Could larger fires help Minnesota moose?
Cloquet, Minn. — For the first time this winter, moose were observed in notable numbers inside the Pagami Creek wildfire area, more than 90,000 acres that were quickly scorched mostly inside the Boundary Waters Canoe Area Wilderness in September 2011.
At least at this point, however, there isn’t complete agreement between a couple of wildlife researchers about what that means for northeast Minnesota’s moose herd.
Mike Schrage, Fond du Lac Band wildlife biologist, initiated an addition to the annual winter aerial moose survey in 2012, adding nine aerial plots that target areas in the moose range that have been impacted by timber harvest, prescribed burning, and large-scale wildfire, all areas of disturbance and long-known as key habitat for the young aspens that pop up afterwards, an important food source for moose.
All of the survey plots are 13.3 square miles, and with the additional nine plots, there are now 53 areas surveyed by air.
Schrage believes what was seen this year inside the Pagami Creek fire area – as well as within plots covering other big fires such as the Cavity Lake and Ham Lake fires near the end of the Gunflint Trail, where higher concentrations of moose have been continually observed in the survey, and the nearly 10,000-acre Trout Lake prescribed fire north of Lake Vermilion – suggest that larger-scale fires may be an important habitat component for moose. This comes as wildlife managers work to recover the population that has been down for more than a decade and attempt to prevent a repeat of the fate of the northwest Minnesota moose population, which has all but disappeared.
But Glenn DelGiudice, the Minnesota DNR’s moose project leader who headed the moose calf study that was shut down last year by Gov. Mark Dayton, and who also is investigating climate change as a potential cause of the moose decline, said it’s too early to say that larger-scale disturbance is any more important to moose habitat than smaller disturbances.
“We have to be cautious,” DelGiudice said. “You can’t just say, ‘We should do some big burns.’ There are so many considerations. … I am not convinced that that is something we can really latch onto now, that it’s all about disturbance and burns.”
But Schrage said the effects of large disturbances should be closely looked at as a way to help the recovery effort. While the DNR and many local and tribal agencies have worked to create disturbances on the landscape in the moose country of Cook, Lake, and St. Louis counties, much of that is on a pretty small scale.
“They are not big enough,” Schrage said. “We haven’t done a large, thousand-acre prescribed fire in a number of years now.”
Indeed, Schrage acknowledges such disturbances are not appropriate everywhere, and even where they are conceivable, they are generally controversial, whether they’re the result of wildfire, timber cuts, or the rare large prescribed fire.
The last prescribed fire of that scale was done north of Trout Lake in 2005, to consume the excess fuels left on the ground by the legendary 1999 blowdown.
There is another fire prescribed by Duncan Lake, a 4,100-acre scheduled burn north of the Gunflint Trail also planned by the Superior National Forest to reduce fuel loads from the ’99 blowdown.
The U.S. Forest Service changed its policy of fire suppression in the late 1970s because such a policy is not healthy for fire-dependent ecosystems such as the Superior National Forest, according to Kris Reichenbach, public affairs officer with Superior National Forest.
Susan Catton, Superior National Forest wildlife biologist, said the Forest Service’s forest-management plans call for taking large-scale looks at the forest and breaking them into sections of 50,000- to 100,000-acre areas, where a mosaic of disturbances can be put onto the landscape.
Catton said she looks forward to watching how moose respond to the disturbance areas going forward.
Fires are tricky, as was recently demonstrated by the Foss Lake fire, which was planned as a small, 78-acre prescribed fire but jumped the line and consumed more than 900 acres.
It’s why the Forest Service generally tries to chip away, one piece at a time, even when it has a larger area slated for disturbance, especially when a fire is prescribed, since smaller fires generally are easier to control.
Luckily, many of those acres near Foss Lake were slated for a prescribed burn anyway, said Lee Frelich, the University of Minnesota’s director for the Center for Forest Ecology.
“They rarely jump the line like that,” Frelich said. “But in one way, it was a good thing, since it burned an area they were going to prescribe-burn anyway.”
The Foss Lake fire demonstrates the potential backlash that can come from the public regarding fires, whether they are planned or not, Frelich said.
He believes a lot of people oppose disturbances in the wilderness, and it’s a difficult thing to convince them that they are a natural and needed part of wild-dependent ecosystems – and may be crucial to the survival of iconic creatures such as moose.
While the Pagami Creek fire was considered large in Minnesota, fires several times larger have long been part of the landscape, Frelich said, dating back to pre-statehood.
While forest managers aren’t going to let valuable stands burn when they can be harvested, logging can play the same role, but it might not be as good as wildfire, which returns rich nutrients to the soil and does an excellent job of regenerating high densities of birch and aspen, Frelich said.
“What is a shame is that some of the best moose country we have were all accidents,” Schrage said. “We can’t rely on out-of-control wildfires for good moose habitat. Maybe we have one this summer, or maybe we don’t have one for 30 years. We need to be more deliberate about when and where to do these.”
Tom Rusch, the DNR’s Tower area wildlife manager, said wildlife biologists for years noted high concentrations of moose inside the area of the large 1971 Little Indian Sioux Fire.
“We saw increased moose numbers there for 30 years,” Rusch said. “The numbers were phenomenal.”
DelGiudice, however, noted that some research coming out of New England and Ontario is finding that small areas of disturbance can be quite beneficial for moose, since they increase edges and allow moose to graze while having nearby cover from predators.