Prairie once covered the western Minnesota landscape, but due to European settlement and farming practices, only a little over 1% of this remains today, mainly on roadsides, hillsides, and other patches too difficult to farm. The native Minnesota purple coneflower, Echinacea angustifolia, serves as a model organism for studying these remnant prairies and whether they are persisting. Echinacea cannot self-fertilize, and it depends on pollination from another echinacea plant to reproduce. In small, isolated populations, we know that mating between closely related plants can cause inbreeding depression which negatively affects a population’s ability to persist long-term. But we don’t yet know whether the size of a remnant prairie itself directly affects that persistence and whether these smaller populations are still worth holding on to. Therefore, to answer this question and inform how conservation resources are directed, we continue “total demo” which is a census that revisits previously recorded flowering plants across remnant prairies. Guided by stake files loaded onto high-precision GPS units, we locate each plant on our total demo visit list and record its identification tag, flowering status, number of flowering heads, number of rosettes, and nearby neighbors. This data lets us compare mortality and persistence in populations of varying sizes.
So far this season, we’ve completed total demo at 25 small sites, visiting 777 locations where flowering plants had previously been recorded with an average of about 31 locations per site, ranging from as few as 1 to as many as 89. Next, we’re moving on to 18 large sites with an average of 104 locations each. Given the time and effort it would take to revisit every recorded plant at these larger sites, we instead visit a representative subsection. To help fill in the gaps, we pair this with a flowering plant survey, which catches flowering heads that aren’t on this year’s total demo list. Total demo will continue to keep us busy for a while!
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