Tuesday, June 24, 2014

Brown's Lake Bog State Nature Preserve

"There are few habitats I love to explore and delve into more than the peaty goodness that is a sphagnum bog". Those words were written down a mere two weeks ago to open a post on a spectacular bog in southeastern Michigan and your narrator meant every word.  So while up in northern Ohio this past weekend with botanical companions Daniel Boone and Tanner Morris to see the previously shared round-leaved orchids at Clear Fork Gorge state nature preserve, it was an easy decision to make the most of our time in the area by making a short additional drive to do some boggin'.

Sphagnum vegetation mat at Brown's Lake Bog state nature preserve

Brown's Lake Bog state nature preserve is located in Wayne county and one of the best remaining sphagnum bogs in the entire state.  Its millennia-old floating vegetation mat on the margins of the open kettle pond is home to a slew of typical bog associates and acidophiles, many of which are quite rare and state-listed species found in few other places.  The bog itself has been on conservationists radars for decades and has been under the protection and stewardship of the Ohio chapter of the Nature Conservancy for almost 50 years and is a designated National Natural Landmark.

Surrounding swamp forest at Brown's Lake Bog

The bog and open kettle pond are surrounded by a lush swamp forest that is the result of previous bog habitat reaching its climax community.  The open nature of the floating sphagnum mat is only a temporary chapter in the life of any bog and gradually fills in with peat and woody vegetation as the forces of natural succession chug along. Given enough time and no intervention, the kettle pond at Brown's Lake Bog will eventually look identical to the photo above and give little evidence it ever existed in its current form.

Red maple, silver maple, and ash make up the majority of the swamp's canopy at Brown's Lake with spicebush (Lindera benzoin), winterberry (Ilex verticillata), smooth alder (Alnus serrulata), cinnamon fern (Osmundastrum cinnamomeum), crested wood fern (Dryopteris cristata), sensitive fern (Onoclea sensibilis), and bluejoint grass (Calamagrostis canadensis) occurring throughout its lush understory.

Water Pennywort (Hydrocotyle americana)
Water Pennywort (Hydrocotyle americana)

One of the more interesting and certainly inconspicuous wildflowers to thrive in the mucky, acidic soils of the swamp woods is the American water pennywort (Hydrocotyle americana).  Its creeping habit can form dense colonies in suitable conditions, where you're much more likely to notice its round, scalloped leaves and completely overlook the tiny flower clusters located in the leaf axils.

Open water of the kettle pond behind a stand of swamp loosestrife

Breaking out of the perimeter swamp forest finds the ever-shrinking 7-acre kettle pond and its surrounding bog mat.  Succession has done a good job of crowding out most open areas of the mat with woody plants like poison sumac (Toxicodendron vernix) and highbush blueberry (Vaccinium corymbosum) along with dense clumps of cinnamon fern but some small, yet significant areas remain free enough to support a diversity of plant life that requires the space and sunlight.

Sphagnum moss is ready for its closeup

Sphagnum moss is the backbone of any bog and a large reason why they exist in the first place.  This genus of moss has the amazing ability to hold exponentially more water weight than the dry weight of the moss itself; in some cases as much as 26 times its dry weight.  Due to the presence of phenolic compounds in the moss's cell walls and the natural anaerobic conditions of a bog, decay and decomposition hardly takes place and instead the moss accumulates on itself as it grows and dies and creates "peat".  As the dead organic matter builds up, further acidification takes places as the peat takes up cations from the environment (such as calcium and magnesium) and releases hydrogen in the process.  This all adds up to create the very specialized habitat conditions required for many bog species to occur and persist.

Scattering of Rose Pogonia (Pogonia ophioglossoides) orchid

One of those species is the spectacular bubblegum pink rose pogonia orchid (Pogonia ophioglossoides).  A dense display of these orchids can be seen on the bog mat at Brown's Lake each mid-June and is well worth the trip.

Rose Pogonia (Pogonia ophioglossides)

Also known as the snake-mouth orchid, rose pogonia is a threatened species in Ohio that only occurs in a handful of sites where its habitat requirement of an acidic substrate and constant water supply can be met.  It's no wonder then that this species does so well on the bog mat at Brown's Lake.

