Global Worming: The critters are coming


(Gunflint Trail, Minn.) Lee Frelich stood at the foot of a 300-year-old cedar tree on the shore of Sea Gull Lake and gave the good news, bad news analysis about global warming.

The good news: The native cedar could survive the warmer temperatures and still could be part of the state’s boreal forest. The bad news: Deer, once infrequent guests here, are moving north, spurred by milder winters. And deer love eating small cedars.

“As the number of deer increase in the warmer climate, it [cedar] won’t be able to reproduce,” said Frelich, director of the University of Minnesota’s Center for Hardwood Ecology, video rolling. “We don’t think it has a very good future in northern Minnesota.”

This is the second 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 first story at The Boreal Forest Monologues.

Frelich, wired for sound, was narrating a video documentary by the Pew Environmental Group on global warming and its impact on the north woods. Pew is putting the video on line and hoping the media uses it as part of its global warming coverage.

The trip offered sightings of loons, fox, black-backed woodpeckers and a brief glimpse of a moose as it trotted into the woods.

But it is the cedar-eating deer and several smaller creatures that would impact the future forest, Frelich said. Even the seemingly innocuous earthworm will change things.

Duff eaters.

This part of the state has no native worms, Frelich said. However, fishermen have dumped their excess—and invasive—worms and night crawlers in the woods. The little wigglers are changing the soil and will affect what trees and plants grow well.

The pristine boreal forest floor has a layer of “duff,” the term for decaying leaves, roots, moss and other organic matter. The worms eat the duff.

“There are thousands of [worm] invasion fronts all over the place because of fishing,” Frelich said.

Call it global worming.

During a hike, Frelich pointed out a “middens,” a pile of leaves that marks a night crawler burrow. The worms are at their limit for cold tolerance, Frelich said. As warming continues, they will become more abundant.

Bait worms are native to Europe and Asia. Worm activity makes the soil more hospitable to European and Asian plants that co-evolved with the worms. Buckthorn and garlic mustard depend on earthworm activity, Frelich said.

Bug attacks

Warmer weather will mean more invasive bugs, beetles and boring insects will survive in northern areas, and have longer seasons to spread and do damage.

“Global warming and invasive species are not separate things from the point of view of the forest,” Frelich said. “There are a lot of things coming that will negatively impact trees.”

We did not see the bugs. They are not here yet. If they get here, it’s going to be ugly.

Frelich rattled off a litany of threats.

The mountain pine beetle is on its way from British Columbia. Warmer winters along the boreal forest’s southern margin are allowing it to spread east. The beetle could wipe out most of the continent’s pine species, Frelich said.

The Christian Science Monitor recently reported that the mountain pine beetle has infected 144,000 square miles of British Columbia’s forest. According to Canadian scientists, from 2000-2020, carbon dioxide emissions from those dying trees “appear comparable to five years’ worth of emissions from Canada’s entire transportation sector.”

The emerald ash borer is coming from the southeast. Minnesota has an estimated 600 million ash trees, and the BWCA has ash trees in every swamp. When the emerald ash borer arrives, Frelich said there would be 600 million dead trees.

Other pest threats include the sirex wood wasp, which attacks pines, and the Asian longhorn beetle, which attacks maple trees, among others.

Forests take a back seat

On his hands and knees, University of Minnesota graduate student Terry Serres examines small plots of land in an area burned by the Ham Lake fire. He swats mosquitoes, counts newly sprouted plants and records notes on his clipboard.

Serres, one of Frelich’s students, has seeded the area with red and white pine and is investigating what topography supports pine growth and what other plants are competing against them.

Frelich said for both research and environmental activism, forests have taken a back seat to agriculture and biofuels.

“We need much more systematic monitoring of what is happening to our native species on a larger scale,” he said. “We have spent a lot more of our resources on ethanol and things like that ….I think it is about time we value forests more.”

Cutting back

So what does Frelich do to cut his carbon?

He has an 885-square-foot downtown Minneapolis condo, he said. He has a car but only uses it to go out of town, doing local trips by bus or foot. Using energy efficient lights and appliances, he got his electric bill down to $14 in May. He has cut back on air travel.

“Every time I fly somewhere, I make sure I walk to the grocery store for the next 100 trips—I am serious about that,” he said.

The changing forest affects the timber industry, the tourist industry and people’s quality of life, he said.

The loss of forest also creates a feedback loop that makes global warming worse.
Trees take carbon dioxide out of the atmosphere and store the carbon in the wood. Losing forests to fires or bug infestations puts carbon back in the atmosphere.

While Frelich personally is trying to cut back on his carbon (see sidebar), he gives a rather bleak forecast for the long-term impact of global warming.

“I am very optimistic about the future of the world. I am just not very optimistic about the future of civilization,” he said. “The earth has been through this sort of things many times in the past and managed to recover just fine. The thing that probably won’t recover is people.”

When Pew finishes the video, a link will be available at

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.