Prairie Talk: Why Burn Our Prairie?

Some people are surprised that an important part of developing and maintaining a prairie is a schedule of regular, controlled prairie burns. Regular, controlled burns are called prescribed burns. If we do not regularly burn our prairie, it becomes more susceptible to an uncontrolled prairie fire caused by a lightning strike or a cigarette thrown out a window. Uncontrolled prairie fires sometimes become dangerous wildfires.

Prescribed burns also are crucial for maintaining the health of an existing prairie and for prairie restoration. One benefit of prescribed burns is removing thatch that blocks the sun from germinating native plants and killing invasive plants and unwanted trees that can overpower native plants. Burning promotes the diversity of native prairie plants that can survive adverse weather conditions, such as drought. A second benefit of prescribed prairie burns is adding nutrients to the soil, stimulating growth of native plants. Finally, burn management promotes growth of a diversity of prairie plants that provide food and cover for pollinators, birds, and animals.

FUMC prescribed burn

FUMC prescribed burn

The timing of a prescribed burn is important for its success. One timing factor is whether the season’s growth of invasive species is sufficient so that a burn will damage or kill these plants. Invasive plants are part of the “fuel load” of a prescribed burn. Most of fuel load is thatch, which is dead plant material that blocks the sun from germinating seeds, further promoting the growth of taller and faster growing invasive plants. Once thatch is burned off, deep roots of native prairie plants untouched by the fire have access to the sun and nutrients released by the fire.

Other important timing factors in deciding when to burn a prairie are air temperature, soil moisture, relative air humidity, and wind speed. There may be only a short window of opportunity when all of these factors combine to create the best conditions for a prescribed burn. Volunteers helping with a prescribed burn must be ready to move when conditions align for a good burn.

Starting the burn

Starting the burn

Do Prairie Burns Contribute CO2 to Global Warming? Scientists have studied how much carbon is released during a prairie burn and compared this to the amount of carbon absorbed by a prairie. Unlike burning fossil fuels, burning a prairie releases carbon that was recently absorbed from the atmosphere. In contrast, carbon released from burning fossil fuels is carbon absorbed by plants hundreds of millions of years ago. Research demonstrates that prairies pull more carbon from the air during a year than is released during a prairie burn. Prescribed burns are conducted on a 3-5 year schedule, so prairies managed by prescribed burns are releasing carbon once every 3-5 years. The capacity of prairies to sequester carbon, remove carbon from the atmosphere and store it in the soil, make prairie restoration an important strategy for responding to climate change. The deep root system of a mature prairie that stores atmospheric carbon rivals the carbon storage capacity of forests. In 2008, the state legislature mandated a study of the potential for carbon sequestration in Minnesota in forests and prairies on state and federal lands. The study concluded that carbon sequestration from state and federal land alone, is insufficient to offset Minnesota’s CO2 emissions. Prairie restoration on private land, like FUMC, has an important role to play in reducing CO2 in our atmosphere.

The burn management plan of the FUMC prairie is designed to maximize the growth and diversity of prairie plants. Above the ground, our managed prairie offers food and cover to pollinators, birds, and animals. Below the ground, the plants’ root system sequesters carbon produced by human activity that contributes to climate change. Prescribed burns play a critical role in maintaining the sustainability of our prairie system.

Monitoring burn

Monitoring burn

Do Prairie Burns Contribute CO2 to Global Warming? Scientists have studied how much carbon is released during a prairie burn and compared this to the amount of carbon absorbed by a prairie. Unlike burning fossil fuels, burning a prairie releases carbon that was recently absorbed from the atmosphere. In contrast, carbon released from burning fossil fuels is carbon absorbed by plants hundreds of millions of years ago. Research demonstrates that prairies pull more carbon from the air during a year than is released during a prairie burn. Prescribed burns are conducted on a 3-5 year schedule, so prairies managed by prescribed burns are releasing carbon once every 3-5 years. The capacity of prairies to sequester carbon, remove carbon from the atmosphere and store it in the soil, make prairie restoration an important strategy for responding to climate change. The deep root system of a mature prairie that stores atmospheric carbon rivals the carbon storage capacity of forests. In 2008, the state legislature mandated a study of the potential for carbon sequestration in Minnesota in forests and prairies on state and federal lands. The study concluded that carbon sequestration from state and federal land alone, is insufficient to offset Minnesota’s CO2 emissions. Prairie restoration on private land, like FUMC, has an important role to play in reducing CO2 in our atmosphere.

The burn management plan of the FUMC prairie is designed to maximize the growth and diversity of prairie plants. Above the ground, our managed prairie offers food and cover to pollinators, birds, and animals. Below the ground, the plants’ root system sequesters carbon produced by human activity that contributes to climate change. Prescribed burns play a critical role in maintaining the sustainability of our prairie system.