Prescribed burns at a conservation site in Saskatchewan help researchers understand importance of fire on the prairie
Bone-dry conditions have put a damper on further research using fire at Old Man on His Back Prairie and Heritage Conservation Area in southwestern Saskatchewan.
A prescribed burn this fall, organized by the Nature Conservancy of Canada and University of Saskatchewan, was cancelled.
“We’re not considering a burn right now. It’s just not safe. It’s obviously weather dependent and we’re responsible land owners and we follow the rural municipality burn bands of course,” said Matthew Braun, manager of conservation science and planning for the NCC-Saskatchewan Region.
“We have a prescribed burn plan that we’re following so we have to make sure the winds are down and the humidity is up so that we can have a good controlled burn out there.”
The prescribed burns are part of a five-year research project to better understand how to influence where cattle and bison graze at the nature conservatory, and how fire changes the plant community.
“One of the things that we’re trying to think about is that fire is something that’s a potential out there at all times and we know that the species that we’re trying to manage for — the rare birds and the rare plants — some of them require the conditions that you get after a fire,” he said.
“The question that we’re asking is how to use prescribed fire instead of wildfire. How to use prescribed fire as a management tool to manage the habitat for species at risk, and also to change the ways bison and livestock move around on the landscape.”
Since 1996, the Nature Conservancy of Canada has been operating the 13,088-acre ranch near Claydon, Sask., after acquiring it from Peter and Sharon Butala.
Most of land is native prairie grassland with about half of it used by local ranchers to graze their cattle (250 this year) while the other half supports a herd of about 75 adult plains bison and their calves.
This past spring, ahead of rural municipality fire bans and nesting migratory birds, and with assistance from the Frontier, Sask., volunteer fire department, researchers were successful in burning two small experimental units.
“It’s a really slow process because we do it very carefully and in small little chunks. It was two separate squares that we burned out with a total of 30 acres. We’re aiming for six units, but the conditions were such that we could only get those two done,” he said.
Timely rains in late April helped fuel fast and abundant regrowth over the burned ground. The new grasses of high forage value quickly attracted a host of wildlife including several bird species and grazing animals such as pronghorn antelope.
However, eager bison could only sniff the wind from their paddock nearby.
“The very first burn that we did do was right across the fence from them. They were stuck with their noses looking through the fence, trying to check out what had happened over there. So they were definitely curious and I’ve heard from other similar experiments in the United States that the bison are definitely investigating those burns almost immediately after they’re out,” he said.
U of S researchers were also able to learn if the grass that grows back following a fire attracts animals to under-used parts of a pasture. Fire may also be used to reduce some of the invasive plants growing at Old Man on His Back.
This winter, researchers plan to study their data before another prescribed burn next spring, weather permitting.
Braun said some livestock producers are also watching the researchers, recognising that prescribed fires may offer a way to manage conditions.
“I’ve talked to ranchers who are concerned about encroachment of aspen onto their grass lands and they’re interested in using this tool as well to maintain forage, not just quality but quantity as well,” he said.