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For the past three years, studying phenology in the remnants has been a major focus of our summer field work. The motivation behind this study is to understand how timing of flowering affects the reproductive opportunity and fitness of individuals in natural populations. Stuart began studying phenology in remnant populations between 1996 and 1999 and several students also studied certain populations in following years. From 2014-2016, we tracked phenology in all of our remnant populations. This year there were 1040 flowering plants (1500 flowering heads).
Flowering began on June 18th with one plant at the East Riley roadside remnant. Sadly, this early bloomer was mowed just 6 days after it started flowering. The latest flowering plant shed pollen in the West Unit of Staffanson Prairie Preserve on August 17th. When we consider all populations together, peak flowering was on July 10th. Peak flowering at Staffanson Prairie Preserve was later, on July 18th, likely due to the prescribed burn in the West Unit setting flowering back.
 Line segments represent the duration of flowering for each remnant population. Click to enlarge! As you can see in the figure above, some populations had much longer duration of flowering than others. Flowering duration at Staffanson Prairie Preserve (‘spp’ in the figure) was longer because the west unit was delayed in flowering. East Riley (‘eri’) has a long duration of flowering, likely due to individuals being mowed early in the season, then resprouting and flowering later. This figure shows the very first and last dates of flowering, but population mean start and end dates of flowering is also informative (see what that flowering schedule looks like here). These figure with generated with R package mateable, which was was developed by Team Echinacea to visualize and analyze phenology data.
Start year: 1996
Location: roadsides, railroad rights of way, and nature preserves in and near Solem Township, MN
Overlaps with: Phenology in experimental plots, demography in the remnants
Physical specimens:
- We harvested a random sample of 5 heads from most remnant populations (we excluded very small populations) and brought them back to the lab, where student interns will process and assess their seed set (‘regRem’ or ‘regular remnant harvest’).
- We also harvested the most isolated, least isolated, earliest flowering, and latest flowering individuals from large populations (‘remnant extremes’). Student interns will also process and assess seed set of these heads.
Data collected: We identify each plant with a numbered tag affixed to the stem and give each head a differently colored twist tie, so that each head has a unique tag/twist-tie combination, or “head ID”, under which we store all phenology data. We monitor the flowering status of all flowering plants in the remnants, visiting at least once every three days until all heads were done flowering to obtain start and end dates of flowering. We managed the data in the R project ‘aiisummer2016′ and will add it to the database of previous years’ remnant phenology records.
GPS points shot: We shot GPS points at all of the plants we monitored except for four, two at SGC and two at ERI, which were mowed (ERI) or dug up (SGC) early in the season. These points were shot under job names following the convention “SURV_2016MMDD_SULU” or “SURV_2016MMDD_CHEK”. The locations of plants this year will be aligned with previously recorded locations, and each will be given an identifier (‘AKA’). We will link this year’s phenology and survey records via the headID to AKA table.
You can find more information about phenology in the remnants and links to previous flog posts regarding this experiment at the background page for the experiment.
 We observed that 95% surviving members of the 1996 cohort were basal in 2016 The oldest Echinacea plants in experimental plot 1 are 20 years old. They are part of a cohort planted in 1996 in a common garden experiment designed to study differences in fitness and life history characteristics of remnant populations. Stuart sampled about 650 seeds (achenes) from eight remnant populations in and near Solem Township, representing the range of modern prairie habitat from small patches along roadsides to a large nature preserve. In 1996, he transplanted seedlings on a 1m x 1m grid, randomly assigning the location of each individual.
Every year, members of Team Echinacea assess survival and measure plant growth and fitness traits including plant status (i.e. if it is flowering or basal), plant height, leaf count, and number of flowering heads. We harvest all flowering heads in the fall and obtain their achene count and seed set in the lab.
Only 15 plants from the 1996 cohort were flowering this year. We were very curious to know if this small number was a result of a low rate of flowering or due to high mortality in the cohort. We found that of the original 650 individuals, 291 were alive in 2016, only 13 fewer than last year. That means only 5% of living individuals flowered. In contrast, 45% of living plants flowered last year (and 37% in 2014, 34% in 2013, 40% in 2012). We’re not sure why so few plants flowered this year; it’s possible that individuals flower less as they age, but we also observed low rates of flowering in younger cohorts in experimental plot 1, suggesting that environmental factors may also be responsible.
Start year: 1996
Location: Experimental plot 1
Overlaps with: phenology in experimental plots, qGen3, pollen addition/exclusion
Physical specimens:
- We harvested all 17 heads and at present they await processing at the lab to find their achene count and seed set.
Data collected:
- We used Visors to collect plant growth and fitness traits—plant status, height, leaf count, number of flowering heads, presence of insects—and it has been added to the database (?)
- We used Visors to collect flowering phenology data—start and end date of flowering for all individual heads—which is ready to be added to the exPt1 phenology dataset
- Eventually, we will have achene count and seed set data for all flowering plants (stay tuned)
Products:
You can find more information about the 1996 cohort and links to previous flog posts regarding this experiment at the background page for the experiment.
