Last weekend was my first visit to the bog in a couple months. Gone were the spring peepers and wood frogs, gone were the slender green leaves of fen sedge, gone were the mosquitoes and black flies! Present were the tamaracks with their golden glow, the fluffy Truffula Tree-like seeds of cotton grass, and the gracefully-twisted dried seed pods of blue flag iris.
Bogs are unique natural communities. In Wisconsin, they have been forming for 10,000 years in sandy bowls left by the glaciers. The bowls were formed when huge chunks of ice broke off of the main glacier ice and were buried in sand and gravel by the many streams draining the melting ice mass. The sediment insulated the ice for a while, but it still melted slowly, eventually leaving a low area where the ice had been. Geologists call these glacial kettles. The high mounds of sand and gravel around them are known as kames. It’s this process that helped create the rolling topography we love on the ski and mountain bike trails all around the Cable area!
Their unique formation has a big impact on the hydrology of bogs, or the way that water flows in an out. Basically, it doesn’t. True bogs don’t have inlets or outlets, and are perched high above groundwater influence, too. All their water comes from rain and snow. Rain and snow are both slightly acidic, and as dead leaves soak in the water, more acids are released. The process is very similar to your morning cup of tea. (In fact, several bog plants make delicious tea!) Without flowing water, there is little oxygen. Organic matter decays slowly or not at all, forming black soil called peat. Sphagnum moss, leatherleaf and many other plants build up a thick mat of vegetation until the bog is almost dry. Sometimes the mat quivers like a waterbed and hides open water underneath.
Some nutrients and oxygen do reach the margins of the bog through rainwater runoff. This causes a narrow band with higher decomposition rates, allowing open water in a ring around the bog. Last May the moat was deep and squishy, and a class of seventh graders almost didn’t make it across (due to squeamishness, not danger). Now the moat is mostly solid and grassy.
As I step out into the golden-brown heath, my mission is to find treasure. Not silver or diamonds, they don’t taste very good. Today, I’m seeking cranberries! Displayed attractively on emerald mosses, the ruby-red fruits do look like jewels. And a hunt it is for this treasure! I scour each hummock for fruit, sometimes finding none, sometimes one, sometimes a dozen. With bent back I nose on to the next mound of moss and twigs. The high places around small tamarack trees seem to be productive. I find one patch of berries tangled in the dried thatch of grass. Some of the little globes have fermented, and burst between my fingers. Others, buried so deep in moss they haven’t been frosted, are still only pale cream with red speckles.
The picking goes slowly. This is partly because the cranberries are few and hidden. It is mostly because I get distracted easily by the other treasures I find! In one flat mossy patch there are about a dozen dried flower spikes, each about eight inches high. Dry weed ID is a fun challenge, so I poke around their bases looking for clues. I find a tiny cluster of mini leaves. Curled tightly like fern fiddleheads they can only be the hibernaculum of a sundew. Sundew are carnivorous plants, well-adapted to the nutrient-poor habitat in bogs. In summer, tiny drops of “dew” glisten on the tips of hairs that cover small spoon-shaped leaves. The sticky mucilage “dew” traps insects and then digests them. Essential nutrients (especially nitrogen) are absorbed through the leaves. Just like trees have prepared for next year by forming leaf buds that will weather the winter, these sundew are ready and waiting for next spring.
Pitcher plants, the other carnivorous plant in our bog, have also shut down for winter. I split open one bright-red leaf (they change colors for fall, too!) and find a bug-cicle inside! The insects caught in the sweet-smelling digestive juices of the pitcher-shaped leaf will have to wait until next spring to be digested. Ice fills every leaf in the cluster of plants.
After about two hours of searching, I have one quart of cranberries, and two cold feet. Back at home, I warm up quickly as a cake bakes and the cranberries simmer with honey and cinnamon. That was the stated goal of my expedition: chocolate cake with cranberry sauce. I could have just gone to the grocery store, but I found so much more than fruit in my secret bog.