Fall Colors on Alaska's National Forests Offer Beautiful Vistas

Posted by Mary Stensvold, U.S. Forest Service Regional Botanist, Sitka, Alaska

Black cottonwood and birch in Girdwood, Alaska near the Chugach National Forest
Black cottonwood and birch accentuate the fall season along Alpine Meadows Drive in Girdwood, Alaska near the Chugach National Forest. Photo by Kate Mohatt.

Did you ever think about fall colors in Alaska? Now’s the time with autumn foliage colors peaking from late August to early October in Alaska’s Tongass and Chugach National Forests. However, since the national forests are in the temperate part of Alaska and are dominated by coniferous trees, the colors are generally not as spectacular as the brilliant colors of interior Alaskan trees and shrubs.

Deciduous trees such as red alder (Alnus rubra), Sitka alder (Alnus viridis ssp. sinuata) and black cottonwood (Populus balsamifera ssp. trichocarpa) occur on the Tongass National Forest. Their foliage generally turns yellowish-brown to brown before being shed. Yet, the Chugach National Forest tells another story, especially on the Kenai Peninsula with the yellows and oranges of quaking aspen (Populus tremuloides), Kenai birch (Betula papyrifera var. kenaica), and black cottonwood. The willow (Salix species) and squashberry (Viburnum edule) shrubs also turn yellow-orange and sometimes an added flash of red adorns the tips of their branches.

Notable fall color changes are visible in mountain alpine plant communities and bogs, where small shrubs and herbaceous plants provide swaths and splashes of color. On the Tongass, the first alpine frosts cause the deer cabbage (Nephrophyllidium crista-galli) to turn yellow-orange on the mountain tops before they are buried in snow. On the Chugach, bright red mountain avens (Geum calthifolium) contrasts brilliantly with bright green lichens above the treeline. Many bog plants gradually change color, with leaves of the tufted bulrush (Trichophorum cespitosum) turning a golden copper and then yellowish-brown. The Lapland cornel (Cornus suecica) and ripening small cranberry (Vaccinium oxycoccus) and ligonberry (V. vitis-idaea) turn a beautiful red, and sometimes sport a range of subtle shades of red. Deer cabbage also grows in many bogs with their leaves gradually changing to yellow.

A high bush cranberry near Glacier Creek in Girdwood, near the Chugach National Forest
A high bush cranberry displays fall colors near Glacier Creek in Girdwood, near the Chugach National Forest. Photo by Kate Mohatt.

Black cottonwoods along Glacier Creek in Girdwood, Alaska with Mount Alyeska in the background
Black cottonwoods feature a fall wardrobe along Glacier Creek in Girdwood, Alaska with Mount Alyeska in the background. This area is adjacent to the Chugach National Forest. Photo by Kate Mohatt.