A little over a year ago a team of prescribed burning tacticians, range managers and ranchers lit up almost 900 acres of Crown grazing south of Longview, Alta. The goal was to remove aspen and willow brush and dead litter along with the timothy and bluegrass that was choking out this historical rough fescue range. Research and other North American burns suggested burning coupled with strategic grazing should revitalize the range and spur the rough fescue to make a comeback.
Two grazing seasons later the signs suggest this is exactly what’s happening.
An underlying goal of this particular burn was to demonstrate that a prescribed burn can be accomplished with minimal risk to surrounding lands. This crew met that expectation with flying colours.
Cattlemen reported last August on the initial Crown lease burn at the Flying E Ranch. However, the plans to burn this aspen-and willow-overgrown parcel of land were in the works for several years before the fire was finally set. The final stages of the two-month burn wrapped up on the May long weekend in 2008. However, it took several years of careful planning, preparation, and lobbying to reach that point. Many government officials and surrounding landowners were clearly worried about the danger of the fire escaping and creating a costly wildfire.
It was a tense time for Kevin France the area range manager with Alberta’s Sustainable Resource Development department who oversaw the burn and Larry Sears and his son Callum of the Flying E. Now, two years down the road, all agree the burn worked pretty well on all counts.
Much of the aspen and willow are now gone or weakened to the point that it is unlikely it will survive. About two-thirds of the deciduous growth is dead or dying. Based on nine separate transects and grazing exclusion cage data, forage production under the burned aspen/willow canopy has exploded, up more than 60 per cent in some areas. Forb production across the parcel has risen by 30 per cent. And the grasslands, following two fairly robust grazings since the fire, rough fescue is making a comeback and overall forage production is up between 40 and 50 per cent depending on the site.
“You can see inside these old tufts of rough fescue the young green material coming up along with new plants and that’s textbook. Exactly what we’d hoped for,” says France.
On some aspen sites where the trees were not uniformly killed by fire suckering had begun to appear. But when Sears placed mineral/salt tubs in the area to draw in the cattle they browsed off the new aspen shoots and all but annihilated the suckers. With far less brush to contend with now moving the cattle is a breeze. “Those thick willow patches were a headache as the cattle used to love hanging out in there,” says Sears. “It’s nice not to have to poke your head or send a dog into every willow patch to find them now.”
Sears also noted a vast improvement in grazing distribution the first time the cattle were turned into the burned area. “They fanned out across the hillside,” he recalls. The cows were everywhere which was not the case on this parcel before. Before they used to go into the aspen areas that were more open but never hang around in there. Now with more grass and forbs they’re
all over the parcel. It’s amazing to see the difference.”
This blast of growth after the burn is caused by the sudden release of nutrients into the soil, increased moisture availability and the removal of stagnant litter that has opened the soil to more sunlight, moisture and microbial activity. But not all areas of this rolling, drainage-laden section burned evenly. From the beginning France and Sears were aware that one burn would probably not be sufficient to cover the whole area.
“There are areas where the helicopter dropped the ignition fuel but you can’t be in the area to check on how the ignition and fire carried, it’s far too dangerous,” says France. “Some areas didn’t get burned well at all, so we plan on a follow-up hand burn of this parcel in about three years.”
For two seasons before the next burn Sears, France and a crew will lower the stocking pressure to allow for more fuel to accumulate and then hand ignite the fire in stages to achieve a very thorough burn, especially in those areas that got off lightly the first time.
There’s a lot to be happy about with this burn. Forage production is way up, rough fescue is coming back on the drier zones, and dead litter and wildfire risks have been addressed in most areas. Wildlife is reaping rewards as well. Deer, elk, moose, cougar, black and grizzly bears have all taken up station from time to time on the parcel since the burn. But there is still room for improvement, which Sears and France expect will come with continued grazing and a second burn.
Overall they give the first burn and follow-up grazing strategy a “B” grade in terms of output. But when it comes to their ability to pull off the burn safely and satisfy the concerns of the public and government officials, they definitely rate an A+.
“We wanted to make sure this fire went off without a hitch. We needed to show you can effectively burn a relatively large parcel of land and the risks in that can be addressed and managed, and we succeeded,” says France. “But in doing so we may have been a bit too conservative on the ignition intensity and strategy. We’ll rectify that next time and be more aggressive. It will certainly be a good burn to watch.”