The Secret Life of Cedar Swamps
The cedar swamp is full of wonder for those who know where to look, from lichens painting tree trunks to the browse lines left behind by generations of white-tailed deer.
Michigan’s cedar swamps are nutrient-rich, forested wetlands dominated by northern white cedar trees (Thuja occidentalis).Over time, waterlogged conditions slow decomposition, allowing layers of partially decomposed plant material to accumulate as peat, storing significant amounts of carbon while helping filter and regulate water flowing into nearby streams and rivers. The slow movement of groundwater keeps the soil saturated and prevents the stagnant, acidic conditions found in bogs. Because the groundwater is close to the surface in cedar swamps, northern white cedars have shallow roots, so when the wind howls, they are easily toppled, creating “windthrows” — huge mounds of exposed tree roots with soil clinging to them.
Cedar swamps create the cool microclimate that trout, birds, amphibians, and other wildlife depend on. During Michigan winters, white-tailed deer rely on the thick evergreen canopy for cover. Cedar fronds and seeds serve as winter food for the deer and habitat for barred owls, pine martens, minks, muskrats, snowshoe hares, and pileated woodpeckers that also live beneath the canopy.
Cedar swamps are fragile. Because deer congregate in them during the winter, they often over-browse young cedar saplings, stalling new tree growth. When cedar trees are logged or blown down, faster-growing species like balsam fir often crowd them out. Human development, road runoff, and invasive species like glossy buckthorn also threaten the delicate chemistry that keeps these wetlands alive.
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Cedar swamps cover roughly 1.35 million acres in Michigan. Most of them are in the upper peninsula, but a few are scattered across the northern lower peninsula. The largest is the Dead Stream Swamp, located about 30 miles northeast of Cadillac at the northwest end of Houghton Lake. Public access is limited due to the lack of roads and marked trails.
But there are smaller accessible representations of this swamp all over. Last month, I checked out the cedar swamps adjacent to Pintail Pond at the Rifle River Recreation area in Lupton, MI. It’s a short hike with a raised trail or boardwalk through the swamp. As always, I walked slowly, stopping often to look and listen.
As I followed the trail, I noticed pale green lichens clinging to the trunks of mature trees, turning bark into living mosaics. Along several stretches of the forest edge, a distinct browse line marked where generations of white-tailed deer had nibbled away the lower branches, creating an open understory beneath the canopy. Fallen logs supported shelves of turkey tail fungus, their bands of color bright against the weathered wood. The forest was alive with birdsong. A black-and-white warbler crept along a tree trunk overhead, moving more like a nuthatch than a warbler as it searched the bark for insects. From deeper in the woods came the calls of other songbirds, layered among the rustle of leaves and the whisper of wind through the trees.
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Then, without warning, a ruffed grouse exploded from the trail's edge in a thunder of wings, startling me from my thoughts and disappearing into the cover of the forest almost as quickly as it had appeared. The rich fragrance of northern white cedar lingered in the air, mingling with the earthy scent of damp soil and decaying wood, reminders that every part of this forest was connected in an endless cycle of growth, decay, and renewal.
Black and White Warbler