Rose Pogonia (Pogonia ophioglossides)

The orchids only occur on the most open and wet parts of the vegetation mat where competition from other plants is the lowest.  They are easily displaced as shade and cramped conditions increase and are at the mercy of any management team responsible for keeping their habitat cleared and open.

Rose Pogonia (Pogonia ophioglossides)
Rose Pogonia (Pogonia ophioglossides)

Not many of our wild orchids seem to bother with being fragrant but the rose pogonia apparently missed the memo on that point.  They emit a refreshing and pleasantly sweet aroma that is reminiscent of raspberries, making them a worthwhile discovery for not only your eyes but your nose as well.

Northern Pitcher Plants
Pitcher with its meal

No bog is complete without the presence of the quintessential pitcher plant among the orchids, sedges, and sphagnum.  Brown's Lake is home to not only the carnivorous northern pitcher plant (Sarracenia purpurea) but another bug-eater in the round-leaved sundew (Drosera rotundifolia) as well.

Large Cranberry (Vaccinium macrocarpon)

Another acidophile no bog should be without is the cranberry (Vaccinium macrocarpon).  This trailing woody vine is adorned with tiny white flowers come summer which are then replaced by tart cranberries a few months later. They are edible but be forewarned: they are quick to make you pucker even when ripe.

Pod Grass (Scheuchzeria palustris)

Of all the vascular plants to call the bog mat at Brown's Lake home, this next taxon has to be the weirdest and most rare of them all.  Scattered among the rose pogonias and pitcher plants is something called pod grass or simply Scheuchzeria (Scheuchzeria palustris), a monocot that is the only member of its genus and family (Scheuchzeriaceae).  It occurs throughout the northern hemisphere in cold, boggy habitats and is currently listed as an endangered species in Ohio with Brown's Lake being one of the very last places it occurs.  Most would hardly take the time or opportunity to notice it and I suppose I can't blame them but I find its unique and strange nature too quirky to ignore.

Prickly Bog Sedge (Carex atlantica var. atlantica)

It wouldn't be a proper bog blog post without some recognition of the Cyperaceae members present within the sphagnum paradise, now would it?  Sedges are largely shunned and ignored by most for their inherent difficulty to identify to species and dizzying diversity but I'm helplessly fascinated and interested in them.  The one pictured above is the nicely named prickly bog sedge (Carex atlantica var. atlantica).

Woolly Fruit Sedge (Carex lasiocarpa)
Mud Sedge (Carex limosa)

The woolly fruit sedge (C. lasiocarpa) is a potentially-threatened sedge species that can be found in both fen and bog habitats despite their respective pH differences and is one rarely seen in fruit for one reason or another.  In fact, this visit was the first time I've ever seen it with intact perigynia.  The mud sedge (C. limosa) should look familiar as it was featured on the Michigan bog post as well but being an endangered species in Ohio and this site being one of its last, it was worth another mention.

Arrow Arum (Peltandra virginica)

Like the aforementioned American water pennywort and its much more conspicuous leaves, the arrow arum's (Peltandra virginica) flowers can be easily ignored or overlooked.  Most botanically-savvy people should recognize this species as belonging to the arum family (Araceae) for the presence of a spadix and spathe, much like its related jack-in-the-pulpit (Arisaema triphyllum) and skunk cabbage (Symplocarpus foetidus) brethren.

Arrow Arum (Peltandra virginica)

This is about as open and "showy" as the arrow arum flowers get with their spadices almost fully enclosed within the protective spathe.  Despite containing calcium oxalate crystals like many other members of the arum family, the Native Americans used to utilize its rhizomes for food but only after many hours of cooking and repeated water changes to leach out the crystals.

I wish Brown's Lake bog wasn't so far away from where I live, as I would love to explore this site at different points in the year and experience the changing seasons and plants as the months roll by.  June is the only time your narrator has ever visited to specifically coincide with the peak bloom of the rose pogonias but fingers crossed a late summer or fall trip can be arranged to catch this wondrous place in a whole new light.

1 comment:

  1. Very informative! I hope to go back to Brown's Lake Kettle Bog this June. It's wonderful site.