Stop 1 — Agricultural Field Overlooking Spongy Lake

Spongy Lake is a kettle lake that was formed when glaciers created a depression through isostasy (the flexibility of the Earth’s surface under great pressure). Isostatic rebound of the surrounding area occurred, but the block of ice melted in the depression and created Spongy Lake.

To reach Spongy Lake, we travel along the edge of a farmer’s field and cross a railroad lined with limestone. From the field, you can see a hill with a communications tower (Baden Hill) which is a kame, a sand and gravel hill that was formed when a glacier was neither retreating nor advancing. Commercial extraction of gravel has been attempted several times in the past but has been prevented due to public resistance.

Wetland succession generally follows this order: pond — marsh — swamp — fen — bog. Currently, Spongy Lake is in the successional stages between a fen and a bog but more characteristic of a fen.

As a fen, Spongy Lake’s soils are acidic and nutrient poor. Consider how the farmer’s field and limestone along the train tracks could influence the soil structure and nutrients surrounding Spongy Lake.

Spongy Lake is the Regional Municipality of Waterloo’s Environmentally Sensitive Protected Area (ESPA) number 14 due to its significance as a groundwater recharge area. Spongy Lake hosts several unique Ericaceous plants (from the family Ericaceae) and several carnivorous plants such as pitcher plant and sundew.

Stop 2 — Upland Forest

Note familiar trees in the area: white pine, staghorn sumac, black cherry, sugar maple, and American beech.

Wild ginger, white baneberry, and a variety of ferns also grow in this area. In the spring, the forest floor is full of spring ephemeral flowers. Ephemerals are plants that take advantage of the early spring sunlight by blooming before foliage appears on the trees and blocks sunlight from reaching the forest floor.

There is some garlic mustard and European buckthorn along the edges of the path. Consider how human interference, invasive species, and edge effects all impact this ecologically sensitive area.

Historically, students have found scrap metal and glass dumped along the side of the path, remnants of a time when forested areas were used for disposal.