The recent feature by MPR’s Dan Kraker on research into interactions between Minnesota’s peatlands and climate change was fascinating. As Kraker reports, although historically viewed as wastelands to be ditched and drained, peatlands deserve superhero status for their ability to sequester carbon. Should we need one, it stands as yet another example of the wisdom of preserving a diversity of ecosystems, for values we now understand as well as benefits that may be revealed to us in the future.
In truth, there are endless reasons to appreciate—and be fascinated by—peatlands. Vast and relatively inaccessible, peatlands are among the most pristine of the state’s landscapes. We owe a debt to those who desperately worked to preserve 18 of the most ecologically-significant peatlands in their natural state back in the late 70s and 80s, when they were under threat from the peat-gasification industry. Norm Aaseng and Bob Djupstrom provide an account of events in the book, “The Patterned Peatlands of Minnesota” (U of MN Press, 1992). Scientists from around the globe have traveled here to study these internationally significant sites, unraveling the secrets of their hydrologic processes, water chemistry and patterns of development. While often described as inhospitable, they provide habitat to wildlife species ranging from bog lemmings to the magnificent great grey owl.
To offer some natural history context for the current news, in this edition of Agate I am sharing with readers an essay titled Sand Lake Peatland, October, that appeared in my book, “Far from Tame: Reflections from the Heart of a Continent.” Please join me as I travel on foot through Sand Lake Peatland and fly over the vast Red Lake Peatland in a small plane, curious to better understand these wild places. With a nod to Halloween, we begin with a mystery.
Sand Lake Peatland, October
It was in Denmark, 1952. Saturday. The men were out in a bog near the village, cutting squares of peat to use as fuel to heat their homes, when they found the body. They cleared away the cold and sodden peat from around the head and shoulders, and then the legs, until the man was completely free from the bog. They saw that the body was hardly decomposed; he could not have been dead for long. A woman from the village said that she could identify the man. It was Red Christian, she said, a peat cutter she had known who had disappeared without a trace. Judging from the man’s teeth, investigators estimated that he had been about thirty years old when he died. They ran a test, called radio-carbon dating, to find out how long ago he had died, how long he might have lain in the bog. The results of the test showed that the man had died more than sixteen hundred years ago. This was no Red Christian of modern-day Denmark. This was a man of the Iron Age.
Hitchcock at his best could not do better than the mysteries written over the centuries by the peatlands of the world. In Canada, it is the muskeg. In the British Isles, moors. In the United States, we call them bogs and fens. All are only different words for places that have one key trait in common. They are places where the process of decay can’t quite keep pace with the process of growth; places of slow and standing water where oxygen levels are too low to effectively break down all the remains of what has died. When something dies in a peatland, be it an Iron Age man, a leaf, or a tree, it adds to the layers of partially decomposed remains that are already there. Most of it will decay, but what does not will build up incrementally in layers over time, reaching a depth of as much as thirty feet. The layers compress under their own weight to make what we call peat, and form the basis of a unique and sometimes bizarre community where the dead are as present as the living, and the roots of plants on the surface never reach mineral soil.
I walk, on this October day, down a railroad track that runs through a bog not far from Ely, Minnesota. I listen for trains, but there is only the occasional call of a raven, the tapping of a black-backed woodpecker on a dead tree, the high purr of a half dozen cedar waxwings. The sky is clear.
The peatlands of northern Minnesota are part of a complex of boreal peatlands that ring the North Pole in North America, northern Europe, and Siberia. They are here because the last glaciers left behind a landscape of shallow depressions and flatlands where water cannot readily drain away. Their growth is nurtured by a cool, continental climate with ample rain and summer temperatures low enough that there is not an excessive loss of surface water from evaporation. Peatland nirvana.
My compass spins in circles, confused by the steel of the railroad tracks until I work my way down the embankment to enter the bog. The landscape before me is blanketed by sphagnum moss and meadows of sedges the color of old burlap with their grasslike leaves bent over into loops. Black spruce trees that look more dead than alive lift their skeletal arms as if beckoning the sky. A rain of needles falls from scattered clusters of tamarack trees turned gold in these shortening days of autumn.
