Large, old trees. The dominant species are Sitka spruce and western hemlock, but other conifers and several deciduous species grow as well. Many are 100s of years old and can reach 250 feet in height and 30 to 60 feet in circumference. Nurse logs. Because of the densely covered ground, many seedlings instead germinate on fallen, decaying trees. As they grow, their roots reach to the ground. When the log eventually rots away, a colonnade, or row of trees on stilt-like roots, remains.