Ecologist talks managing heavily burned and disturbed rangelands

The 2017 drought may be the silver lining for rangeland hit by the East Fork Fire, a rangeland plant ecologist at Montana State University said, but some burned areas might require special attention from landowners to help them recover quality, healthy livestock forage.

“You were pretty dry up there — it may very well be that the level of damage is pretty minor given that the plants weren’t growing,” Craig Carr, assistant professor of rangeland ecology at MSU in Bozeman, said. “The time to burn vegetation that has sort of the least amount of potential to damage that vegetation is when it’s not actively growing, that certainly would have been the case this year.”

Some landowners were already reporting seeing grass sprouts after the Sept. 14-17 rains that brought anywhere from about 1 inch to about 2 inches of moisture.

Carr, who researched plant growth in an area burned by a previous wildfire on the Northern Agricultural Research Center’s Thackeray Ranch in the Bear Paw Mountains, said the problem areas are going to be those that burned hot, long and more severely, along with areas torn up by machinery for fire breaks and by other heavy vehicle travel.

“Those areas you might see a little more potential for damage and loss of plants,” Carr said.

Clayton Marlow, professor of range sciences at MSU, said for an article that appears in the October Farm and Ranch special section, that areas which had black ash after the fire went through will likely recover quickly and be able to be grazed next year with judicious range management. But areas with white or gray ash were harder hit and might need more management efforts.

Now that moisture has come, including the rain and snow this week, Carr suggested using a more hands-on approach to helping evaluate land for plant health.

“They can actually dig into the soil and pull up some plant crowns and roots and see if they are more pliable or if they’re just charred up and crispy because that’ll tell you something. Charred up and crispy plants will have a hard time growing next year, and they probably won’t,” Carr said. “But if they still got a little bit of pliability, they look like they’re still alive, have some greenness, maybe they’re going to be OK.”

Carr added that on the Thackeray Ranch they found that “the burn had no impact on the vegetation so one year out (the burned and unburned areas were) very similar in terms of the species that were there, very similar in terms of the coverages and the abundances that were there, with the exception of the litter, which makes some sense because fire consumed that.”

For the severely burned areas, though, and the fire lines that were dug in, the results were much different, he said, and those areas will require some vigilance at least and possibly reseeding and erosion control.

“That’s what we noticed on the fire lines at the Thackeray — and this is first year and second year post fire — was those fire lines were just thick with annual invasive plants, primarily cheat grass and Japanese bromes and mustards,” he said, adding that the same problem occurred where severe fire killed the native plant growth. “And we don’t know how our native grasses from up there can compete against, how they can move into, an established annual grass patch. The annual grasses have a hard time getting in when those native grasses are there, but if we remove them, then the annual grasses become dominant and we don’t understand how well native grasses can re-establish in those sites.”

Most research on controlling cheat grass has been in the Great Basin, he said, so it doesn’t translate well to northern areas.

His recommendation, though, is to get grass seed down in late fall before the more permanent winter snows come. The seed can be broadcast in areas that a seeder can’t be brought in, but, he added, somehow the seeds need to be bedded for a higher soil to seed contact ration, even if producers simply drag a length of chainlink fence over the seeded area with a four-wheeler.

If cheat grass does get established, he said, targeted grazing and even fire can help with control, but some herbicides are available, too.

Roundup can kill the cheat grass, but it isn’t selective, he said, so another option is pre-emergent herbicides with imazapic, like Plateau and Journey, which can be sprayed in the fall to deter growth from seeds. That said, he added, killing the cheat grass, brome and mustard are only part of the equation and landowners can consult with area range and seed experts to find out what seeds would be best for specific sites needing replanted.

If the area is steep and has dramatic vegetation kill, then landowners should think about added erosion control measures, he said.

While Marlow cautioned that introducing straw bedding and straw wattles might introduce weeds, he added that it might be the lesser of two evils.

Carr said that in the first year post fire damage one portion of fire line that went straight up a steep slope on the Thackeray Ranch had a spot of erosion that was hip high.

If grasses are coming back in the spring, grazing uses next year should not be different from other years, Carr said. If reseeded areas are within pastures that are otherwise able to be grazed, producers might want to think about temporary fencing in those areas, he added, or if possible, manage livestock use of the sites with salt and water sources until the native grasses, or planted grasses, get established.

“That said, check grasses next spring to decide how long to keep livestock on and to give pastures adequate time to recover from grazing,” he said. If you’re practicing good range management, you should be OK on places that burned lightly.”