I smile as I remember the words that Colonel William Byrd III wrote in his journal in 1736 about traveling through a peatland. “Never,” he said, “was Rum, that cordial of Life, found more necessary than in this Dirty Place.” With my second step, the water comes up, over, and inside my boot. The third step is more complicated. It seems that my right foot is fond of where it is. Would like to stay for a while. Somewhere in the neighborhood of sixteen hundred years. I begin to understand why there hasn’t been much in the way of tourism in the peatlands, and why they are considered by some to be the region’s last true wilderness.
I extricate my foot. Within a short distance I’m beyond the deep water that rings the bog like a moat, and moving gracelessly across the hummocks of green and burgundy sphagnum. It’s a little like walking on a trampoline; people have been known to get seasick walking on a bog. The earth gives way beneath my weight. Behind me, I hear the gurgle of water as it rushes back in where my footsteps had displaced it. This place will not miss me when I’m gone.
Peatland communities offer a lean environment for plant to make a living. As I walk, I know that I tread on nutrients held hostage in the peat—nutrients that the living plants cannot use unless they are set free by the peatland’s reluctant process of decay.
The raised surface of the bog and its dense peat base further isolate the plants from the flow of runoff and groundwater. These waters carry dissolved mineral ions that would provide nourishment for plant growth and a buffering of the acids formed within the sphagnum moss. Without them, a bog is left poor in nutrients and high in acids. It is this that distinguishes the two peatland communities termed bogs and fens. A fen, by definition, lies within the path of mineral-laden waters. The surface of a fen is not raised, so it is accessible to runoff. Groundwater that wells to the surface may also travel through the low-lying plants of a fen, bringing a boost of nutrients and bicarbonate or other base from surrounding sediments that buffers the acidity of its waters.
In diversity of species, a fen is considered to be much richer than a bog. Its outside source of sustenance and more alkaline waters allow it to support a greater array of plants. A bog is “fed” only by rain, snowmelt, and what ions the winds can carry from surrounding uplands. Few species of plants can survive in a bog. Even fewer can thrive. Peatlands are often a mosaic of bogs and fens, with the bogs differentiated more by what they lack than what they contain.
Part of the intrigue of a peatland community, be it bog or fen, is the pairing of life and place. As the albatross can soar above the sea for hours without even a flap of its long wings by using the aerodynamic lift created in the friction of air and waves, so too has the life in a peatland found its own way to get along with the conditions it offers.
The black spruce and tamarack I see around me in the bog are able to grow new roots from their trunks and lower branches as the water level rises around them. When high winds throw a black spruce down, upright stems can sprout along the length of the fallen truck to form new trees. The Labrador tea and leatherleaf plants have waxy and hairy surfaces on their leaves that may help to prevent the loss of water through evaporation during the extended winters of the north when their roots are ineffective in the frozen peat. Many plants, like the bog rosemary, have small leaves and hang on to them for a long time, saving some of the energy that it takes to produce and maintain them. Others reach beyond a diet of sun and rain. A pitcher plant lies in wait for an insect, nestled in the moss with its palmful of acid cupped in blood red leaves.
Animals also find a home in the range of habitats offered by these northern bogs and fens, or weave their days between the peatlands and surrounding upland forests. Their presence in and use of the peatlands vary with the season. Sandhill cranes nest in summer in the open fens. Male black bears seek their winter dens in tamarack or black spruce stands. In early spring, the great gray owls wing the spaces between these scattered trees, hooking lemmings and red-backed voles in their talons to feed the owlets that wait in an old raven’s nest back in the recesses of the bog.
Northern leopard frogs, spring peepers, wood frogs, and boreal chorus frogs ensure that the peatlands will not lack for song; their reproductive success is greater in the fens where their eggs fare better in more alkaline waters. Bobcats and coyotes stalk their prey among the moss-covered mounds, and a myriad of songbirds live and breed in the peatlands. More than a third of Minnesota’s species of birds are said to be major users of peatland habitats. Many of them, like the Connecticut and palm warblers, feed on the plentiful supply of insects that bog and fen communities provide.
