| Look carefully near the ground at the tree just off the trail. It is a red maple that has “root sprouted” into at least three main stems, one of which was cut off to clear the rail trail. The bark of the tree is covered with lichens, an association between an algae and a fungus: the fungus provides structure and the algae combines nutrients with carbon dioxide (photosynthesis) to make food for the whole organism. Look for large circles of foliose “green shield” lichens. The lichens do not harm the tree; in fact, they are often an indicator of good air quality—something we work hard to protect in Londonderry! (Notice that the lichens are heaviest on the north side of the tree, where it is less likely to dry out. So, you have an indication which way is north, even on a cloudy day.) |
Londonderry Trailways 