Naturally occurring fires and fires set by Native Americans were a part of the ecosystems in the Burnsville area for a long time. Local plant communities are adapted to survive, and even thrive, after these fires. As land use in the area changed, these fires were suppressed. This resulted in major changes in the habitat, with many prairie and savanna areas becoming overgrown with weedy trees and invasive species.
Controlled burns are an important part of Burnsville's habitat management program, especially for prairie and savanna habitats. Controlled burns help return nutrients back to the soil that are bound up in dead vegetation. They also help control invasive plant species like common buckthorn. Some trees species, like bur and white oaks, are especially dependent on these fires. Periodic fires help keep the understory open, creating the conditions needed for sun-loving oak seedlings to grow. The mature oak trees are protect from the fires by thick insulating bark. When burns are conducted on large sites, a portion of the habitat is always left unburned to provide refuge areas for wildlife. After a controlled burn, the sun warms the black, ashy soil and re-sprouting plants rapidly appear.
The City conducts controlled burns in select natural areas on a rotational basis with burns typically occurring every 2 to 6 years, depending on the site conditions and goals. Controlled burn plans are approved and permits issued annually by the fire department and the Minnesota Department of Natural Resources. To complete these projects, the City hires companies with trained staff who specialize in conducting controlled burns for habitat management purposes. Burns are typically conducted in spring and late fall. The exact timings depend on weather conditions and contractor availability.