The Alnus Rubra
is commonly known as Oregon Alder
, Pacific Coast Alder
, Red Alder
, as well as Western Alder< Go Back
Red alder is confined to the Pacific Coast region from southeast Alaska
to southern California. Although there is an isolated population
growing along streams in northern Idaho, it ordinarily occurs no further
inland than 100 miles (160 km) at elevations below 2,500 feet (762 m)
]. Red alder is cultivated in Hawaii [71
The currently accepted scientific name of red alder is Alnus rubra Bong.
]. There are no recognized subspecies, varieties, or forms.
Red alder communities, both upland and riparian, generally are found
within coniferous forests dominated by Douglas-fir (Pseudotsuga
menziesii), western redcedar (Thuja plicata), western hemlock (Tsuga
heterophylla), grand fir (Abies grandis), and Sitka spruce (Picea
sitchensis) [18,19,67], or as components of deciduous forests of
floodplains or swamps [18,19]. Generally, five types of red alder
communities have been described [18,19,21,32,67]:
(1) Upland, pure even aged stands of red alder, with a dense shrub
undergrowth dominated by salmonberry (Rubus spectabilis) or
elderberry (Sambucus melanocarpa), occurring within coniferous
(2) Upland mixed stands of red alder/other deciduous trees and
shrubs/conifers within coniferous forests less than 100 years
old, with red alder occurring as a dominant or codominant.
(3) Riparian red alder communities within coniferous forests.
(4) Mixed stands within deciduous riparian forests, red alder
occurring as codominant with black cottonwood (Populus trichocarpa)
and bigleaf maple (Acer macrophyllum).
(5) In swamps often occurring with, or codominant with, western
redcedar. In this type of community, red alder appears to be a
Red alder communities were primarily restricted to streams and wet areas
during presettlement times. Since then, disturbances such as logging
have provided an abundance of open sites with bare mineral soil, which
favor red alder colonization. Today red alder communities are common
throughout much of coastal Oregon and Washington.
Published classification schemes listing red alder as an indicator
species or as a dominant part of the vegetation in community types (cts)
or plant associations (pas) are presented below:
Area Classification Authority
AK general veg. cts Viereck & others 1992
CA hardwood forest & Barbour 1987
CA general veg. cts Thorne 1976
s CA general veg. cts Paysen & others 1980
nw CA,w Or,w WA general veg. cts Franklin 1979
OR: Siuslaw NF general veg. pas Hemstrom & Logan 1986
OR postburn veg. cts Bailey & Poulton 1968
s OR: Cascade Mtns forest pas Atzet & McCrimmon 1990
OR, WA general veg. cts Franklin & Dyrness 1973
Pacific NW general veg. cts Hall 1984
< Go Back
Much of the information presented here is attributed to:
Uchytil, Ronald J. 1989. Alnus rubra. In: Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service,
Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available at USDA Forest Service.