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Plot Layout

Long-term prairie research sites for this project required specific ecological and management conditions. Many sites did not meet these conditions, as they were inaccessible, too wet, or poorly managed for weeds or woody plants. The project team reduced the regional site locations to three, which spanned the moisture and temperature gradient in western Minnesota. The northwest region is located near Crookston, the central region is near Morris, and the southwest region is near Windom, Minnesota.  

plot maps

Plots in the northwest region were established on WMAs and on privately-owned parcels enrolled in the Conservation Reserve Program (CRP).  Plots in the central region were established on federally-owned Waterfowl Production Areas (WPAs) and on MN State Park land. All plots in the southwest region were established on DNR-owned Wildlife Management Areas (WMAs). 

Sites were chosen based on availability of funds, feasibility of the sites, uniformity within its climate and soils, and the ability to conform to randomized block design. Each site has four blocks containing four 20-acre plots. One block represents one repetition with four treatments within it.
 
The treatment imposed is harvest intensity. Each 20-acre plot is harvested in autumn leaving a certain size and shape refuge of standing vegetation for wildlife. 
 
1) Control - no harvest; all vegetation is left standing 
2) 75% harvest strip   - 75% of the plot is harvested and the rest serves as a wildlife refuge; harvesting occurs in 30-meter strips across the plot
3) 75% harvest block - 75% of the plot is harvested and the rest serves as a wildlife refuge; unharvested block rotates yearly within the plot
4) 100% harvest - no refuge left standing
 
1.)                                2.)                           

 75% strip harvest
  3.)                              4.)
75% block harvestFull harvest

Two additional treatments were supported with NFWF funding in the southwest region: 

5) 50% harvest block - two opposite quarters of the plot are left standing as refuge; halves are rotated yearly
6) 50% harvest strip -  thirty-meter wide harvest strips are cut; strips rotate yearly 

  5.)                                6.)

50% block harvest50% strip harvest