhD project over the past few years, studying how timing and location of flowering influences reproductive success, so she was a great help as we commenced our analysis!

After having meticulously cleaned, counted, and classified innumerable Solidago and Liatris flowering heads, Julie and I wondered how the vast differences in head count between these two species may impact each plant’s fecundity (when Liatris plants generally have 10-20 heads, and many Solidago plants have hundreds or even thousands) . Further, knowing that human populations have largely suppressed the occurrence of natural fires in today’s prairies, we were also interested in analyzing the effects of prescribed burns on these common prairie species. We put these two questions together in our data analysis by forming a statistical interaction model–one in which the effect of fire would interact with the effect of flowering head count to influence reproductive success–and fitting it to our Liatris and Solidago data. Interestingly, we did not uncover the same results for these two closely-related plants! For Liatris, the interaction model was highly supported by our data: the head count of plants seemed to have more effect on seed set (a measure of fecundity) in plants that had not been recently burned than in plants that had been recently burned. Yet, for Solidago, this pattern was not present. Our findings suggest that prairie management strategies, of which prescribed burns are an integral part, should carefully consider the species composition of a prairie before burning, because different species may react to burn treatment in different ways. Check out our poster, attached here, for a more detailed analysis, as well as plots of our models!

Before I sign off, I want to send a huge ‘thank you’ to every member of Team Echinacea! This opportunity was incredibly influential for me–this was my first real research experience, and I learned so much about ecology, networking, career paths, data collection, statistics, and more. I had an amazing time, and I hope to see some team members again someday!

Thank you again,

Sarah

PDF version below:

Soliatris2018 Poster

Riley’s Fall Semester Update

Hello Echinacea folks! After a great summer at the Echinacea Project, I returned to Gustavus to work on the morphological and physiological data I collected at experimental plot 7. In my time at Gustavus so far, I wrote a proposal for my project so I can analyze my data and undertake a senior honors project under familiar Echinacea advisors Pamela Kittelson, Stuart Wagenius, and Sanjive Qazi. I have also worked on a methods section for my final honors paper and made a poster (attached below). In addition to my project, this fall I have been working on a project to implement composting and sustainable practices in Saint Peter restaurants and a project analyzing microRNA-mediated stress response in smooth cordgrass. The next steps for my honors project are to write up an introduction and do statistical analysis over our January-term. I will be performing aster and cluster analyses and am really excited to get back into some R coding! echinaceaPoster1_Thoen

The Sweetener Flog

“When life deals us cards

Make everything taste like it is salt

Then you come through like the sweetener you are

To bring the bitter taste to a halt”

Ariana Grande, in the song “Sweetener” off of her latest album Sweetener (2018).

Greetings from the College of Wooster, or Team Echinacea East

This summer I helped conduct research about the differences in pollen removal and deposition (a measure of pollinator efficiency) across different taxa of solitary bees that visited Echinacea flowers, out at P2 (with Evan, Mia, and Jennifer Ison). In order to quantify pollen removal we collected anthers (the male part of the flower that presents pollen) before a bee visited and again after the visit; we suspended the anthers in water. In order to quantify the number of pollen grains in each sample. But what to do with these samples?

Here are all the sweet anther samples!

In order to quantify the number of pollen grains present in each sample I first break apart and shake up the anthers, to try to get the pollen evenly distributed in the solution; then I count a small amount of this pollen solution on a hemocytometer under a microscope (a hemocytometer is a sort of microscope slide with a grid that is used to count red blood cells in blood; I use it to count pollen particles in water).

Here’s the hemocytometer all loaded up with sweet pollen to count!

Now that the summer field season is over I’ve been able to spend quite a bit of time counting pollen. While I’ve been counting pollen I’ve been listening to music on my roommate’s portable speaker. Mostly I’ve been listening to Ariana Grande’s new album Sweetener. The title track which opens this flog post speaks directly to the relationship that I have developed with the act of counting pollen. It is the sweetener to my life. I struggle to leave the lab each night; wanting to get just a little more of that sweet taste of pollen counting. It brings the bitter taste of college life to a halt. I don’t know what it is about pollen counting that I like so much. Is it the repetitiveness of it? The simplicity? The repetition? It’s impossible to say. All that I know for sure is that I really hope that everyone can experience the sweetness that counting pollen brings to my life.

P.S. I really hope I find something to fill the void that will be left in my existence once I run out of pollen to count (I only have 340 samples or so, and I’m more than half way through them).

Thanks

Riley’s P7 Physiology Update

Hello Echinacea Project readers! My personal project is actively taking place in experimental plot 7, a hybrid plot planted in fall of 2013. The primary purpose of the plot is to assess relative survival and fitness in Echinacea angustifolia and pallida, as well as hybrids of the two species. Data on survival, number of leaves, and size of these plants has been collected over the years. I will be using this data in an aster analysis to determine which cross type is the most fit. Unfortunately, only one individual has flowered over the time this plot has been around, and it was a pure E. pallida. From preliminary looks at the data, conspecific angustifolia seem to have the lowest survivorship and have the smallest average leaf length!

