Prescribed burning

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 "Smoky the Bear" campaign reflects this perspective. 

As a result, it is natural to have questions about the Forest Preserve District of Will County's prescribed burning practices, and we hope to answer those questions here.

Why is fire important?

In recent times, biologists have realized the benefits of fire in natural areas. Today we understand that our ecosystems and the plants within them evolved with fire, and many species are dependent on fire to maintain the habitat in which they live. 

For example, the key growing part of most prairie plants is below ground, where the heat of the fire does not penetrate, allowing the 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.

Historically, the landscape of Will County was dominated by prairie and wetlands, with scattered areas of timber that supported a wide variety of wildlife. While this landscape was molded through millennia by geology, topography, hydrology, and climatic factors, it was also strongly influenced by fire.

Explorers and early settlers remarked on the awesome power of the nearly annual prairie fires, and how in the absence of fire, trees became more common across the landscape. Fire so profoundly influenced the landscape that trees could only persist in areas sheltered from intense fire by natural firebreaks such as rivers and hills.

These firebreaks provide opportunities for the fire to go out or burn around and skip some areas. These skips and areas of reduced fire intensity allow saplings to grow large enough to withstand the fires and grow into the next generation of mature trees, sometimes forming woodlands or more sparsely timbered savanna communities. 

In the absence of natural firebreaks where fire could burn most intensely, tree growth was prevented and prairie was maintained. The different plant species that dominated the prairie, woodland, or savanna landscapes provided the diversity of habitats which supported the large array of animal species we know today.



What is prescribed burning?

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.

Fire can also be an important tool to attain specific maintenance objectives such as controlling 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.

The Public Land Survey (1821-1837) recorded almost 1,500 trees while surveying Will County to establish the system of townships and sections that is still used today. Over 90% of those trees were oaks and hickories. Less than 1.5% of the trees recorded were ash, sugar maple, hackberry, or black cherry.

Now these once uncommon trees have rapidly colonized our landscape, threatening to overwhelm the oak/hickory woodlands and the plants and animals that have evolved with them. The one factor that these native invaders have in common is that their saplings are much more easily harmed by fire than those of oaks and hickories. Experiments have shown that reintroducing fire into oak/hickory ecosystems is an effective means of reestablishing oak and hickory sapling dominance.

Controlled burning is also an important tool providing many benefits for restoring our natural plant communities to lands that have been disturbed. Fire is used to clear the ground of existing vegetation in preparation of seeding and planting more desirable plant species. Burning allows the seeds to make better contact with the soil and therefore improves the chances of successful germination. 

Fire is used to reduce the competition between weedy species and native species as a restoration area matures to encourage better establishment of the native vegetation which slowly displaces the weeds. Controlled burning also returns nutrients to the soil, making them readily available for the next generation of vegetation growth.

How is prescribed burning done?

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

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. The burn boss and some of the fire crew leaders also have extensive training in modeling fire behavior to assist with understanding expected and observed conditions.

A written plan is developed for every area to be managed with controlled burning. This burn plan identifies the limits of the burn unit and control line needs, potential hazards and safety issues, procedures for ignition, acceptable weather and fuel conditions, personnel and equipment needs, as well as the management goals and objectives of conducting the burn. Before every fire, burn plans are reviewed and updated as needed. 

Fire control lines are installed prior to the day of the burn and checked immediately before ignition. If necessary to protect site visitors, access to portions of a preserve may be restricted or the preserve may be closed for the duration of the burn. 

Data is recorded during and at the conclusion of each burn, including weather conditions, observed fire behavior, and extent of burn coverage, in order to help staff evaluate the effectiveness of the fire in achieving site management objectives, as well as safety and operational procedures. The controlled burn season spans mid-October to mid-April when most vegetation and many animals are dormant.

How are injuries to wildlife avoided?

For those who have never seen the aftermath of a controlled burn, it may appear shocking at first. A blackened and smoking landscape greets the eye, and it appears as if all life has been destroyed. The reality is far different.

We carefully plan and time our burns to minimize harm to wildlife. 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. Most insects are underground during controlled burns, but some species are in the plant litter and are thus consumed in the flames. However, leaving unburned areas ensures there are enough insects to accomplish the pollination and decomposition needs of the next growing season.

Is it dangerous?

Of course, any fire can be dangerous if not kept under control. Prior to a controlled burn, variables affecting fires are carefully studied. Our ecologists and fire control crews who are trained to meet National Wildfire Coordinating Group (NWCG) standards monitor wind conditions, humidity, temperature, and the amount of moisture in plant material. 

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.

We strive to implement our controlled burn program with the greatest attention paid to the safety of the general public. 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. Facilities with important fresh air intake systems like hospitals and schools are also vulnerable.

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.

We constantly update our burn plans to identify the location of these smoke sensitive receptors. If you or a family member has a health condition which could be triggered or aggravated by smoke, or could otherwise be negatively impacted by controlled burn activities, please contact us so that we can include your information in the appropriate burn plan(s). We will be sure to give you advance notification of planned controlled burn activities so that exposure to smoke or other impacts can be avoided.

Can I participate?

Yes. Anyone interested can assist District staff and participate in a controlled burn. Participants must first register as a Prairie People Volunteer with the District and complete the required safety and orientation training. Of course, basic controlled burn training is also required, but is provided by the District as is most necessary personal protection equipment. Once trained, volunteers may participate in burns as often as they wish.


The Forest Preserve District protects and enhances Will County’s natural and cultural resources for the benefit of current and future generations.


Bringing People and Nature Together

Guiding principles

  • Staying true to our purpose.
  • Being good stewards.
  • Connecting people and nature.
  • Focusing on wellness.
  • Working with others.
  • Promoting sustainability.