Where did it begin, I wonder, the notion that a land without people is uninhabited?
I lean over to pick a ripe cranberry from its trailing stem, pop it in my mouth and cringe at the bite of juice on the back of my tongue. The flavor of bog.
A few days ago, I flew in a small plane over the more than 87,000-acre Red Lake Peatland north of Bemidji, Minnesota. The Red Lake Peatland is among the world’s most stunning examples of what is called a “patterned peatland.”
Unlike the confined peatlands that dwell in small depressions, a patterned peatland forms on broad expanses of flat or gently sloping ground. In the case of the Red Lake Peatland, formed in the ancient bed of Glacial Lake Agassiz, the “slope” represents a drop of only one to five feet per mile. Groundwater that seeps up at the upland end of the peatland, along with surface waters contributed by runoff, cannot drain through the impermeable substrate. The water has nowhere to go but to creep downslope at a rate of only a few feet in a week’s time, seeking its course as topography and the plants of the peatland allow.
In this setting, in a dynamic and still not fully understood interplay between hydrology, topography, water chemistry, and climate, are created the striking landscape designs for which patterned peatlands are named. They are best seen from the vantage of a bird or a cloud.
The plane passed over Upper Red Lake, the pilot pointing out the wild rice cultivated by farmers along its margins. Then the lake was behind us. What I saw ahead through the dust of that plane’s window could well have been the face of another planet.
The features on the surface, though made with a wild hand, were strangely ordered. A vast plain stretched flat and tight as a drum skin out to the circle of the horizon. From it arose islands the shape of teardrops, all oriented with their rounded heads to the west and their trailing tails to the east. Between the teardrops, the surface broke into a phalanx of quavering stripes; broad bands of gold and green that could have been the plow furrows of a farmer with a little too much coffee in their veins. A lone meandering stream and occasional mirrored flash of the sun off the surface were the only visible signs of the water that I knew was moving below the plants as a great, patient river across the landscape.
The illusion was that we were witnessing a suspended parade formation that would begin as soon as we looked away. But the truth is that it was proceeding as we watched, our sense of time too hurried to perceive its infinitesimal steps.
Science has found names, and reasons, for these patterns. The reasons, like all reasons, are theories. The teardrops are called “tree islands.” They are aligned parallel to the flow of water through the peatland, and are not islands in the traditional sense of elevated land, but rather are clusters of trees with moss hummocks at their feet. The stripes are alternating pools of water called “flarks” and ridges of peat called “strings” that are dominated by sedges. They run transverse to the migration of water. Tree islands, strings, and flarks form in the channeled water tracks of the Red Lake Peatland that are classified as patterned fens. Their ordered arrangement is thought to be primarily a response of plant growth to the distribution of nutrients carried in the water as it flows. Between the water tracks, but out of reach of their nutrients, are raised bogs whose forested crests give way to lawns of sphagnum moss.
The roaring of the engine in my ears was nothing compared to the silent roar of the landscape below the plane; in the face of our labels and hard-earned understandings, still inscrutable. Remote.
I had thought that it would feel different here on the ground. Immersed in this musky smell. Standing in the light filtering through humid air. Able to set my feet in the soft moss, to reach my hand down into the peat and close my fist around the living dead in its icy, pulpy mass. Yet it is no less elusive in its very midst, reeking of time and exquisite otherness, the way a longtime lover can suddenly seem less known than is a stranger.
I wonder when the train comes.
Both Sand Lake Peatland and Red Lake Peatland have large expanses designated as Minnesota Scientific and Natural Areas (SNAs). Explore and find out more about the state’s protected peatland landscapes (and other wonderful natural areas) on the website of the Minnesota Scientific and Natural Areas Program. Other destinations to put on your bog adventure list include the Northern Unit of Big Bog State Recreation Area in Waskish, MN, (recommended for fans of dry feet, with a mile-long boardwalk through the bog), and Sax-Zim Bog, best known for its birding opportunities but richly diverse in all manner of native species, from orchids to dragonflies.
Special thanks to Kelly Randall of the SNA Program for his assistance with images for this story.