The Estivant Pines Nature Sanctuary, protecting the largest remaining stand of old growth white pines in Michigan, celebrates its 45th anniversary.
By William Rapai
Time passes slowly at Estivant Pines.
Nobody knows that better than Gary Willis, a forester with the Michigan Department of Natural Resources and former assistant professor at Michigan Technological University. Willis knows this place better than most people. When you see this preserve through his eyes you begin to understand that the best way to truly appreciate this place is not to consider time in hours, years, and decades but in centuries, periods and eras.
Estivant Pines is the Michigan Nature Association’s 510 acre sanctuary in the Keweenaw Peninsula. Despite its remote location—down a pothole-strewn dirt road south of Copper Harbor—it is one of the organization’s most popular sanctuaries. Every summer, thousands of people from across the United States visit, wandering two looping trails to marvel at white pine trees that stand 120 feet tall.
But there aren’t many visitors to Estivant Pines in the late winter or early spring because the road that leads to the sanctuary is usually under several feet of snow or too muddy to be drivable. However, the period after snowmelt and before trees emerge from dormancy is the best time to see and understand time’s impact by looking down—not up—and closely examining what is and isn’t here.
What is here is volcanic bedrock that dates back to the earliest period of Earth’s history and carbonized tree stumps that are the remains of a cataclysmic forest fire more than 200 years ago. What isn’t here is surprising and confounding. The plant life in the understory is healthy—lots of lichens, mosses, ferns, maples, birches, cedars, spruces, and balsams. Surprisingly, there are few young white pines even though these 240-300 year-old trees have produced millions of viable seeds during their lifetimes.
Willis gained these insights when he was a forester for the Michigan Nature Association. In the late 1990s he started working at Estivant Pines at the request of Michigan Nature Association’s founder Bertha Daubendiek. Willis was given a unique opportunity to study these ancient trees after a logger accidentally trespassed on the sanctuary and cut a number of the trees along one of the boundaries.
Daubendiek sent Willis out to write a damage report, but during the process he started to see this incident as a unique opportunity to study how these giant trees grew. As he measured the width of the stumps and correlated individual ring-widths he began to understand these trees through the prism of time.
But it’s not just the trees that are measured in time. Much of this sanctuary sits on a high ridge of volcanic bedrock that runs between Annie Creek and the Montreal River that dates back to the earliest period of Earth’s history, some 1.1 billion years ago. In fact, Willis said, other researchers at Michigan Tech have discovered the Keweenaw was once one of the most active volcanic regions on Earth.
It’s difficult to see it from the landscape level, but Willis says if you look at an aerial photo of the peninsula, you can see a series of ridges left behind from that volcanic flow. Those ridges run parallel to the shoreline and curve as the shoreline curves and narrows as it reaches the tip of the Keweenaw Peninsula.
Even though we tend to think of these trees as old, the plant community here is in its infancy, relatively speaking. Plants—trees, shrubs and grasses—established themselves only about 10,000 years ago following the withdrawal of the Wisconsin Glacier.
Multiple glaciers over the past 2.5 million years left behind a thin layer of soil that can support plant life but generally is not deep enough to anchor a 100-foot-tall tree. To compensate for the lack of soil, most of the pines have grown roots deep into fractures and crevices in the bedrock. Some trees have been lost to windstorms but remarkably few considering that the sanctuary sits at an altitude that varies between 200 and 500 feet above lake level. That altitude leaves these trees exposed to powerful winter winds that blow across Lake Superior. In the winter, this sanctuary can get more than 275 inches of snow in a single season. The combination of heavy, wet snow and strong wind can bring even the hardiest tree down, says Donald Dickmann, professor emeritus of silviculture and physiological ecology at Michigan State University and co-author of The Forests of Michigan. Fortunately, most of the snow that blankets the Keweenaw’s rocky ridges is light and fluffy lake effect powder.
Summer brings heavy thunderstorms and gusty winds, and the trees, which tower above the hardwood canopy, are sitting ducks for lightning strikes. One of those lightning strikes more than 200 years ago might have been the spark for a fire that ravaged this area and set the stage for the Estivant Pines as we see them today.
Those carbonized tree stumps and little bits of charcoal strewn across the landscape point to a potent wildfire that swept through the area in the late 1700’s. Willis said it likely wiped out most of the white pines that had been standing on that spot perhaps for centuries. Just as the towering, mature pines today prevent the young pines from growing underneath, those earlier pines prevented any new ones from growing beneath them. It’s not that these trees are refusing to reproduce; it’s just their reproductive strategy. Barring a major fire, disease or insect threats, these pines could be here for another 300 years before they reach the end of their natural lifecycle. As that happens, the maples, birches, spruces, and balsams that make up the understory will continue to grow and mature and create a thick new canopy 50 feet or more under the tops of the pines. As those trees mature and die, fuel for a future fire will continue to build up on the forest floor, waiting for a spark.
When that fire eventually arrives, the pines’ continued existence will depend on its intensity. A moderate fire may not cause any damage because the old trees are protected by a thick layer of bark. But if the fire is intense enough the heat will fry the layer under the bark that transports water and nutrients up the trunk. That will kill the tree even if the fire does not reach the top branches. If that happens, the tree, knowing that it will soon die, will put all its energy into seed production. The year following the fire, massive amounts of seeds will cover the now-bare, ash-covered soil and thousands of new white pine trees will germinate if there is enough rain.
And the cycle will begin again.
Ancient white pine trees like the Estivant Pines once covered a good portion of Michigan. In the late 19th century, lumberjacks cut these trees to supply wood for houses, barns, and carriages needed by a fast-growing nation. At the time, it was thought that Michigan had an inexhaustible supply of white pine.
Only a few stands of virgin white escaped the lumberjack’s gluttony—this one, of course, one at Hartwick Pines State Park northeast of Grayling, and another stand on private property east of L’Anse are the three best known. But Don Dickmann of Michigan State says he has found small stands of them in other places in the Upper Peninsula. Those stands, like Estivant Pines, were spared through random chance and, more recently, the passion of local citizens who wanted to preserve these trees for what they represent.
Two people who have come to deeply appreciate the history represented by these pines are Bill and Nancy Leonard, who organize volunteers and stewards for the Michigan Nature Association in the Keweenaw Peninsula. They work closely with sanctuary stewards Ted and Alice Soldan to maintain the boardwalks and trails. Bill Leonard said that as he’s working he enjoys talking with visitors and is always amazed by how many people from faraway places around the country come to see these giants multiple times.
“It just pulls people back,” Leonard said.
Indeed it does. But those visitors? For now, it seems, they can take their time.
William Rapai is the author of three Michigan Notable Books including The Kirtland’s Warbler (University of Michigan Press) and Lake Invaders (Wayne State University Press). He is also the president of Grosse Pointe Audubon.
As seen in the feature story in the Winter 2018 issue of the Michigan Nature magazine.