Climate change’s global impacts have not spared the Boundary Waters Canoe Area Wilderness.
Human activities like burning fossil fuels, far from the loon on the lake and the wind in the pines, are transforming the wilderness we love. Already, warming is well underway in northern Minnesota, and impacts are already being observed.
The region is the fastest-warming part of Minnesota, a trend which is most dramatic during the winter. Northern Minnesota’s winters have been warming ten times faster than its summers–with the average winter temperature rising one degree Fahrenheit per decade.
In fact, Minnesota’s winters are warming faster than any other region of the country, with average temperatures increasing by up to 7.5 degrees since 1970.
Warmer winters share part of the blame for dwindling numbers of moose, and are also likely why the Arrowhead region is experiencing more severe windstorms and extreme rainfall events.
Future impacts on the boreal forest
In 100 years, visitors to the wilderness will likely paddle through a dramatically different landscape. The Boundary Waters is on the southern edge of North America’s boreal forest. All of the boreal tree species in the wilderness are within 100 to 300 miles of the southwestern edge of their range.
Tallgrass prairie exists only 120 to 200 miles away.
Climate change means both ecosystems will shift north. Oaks and maples will eventually replace much of today’s boreal pine forests and some areas will convert to grasslands.
Dr. Lee Frelich, an ecologist from the University of Minnesota, has monitored plots of land in the wilderness to examine how the forest is changing. Red maples are sprouting in previously pine-dominated forests, and when the existing pines die, they are being replaced by deciduous tree species.
Pine forest to oak savanna
In the next 100 years, the western Boundary Waters is expected to transition slowly to oak savanna, with widely-spaced deciduous trees amid grasslands.
This scenario takes into account how the thin soils of the Boundary Waters dry out easily, leaving forests prone to drought and fire. Oak savanna thrives where summers are hot and relatively dry. In the eastern half of the wilderness, temperate forest dominated by maples and basswood will likely prevail.
Boreal forest may survive on cooler north-facing slopes or other protected areas.
These longer, hotter summers will also contribute to increase water temperature in lakes. This could mean changes in vegetation, water clarity and quality, increased algae blooms, and degradation of fish habitat. As cold-water lakes disappear from much of Minnesota, the Boundary Waters’ deep lakes might remain cold enough to provide refuge for species like cisco and lake trout.
This is what climate models predict
Scientists anticipate two possible scenarios for precipitation in the region.
- Climate models predict the same amount of rain and snow with more evaporation due to warm temperatures, or
- Increased precipitation, but more concentrated during certain seasons, with other times of the year having drought-like conditions.
If wilderness peatlands dry out due to changes in precipitation, they could rapidly release the carbon they store into the atmosphere, compounding the rate of climate change.
An important role for the Boundary Waters
As the planet gets hotter, we will see how an ecosystem without much on-the-ground management is affected, compared to places with more human manipulation. And, as our cities grow and the world becomes more crowded, the canoe country’s solitude and wildness will be even more important.
On the 40th anniversary of the creation of the BWCAW — and as part of our longtime leadership in protecting, preserving and restoring this national treasure — the Friends of the Boundary Waters Wilderness has compiled a State of the Boundary Waters Canoe Area Wilderness report. Examining the current situation in the Boundary Waters, it provides an overview of the ecological health, human experiences and emerging threats.