Post contributed by Brett Stolpestad, Conservation Corps of Minnesota, Youth Outdoors Crew Member:
|Photo by Brett Stolpestad - Prescribed fire at Bruce Vento Nature Sanctuary|
Spring has arrived, and so has the prescribed fire season. As the ground thaws, the cool soil hosts the growth of a variety of familiar plant species in Minnesota. Unfortunately, many of the species we have come to know are invasive.
Crab grass, smooth brome, burdock, garlic mustard, motherwort, and reed canary grass, are just a few among many cool-season weed species in Minnesota that are the first to break through the soil in the spring. This is primarily because many of Minnesota’s invasive species require lower soil temperatures to be able to grow.
|Photo by Brett Stolpestad|
Thankfully, this problem has a relatively simple and natural solution. Fire. Prescribed fire is an effective management technique, controlling invasive species and promoting growth for native species. Fire accomplishes this in several ways. First, fire knocks back the progress of invasive species. Second, the burned plant material adds nutrients back to the soil for native species to use. Third, after a fire has moved through an area, the blackened surface of the soil is able to absorb more radiant heat from the sun, increasing soil temperatures, giving native species a much-appreciated boost.
On March 19th, Saint Paul Natural Resources staff kicked-off the burn-season near Lake Phalen. In addition to a larger Lake Phalen restoration project, Saint Paul staff took the lead on a prescribed fire designed to burn approximately three acres of oak savanna on the northwest side of the lakeshore, with the goal of further transitioning the area to a true oak savanna.
Two days later, the Saint Paul Natural Resources team led a small group of volunteers on another prescribed burn at Bruce Vento Nature Sanctuary. Once an old train yard, Bruce Vento is now host to a variety of native grasses including little blue stem and native switch grass. Bruce Vento is also host to a variety of invasive and weedy species such as spotted knapweed, sweet clover, and non-native brome.
|Photo by Brett Stolpestad - New growth emerging a few weeks after prescribed burn|
Within three weeks of completing the prescribed burns at Bruce Vento, visitors can now observe the invigorating sight of new green grasses covering the blackened patches of soil.