Landowners are advised not to burn brush or grasses in low-lying areas at this time, due to a high incident of peat fires across the region, according to the Minnesota Department of Natural Resources.
Peat is an accumulation of partially decayed plant material, often found in wetlands or areas that had been wetlands at one time. Peat soil generally absorbs moisture, but unusually dry conditions have created the potential for peat soils to burn this fall. Minnesota has more than 6 million acres of peat, the highest total acreage in the contiguous United States.
“In spite of recent rains, peat fires continue to be a real threat this year,” said Tom Romaine, DNR assistant regional forestry supervisor. “Months of dry weather have not replenished moisture in most of our peat. Heat from burning brush piles, grass or other vegetation can be conducted from the surface fire into the dry peat soil and cause it to ignite.”
Romaine said that peat fires can be extremely difficult to battle, since the fire smolders beneath the ground as a glowing combustion rather than an open flame. Pumping water on a peat fire is often ineffective. Heavy equipment may be needed to alternately work and pack the soil, exposing hot pockets and then sealing them off from surface oxygen. A peat fire can take weeks or months to extinguish. Costs to fight the fire can be substantial.
Peat fires can also pose health hazards since they burn at a lower temperature and create more smoke than other types of fires. The heavy, dense smoke combined with airborne peat particles can cause respiratory problems in people and livestock. Grains and livestock feeds can become tainted. Peat smoke will hang like fog in low areas, creating low visibility and hazardous conditions for motorists.
If a peat fire is discovered, the local fire department should be contacted immediately. Quick action can significantly limit the negative impact a peat fire can have.
“The best defense against a peat fire is prevention,” Romaine said. “Please don’t burn in low areas this fall.”