2021 Update: Demographic census in remnants

Since 1995, the Echinacea Project has been mapping and collecting demographic information on Echinacea angustifolia to generate detailed, long-term records of individual fitness in prairie remnants. In summer 2021, Team Echinacea visited 34 prairie remnants to search at 2899 locations where adult Echinacea plants had been previously mapped. At small sites, the team searched for all adult plants, and at large sites, they visited a subset of the adult plants.

At each Echinacea plant, the team used handheld data collectors (visors) to record the flowering status, number of flowering heads, number of rosettes, and near neighbors of the plant. They then mapped the location of every flowering plant within each prairie remnant using a high-precision GPS unit. This year, the Echinacea Project purchased a second GPS unit, named Collins, to facilitate faster mapping.

In summer 2021, Team Echinacea took 4768 demographic records (demo) and shot 1788 GPS points (surv). In total, they recorded data on 1662 flowering Echinacea angustifolia plants, after removing duplicate records. Landfill had the most flowering plants (327), followed by Loeffler’s Corner (272) and Aanenson (146). The demo and surv datasets are in the process of being combined with previous years’ records of flowering plants in “demap,” the spatial dataset of remnant reproductive fitness that the Echinacea Project maintains.

The following sites were burned in fall 2020 and spring 2021: Dog, East Riley, KJ’s, Landfill East, Loeffler’s Corner East, Steven’s Approach (east and west), and Yellow Orchid Hill (east and west). In 2021, Team Echinacea did not do total demo at Railroad Crossing Douglas County (rrxdc). To avoid confusion at Hegg Lake WPA, a site which also contains recruitment plots RHE, RHP, RHS, and RHX, site “hegg” (Hegg Lake) was renamed “nrpal” (Near Pallida) in the demo and surv datasets.

Over the course of the summer, Team Echinacea spent a total of 25,245 minutes (421 person-hours) on demo and surv. This includes flowering demo (131 person-hours), flowering surv (72 person-hours), total demo (161 person-hours), and demo/surv rechecks (57 person-hours).

• Start year: 1995
• Location: Remnant prairie populations of the purple coneflower, Echinacea angustifolia, in Douglas County, MN. Sites are located between roadsides and fields, in railroad margins, on private land, and in protected natural areas.
  • Total demo: Bill Thom’s Gate, Common Garden, Dog, East of Town Hall, Golf Course, Martinson’s Approach, Near Pallida, Nessman, North of Golf Course, REL, RHE, RHP, RHS, RHX, RKE, RKW, Randt, South of Golf Course, Sign, Town Hall, Tower, Transplant Plot, West of Aanenson, Woody’s, Yellow Orchid Hill
  • Annual sample: Aanenson, Around Landfill, East Elk Lake Road, East Riley, KJ’s, Krusemarks, Loeffler’s Corner, Landfill, North of Railroad Crossing, Northwest of Landfill and North of Northwest of Landfill (lumped), On 27, Riley, Railroad Crossing, Steven’s Approach, Staffanson Prairie
• Overlaps with: Flowering phenology in remnants, reproductive fitness in remnants, EA fire and fitness, fire and flowering at SPP
• Data collected:
  • Plant status (can’t find, basal, dead this year’s leaves, dead last year’s leaves, flowering), number of rosettes, nearest neighbors, and head count, if flowering
  • All GPS files are found here: Dropbox/geospatialDataBackup2021
  • All demo and surv records are stored in the aiisummer2021 repo
  • The most recent copies of allDemoDemo.RData and allSurv.RData can be accessed at Dropbox/demapSupplements/demapInputFiles
• Samples or specimens collected: NA
• Products:
  • Amy Dykstra’s dissertation included matrix projection modeling using demographic data
  • The “demap” project is a long-term dataset that combines phenological, spatial and demographic data for remnant plants

You can read more about the demographic census in the remnants, as well as links to prior flog entries about this experiment, on the background page for this experiment.