The Boreal Forest Monologues

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(Gunflint Trail, Minn.) Christopher Cox, Pew Environment Group’s Minnesota representative, stood amid the burnt trees of a recent north woods forest fire and talked about global warming.

“Global warming is not something that just happens in sub-Saharan Africa or the polar ice cap,” Cox said, videotape rolling. “It is something that happens right here in our back yard.”

This is the first of two Daily Planet stories on global warming in the Boundary Waters. Pew invited The Daily Planet to cover the trip, (and the paper covered its own costs.) Read the second story at Global Worming: The critters are coming
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Warmer temperatures, forest fires and invasive plants and pests will be changing Minnesota’s iconic black spruce and jack pine forest and the animals that live there. Cox wants that “back yard” story of global warming to get more coverage, but it’s difficult getting news crews to the Boundary Waters’ boreal forest. Pew is making a video, posting it on-line—and hoping media will use it, ultimately promoting greater public awareness pressure for political action.

For the bulk of the video shoot, Lee Frelich, director of the University of Minnesota’s Center for Hardwood Ecology, guides the viewer through the woods and provides commentary. He has done research here since the early 1990s.

You could call this trip the Boreal Forest Monologues.

Deer increasing, moose declining

There are still lots of pine and birch trees up here, though Frelich pointed out last year’s drought hit the birches hard. To the casual observer, this “back yard” still pretty much looks like the north woods; the changes are subtle.

Frelich sees signs of change everywhere.

He surveyed the early greening amid the charred remnants of last year’s Ham Lake fire, near the end of the Gunflint Trail. He bent over and examined a red maple sapling. A deer had chewed it.

The red maple and its deer chomp are two small signs of global warming, he said. Warmer weather favors red maple, “They are growing like weeds,” he said. “We are on the northern edge of the [red maple] range and it is expanding rapidly.”

Further, as winters get shorter and the snow pack shallower, deer are moving north. Deer sightings are becoming more frequent, Frelich said.

At the same time, the state’s moose population is moving out. Moose don’t do well in warmer temperatures. And as the deer population increases, moose should decline. Deer carry a parasite that can kill a moose.

It is possible that in two or three decades, Minnesota’s moose will have retreated to Canada, Frelich said.

Global warming, take one

The Intergovernmental Panel on Climate Change issued a 2007 report that calls global warming “unequivocal.” It says most of the increase in global average temperature since the mid-20th century and the widespread melting of snow and ice are “very likely due” to human activity.

The earlier arrival of spring and shifts in plant and animal ranges toward the poles “are with very high confidence linked to recent warming,” it said. (For more, see http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr_spm.pdf )

To document changes in northern Minnesota, the Pew Environment Group organized a five-person trip, including Frelich and video producer Jeffrey Huxmann. (Pew also invited the Daily Planet, which covered its own costs.)


We boated (yes, gas-powered) on Sea Gull Lake, just outside the Boundary Waters Canoe Area (BWCA), and climbed a hill for a panoramic view of the impact of the 2007 Ham Lake Fire, the 2006 Cavity Lake Fire, and the 2005 Alpine Lake Fire.

The charred forest gave the video dramatic visuals. But using burned trees for backdrops doesn’t prove global warming. Fires are part of forest ecology. This same forest had fires in 1692, 1801 and1864, Frelich said—and he can tell you some of the individual trees that got their start after specific fires.

Jack pines even need fire to spread their seeds. Jack pines dominate the northern forest after a fire. As the forest matures, it gets more birch, fir, cedar and aspen.

Terry Serres created a map of the fire history around the Gunflint Trail. Download the map at https://wiki.umn.edu/pub/Main/TerrySerres/standorig_600dpi.pdf

The case Frelich made is that the fires will become more frequent and intense, and different trees are better adapted to the changing environment, and will overtake the pine-spruce forest that has stood here for thousands of years

There will be “more storms, more fire, more deer, more insects, more invasive species all coming at once,” Frelich said. “That is what is going to transform these forests.”

A different kind of fire

When Frelich began his research here, the spruce-pine canopy shaded the ground, and its inch-thick moss. Today, walking through an area cleared by the Cavity Lake fire, it is open and sunny. Bicknell’s Geranium, bunchberry and wild roses are blooming. The aptly named bindweed grabs your ankles.

The Cavity Lake fire was particularly intense. The 1999 “blow down” (high intensity straight-line winds that flattened many trees) put 100 tons of fuel per acre on the ground.

The fire caught during the 2006 summer drought, and burned extremely hot, consuming soil and exposing bedrock. Because the jack pines were blown down, their cones were on the ground and burned, too.

Expect more extreme droughts, more blowdowns and more intense fires like Cavity Lake, Frelich said.

“Geologists are thrilled. They can see the rock formations for the first time,” he said.

A million acres of buckthorn?

During one video shoot, an inquisitive passing fisherman saw the equipment and asked about the video project. Cox’s intern Matt Roznowski told him it was a documentary on global warming, the recent blow down and fires.

The fisherman’s gut reaction: “That can’t be from global warming.”

The video’s impact remains to be seen. But as Frelich sees it, the now subtle changes will become more and more evident. Every time the forest is disturbed—by fire, blow down, or bug infestation—it opens the door for new species to move in.

The BWCA is near the prairie border. That means a small climate change here could mean an opportunity for deciduous trees to advance.

One possible long-term change is the burr oaks coming to the BWCA. They can survive regular fires and high winds, even tornados, Frelich said. They have a low center of gravity and strong, flexible wood.

The Boundary Waters could become an oak savannah, he said. “But we would have to make sure it makes a graceful transition … and it doesn’t become a million acres of buckthorn.”

When complete, the Pew video will be available at http://www.pewtrusts.org/our_work_category.aspx?ID=110

Tomorrow—Global Worming: The critters are coming

Scott Russell is a journalist. He wrote for the Southwest Journal and Skyway News (now the Downtown Journal) in Minneapolis from 1999-2005. He also wrote for The Capital Times, a Madison Wisconsin daily, from 1993-1999.

ErrataCorrected from first version posted: it’s Pew Environment (not Environmental) Group. Matt Roznowski is actually an intern with Grass Roots Solutions, working for Chris Cox.