Stop 5 — On Peat and Boardwalk

At this point in the tour, the ground has a buoyant quality. Students enjoy jumping on the peat mat and feeling it move up and down. Ferns and plants such as Labrador tea, bog bean, bog laurel, pitcher plant, leatherleaf, cranberry, and blueberry that are all commonly found in acidic and nutrient-poor soils become more prevalent as we move further away from the lagg zone.

Here, growth limiting factors become more obvious.

• Water: despite being so close to the water, many plants here have water conservation characteristics similar to desert plants such as thick waxy or hairy leaves to reduce water loss.
• Nutrients: this fen is nutrient-poor and as such the vegetation has adapted to sourcing their nutrients in other ways. For example, pitcher plants and sundew get nitrogen and phosphorus by digesting insects that they trap in their leaves.
• Low pH: the low pH is maintained in the fen through precipitation, acidic biomass such as coniferous needles and sphagnum peat moss, and the recycling of basic elements by the upland forest.
• Oxygen: plants adapt to low oxygen conditions with slow growth. The dwarf trees and abundance of shrubs found on the peat are evidence of this slow growth. In addition, shallow root systems along the surface allow plants to access atmospheric oxygen.

All these conditions contribute to the unique ecosystem that can be observed in Spongy Lake.

Stop 6 — Open Water

Pitcher plants, cranberry, blueberry, and sweet flag can be observed along the water’s edge. Also note the leatherleaf, tamarack, and silver maple. In the water, water lilies, sedges, and cattails grow. Cattails, which generally prefer more neutral soils, are potential evidence of a decrease in acidity in the fen. This may be due to runoff from the surrounding agricultural fields. Note the areas of invasive common reed grass Phragmites australis that has the potential to spread rapidly, impact water levels, and dominate the vegetative landscape.

In summary, general features of a bog or nutrient-poor fen include:

• An open water zone
• A sedge zone with a floating mat of grasses, cattails, and sedges
• A shrubby zone with cranberry, blueberry, sphagnum, et cetera
• A treed/shrubby zone with tamaracks, pines, Ericaceous plants, and willows