What you need to know
about prescribed burns

It's a vital tool in restoration


Fire is as natural a force as wind, water, drought, floods, blizzards, and insect infestations. Before Europeans settled in North America, fires regularly occurred naturally due to lightning strikes, but were also started accidentally and intentionally by man.

Deliberately set fires were an important tool of Native Americans who used fires to hunt, improve visibility, protect themselves and their villages from wildfires, make traveling through the tallgrass prairie easier, and for many other reasons.

As the continent was populated and developed, fire was widely suppressed because of its inherently destructive impact to many human interests and its potentially deadly affect on human life. The "Smokey the Bear" campaign reflects this perspective.

However, there are many benefits to burns when done for specific purposes.


Here's what you need to know about the Forest Preserve District of Will County's prescribed burns:

What is Prescribed Burning?

A before, during and after view of a controlled burn.

Before (right), during (far back) and after. (Photo by Glenn P. Knoblock)

Prescribed (or "controlled") burning is a means of reintroducing this natural process. A controlled burn involves identifying the area to be burned (the "burn unit"), establishing control lines in order to prevent the fire from burning unintended areas, and intentionally setting the burn unit on fire.

Areas within the county are managed by the District with controlled burning when there are reasonable assumptions that wildfire was an important ecological process that shaped composition and structure of a particular ecosystem type, and that maintenance or restoration of that community type cannot be achieved without its use.

Why Do We Do It?

A view of a controlled burn in a field.

Photo by Glenn P. Knoblock

Many species are dependent on fire to maintain the habitat in which they live. The key growing part of most prairie plants is below ground, where the heat of the fire does not penetrate, allowing the native grasses and wildflowers to flourish once again following a fire event.

Many native trees such as oaks and hickories have evolved adaptations to protect them from fire injuries such as thick bark. There are species of evergreen trees which cannot germinate until the cones are exposed to the heat generated by fire.

Fire can be an important tool to attain specific maintenance objectives:

  • It can control tree and shrub growth along the embankment of a flood control reservoir where the roots systems can threaten structural integrity.
  • The disturbance created by periodic fires is important in maintaining our remnant oak/hickory forests and savannas because it prevents uncommon trees from overtaking the landscape.
  • Fire encourages the better establishment of native vegetation, which slowly displaces weeds.
  • Controlled burning returns nutrients to the soil.

How is Prescribed Burning Done?

An aerial view of a controlled burn.

Photo by Chad Merda

Controlled burning requires extensive planning, training, personnel, and equipment. Planning is often required six months or more prior to implementation.

As part of the preparation process:

  • An open-burn permit from the Illinois Environmental Protection Agency must be obtained. Adjacent landowners and the appropriate local Fire Chiefs are notified by mail well before the day of the burn. Dispatch centers, fire chiefs, and Forest Preserve District Police are also notified on the day of the burn.
  • All participants of our controlled burns have received special training, which involves learning fire behavior, methods of ignition and suppression, proper use of equipment, and more.
  • A written plan is developed for every area to be managed with controlled burning. It identifies control line needs, potential hazards, weather conditions and management goals and objectives. The plans are reviewed prior to a burn and updated as needed.


How are Injuries to Wildlife Avoided?

A mourning dove on a branch.

A bird finds a tree during a recent burn at Lockport Prairie Nature Preserve. (Photo by Glenn P. Knoblock)

Burns are conducted from mid-October to mid-April when most vegetation and many animals are dormant.

Whenever practical, sites are divided into multiple burn units so that there is always unburned habitat within the preserve. While an occasional mouse or snake may be harmed in a burn, it is far more common to see a mouse, rabbit, or deer dart through the flames to safety than to see one actually harmed.

Controlled burn participants routinely walk through the burn units afterward to look for injured animals and have learned to burn in a manner that results in very few injuries or mortalities.

Is it Dangerous?

Two men participating in a controlled burn.

Photo by Chris Cheng

Of course, any fire can be dangerous if not kept under control.

Through training and experience, the controlled burn crews are able to anticipate problems and take remedial actions that have allowed this program to effectively manage our natural lands while maintaining public and burn participant safety for over 25 years without a single significant incident.

An important element of this is smoke management. Common smoke management considerations include excessive smoke on roadways which creates visibility concerns for motorists, and individuals with health conditions which can be aggravated by smoke such as asthma or allergies.

Several strategies exist for minimizing impacts resulting from smoke, including monitoring weather conditions which influence smoke dispersal, altering ignition strategies, and proper site selection the day of the burn.

A view of a recent controlled burn at Lockport Prairie Nature Preserve.

The scene after a recent burn at Lockport Prairie Nature Preserve. (Photo by Glenn P. Knoblock)

(Lead image by Glenn P. Knoblock)

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