Park Natural History
Developing old-growth forest canopy
As the canopy opens and more light penetrates, the shade-tolerant species, such as western hemlock and western red cedar, start to grow faster, some eventually becoming part of the forest canopy. Thus, both large, old trees and variable tree density and sizes characterize old-growth forests. Also typical of old-growth forests is a high diversity of mosses, lichens, and other plants that grow as epiphytes on the surface of living trees and shrubs, and dead wood. The photo to the left shows the development of epiphytes on 500-year-old old-growth forest near the Columbia River.