Minnesota's old-growth forests stand the test of time

As spring works out the kinks from winter dormancy, the cycle of rebirth is ever welcome in Minnesota. Few lifeforms have experienced that cycle as often as old-growth forests. These ancient timber stands are home to behemoth trees, diverse wildlife and rare plant species native only to where they grow.

Unfortunately, Minnesota's old-growth forests have nearly vanished. Where they once flourished 150 years ago, old-growth forest has declined by 96 percent. That makes them all the more precious. For anyone with a springtime itch for a sense of history and ecological interdependence, outdoor recreation in these forests are available throughout the state.

The Minnesota Department of Natural Resources describes old-growth forests as those that have developed naturally for at least 120 years. The forests hold some trees that are more than 400 years old, with trunks often 3 feet in diameter. These stands also have not succumbed to severe disturbances such as fire, windstorms or logging. They can be dominated by sugar maples, white spruce or white cedar. Others are primarily red pine, white pine and red oak.

Old-growth forest made up 51 percent of Minnesota's timberland in 1850, according to the DNR. But by 1994, a study showed that had been reduced to under 4 percent, largely due to intense commercial timber harvest from 1850 to 1920 that, too, fueled the state's early economy.

Today, old-growth forests are protected for more than their historical significance. John Nelson, a planner and outreach manager for the DNR forestry division, said old-growth provides a scientific benchmark to compare with the agency's current forests. But it also offers something extra for visitors.

"There's kind of the aesthetic appeal of old-growth … You go and see an old-growth stand [and] they look different," he said. "There's also kind of a spiritual side for some folks [who] just find something very interesting or appealing in an old-growth stand that they know has had nothing major happen to it for hundreds of years."

The DNR states that current old-growth forest presents new opportunities in research and management (such as prescribed burns and harvests around and between old growth) that help preserve and enhance the areas for wildlife. Recreational users benefit, too.

Minnesota has eight designated old-growth stands that afford visitors a chance to immerse themselves in their majesty. They're easily accessible and located in state and national forests, state parks, and scientific and natural areas (SNAs). They are:

• Spring Beauty Northern Hardwoods SNA in the Grand Portage State Forest

• George H. Crosby-Manitou State Park in Lake County

• Tettegouche State Park in Lake County

• Lost 40 SNA in Itasca County

• Wolsfeld Woods SNA in Hennepin County

• Townsend Woods SNA in Rice County

• Sakatah Lake State Park in Le Sueur County

Most of these old-growth forests offer hiking, wildlife observation, photography, snowshoeing, cross-country skiing and scenic vistas. Other uses on state lands either within or surrounding these forests expand the smorgasbord of activities: berry-picking, fishing, hunting, rock climbing, horseback riding, camping and more.

Not all old-growth forests reside on state land. Some are under private ownership or belong to land trusts such as the Nature Conservancy. In 2016, the Conservancy bought a 240-acre parcel of old-growth forest northwest of George H. Crosby-Manitou State Park. Some of the mammoth trees are estimated to be more than 300 years old.

"We were concerned that if it had been developed, it would kind of punch a hole in this really nice landscape that could introduce invasive species … and could basically degrade the quality of the area," he said.

The DNR encourages visitors to enjoy the undisturbed natural quality of old-growth forests. The agency website features A-Z lists of state forests, state parks and SNAs. Webpages include maps of the areas and list types of recreation, trails, camping, day-use locations and other special features. For further details, visit dnr.state.mn.us. Click on the Destinations drop-down menu for forests, parks and SNAs. Select the Nature menu and go to Forests for information specifically on old-growth forests.

Similarly, most of the conservation group's preserves are open year-round. However, they are on private land and access is sometimes restricted based on the sensitivity of the natural features. For visitation guidelines, maps and recreational uses, visit nature.org/Minnesota and click on Places We Protect.