Successful pollination leads to full achenes and higher fitness later in the season!
This summer we counted shriveled and non-shriveled rows of styles three times per week for every Echinacea head in 8 of the 28 remnant populations. We also harvested 121 Echinacea heads to be analyzed for seedset data. This year we selected heads for harvest based on their position within randomly selected plots where Tracie Hayes and Lea Richardson collected vegetation data. In every randomly selected vegetation plot, all species were identified and we recorded their abundance. We marked any Echinacea head within a vegetation plot for harvest. Harvested heads are ready to be processed by citizen scientists at the Chicago Botanic Garden. In the lab, heads will be cleaned so that all achenes can be counted and x-rayed to determine seedset.
Measuring the reproductive success of an Echinacea angustifolia head gives insight into the fitness of the individual. In remnant populations, we measure reproductive success using two methods: style persistence and seedset. Seedset is the proportion of all seeds that are viable in an Echinacea head, and is measured in the lab after heads have been harvested. Style persistence is a fitness measure that can be taken during the field season. Styles, the showy female reproductive structures that emerge from every floret in an Echinacea head, shrivel within 24 hours if they receive compatible pollen. Keeping track of how many styles shrivel and how many persist can give us a sense of the reproductive success of that head without any lab work.
Year: 1996
Location: Roadsides, railroads and rights of way, and nature preserves in and near Solem Township, Minnesota.
Overlaps with: flowering phenology in remnants, mating compatability in remnants
Physical specimens: 121 harvested heads, currently at the Chicago Botanic Garden
Data collected:
- Style persistence data for each flowering head, collected three times per week, stored in remData
- Dates and identities of harvested heads, stored on paper datasheets entered electronically into richHood
GPS Points Shot: A point for each flowering head, stored under PHEN and SURV records in GeospatialDataBackup
Products:
- Wagenius (2004), Wagenius (2006), Wagenius and Lyon (2010), Ison and Wagenius (2014) are published papers that use past style persistence and seed set data
- 2016 poster by James Eckhart about edge effects and style persistence
- 2012 poster by Karen Taira and Lee Rodman on style persistence in two non-Echinacea aster species
You can find out more about reproductive fitness in the remnants and read previous flog posts about it on the background page for the experiment.
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