Black spruces and sedges in a northern bog
After a work day in northern Michigan this past summer, a friend invited me to hike a riverside trail on the back side of one of Michigan’s beautiful state parks. He wanted to scout a new access point for fishing. Afterward, we would hit the nearby town for dinner and a milkshake. “It’ll be fun” he said, “we can check out a little bog I know on the way”.
We never even made it to trailhead.
The way to the little bog is hidden save for a wide spot on the edge of a sandy two-track snaking through the pines. If you know where to step through the roadside alders, a trail is revealed leading off through the relative darkness of closely growing northern white cedars, eastern hemlocks, and stately white pines. The trail traverses a decrepit little boardwalk in the wetter areas and I even found a regulation state park interpretive sign pulled up by its post and laying face-down along the trail. The State Park was evidently once proud of this little bog but no longer.
Debris left by retreating glaciers often contained enormous blocks of ice that melted to create landlocked little depressions known as kettle holes. With no inflow or outflow, these little depressions filled with glacial melt and then remained full due to the abundant rain and snow of the Great Lakes region and remained isolated by the poor drainage of the clay deposits – hence even at birth, they were destined for stasis.
rose pogonia (Pogonia ophioglossoides)
Bogs are nutrient-poor wetlands whose water supply is mostly dependent on precipitation rather than nutrient-rich run-off. This one is classified as a northern bog (
http://water.epa.gov/...) and northern bogs concentrate in the Great Lakes region owing to the unique intersection of glacial history and short growing seasons. Bogs form when plant life consumes most of the available and already scarce nutrients, inhibiting microbes responsible for decomposition. Incomplete decomposition turns the water acidic which further sequesters nutrients. Characteristically hardy and nutrient-stingy plants begin growing on the shoreline. They grow slowly, senesce, and die and as dead plant material accumulates slowly, it coalesces slowly into a floating fibrous mat called peat - slowly. Other bog plants anchor themselves in the peat and contribute to it as they themselves die back. Peat forms at the edges initially and slowly encroaches on the water surface, eventually closing it off entirely. Slowly – always slowly.
The trees and shrubs give way and our path enters what superficially looks like a low meadow. The board walk terminates at a sodden little observation platform in the center of the bog. We see no open water but the pitching of the boardwalk and the platform as we walk betrays the reality of a mat of sphagnum peat supporting us, itself floating over a deep kettle hole of water. Bogs are nature’s time capsules. While the peat mat is closing, the still surface catches airborne pollens and ash. These rain down and are preserved in the dark acid water creating a record in the sediments of the climatic and disturbance-mediated changes in the vegetation of the surrounding landscape. Fire cycles, drought cycles, the retreat and advance of the pines and hardwoods, the advance of agriculture...its all recorded. The sediments are quite literally testaments of long periods of time compressed. With the closing of the peat the record stops and given the constant ground-water temperature and unique chemistry, time under the mat essentially stops as well.
pitcher plant (Sarracenia purpurea)
Indeed the topography of a bog is a perfect analog to the two-dimensional drawings that astronomers and physicists use to illustrate how black holes distort space-time with their unfathomable mass (picture a marble falling into a depression on an otherwise flat surface). Similarly, bogs distort space and time. This bog is ringed with ancient black spruces whose size is dwarfed by the white pines upslope. Yet if time and persistence were the measure, the tiny black spruces would be the giants. Profligate white pines live and die in ecstasies of photosynthesis and growth while the miserly and stubborn black spruces lay on growth ring after microscopic growth ring – doing so with no more photosynthetic tissue than a modest Mother’s Day bouquet. We'd be better caretakers of this planet if we would consider viewing time relative to the lifespans and memory of trees. If you let it, the bog will draw you in. If you lend it your imagination, you will leave human time behind.
grass pink (Calopogon tuberosus)
I think about the dark, inert world under me while my friend and I stop and listen and look. Time passes and under another circumstance, it would feel awkward to go so long without conversation. After a time, he pulls out an ipod and plays the territorial call of a Canada Warbler. We hear the real thing answer and before long he shows himself – a flitting of brilliant yellow among the grey bristly branches of the black spruces. We are at the southern margin of this species’ summer range and he’s likely here because the spruce and sphagnum are discrete patches of boreal character here in the temperate zone. Similarly, we begin to notice pinpoints of color among the sedges. We look more closely and the pin points reveal themselves to be elegant little bog orchids, grass pink and rose pogonia. We look more closely and find pitcher plants and if I get down and peer through the sedges to the surface of the peat itself, I find tiny sundews starting to flower. These plants are small and rare and their leaf and flower parts are highly modified reflecting life history strategies like carnivory and pollinator selectivity – evolutionary solutions for clinging to life in an environment where every molecule of nutrient is hard-won and precious and there is no budget for wasted or redundant tissues. Orchids may wait many years before going for broke in the energetic and reproductive gamble of producing a single flower. It’s such a contrast to the plants who flower annually in the rich prairie near my home. Prairie plants flaunt their riches with big flashy simple flowers and plumes of pollen. Showy displays of extravagant biomass versus tiny displays of extravagant detail and complexity. It’s the difference between a 3-chord rock anthem blowing the lid off of a cavernous stadium and a classical piano concerto swelling in the acoustic sweet spot of a small concert hall. Both are affecting but though utterly different strategies.
sundew (Drosera rotundifolia?)
Years ago at a different bog, my visit coincided with that of a student group. While most were earnestly recording their instructor’s teaching in their notebooks, I watched one young man jumping up and down on the edge of the bog mat showing off and delighting in the shrieks from the young women he was distracting. And then the bog mat gave way…and he disappeared like a cartoon character falling through a trap door. After a second or two, he re-appeared and clawed his way back into the sunlight completely drenched in coffee-colored water, flecks of sphagnum in his hair, and a look of terror in his eyes. In the space of a few seconds, he traveled from present to distant past and back and emerged with (I surmise) a new-found respect for his surroundings - reborn following baptism in Pleistocene memory. I often wonder about that instant, what it must have been like to be suddenly suspended in that dark cold water between the ancient sediments below and the present reality above. Those seconds must’ve seemed like an eternity. I wonder what bits of himself, flakes of skin perhaps or bits of hair, might have settled and become preserved among the sediments.
I look at my watch and note that our plans for the afternoon have utterly evaporated. The sun is setting and the shadows are encroaching. I’ve been no less immersed in this little bog.
Elsewhere in the park, tourists are dutifully viewing the displays in the beautiful new visitor’s center, studying dioramas and displays intended to teach them about the history, natural and otherwise of this region. I love the work that interpreters do in our parks and natural areas but deep appreciation of a place requires more than just getting the facts right. Those tourists should stand here on this platform. They should stand here and simply let the sights sounds and smells seep into their imagination. They should stand here as the coolness of the evening draws the ground fog out of the sedge hummocks and leatherleaf, softening the horizon and distorting depth perception. They should stand here and peer back through shadowy time and memory and wonder what ancient anxieties this same view evoked for the first humans, those whose ancestors crossed Beringia, to stand here with bog water seeping through their moccasins.
Now about that milkshake…
8:08 AM PT: Thank you to the rescue rangers!