Moose survey examines benefits of burns
By Javier Serna
Cloquet, Minn. — The Greenwood Fire, which burned nearly 27,000 acres in Lake County last year, was included in the Fond du Lac Band of Lake Superior Chippewa’s Moose Habitat Survey this year. But no moose were observed in the 8,500-acre survey plot that was chosen to represent the fire area.
“There were eight total plots impacted in one way or another by the Greenwood Fire,” said Mike Schrage, wildlife biologist for the Fond du Lac Band. “We wanted to look at the Greenwood Fire, at least on a semi-permanent basis for the next couple of years, because it’s the first large wildfire to happen outside of the Boundary Waters (Canoe Area) Wilderness. It’s likely to be managed differently than if it were in the wilderness (where no timber harvest occurs). There are private lands there. We wanted to look at the fire to see if the moose responded differently than they have been inside the Boundary Waters.”
The Fond du Lac band is one of the partners in the larger moose population survey that’s flown every winter and led by the Minnesota DNR.
Neither survey was flown last winter due to the pandemic and the inability to socially distance in the small aircraft used for the survey.
The habitat survey, including nine set habitat plots, representing different phases of timber harvest, wildfire, and prescribed fire, was added to the larger survey effort in 2012.
The addition of a Greenwood Fire plot added a 10th habitat plot, Schrage said, instead of substituting it for another plot.
Semi-permanent is a good way to describe all of the moose habitat survey plots, because the data they offer over time changes and ultimately each plot’s usefulness to moose deteriorates over time. That’s unlike the larger moose survey, which draws randomly selected plots each year.
Moose need lots of early-successional forest habitat, or young forests, for forage purposes. They prefer the buds of young aspen trees, for instance.
The habitat survey has shown what moose need for habitat.
Schrage said it wasn’t a surprise that no moose were seen on the Greenwood plot this year, although it was chosen in part because random surveys of these plots had included moose observations in previous years.
“By random chance (as part of the larger moose estimate survey), we selected two other plots over the fire,” Schrage said. “We saw one deer and no moose. I am not terribly surprised by that result.”
That’s because there were no moose observed on the plot that was representative of the Pagami Creek Fire for five years.
“I suspect there will be a lag before enough vegetation recovers,” Schrage said. “In January, it has to be standing up above the snow line.”
The Pagami Creek Fire, which occurred in 2011, like two other fires in the habitat survey (the earlier Cavity Lake and Ham Lake fires, which occurred in 2006 and 2007, respectively) burned hotter and harder than did the Greenwood Fire, scorching vegetation to the earth in large swaths.
“That was part of the delay with the Pagami Creek Fire,” Schrage said. “It was a severe fire. It scorched a lot of the vegetation that took time to recover. We had several deep-snow winters there. Moose are not going to spend a lot of time digging for food.”
The other two severe burns areas in the survey, Cavity and Ham, have continued to produce a lot of moose observations, although this was the first year, Schrage noted, that observations were lower this time than they had been in previous years. The same could be said for the Trout Lake prescribed burn also included in the survey.
“It’s a head-scratcher at this point,” Schrage said. “Is this just noise in the data? There is always variation in moose numbers, or is this the start of a downward trend in moose use of those areas?”
At least the case of the Cavity Lake Fire plot, where six moose were observed this January, as opposed to more than 50 back in 2014, Schrage tends to think it may be noise.
The nearby Ham Lake Fire plot turned up 16 moose in January.
“It was only a year after the Cavity Lake Fire,” Schrage said, offering his reason for why he isn’t ready to give up on the Cavity Lake Fire as solid moose habitat yet.
Each fire is a little different. For example, the Pagami Creek Fire largely is coming back quick with jack pines that could shorten its window as solid moose habitat, Schrage said.
“That is rapidly closing in,” he said.
That means the deciduous species, such as aspen and birch that moose prefer to eat, may be crowded out.
“I think we will see much of that fire fall away as good moose habitat as that jack pine matures, even though it is a more recent fire than Cavity and Ham lakes,” he said.
At the Greenwood fire, the fire did not burn as intensely as did fires at Cavity and Ham lakes or at Pagami Creek.
“We don’t know yet, but if more of the canopy survived, you are probably not going to get the flush of deciduous trees and shrubs that would be more attractive to moose as forage,” Schrage said. “We will just have to see. There are certainly pockets that did burn severely. We’ll let the moose tell us in coming years how much they did or didn’t like that fire.”
The moose seem to be saying good things about the Kekspider prescribed burn around Kekekabic Lake in the BWCAW.
On Jan. 21, moose were observed in that plot, the most since the 4,961-acre burn was pulled off in 2010.
“It has been encouraging to see moose responding there,” Schrage said. “It seemed to take longer than some of the other places, but it is now producing a decent number of moose.”
That brings up planned prescribed burn plot that has yet to be burned – at Duncan Lake, which has been scheduled for a prescribed burn since the infamous July 1999 BWCAW blowdown event left lots of fire fuel on the ground.
The U.S. Forest Service has had a couple of opportunities to pull off that burn in recent years, but ill-timed prescribed burn pauses brought that to a halt. The first of those stemmed from health concerns about smoke at the outset of the pandemic and the second pause was earlier this year following political pressure after a prescribed burn that got out of hand in New Mexico. Schrage criticized the feds in both instances.
“We didn’t think it was going to take this long,” he said of the plot that has been included in the habitat survey since its inception. “It is still out there and for the purposes of this survey, I hope it gets lit. I think we would see a very positive response.”
Eight moose were observed on the plot in January.