Jefferson County Park undergoes controlled burn

FAIRFIELD — Fairfield residents might have wondered what the plume of smoke was about coming from Jefferson County Park Tuesday afternoon.

The Jefferson County Conservation Office was conducting a controlled burn of two to four acres of timber in the park. Conservation officials targeted an oak and hickory forest that they wanted to improve.

Though it might seem counterintuitive to help a forest by burning it, periodic fires are essential to keeping a timber healthy. Officials have noticed that the park has become full of invasive species such as bush honeysuckle, autumn olive and garlic mustard.

Jefferson County Conservation Director Shawn Morrissey said these invasive species grow so thick that they block sunlight from reaching the forest floor, preventing the beneficial trees like oaks and hickories from growing. He said oaks need room for their acorns to take hold and grow into tall trees, but there are now too many competitors for space and sunlight.

In a controlled burn, fire spreads through the forest killing the little plants on the bottom that the conservation officials don’t want, but Morrissey said the big trees are able to withstand the heat, so they’re unharmed.

In a Facebook post explaining the reason for the controlled burn, Jefferson County Conservation wrote, “Some forests may look healthy at first but if they are full of invasive species, they are being deceptive. Invasive species provide minimal food supply for the animals, especially birds who need high protein food sources. They also shade out our variety of native plants and in turn offer only a few food sources.”

Morrissey said Iowa had large oak and hickory woodlands prior to its conversion into mostly farmland. For hundreds of years, oaks and hickories have offered wildlife cover, food in the form of acorns and nuts, and their flowers attract birds and springtime insects.

“We’re losing the oak component of our woodlands, and they’re not as healthy as they can be,” Morrissey said. “We have to do a little management of our woodlands. People don’t always understand why we do [controlled burns], but if you come back to them once they’re green in the spring, they will look better than those places we didn’t work on.”

Morrissey said Tuesday’s controlled burn was partially successful, with the fire spreading better in some parts of the acreage than others. He said it would have spread better had it been windier that day. If the weather stays dry, conservation officials might try more controlled burns later this winter.