Native Prairie and Oak Savanna Enhancement

The oak savanna and prairie habitat, which was once widespread and occupied 50% of the Midwest's landscape, has been diminished to approximately 0.02%, and less than 4% respectively of what existed pre-European settlement; making each of these habitats some of the rarest and most threatened in the world. The encroachment of many exotic species into the oak savanna and prairies, such as Black Locust, Siberian Elm, buckthorn, and leafy spurge has greatly affected the natural processes of the habitat. In both habitats, these invasive species have resulted in profound negative impacts on the diversity of native plant and animal populations. Prairies and oak savannas are mosaics of plant communities with multiple successions from open grasslands to mature oak forests, which provides robust structural diversity to support a wide range of species. In order to restore the natural functions of Sherburne National Wildlife Refuges prairies and savannas, ecological disturbance is key to keeping out woody and herbaceous non-native species. Naturally occurring fires and grazing by herds of North American ungulates kept out the woody natives, however migrating Europeans soon forced these two disturbance tools off of the landscape and brought with them native plants from their home country, which soon would become invasive. However, even utilizing modern prescribed fire and grazing is not enough to reduce the spread of invasive species. In most cases, invasive plants seed out every year, already adding to an extensive seed bank in the soil, and land managers can rarely if ever apply disturbance to the same unit, every year. The goal of this project is to hire a Conservation Core of Minnesota crew, and under the guidance of the Refuge biologist, aggressively treat several of our invasive species prior to them seeding out, while continuing to implement natural disturbance into some of these areas and return Sherburne's prairies and savannas back to their fully functioning state.