 

The other part of my project is assessing the physiology of these plants. For this, I have been using a Licor Li-6400xt, which can assess rate of carbon assimilation as well as transpiration (loss of water) in leaves. Getting the machine to work properly on Echinacea leaves took a ton of stress and time from me, but luckily it is up and running now. Using these measures can hopefully give us insight into why pure angustifolia crosses have lower survival than others. As I post this, I have made many observations on what factors affect photosynthetic rate the most in the plants. More shaded, thinner, lighter leaves, and partially consumed leaves all seem to display lower efficiency! I am really excited to integrate all of this data and ultimately analyze it!

Taking apart the Licor chamber to get it to work on Echinacea leaves… This was stressful.

A tiny basal Echinacea in pt7. The variation is incredible!

Recap of past year & summer 2017 field season

It’s time to prepare annual reports to NSF for our two long-term awards through CBG & through UMN. The period covers 1 April 2017 through 31 March 2018. So, here’s a brief recap of activities from the past 12 months including the summer 2017 field season.

Last spring we were busy in the lab. Led by interns Amy & Scott, volunteer citizen scientists at the Chicago Botanic Garden started cleaning heads harvested in summer 2016 to count all of the achenes to generate a detailed and precise dataset of annual plant reproductive fitness. We were way behind because of the huge flowering year in 2015. We worked all fall & winter and we are in good shape now. Led by Tracie, we are cleaning 1148 heads harvested from plots in 2017, which we will finish over this summer.

Several undergraduate students have worked on projects in the lab, including Nicolette, Ashley, Marisol, Nina, Trevor, and now Danielle. They are all gaining experience, learning a lot, and contributing to science! Graduate students are hard at work too. Lea has analyzed all of her summer phenology data on Solidago & Liatris. Kristen is working on the bee collection from last summer with Mike. They are both making research plans for summer 2018.

Last December, we submitted a paper to Oikos titled “Pollinator-Mediated Mechanisms for Increased Reproductive Success in Early Flowering Plants.” We haven’t heard anything for 101 days & wonder if it has disappeared into a black hole.

Our team accomplished a lot in summer 2017! The 2017 summer team, shown below, included three undergraduate students (Ashley, Will & Wes), a high-school student (Anna), two graduate students (Lea & Kristen), and two recent college grads (Tracie & Alex)–not to mention the usual suspects, Gretel, Ruth & Stuart. We summarized progress on many summer projects last fall & made flog posts. Here are links to the updates organized into six groups.

First, we measured survival, growth, and flowering effort of our model plant, Echinacea angustifolia, in several experimental plots. The earliest was established in 1996 and the most recent in 2015:

Second, we measure other traits in these plots, including flowering phenology. We also have some treatments, such as pollen addition and aphid addition, which we apply every year. Will has super-cool estimates of the heritability of flowering timing. He is polishing the manuscript and will submit it soon. Amy W. has a manuscript in review that quantifies reproductive synchrony in the 1996 cohort of plants. She estimated how much within-year synchrony (daily phenology) and among-year synchrony (annual flowering) contribute to long-term mating opportunities.

Third, we make observations of Echinacea plants in natural prairie remnants in our study area, including flowering phenology, survival, reproduction, and incidence of disease. Scott is investigating effects of fire on population growth rates in our remnants using a life-table response experiment approach. While she is on sabbatical, Amy D. is analyzing the seedling establishment dataset.

Fourth, we study plant species other than Echinacea angustifolia and we are very interested in pollinators, including native solitary bees.

Fifth, two REU participants worked on our Team last summer. Here are updates of their projects.

Sixth, we are worried about non-native Echinacea plants that are used in restorations and how they impact populations of the native Echinacea angustifolia. We have several ongoing experiments that investigate a population of Echinacea pallida introduced within our study area.

The Team from summer 2017


2017 update: Echinacea pallida flowering phenology

Anna and Will decapitate a plant. It’s Echinacea pallida which is not native to Minnesota.

Echinacea pallida is an Echinacea species that is not native to Minnesota. In July 2017, we identified 100 flowering E. pallida plants with 222 heads that were planted in a restoration at Hegg Lake WMA. Every year for the past several years, we have visited the E. pallida plants, taken phenology data, and chopped off their heads. On July 7, 2017 when we collected the data, the maximum male row was 19, meaning flowering started about 19 days earlier–June 18, 2017. E. angustifolia in the remnants started flowering on June 24, about a week later. 17 of the 222 E. pallida heads were still buds on 7 July, so these plants would have continued flowering for awhile.

We went back to check if we missed any heads on 31 August and found two. They were done flowering, but hadn’t dropped seeds.

Start year: 2011

Location: Hegg Lake WMA restoration

Overlaps with: Echinacea hybrids (exPt6, exPt7, exPt9),  flowering phenology in remnants

Physical specimens: 222 heads were cut from E. pallida plants and likely decomposed. We brought two heads back with us to Chicago.

Data collected: A csv in ~Dropbox/remData/105_assessPhenology/phenology2017 with tag, row number the male florets were at on July 7, 2017 for each head, and initials of the data collector.

