All over the world, climate change is altering habitats that are already stretched to their limits. In northeast Minnesota, near the Canadian border, lies a boreal biome at the southern edge of its climate range. This strip of mixed coniferous forest now transitions to temperate forest in the south of the state and drier forest and prairies in the west. Warmer winters, longer and hotter summers, and more variable ranges of precipitation are currently changing this boreal zone, and these shifts are having profound effects on the region’s vegetation and wildlife.
Benjamin Olsen began photographing this ecosystem in 2008 at the age of 19, which enabled him to notice and document these slow changes. “The changes in wildlife, landscape and weather that I’ve seen are significant,” he says. “What keeps me going when it gets too much is this: We can see major ecological developments throughout our lives. While this is depressing in some aspects, I find it absolutely fascinating.”
View the Boundary Waters Canoe Area Wilderness, the country’s most visited wilderness, and the surrounding Superior National Forest. Boreal conifers have long thrived there. But over the next century, if climate change continues unabated, models predict the ecosystem could cede some or all of its soil to temperate forests or even savannas, says Lee Frelich, director of the University of Minnesota’s Center for Forest Ecology. Today, deciduous trees, including species from temperate forests such as red maple, are increasingly taking root after wildfires, wildfires, and other disturbances. Red maples are relatively small now, but they are a remarkably growing presence for experts deeply familiar with these locations.
These include climate-sensitive birds like the spruce grouse, which feeds exclusively on short needles from conifers in winter and creates shelter by diving under snow to stay warm and hide from predators, and the boreal chickadee, one of the few perennial boreal songbirds Species threatened with extinction.
“Spruce grouse are a species that really depend on coniferous forests. In Minnesota, we’re on the edge of the boreal region, and we expect that to shift north with climate change,” says Charlotte Roy, a research scientist at the Minnesota Department of Natural Resources who is conducting a comprehensive study of game bird populations and habitat needs in the Country. “At this stage, we’re really trying to think: what does this species need and how could this be influenced by a variety of different factors?” Not only is the grouse’s habitat shifting north, she says, warmer winters are also leading to snow , which melts and freezes again. This creates icy layers that can make it harder and more dangerous for grouse to hide.
Mammals can also be affected. For example, because the spring snow melts earlier, scientists believe that the snowshoe hare’s white winter camouflage could become increasing do not match the season, making them easier prey.
An icon of the upper Midwest, common loons face many threats such as: B. the recording of lead fish. But warming temperatures and changing rainfall patterns are raising the stakes in myriad ways, including by boosting blackfly populations.
The birds don’t readily leave their nests, but when they do, fly attacks (pictured below on Lake Superior’s north shore) are often the culprit, says Walter Piper, a scientist in Minnesota National Loon Center and Professor at Chapman University. His data over the past decade shows that loons in Wisconsin abandoned their nests more frequently during blackfly years, contributing to local declines. Now he’s expanding his research to understand if this is true in Minnesota. If global warming hits 3 degrees Celsius, which could happen as early as 2080, Audubon’s climate model project Loons could almost completely leave the land of 10,000 lakes.
Land and wildlife managers in Minnesota’s boreal zone are actively considering how to make ecosystems more resilient to help them withstand stresses from insect invasions, extreme weather and warming, and to benefit trees and animals species move and adjust. For example, in 2021 the Superior National Forest was experiencing unusually severe drought-triggered wildfires. Conservationists and scientists there have been monitoring regrowth. In an experiment using a strategy called assisted migration, the Nature Conservancy this summer worked with officials to replant some trees they hope can tolerate a hotter future.
In Beltrami Island State Forest, located on the state’s drier western boreal margin, one of several adaptation strategies is to increase the diversity of tree species within and between forest stands. “If we lose a species, at least we still have a forest,” says Charlie Tucker, a wildlife warden in the Fish and Wildlife Division of the Minnesota Department of Natural Resources.
Tucker and his colleagues have already selected several climate-sensitive birds, including spruce grouse and boreal chickadees, to actively manage and monitor on Beltrami Island. The resident capercaillie live in the area’s dense jack pine forests, where they feed on conifer needles, but these habitats may transition to thinner forests as the climate dries. “If Jack Pine doesn’t regenerate as well under drier scenarios, then it doesn’t bode well for Spruce Grouse in that area. We suspect they are already experiencing a range shrinkage northward, but data is lacking—except anecdotally,” he says. Conversely, while there are currently no Kirtland warblers in Beltrami Island State Forest, there could be many forest areas suitable for them in the future, he says. Managers there are also conducting experiments with timber harvesting patterns in parts of the state forest to see how best to help birds that may be at risk.
Some of Minnesota’s species are engineers of their own destiny. Beavers are highly adaptable mammals that scientists believe will cope well with global warming. When extreme flooding occurs, like that experienced across the state in 2022, beaver dams help strengthen the region’s resilience by storing sediment and filtering water. These structures even shape the flow of water in the landscape decades into the future, according to recent research from the University of Minnesota Duluth. And wherever beavers ply their trade in a forest, wetlands follow, creating a habitat that attracts various types of bird species, including waders like the gray heron and a variety of waterfowl.
This photo essay originally appeared in the Fall 2022 issue as “On the Edge.” To receive our print magazine, become a member at donate today.