Every year we keep track of flowering phenology in our main experimental plots, exPt1 and exPt2. Fewer plants than usual flowered in exPt1 in 2016: 149 plants (179 heads) flowered between June 24th and August 7th. The population’s mean start date of flowering was July 5th and the mean end date was July 18th. Peak flowering in 2016 was on July 10th, when 143 heads were in flower. For comparison, peak flowering in 2015 was on July 27th, when there were nearly 10x as many heads flowering as on this year’s peak. The earlier phenology and low numbers of flowering we observed this year relative to 2015 is likely due at least in part to the plot burn schedule (2015 was a burn year and 2016 was a non-burn year), but there were still many fewer flowering plants than any season, burn or non-burn, in the past 10 years.
We kept track of 934 flowering heads in ExPt2, where the first head started shedding pollen on June 22 and the latest bloomer ended flowering on August 8th. Peak flowering was on July 7th, when 810 heads were flowering. ExPt2 was designed to study the heritability of phenology—you can read more about progress of that experiment in the upcoming 2016 heritability of phenology project status update.
At the end of the season we harvested the heads and brought them back to the lab, where we will count fruits (achenes) and assess seed set.
 ExPt1 and Expt2 flowering schedules from 2016. Dots represent the number of flowering heads on each date. Horizontal line segments represent the duration of each heads 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. 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: We harvested 177 heads from exPt1 and 870 from exPt2. Attentive readers may note that we harvested about 64 fewer heads than we tracked for phenology. That’s because before we could harvest many seedheads at exPt2, rodents chewed through their stems and ate some fruits (achenes). We recovered most of the heads that were grazed from the ground and made estimates of number of fruits lost due to herbivory, but we couldn’t find some heads. Arg. We brought the harvest back to the lab, where we will count fruits and assess seed set.
Data collected: We visit all plants with flowering heads every three days 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 the full dataset. The figure above was 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.
Hi Flog! It’s me, Amy!
This winter we’ve been working on ‘demap’, a project to coordinate 20+ years of demography and spatial data from remnant populations of Echinacea in Solem Township. When we are done we will have a great long-term dataset of over 3000 individuals in 27 remnant populations. We can use that information to answer all kinds of questions about flowering dynamics in natural populations, population growth, and the consequences of disturbances such as habitat fragmentation and fire! In particular, this January we focused our efforts on answering questions about the demographic consequences of fire. Does fire’s stimulation of flowering contribute to increased population growth over the long term? Do reproductive benefits of fire outweigh potential survival costs? We’re not sure, but we hope to find out by analyzing four populations– a large population that had one fire event, a large population that has not been burned in the past 20 years, a small population that burned once, and a small population that has not burned in the past 20 years. We’ll combine our demography data about flowering and survival with other information, such as the seedling recruitment and remnant seed set data, to project population growth.
Will was here to help out with the project in the first two weeks of January. We got a lot done with demap and made meaningful progress on other big questions such as “Is kale overrated?” and “What does overrated mean statistically?”. We also made big strides in terms of professional development by studying business mogul DJ Khaled’s keys to success. Stay tuned for updates!
Sincerely,
Amy
 Demap is a team effort! In this shot, we are helping Will find a plant on the computer.
 Echinacea purpurea at Yellow Orchid Hill Non-native and invasive species are present in many of our study sites and may compete with native species for resources, such as light, space, or pollinators. Some invasive species, such as brome (Bromus inermis) and sweet clover (Melitotus officinalis), are already so widespread and abundant that we don’t keep track of where they are. However, this summer we noticed new appearances of several other non-native species, Echinacea purpurea and Rudbeckia hirta*, that could become more dominant in years to come. We documented their presence by taking photos and shooting GPS points. Most of the places where we saw these species were nearby or part of a restoration where the non-native species was introduced as part of the seed mix. Going forward, we will return to the locations where these species were found in 2016 and monitor the expansion of their populations.
Year: 2016
Location: RRX (Rudbeckia hirta), north of WAA (Rudbeckia hirta), RLR (Rudbeckia hirta and Echinacea purpurea), YOHW (Echinacea purpurea), and the corner of Tower Rd and 27 (Rudbeckia hirta)
Data collected: The photos we took are stored in Dropbox (summer2016pics/invasives)
GPS points shot: We shot GPS points at: RRX (1 pt), RLR (approximately 10 pts), YOH (1 pt). The restoration near WAA had too many plants to shoot individually, so we just took pictures. We couldn’t find the Rudbeckia at the corner of Tower Rd because the area where it had been was disturbed by electrical work. These points are stored in the job ‘ECHPURP_RUDBHIRT_20160914_SULU.tsj’.
*You might be thinking, “Isn’t Rudbeckia native?” and the answer is yes, in other parts of Minnesota. However it is not present in any of the high-quality remnant prairies in our study area and so we consider it to be non-native to our sites.