GPS points shot: We shot points for the 100 flowering E. pallida plants.

Products: In Fall 2013, Aaron and Grace, externs from Carleton College, investigated hybridization potential by analyzing the phenology and seed set of Echinacea pallida and neighboring Echinacea angustifolia that Dayvis collected in summer 2013. They wrote a report of their study.

Previous team members who have worked on this project include: Nicholas Goldsmith (2011), Shona Sanford-Long (2012), Dayvis Blasini (2013), and Cam Shorb (2014)

You can find more information about Echinacea pallida flowering phenology and links to previous flog posts regarding this experiment at the background page for the experiment.

2017 update: Flowering phenology in experimental plots

This year, the number of flowering plants in our main experimental plot (exPt1) dropped in half compared to last year. This might be due to the lack of a burn in the prior fall or spring. Plot 2 (exPt2) had about the same number of heads in ’16 & ’17.

In exPt1, we kept track of approximately 72 heads. The peak date was July 19th. The first head started flowering on July 2nd and the last head finished up on August 21st. In contrast, we kept track of 1076 heads in exPt2, about 140 more than last year! The peak date for these Echinacea was a bit earlier, July 13th. exPt2 heads also started and ended earlier (June 22 – August 19).

We harvested the heads at the end of the field season and brought them back to the lab, where we will count fruits (achenes) and assess seed set.

Flowering schedules for 2017 in exPt1 and exPt2. Black dots indicate the number of flowering heads on each date. Gray horizontal line segments represent the duration of each head’s flowering and are ordered by start date. The solid vertical line indicates peak flowering, while the dashed lines indicate the dates when 25% and 75% of heads had begun flowering, respectively. Note the difference in y-axes between the two plots. Click to enlarge!

Start year: 2005

Location: Experimental Plots 1 and 2

Overlaps with: Heritability of flowering time, common garden experiment, phenology in the remnants

Physical specimens: Harvested heads from both experimental plots are in the lab at CBG. The ACE protocol for these heads will begin soon.

Data collected: We visit all plants with flowering heads every 2-3 days starting before they flower until they are done flowering to record start and end dates of flowering for all heads. We managed phenology data in R and added it to our long-term dataset. The figures above were generated using package mateable in R. If you want to make figures like this one, download package mateable from CRAN!

You can find more information about phenology in experimental plots and links to previous flog posts regarding this experiment at the background page for the experiment.

 

 

2017 update: Ridley’s next generation rescue

geneticRescueSlideIn 2017 Stuart and Lea relocated and measured 19 individuals of the 381 seedlings originally found. These plants had 1-4 leaves; the longest leaf was 32 cm. It should be interesting to see which individuals are hanging on!

Caroline Ridley established this experiment to compare fitness (recruitment and survival) of seeds originating from individuals with parents from three different backgrounds: 1. both from a large remnant population, 2. both from a small remnant population (not rescued), and 3. one from a large population and one from a small population (genetically rescued). Caroline sowed achenes in an experimental plot at Hegg Lake WMA and marked seedlings with colored toothpicks in May 2009.

Start year: 2008

Site: exPt 4 at Hegg Lake WMA

Overlaps with: crossing experiments qGen1, qGen2, qGen3 & recruitment experiment; INB1

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

2017 Update: Echinacea hybrids — exPt 9

This summer, we measured open-pollinated hybrid Echinacea plants in experimental plot 9 at Hegg Lake. The table below shows the number of plants found alive during each search since the experiment started in 2014. Of the surviving plants in 2017, 90% had fewer than 3 leaves, the mean length of the longest basal leaf was 25 cm, and only six plants had more than one basal rosette. This year we searched for plants once then rechecked every position where we didn’t find a plant during our first search. No plants flowered this year.

Year / Event Number Alive % Original remaining % Of previous year
Planting (2014) 746 100
2014 638 85.5 85.5
2015 521 69.8 81.7
2016 493 66.1 94.6
2017 401 53.8 81.3

This experiment comparing the fitness of Echinacea hybrids with pure-bred E. angustifolia and E. pallida will give insight into the possible consequences of non-native E. pallida being planted in restorations in Minnesota, where E. angustifolia is the only native Echinacea.

Measuring at Hegg Lake

Start year: 2014

Location: Hegg Lake Wildlife Management Area — experimental plot 9

Overlapping experiments: Echinacea hybrids — experimental plot 6Echinacea hybrids — experimental plot 7

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.

2017 Update: Echinacea hybrids — exPt 7

This summer, we measured hybrid Echinacea plants in experimental plot 7 at Hegg Lake. 159 of the original 294 planted seedlings (54%) were found this year. We searched 243 of the 294 positions where plants were originally planted (the other 51 positions were not searched because plants have not been found for at least three years in a row). The table below shows the fate of plants in 2017 summarized by cross-type — the first name in the cross type is the maternal species, and the second name is the paternal species (e.g., ‘ang x pal’ is angustifolia mother and pallida father).

Status 2017 ang x ang ang x pal pal x ang pal x pal
not found 53 10 33 35
found 21 18 52 72

Flowering Echinacea angustifolia.

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.