By Kevin Sedivec and Miranda Meehan
There is a high fire risk across much of North Dakota and eastern Montana due to a high fuel load created by abundant old, dry plant material and drought conditions. The region experienced a higher number of wildfires in the fall of 2024, and spring is starting with several wildfires, affecting thousands of acres of grazing land.
This fire season will continue until the region receives ample moisture and adequate conditions for new plant growth, according to Kevin Sedivec, North Dakota State University Extension rangeland management specialist.
With very little snow this winter, drought conditions have expanded from last fall, with 57% of the state experiencing some level of drought. If drought continues, spring green-up may be delayed, extending the spring fire season.
Drought alone will hurt forage production this spring. However, these impacts will be magnified in areas that have experienced a wildfire either last fall or this spring.
Forage production impacts in 2025
Fire impacts different types of plants differently. Warm-season grasses usually respond by producing greater biomass after a fire when moisture conditions are average or above average. Cool-season grasses lose vigor after a burn, creating less biomass after a fire. If the drought continues into the spring, biomass from cool-season grasses burned this spring or even last fall will be negatively impacted.
Because North Dakota is a cool-season, grass-dominated state, Sedivec explains, ranchers should expect about a 30% to 40% decline in forage production in 2025 due to the fires last fall and this spring if normal spring precipitation occurs. NDSU researchers found fall wildfires reduced forage production by 39% the following year with slightly below-average precipitation. An NDSU study determined spring fires reduced forage production by 35% in normal spring precipitation conditions.
Because these areas are also in severe to extreme drought, cool-season grasses did not develop tillers last fall. The fall drought could create an additional 10% to 20% loss, even with average spring precipitation. Spring droughts are even more detrimental to forage production, with losses of greater than 50% when spring moisture is 50% to 70% of normal.
Given these compounding impacts, ranchers should plan for 40% to 60% less forage in 2025 in areas impacted by the wildfire and the fall drought. If dry conditions persist in 2025, forage production will be further reduced.
Wildfire impacts on the plant community
Although wildfires can be very destructive, the impacts of fire on the plant community will be mostly positive in the long term. Based on research from the U.S. Department of Agriculture’s agricultural research stations in Miles City, Montana, and Mandan, North Dakota, and research conducted by NDSU, native grasses and forbs do not experience long-term negative impacts due to fire. However, introduced invasive grasses such as Kentucky bluegrass and smooth brome can be severely injured and reduced within the population. Many woody species also do not tolerate fire, with most coniferous trees, such as cedar and Rocky Mountain juniper, killed by fire.
One negative within the grass community is the removal of all above-ground plant material, leaving soils exposed to erosion until new plant growth occurs. Based on research in North Dakota and South Dakota, litter will be significantly reduced for the first year after a fire but back to normal by year two or three.
Recommendations for 2025
The primary concern for ranchers impacted by the wildfires in the Northern Plains will be a significant decline in forage production, according to Miranda Meehan, NDSU Extension livestock environmental stewardship specialist. The current drought conditions will exaggerate this loss. Grazing recommendations include the following:
- Grazing can occur in 2025, but spring deferment from grazing will be required. Ranchers should delay turnout until mid-June if moisture conditions are above average, end of June if moisture is average or mid-July to early August if the drought continues.
- Expect a loss of forage production by 40% to 60% if moisture conditions are near normal.
- Stocking rate of either days or livestock numbers could be reduced by 50% to 70% if dry conditions continue into spring.
Fires will not have any negative long-term effects on the grassland community.
- If drought conditions occur next year, expect a flush of annual weeds. However, these annuals will decline in time.
- Although litter will be reduced, it will return to normal levels unless overgrazing occurs.
- Native grass and wildflower populations will either not change or increase in population.
- Invasive cool-season grasses will decline, at least temporarily.
- The nutritional value of the grass, flowers and shrubs will be greater, providing a higher-quality diet through late summer.
- Do not reseed native rangelands or perennial grass pastures following a fire
Wildfire will negatively impact forage production in 2025. So, plan for fewer grazing days or livestock numbers.
“However, with proper grazing management,” says Meehan, “these sites will recover forage production.”
Fires will likely provide benefits to the plant community, improving diversity and the long-term resilience to future droughts and wildfires.
Source : ndsu.edu