Black Spruce Glen and Hidden Marsh
Along the Green Trail to Hidden Marsh
The Black Spruce Glen is the newest addition to the Arboretum and it is truly a unique treasure. It comprises three distinctly different ecosystems that have been created by subtle changes in elevation and moisture levels. The BSG can be accessed from Maude Adams Road past the entrance to the East Meadow. Trails within BSG include the Green Trail Loop and the Perimeter Trail.
Follow the map on the left to visit the features listed below.
1.Transitional Disturbance. Think of the trail you’ll follow as tracing the elevated fingers of a glacial hand that reaches out to the marsh below. As you begin on the trail from Maude Adams Road, you’ll have your first encounter with disturbance, the road itself. The road edge and historical presence of landscaped lawns and gardens creates an opportunity for invasive (or introduced) growth to occur. Along with the ash, red maple, beech and sugar maple trees that live along this part of the trail, you’ll find Japanese honeysuckle, taking advantage of the edge opening around the trail. Here, the honeysuckle successfully competes with native shrubs. As you move away from the road and into the forest, the honeysuckle is less evident before it disappears completely.
2. The Emerald Bog. On each side of the Green Trail, there are depressions, long boggy bowls on your left, or slopes on your right that fall away to the stream flowing down to the marsh. The boggy bowls are nurseries for black spruce and home to lady slipper orchids in the spring.
3. Spruce Nursery. Notice that the forest tree species are changing. Look for hemlocks, yellow birches and the occasional black cherry, hornbeam and basswood. Look for signs of age in the deep furrows of their bark. They’re measuring time in hundreds of years. Notice the standing snags that are home, until they fall, to shelf mushrooms and various forest dwellers. Once on the ground, fallen trees and snags may become “nurse logs” for new trees, or part of the forest’s water reserve, holding water like sponges in times of drought, before finally rotting away, processed by the millions of miles of fungi and biota under your feet right now.
4. Hemlock Ridge, is one of several ridges in this area that were formed by glacial action as the glacier receded from this region about 13,000 ago.
As we near the marsh, descending as we go, the number of black spruce trees increase. The land is boggier; the water table is probably high. Commonly known as a “bog spruce” or “swamp spruce,” it’s a rugged tree of high elevation and deep cold, medium sized, with cones it may hold for years before dropping. You can distinguish the mature black spruces from the hemlocks around them by their pebbly or scaly, dark, uniform bark. Old growth hemlocks, like those around you in the Glen, have deep furrows and ridges thick enough that the reddish brown bark seems broken into irregular blocks.
5. Hidden Marsh
The Hidden Marsh can also be called a fen. Fens, are peat-forming wetlands that receive nutrients from sources other than precipitation: usually from upslope sources through drainage from surrounding mineral soils and from groundwater movement. Fens differ from bogs because they are less acidic and have higher nutrient levels. A fen can support a much more diverse plant and animal community than a marsh. Fens are covered by grasses, sedges and rushes, along with some shrubs and trees. This area is only just beginning to be studied. The vegetation on the far bank, which is the Western side of the marsh, the site of more disturbance and habitation, is different from the near bank vegetation.
6. The Bark Road
If you return along the Bark Road portion of the Green Trail, you may notice remnants of an old pit (tanning pit? old homestead?), stonewalls, and traces of an old road. Historical research and archeological work awaits.