By KEVIN ROHLING

U of I Extension

Why do we use prescribed fire in natural areas?

The main reason is that overall biodiversity is typically greater in natural areas maintained by low-moderate severity fires in our region. 

Several factors can contribute to declines in biodiversity that fire helps to alleviate. Such factors include woody species encroaching on habitats that would otherwise be more open, such as in the hill prairies along the Mississippi River bluffs where frequent fires prevent many woody plants from overtaking more sun-loving plants – or areas threatened by invasive species that outcompete native species and can be set back by fire, such as bush honeysuckle and autumn olive. 

Mesophication is another problem for biodiversity conservation. Mesophication is a process where more shade-tolerant tree species, such as maple and beech, overtake oak trees as the dominant canopy species, primarily due to insufficient fire frequency. 

Fewer oaks on the landscape is a problem because the number of species that rely on oaks is significantly greater than that of maple and beech. Fire gives the competitive advantage to oaks that have adaptations encouraging fire, such as leaves that curl and are more likely to combust versus those of maple and beech that lay flat and are less likely to carry fire, or the thick bark of mature oaks to resist fire and greater ability to re-sprout following fire exhibited by many oaks but not by species less tolerant of fire. 

Those are all good reasons to apply prescribed fire in our natural areas. 

Still, we need to make decisions about fire based on science and use best practices to execute fires safely and minimize potential adverse effects. 

One of the best examples of the need to reduce the negative effects of fire concerns invasive plants. Some invasive species, as mentioned above, can decrease following fire.  However, some species, such as stiltgrass, typically increase with fire, and others, like garlic mustard, may increase or decrease depending on the timing, frequency, and/or intensity of a burn and other factors. 

Check out this webinar on invasive plants and fire for more details on that topic: go.illinois.edu/fireinvasives 

Wildlife should also be considered when planning burns. Because so many habitat types rely on fire to maintain species communities and habitat characteristics, prescribed fire is critical to ensure the habitat remains suitable for many wildlife species.  That said, there are some important considerations to remember. 

Some insect species, for example, overwinter in leaf litter and other vegetative matter that will burn in prescribed fires during the dormant season. Therefore, it is vital to have refugia, either nearby or within the burn unit, where insects may repopulate. 

State-threatened species, such as ornate box turtles and timber rattlesnakes, may be susceptible to fire depending on the time of year a burn is conducted. In areas where reptiles emerge from hibernacula in the spring, the animals can react slowly. Timing fires while wildlife is dormant in areas with sensitive species will minimize adverse effects.  

It is also important to remember that without fire, the habitat would not be suitable for many wildlife species, so not conducting fires is not a solution that will benefit wildlife.  

Safe and effective use of prescribed fire is critical for maintaining habitats in Illinois and beyond. You can help. 

Organizations like Clifftop need volunteers to help safely and effectively conduct prescribed fires. For those interested in learning more, Clifftop is partnering with the University of Illinois Extension Forestry on a prescribed fire training event Jan. 25 in Waterloo.  

For more information or to register, visit go.illinois.edu/firetraining

CLIFFTOP, a local nonprofit organization, is focused on preserving and protecting area bluff lands. For more information, view the Clifftop website at clifftopalliance.org or email Cliffmbr@htc.net.