Prescribed Burns

These fires were set by lightning or ignited by Native Americans who used fire for the management of agricultural lands and for hunting purposes.

As the European settlers moved westward, prairies were plowed for agricultural production, savannas were grazed and logged, and wetlands were drained. The settlers introduced cool-season grasses and suppressed the seasonal fires utilized by Native Americans. The increased establishment of non-native plants and encroachment of woody species, in areas previously dominated by native herbaceous plants, is directly related to the removal of fire from the Midwest landscape.

In order to mimic the fire regimes prior to European settlement, land management agencies utilize controlled burns to manage remnant natural areas and supplement restoration projects. Prescribed burns kill invasive woody species, remove thatch from previous growing seasons, facilitate seeding and herbicide treatments, cycle nutrients back into the soil, and deter the early spring growth of cool-season non-native species.

In 2001, the Lake County Forest Preserve District Board of Commissioners approved our current Prescribed Burn Policy.  On average, and totally weather dependent, we now burn approximately 2,500 acres throughout the preserves each year.

Before starting a prescribed burn, we obtain all necessary permits and contact local fire departments. We notify neighbors who are adjacent to our preserves. At each site, designated burn areas are mapped out, bounded by trails, streams and other barriers that help keep the fire contained.

Wind, relative humidity, temperature, soil moisture, fuel moisture, air mass stability and topography are important elements that are considered when planning and implementing a prescribed burn. These elements influence flame height, rate of spread, how smoke will dissipate, and the overall success of meeting the burn objectives. We develop a plan for every site that specifies the proper weather conditions in order to minimize the impacts of smoke to area residences, business, roads and schools. Crews patrol all fires to ensure that the burn is contained and smoke blows away from nearby homes and highways, in compliance with the Illinois Environmental Protection Agency smoke management plan.

Oaks, hickories and a few other native trees grow thick bark that protects them from fire. Big bluestem and many other prairie and savanna plants keep their buds safe just beneath the soil's surface.

Native wildlife is also adapted to fire. Many animals simply leave the area during a prescribed burn and return afterward. Others seek shelter in their underground burrows. Before a prescribed burn is ignited, our trained crews examine the proposed burn area to search for nests, dens or other wildlife issues that need to be avoided.

Following a prescribed burn, many native plants are more robust and produce more seeds. Fire lengthens their growing season, recycles nutrients and, for a few species, is critical for their seeds to sprout.

Non-native invasive plant species aren't so well adapted; therefore, burning keeps them in check.