Prescribed Burn at Coldwater Spring

May, 2018

by Marianne (Marnie) Sciamanda, Community Volunteer Ambassador (AmeriCorps) for the Mississippi National River and Recreation Area

If you have visited Coldwater Spring lately, you may have noticed a major change to the landscape. In early May, approximately 12 acres of prairie habitat at Coldwater Spring were burned in a prescribed burn. With a prescribed burn comes a lot of questions about the fire – read below to find out why we burned at Coldwater, what effects the burn has on the landscape, and when we can expect new plants to begin growing.

Why did we burn at Coldwater Spring?

Although we perceive fire as harmful, fire is actually beneficial to the prairie and oak savanna habitats at Coldwater Spring. Both of these habitat types are fire-dependent, meaning they rely on occasional fires to flourish. As Coldwater Spring is an active restoration site, the prescribed burn functioned to provide the necessary disturbance of fire at the site in a controlled manner.

How does a prescribed burn benefit vegetation?

One benefit of prescribed burns is nutrient recycling. Nutrients that are trapped in previous years’ perennial vegetation are burned, and returned to the soil for this year’s plants to use. This increases soil productivity, which is an important feature of a healthy prairie ecosystem.

What are the best conditions for a prescribed burn?

Optimal conditions for a prescribed burn are site-specific. Some important factors include humidity level, wind direction, time of year, and the smoke dispersion index. At Coldwater, the conditions are especially important because of its location in the middle of the Twin Cities, right near the airport, a major hospital, and a large highway. For example, the burn could not occur unless the wind was blowing from the south, southwest, or west. Forecasts are checked weeks in advance and hourly on-site of the prescribed burn to ensure conditions remain safe.

Do prescribed burns harm wildlife?

A prescribed burn could harm wildlife but precautions are taken to decrease potential harm. Burns are performed in either the spring or fall, which are times that have lower impacts on wildlife. The burn rate at Coldwater Spring specifically was slow so that animals on site had more time to take refuge from the burn. The entire landscape wasn’t burned either – areas were left unburned in order to provide refuge for animals on the site. Although there are still risks to present individual wildlife, the improved habitat and vegetation will benefit a species’ population in the long-term.

How long will it take for new plants to appear?

Plants at Coldwater should, with rain, begin to regrow in 1-2 weeks. Grasses and other plants have already begun growing in areas of land that were burned. Be sure to stop by and visit the site to observe the transformation of the burned landscape to vegetation regrowth this season.

 Thank you to Neil Smarjesse, biologist at Mississippi National River and Recreation Area, for providing the information used to write this blog.