Location #7

This area of disturbed ground gives us an opportunity to learn about forest succession in Southeast Alaska. Forest succession occurs not only where humans have modified the landscape with roads and ballfields, but also when rivers change course or even when glaciers recede. On recently exposed rock, like at the face of a receding glacier, lichens are the first living things to move in, growing in flat discs pressed onto the rocks. As these lichens slowly build up soil, moss can take root, along with sedges and grasses, pink fireweed and purple lupine. Eventually shrubs and small trees like the willow and alder you’ll see along this path appear, followed by small Sitka spruce and cottonwood. You can recognize short, bushy willows by their smooth, elongated oval leaves. These contrast with the red alder, which has tooth-edged leaves that are rust-colored underneath. Alder can grow in poor soil and can “fix” nitrogen like the peas and beans we grow in our gardens. This makes them particularly important in reforestation. They have a symbiotic relationship with bacteria that can gather nitrogen from the atmosphere. This nitrogen nourishes the tree, while the alder provides sugars to the bacteria through photosynthesis. See if you can you pick up the light sweet scent of the alder as you pass by. As you eventually descend a short hill toward Eighth Street, notice the well-defined edge where the good drainage provided by the ballfield fill stops and we return to the poorly-drained muskeg landform that was here originally.