We had the smallest crew of the season yet today with Lea’s departure and Stuart still being in Chicago. Nevertheless, James, Scott, Will, and I managed to get a few things done today. We had a late start after flash flood warnings in Douglas County until 9:30. We made the best of the wet conditions and did some weeding of thistle and bird’s foot trefoil in p1. After things had dried out a little, we split up and harvested heads in the remnants. We reconvened for lunch. In the afternoon, Will and I went to Staffanson to harvest the ‘sppBonus’ plants, which are a sample of plants that have flowered in both burn and non-burn years that we harvest in addition to our regular remnant harvest. We found all of our target plants, which was a little trickier than anticipated because so many of the heads on the west unit had been toppled by weevils or grazed. Meanwhile, Scott and Jame went to Landfill and On27 to finish up harvest there. Once they finished, they met Will and I at Staffanson to work on total demo. We estimate that we are about halfway done with all demo at Staffanson. It is a big job! Fortunately, by now we are all experts and, also fortunately, the mosquitoes were not quite as bad as they were on Friday. That’s good because between the rest of demo and Lea’s phenology project we’ll be spending plenty more time there in the coming days!
 Jame and friends
Good evening floglanders,
 Computers in the prairie!! No parents no rules!! Stuart took the train back to Chicago this morning, leaving us kids in charge of fieldwork for the rest of the week. In the absence of responsible adults, we did all kinds of wild and crazy things. Lea and Scott assessed phenology for Lea’s experiment at Staffanson while Will, Jame, and I did demo at RRX and NRRX. Will and I left James to set up seedling refinds at Staffanson and went on to harvest a few remaining heads from the remnant harvest sample that we started yesterday. After lunch we did total demo on the south side of the road at Aanenson and after that we did seedling refinds at Staffanson. It was totally OC (outta control). We wrapped up the day by getting the ice cream out of the freezer and having root beer floats for the second day in a row. Woohoo!!! Don’t tell Stuart or Gretel.
Til next time,
Amy
Hi Flog,
It’s great to be back in Minnesota after a muggy and fun week at ESA in Ft. Lauderdale. On Thursday, I presented my poster, “Two temporal scales of reproduction affect mating opportunity in long-lived perennials.” The poster was displaying work that I did this past year looking at the 11-year phenology dataset we have from the individuals in p1. The question I tried to answer, basically, was whether it flowering on a high-flowering day or in a a high-flowering year was more important for an individual’s number of opportunities to mate. For example, this year is a low-flowering year in p1, whereas last year was a high-flowering year. Would it be better to flower on the population’s peak date of flowering this year or to have flowered off peak last year? It turns out that in this system, the year is more important relative to the day. I think this is because all flowering within a season is synchronous enough that most individuals don’t totally miss out on opportunities to mate, even if they are early or late flowering. I still have some work left to do on my analysis, but it was super helpful to hear what questions people had and get some useful insights as well!
 Here’s me with my poster
Here’s a link to my poster if you want to take a closer look!
Dear Flog,
The team comforts Roxy as she contemplates life’s transience Today was bittersweet. We began the day by assessing phenology in the remnants, a task which takes far less time now than it did a few weeks ago. Many sites are completely done flowering, so we won’t visit them any more. To make matters worse, today was Jennifer’s last day. Roxy was so upset that she hitchhiked to Barrett in a last ditch attempt to make Jennifer stay. However there were also some rays of hope today. Most notably, Lea found a shirt that Alyson had left in Staffanson two weeks ago. We thought it was gone forever! Also, Ruth and Carlee, an REU student, visited. We all had a very productive afternoon measuring hybrid plots at Hegg. The day kept getting better. After work we went and had a nice dinner at Mi Mexico, a well-decorated restaurant in Alexandria. Tomorrow, Will, Gretel, and I will head up to Pembina to check seed set of the western prairie fringed orchids that we found earlier in the summer. Hopefully it will help take my mind off of the sad thought that more team members will be leaving soon.
Yours truly,
Amy
 Easy, breezy, beautiful Good evening, Flogland. I’m here in Kensington after a quiet Sunday compared to yesterday’s festivities. After confirming that Scott, with help from Lea, had indeed reenacted every image in my basement last night, we headed back toward Kensington.
 (L to R) Rudolph, Santa Notable events from the drive include conducting an experiment to see how accurately we could identify Skittles flavors. I was pretty bad at distinguishing the variation in flavor profiles but Will did pretty well. After returning home, people at Town Hall spent most of the day napping, cooking, and working on independent projects.
 The champion We are saving our energy for another day of Xtreme phenology tomorrow, which is when we combine xamining phenology with xercising our xpertise in pollinator observations and get everything done xtremely fast! It is very xciting, although with the number of plants xhibiting pollen getting smaller every day, I’m xpecting it to go even faster than Friday. Stay tuned for updates.
Peace,
AW
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