2017 update: Common garden experiment–1996 cohort

In 2017 only 2% of the surviving members of the 1996 cohort flowered!

In 2017 only 7 plants flowered of the surviving 284 plants in the 1996 cohort. That means that 44% of the original plants are surviving and only 2% of the living individuals flowered! Five percent of living individuals flowered in 2016. In contrast, 45% of living plants flowered in 2015, followed by 37%, 34%, and 40% from 2014 back to 2012. We found that of the original 646 individuals, 284 were alive in 2017, only 7 fewer than last year. We are not sure why so few plants flowered this year. It’s possible that lack of fire in the plot influenced flowering rates. This plot was due for a prescribed burn in spring 2017, but weather and scheduling conflicts kept us from burning.

The 1996 cohort has the oldest Echinacea plants in experimental plot 1; they are 21 years old. They are part of a common garden experiment designed to study differences in fitness and life history characteristics among remnant populations. 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, count all achenes, and estimate seed set for each head in the lab.

Start year: 1996

Location: Experimental plot 1

Overlaps with: phenology in experimental plots, qGen3, pollen addition/exclusion

Physical specimens:

  • We harvested 8 heads. At present, they await processing in 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—these data have 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)


  • See the exPt1 core dataset where yrPlanted == ‘1996’ for 1996 cohort fitness measurements

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.


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