I was out for a run with my dog at Pine Point Regional Park when I discovered something that piqued my curiosity. The park has a small restored prairie on the north end that changes with the seasons – pale green in early summer, dappled purple and yellow in August and September, and soft pinkish gold in the late fall, when flowers fade and only the grasses remain. On this November day, however, I was surprised to crest a hill and find the prairie looking like a scene from a Monet painting, complete with smooth, round bales that cast shadows in the setting sun. Why had the prairie been harvested like a hay field?
After talking with a few colleagues, I quickly learned that Washington County Parks is haying the prairie to imitate natural processes that would occur if the land were being grazed by bison or other large herbivores. According to Laurie Schneider from Pollinator Friendly Alliance, “It's considered ‘conservation haying’ in this scenario. The big blue stem was taking over a bit, so by cutting it in the early winter, birds are not harmed, most of the seed will fall back onto the prairie, and the big blue stem will be subdued so that other species can prosper in the spring.”
Washington County Parks has been working with Pollinator Friendly Alliance and Washington Conservation District to enhance the existing low-quality prairie at Pine Point to provide better pollinator habitat. Restoration efforts have focused on increasing the ratio of forbs (flowering species) to grasses, and adding additional nectar plants for threatened and endangered pollinator species such as the Karner blue butterfly and the Rusty-patched bumblebee.
Prairie and oak savanna are dynamic systems that evolved over thousands of years, in conjunction with wind, fire, drought, thundering bison, burrowing gophers, vast societies of insects, and native people who began living here 10,000 years ago. When Minnesota became a state in 1858, prairie and oak savanna covered 18 million acres of land – roughly 25% of the state. Today, less than 2% still remains.
In a few places in Minnesota, people have re-introduced bison to remnant and restored prairies. Roughly 80 adult bison live year-round at Blue Mounds State Park in the southwestern corner of the state. Belwin Conservancy in Afton began bringing in bison in 2008 through a partnership with NorthStar Bison, a family-owned ranch in Rice Lake, Wisconsin. The Belwin bison run out of a truck and into the prairie every summer and then head back to the ranch at the end of the fall. According to the Minnesota DNR, all of the bison living in the plains states today are descended from less than 100 survivors that remained at the end of the 19th century.
In pocket prairies too small for bison, like the one at Pine Point Regional Park, people can partially replicate the impact of grazing by harvesting the plant material above ground that would “normally” get eaten by an animal. As Stephen Lawrence Thomforde, Senior Ecologist at Stantec, explains, haying does more than just take away dried grasses so that flowers can grow in the spring. It also helps to remove excess nitrogen that builds up in the top layer of the soil. Without bison grazing, native grasses gradually become less edible and invasive weeds and earthworms begin to flourish. Says Tara Kelly, a natural resource specialist at Washington Conservation District, “Haying removes biomass and nitrogen, much like grazing.”
Over the years, Washington Conservation District has helped dozens of private landowners in Washington County to covert turf and fallow cropland back to prairie. Staff provide free site visits, recommend local contractors, and connect landowners with grants and other assistance (site visits will resume in the spring of 2021). Resources for smaller projects such as rain gardens and native plantings are also available online at www.mnwcd.org/planting-for-clean-water. Additional online resources can be found at www.BlueThumb.org and www.dnr.state.mn.us/prairierestoration.
Pine Point Regional Park is located five miles north of Stillwater on Norell Ave. and can also be accessed via the Gateway State Trail. A Washington County Parks pass is required ($7/day or $30/year) for all vehicles.